US20110092812A1 - Method and system for creating three-dimensional images using tomosynthetic computed tomography - Google Patents
Method and system for creating three-dimensional images using tomosynthetic computed tomography Download PDFInfo
- Publication number
- US20110092812A1 US20110092812A1 US12/885,910 US88591010A US2011092812A1 US 20110092812 A1 US20110092812 A1 US 20110092812A1 US 88591010 A US88591010 A US 88591010A US 2011092812 A1 US2011092812 A1 US 2011092812A1
- Authority
- US
- United States
- Prior art keywords
- image
- projected
- images
- cos
- tan
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims description 37
- 238000002591 computed tomography Methods 0.000 title description 5
- 230000005855 radiation Effects 0.000 claims abstract description 65
- 239000003550 marker Substances 0.000 claims description 63
- 230000009466 transformation Effects 0.000 claims description 18
- 239000011159 matrix material Substances 0.000 claims description 10
- 230000002194 synthesizing effect Effects 0.000 claims description 9
- 238000013507 mapping Methods 0.000 claims description 3
- 230000003247 decreasing effect Effects 0.000 claims description 2
- 238000004590 computer program Methods 0.000 claims 8
- 230000001678 irradiating effect Effects 0.000 abstract description 2
- 238000006073 displacement reaction Methods 0.000 description 12
- 230000000875 corresponding effect Effects 0.000 description 9
- 230000008569 process Effects 0.000 description 9
- 238000013459 approach Methods 0.000 description 6
- 238000009795 derivation Methods 0.000 description 6
- 238000010276 construction Methods 0.000 description 5
- 238000003384 imaging method Methods 0.000 description 5
- 230000001902 propagating effect Effects 0.000 description 5
- 238000013519 translation Methods 0.000 description 5
- 230000014616 translation Effects 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 238000001444 catalytic combustion detection Methods 0.000 description 4
- HVYWMOMLDIMFJA-DPAQBDIFSA-N cholesterol Chemical compound C1C=C2C[C@@H](O)CC[C@]2(C)[C@@H]2[C@@H]1[C@@H]1CC[C@H]([C@H](C)CCCC(C)C)[C@@]1(C)CC2 HVYWMOMLDIMFJA-DPAQBDIFSA-N 0.000 description 4
- 230000033001 locomotion Effects 0.000 description 4
- 238000000844 transformation Methods 0.000 description 4
- 238000012935 Averaging Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 230000001131 transforming effect Effects 0.000 description 3
- 238000002604 ultrasonography Methods 0.000 description 3
- 229930091051 Arenine Natural products 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 230000001413 cellular effect Effects 0.000 description 2
- 235000012000 cholesterol Nutrition 0.000 description 2
- 239000003086 colorant Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 238000002595 magnetic resonance imaging Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 238000001454 recorded image Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- PXFBZOLANLWPMH-UHFFFAOYSA-N 16-Epiaffinine Natural products C1C(C2=CC=CC=C2N2)=C2C(=O)CC2C(=CC)CN(C)C1C2CO PXFBZOLANLWPMH-UHFFFAOYSA-N 0.000 description 1
- 238000003917 TEM image Methods 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000003190 augmentative effect Effects 0.000 description 1
- 238000012742 biochemical analysis Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000635 electron micrograph Methods 0.000 description 1
- 238000001493 electron microscopy Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 210000002288 golgi apparatus Anatomy 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000001404 mediated effect Effects 0.000 description 1
- 230000000813 microbial effect Effects 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 238000009420 retrofitting Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/50—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications
- A61B6/51—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications for dentistry
- A61B6/512—Intraoral means
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
- A61B6/12—Arrangements for detecting or locating foreign bodies
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T11/00—2D [Two Dimensional] image generation
- G06T11/003—Reconstruction from projections, e.g. tomography
- G06T11/005—Specific pre-processing for tomographic reconstruction, e.g. calibration, source positioning, rebinning, scatter correction, retrospective gating
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T11/00—2D [Two Dimensional] image generation
- G06T11/003—Reconstruction from projections, e.g. tomography
- G06T11/008—Specific post-processing after tomographic reconstruction, e.g. voxelisation, metal artifact correction
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2211/00—Image generation
- G06T2211/40—Computed tomography
- G06T2211/436—Limited angle
Definitions
- the present invention relates to a method and system for creating three-dimensional displays or images from a multiplicity of two-dimensional projections and, more specifically, to a method and system for use in computed tomography systems in which random relative positional geometries between the source of radiation, the object of interest, and the recording means may be used for recording radiographic images for tomosynthesis.
- tomosynthetic imaging techniques has previously been demonstrated to be useful in examining three-dimensional objects by means of radiation. These imaging techniques differ in the size and configuration of the effective imaging aperture. At one extreme, the imaging aperture approaches zero (i.e., a pinhole) and the resulting display is characterized by images produced from a single transmission radiograph. This yields an infinitely wide depth of field and therefore no depth information can be extracted from the image. At the other extreme, the aperture approaches a surrounding ring delimiting an infinite numerical aperture resulting in projection angles orthogonal to the long axis of the irradiated object. This yields an infinitely narrow depth of field and hence no information about adjacent slices through the object can be ascertained. It therefore follows that a “middle ground” approach, which provides the ability to adapt a sampling aperture to a particular task, would be highly advantageous.
- the key to achieving the full potential of diagnostic flexibility lies in the fact that perceptually meaningful three-dimensional reconstructions can be produced from optical systems having any number of different aperture functions. That fact can be exploited since any aperture can be approximated by summation of a finite number of appropriately distributed point apertures.
- the key is to map all incrementally obtained projective data into a single three-dimensional matrix. To accomplish this goal, one needs to ascertain all positional degrees of freedom existing between the object of interest, the source of radiation, and the detector.
- the relative positions of the object, the source, and the detector have been determined by fixing the position of the object relative to the detector while the source of radiation is moved along a predetermined path, i.e. a path of known or fixed geometry. Projective images of the object are then recorded at known positions of the source of radiation. In this way, the relative positions of the source of radiation, the object of interest, and the detector can be determined for each recorded image.
- the present invention relates to an extension of tomosynthesis which facilitates three-dimensional reconstructions of an object from any number of arbitrary plane projections of the object produced from any number of arbitrary angles.
- the information required to produce the three-dimensional reconstructions is derived from fiducial analysis of the projection themselves or from analyses of functional relationships established through known fiducial constraints.
- a system and methods are provided for creating three-dimensional images using tomosynthetic computed tomography in which the system and methods significantly simplify the construction of image slices at selected slice positions through an object. Following a one-time transformation of a series of projected images, only simple offset and averaging operations are required in selected embodiments of the invention for a variety of subsequent reconstructions of a volumetric region within which projective variations may be considered negligible.
- the system comprises an identifiable fiducial reference located in a fixed position relative to the object.
- the fiducial reference comprises at least two reference markers which are in a fixed geometry relative to each other.
- One of the reference markers may be used as an alignment marker during construction of a tomosynthetic slice through the object.
- the other reference marker or markers may be used to projectively warp or transform a projected image from an actual projection plane to a virtual projection plane.
- Each reference marker may be small enough to be considered point-size or, alternatively, may be finite in size.
- markers of a known geometry such as spherical markers with a measurable diameter.
- the fiducial reference comprises five point-size or finite reference markers that are arranged so that four of the reference markers are co-planar and no three or more reference markers are collinear.
- a radiation source is provided for irradiating the object with the fiducial reference in a fixed position relative to the object.
- the preferred radiation source depends upon the particular application.
- the present invention may be practiced using x-rays, electron microscopy, ultrasound, visible light, infrared light, ultraviolet light, microwaves, or virtual radiation simulated by manipulation of magnetic fields (magnetic resonance imaging (MRI)).
- MRI magnetic resonance imaging
- a recording medium or detector is used to record a series of projected images.
- Each projected image may include an object image of the object and a reference marker image for each of the reference markers.
- the recording medium may be in the form of a photographic plate or a radiation-sensitive, solid-state image detector such as a charge-coupled device (CCD), or any other system capable of producing two-dimensional projections or images suitable for digitization or other analysis.
- CCD charge-coupled device
- the system of the present invention is used to synthesize a three-dimensional reconstruction of the object to obtain, for example, an image slice through the object, at a selected slice position through the object, from a plurality of projected-images detected at the recording medium.
- the simplification of the construction method is achieved by warping, i.e. transforming or mapping, a series of projected images onto a virtual projection plane to yield modified images that would match those that would have been generated had the detector been in a fixed position relative to the object.
- warping the projected images onto the virtual projection plane the computation required for each image slice construction is greatly reduced.
- the solution of the projective transformations can be performed via a direct method that is both efficient and computationally robust. Further, magnification differences can be compensated for by appropriate scaling of the images.
- a series of two-dimensional projected images of an object with an associated fiducial reference is recorded.
- the fiducial reference markers are coupled in fixed position relative to the object.
- the projected images can be recorded with (i) the source, (ii) the recording medium, and (iii) the fiducial reference markers coupled to the object, in various or arbitrary projection geometries.
- the projection geometry preferably varies from projected image to projected image. Some variation is required to produce a finite depth of field.
- the virtual projection plane may preferably correspond to the position of a plane through at least one of the reference markers in real space or to a plane defined by one of the existing projected images.
- Imaging systems that use projective geometries, which include optical and radiographic systems, can be appropriately warped using a projective transformation matrix.
- the projective transformation matrix is generated by solving each projected image relative to the virtual projection plane.
- the resulting transformations compensate for magnification and/or projective differences between the various images. Such differences are introduced when the source is sufficiently close to the object and/or the source moves in a direction which is not parallel to the projection plane.
- FIG. 1 is a schematic representation of a system for creating three-dimensional radiographic displays using computed tomography in accordance with the present invention
- FIG. 2 is a flow chart showing the steps involved in creating three-dimensional radiographic displays using computed tomography in accordance with the present invention
- FIG. 3 is a flow chart showing details of a method of projectively warping or transforming a projected image from an actual plane of projection onto a virtual projection plane;
- FIG. 4 is a schematic representation of a system having nine degrees of freedom in which a source is shifted and displaced relative to an original projection plane and in which a projection plane of a recording medium is shifted, rotated, displaced, and tilted relative to the original projection plane;
- FIG. 5 is a schematic representation showing an arrangement of reference markers in accordance with the an embodiment of the present invention, wherein five spherical reference markers are positioned at five of the eight vertices of a cube;
- FIG. 6 is a schematic representation of a system having seven degrees of freedom in which an infinite point source is shifted relative to an original projection plane and in which a projection plane of a recording medium is shifted, displaced, and tilted relative to the original projection plane;
- FIG. 7 is a schematic representation of a system having four degrees of freedom in which an infinite point source is shifted relative to an original projection plane and in which a projection plane of a recording medium is shifted relative to the original projection plane;
- FIG. 8 is an exploded, schematic representation of a charge-coupled device (CCD) for use as a recording medium;
- CCD charge-coupled device
- FIG. 9 is a schematic representation of an embodiment of the present invention wherein the recording medium is smaller than the projected image of the object;
- FIG. 10 is a schematic representation of an embodiment of the present invention wherein the source is a hand-held X-ray source with a laser aiming device;
- FIG. 11 is a schematic representation of an embodiment of the present invention wherein the reference markers of the fiducial reference are positioned at the vertices of a square pyramid;
- FIG. 12 is a schematic representation of an embodiment of the present invention wherein the source is a hand-held X-ray source which is constrained relative to the recording medium by a C-arm;
- FIG. 13 is an enlarged schematic representation of the object of interest and the recording medium depicted in FIG. 14 ;
- FIG. 14 is a schematic representation of an embodiment of the present invention wherein the reference markers of the fiducial reference are positioned at the centers of the faces of a parallelepiped;
- FIG. 15 is a schematic representation of an embodiment of the present invention wherein the corners of a frame define four reference markers;
- FIG. 16 is a schematic representation of a reference image cast by a spherical reference marker showing the resulting brightness profile
- FIG. 17 is a schematic representation of the parameters associated with a system comprising three spherical, non-collinear reference markers wherein the orthogonal distance between the radiation source and the recording medium is fixed at a distance short enough so that the images cast by the reference markers are magnified relative to the size of the actual reference markers;
- FIG. 18 is a schematic representation of the relevant parameters associated with a reference image associated with a spherical reference marker
- FIG. 19 is a schematic representation of an embodiment of the present invention wherein the fiducial reference comprises a radiopaque shield with a ring-like aperture;
- FIG. 20 is a schematic, perspective view of an embodiment of the present invention, wherein the detector comprises a charge-coupled device (CCD) and the fiducial reference comprises a frame, shown with the front and a section of the top removed;
- CCD charge-coupled device
- FIG. 21 is a sectional view of the embodiment depicted in FIG. 22 taken along the 23 - 23 line;
- FIG. 22 is an alternate embodiment of a laser aiming device in accordance with the present invention.
- FIG. 23 is a graph of the projection angle, q, versus the major diameter of the reference image, d p ;
- FIG. 24 is a graph of the distance from the center of a reference marker to the source, a p , versus the major diameter of the reference images, a;
- FIG. 25 is a graph of the projection angle, ⁇ , versus the major diameter of the reference images, a;
- FIG. 26 is a graph of the offset correction distance, delta, versus the projection angle, q;
- FIG. 27 is a graph of an ellipse showing the variables x, y, b/2, and a/2;
- FIG. 28 is a graph of a plot of y versus x for the equation of the ellipse shown in FIG. 27 .
- the present invention generally relates to a system 20 , as depicted schematically in FIG. 1 , for synthesizing an image of an object 21 at a selected slice position 35 through the object 21 from a plurality of radiographic projected images 38 of the selected object 21 .
- a fiducial reference 22 is held in a fixed position relative to the selected object 21 , for example, by directly attaching the fiducial reference 22 to the object 21 .
- the fiducial reference comprises two finite sized, identifiable reference markers, 23 and 123 , which are maintained coupled together in a fixed geometry relative to each other by a radiolucent bar 24 .
- the fiducial reference 22 may comprise various numbers and arrangements of reference markers 23 .
- a radiation source 27 is provided to irradiate the object 21 along with the fiducial reference 22 . Irradiation of the object 21 casts a projected image 38 onto a recording medium 31 .
- the projected image 38 comprises an object image 40 of the object 21 and reference images, 39 and 139 , of the reference markers, 23 and 123 , respectively.
- the pattern of source 27 positions does not need to be in any fixed geometry or position. Indeed, the position of the source 27 may be totally arbitrary in translation and displacement relative to the object 21 . Likewise, the recording medium 31 may also be arbitrarily movable relative to the object 21 by translation, displacement, tilting, or rotation. The only requirement is that for every degree of freedom in the system resulting from movement of the source 27 or the recording medium 31 relative to the object 21 , the fiducial reference 22 must include sufficient measurable or defined characteristics, such as size, shape, or numbers of reference markers 23 , to account for each degree of freedom.
- the minimum number of reference markers required to completely determine the system depends on the constraints, if any, imposed on the relative positions of (1) the radiation source, (2) the object and fiducial reference, and (3) the recording medium.
- the system may have a total of nine possible relative motions (2 translations and 1 displacement for the radiation source relative to a desired projection plane and 2 translations, 1 displacement, 2 tilts, and 1 rotation for the recording medium relative to the desired projection plane).
- Each of these possible relative motions must be capable of analysis either by constraining the system and directly measuring the quantity, by providing a sufficient number of reference markers to enable the quantity to be determined, or by estimating the value of the quantity.
- Each unconstrained relative motion represents a degree of freedom for the system. For a system to be completely determined, the total number of degrees of freedom in the system must be less than or equal to the total number of degrees of freedom associated with the fiducial reference.
- More than the minimum number of reference markers can be used. In such cases, the system is overdetermined and least squares fitting can be used to improve the accuracy of the resulting image slices. If, however, less than the minimum number of reference markers is used, then the system is underdetermined and the unknown degrees of freedom must either be estimated or measured directly.
- the reference markers can be essentially any size and shape, spherical reference markers of known diameter may be used. When using spherical reference markers of a finite size, a single reference marker can account for up to five degrees of freedom.
- the reference image cast by the spherical reference marker is elliptical and is independent of any rotation of the reference marker. Determining the position of the reference image in the projection plane (X- and Y-coordinates) and the magnitudes of the major and minor diameters of the elliptical image accounts for four degrees of freedom.
- the reference image will be magnified relative to the actual size of the reference marker, thereby accounting for an additional degree of freedom.
- only two degrees of freedom are typically associated with the reference image of a point-size reference marker.
- FIG. 4 The most complex, yet most generally applicable, arrangement is depicted in FIG. 4 , wherein the radiation source 27 and the recording medium 31 are completely unconstrained and uncoupled from the selected object 21 .
- this arrangement there are nine degrees of freedom: 2 translational ( ⁇ X and ⁇ Y) and 1 displacement (AZ) degrees of freedom for the radiation source 27 relative to an original or desired projection plane 37 and 2 translational ( ⁇ X′ and ⁇ Y′), 1 displacement ( ⁇ Z′), 2 tilting ( ⁇ and ⁇ ), and 1 rotational ( ⁇ ) degree of freedom for the recording medium 31 relative to the original or desired projection plane.
- a fiducial reference system sufficient to solve a projection system having nine degrees of freedom is needed to completely determine the system.
- One embodiment of the present invention that permits this general arrangement to be realized conveniently involves two-dimensional projected images from a system comprised of a fiducial reference having five point-size or finite reference markers.
- This approach conveniently facilitates three-dimensional reconstructions when exactly four reference markers are coplanar and no three or more reference markers are collinear. Under these conditions, only the projection from the non-coplanar marker need be distinguished from the other four because the projections from the latter always bear a fixed sequential angular arrangement relative to each other which simplifies identification of homologous points in all projections.
- the reference markers can be placed at five contiguous vertices of a cube as shown in FIG. 5 .
- Fiducial reference 122 comprises five reference markers, 23 , 123 , 223 , 323 , 423 , positioned contiguously at five vertices of a cube.
- the object 121 is preferably positioned within the cube.
- the four co-planar reference markers, 23 , 123 , 223 , and 323 then can be used for projectively warping or transforming the projected images onto a desired projection plane while the remaining reference marker 423 serves as the alignment marker required to determine the normalized projection angle as described in U.S. Pat. No. 5,359,637.
- FIG. 11 Another useful arrangement of the fiducial reference comprising five reference markers is shown in FIG. 11 , wherein a fiducial reference 222 employing a pyramidal distribution of reference markers 323 is used.
- the fiducial reference 222 comprises five reference markers 23 , 123 , 223 , 323 , and 423 , which are held in a fixed relationship relative to each other and to the object 221 .
- four of the reference markers, 23 , 123 , 223 , and 323 lie in a plane that can be used to establish the desired projection plane.
- they define the four corners of the base of a pyramid.
- the fifth reference marker 423 is positioned to define the apex of the pyramid and serves as the means for determining the projection angles relative to the desired projection plane as described in U.S. Pat. No. 5,359,637.
- the fiducial reference 222 may be attached or fixed relative to the object 221 such that the base of the pyramid is proximate to the recording medium and the apex of the pyramid is proximate to the source.
- a fiducial reference 322 having an alternative arrangement of reference markers in a pyramidal distribution is shown.
- the fiducial reference 322 comprises a radiopaque frame 25 having a radiolucent central window.
- the four inside corners of the radiopaque frame 25 define four reference markers, 23 , 123 , 223 , and 323 , at the base of the pyramid.
- the fifth reference marker 423 is positioned at the apex of the pyramid.
- the object 321 is positioned between the frame 25 and the reference marker 423 .
- Fiducial reference 422 which is also useful for solving a system with nine degrees of freedom is shown.
- Fiducial reference 422 comprises a rectangular parallelepiped 33 with radiopaque reference markers, 23 , 123 , 223 , 323 , 423 , and 523 , centered on each of the six faces of the parallelepiped 33 .
- the reference markers, 23 , 123 , 223 , 323 , 423 , and 523 are marked with distinguishable indicia, such as X, Y, Z, ⁇ circle around (X) ⁇ , ⁇ circle around (Y) ⁇ , and ⁇ circle around (Z) ⁇ so that the reference images cast by the markers, 23 , 123 , 223 , 323 , 423 , and 523 , can be identified easily and distinguished from one another.
- two or more of the edges of the parallelepiped 33 may be defined by radiopaque bars 26 such that the intersections of the bars 26 provide additional reference markers, such as reference marker 623 located at the intersection of the three bars labeled 26 in FIG.
- FIGS. 12 and 13 An arrangement of the system of the present invention which is somewhat constrained is depicted in FIGS. 12 and 13 , wherein a hand-held X-ray source is provided such that the orthogonal distance between the radiation source 127 and the recording medium 131 is fixed by a C-arm 129 at a distance short enough so that the image cast by the fiducial reference 122 is magnified relative to the size of the actual fiducial reference 122 .
- the C-arm 129 is connected to the recording medium 131 by a concentric swivel collar 149 to allow the C-arm 129 to be rotated relative to the recording medium 131 .
- a disposable and crushable radiolucent foam cushion 130 may be attached to the surface of the recording medium 131 to permit comfortable customized stable adaptation of the detector 131 to the object 121 .
- the other end of the C-arm 129 is attached to a potted X-ray source 145 so that radiation emanating from the potted X-ray source 145 impinges upon the recording medium 131 .
- a trigger 146 is provided for operating the source 127 .
- the source 127 optionally comprises a circular beam collimator 147 for collimating radiation emanating from the source 127 .
- the collimator 147 may provide a relatively long focal-object distance to provide nearly affine projection geometries.
- a handle 148 is also provided to enable the operator to more easily maneuver the source 127 .
- the hand-held X-ray source 127 is connected to a computer/high voltage source 128 for controlling operation of the device.
- a disposable plastic bag 132 can be positioned around the detector 131 for microbial isolation.
- the source 127 can optionally comprise a rotatable transparent radiopaque plastic cylinder 119 and a transparent radiopaque shield 152 to protect the operator from scattered radiation. In this arrangement, there are 3 degrees of freedom (two translational and one displacement for the radiation source 127 ).
- a fiducial reference compensating for at least three degrees of freedom is necessary to completely describe or analyze the system.
- a fiducial reference 122 comprising a single radiopaque sphere of finite diameter. Under those conditions, the length of the minor axis of the resulting elliptical shadow plus two translational measurements are sufficient to define the projection geometry completely.
- c is the fixed distance between the source and the projection plane;
- P s is the orthogonal projection of the source onto the projection plane;
- B, M, and T are the reference markers;
- r is the radius of the reference markers;
- a p is the distance from the center of a reference marker to the source;
- ⁇ is the angle subtended by the center of a reference marker relative to a line orthogonal to the projection plane through the source;
- ⁇ is the angle at the apex of an isosceles triangle having a base of length r and a height of length a p ;
- B s , M s , and T s are the reference images associated with the reference markers;
- a (or, alternatively, d p ) is the major diameter of the reference images;
- b is the minor diameter of the reference images;
- x is the length of a section of an arc associated with a reference image measured from the projection of the center of the corresponding reference marker onto the projection
- FIG. 25 illustrates a graph of the solution for the projection angle, theta
- FIG. 26 illustrates a graph of the solution for the offset correction distance, delta.
- x y ⁇ ⁇ b ⁇ x ⁇ a - x a 0 0 0.1 0.312 0.2 0.436 0.3 0.527 0.4 0.6 0.5 0.661 0.6 0.714 0.7 0.76 0.8 0.8 0.9 0.835 1 0.866 1.1 0.893 1.2 0.917 1.3 0.937 1.4 0.954 1.5 0.968 1.6 0.98 1.7 0.989 1.8 0.995 1.9 0.999 2 1
- FIG. 6 another arrangement of the system of the present invention is depicted wherein the radiation source 27 is located at a fixed distance from the selected object 21 and sufficiently far so that magnification is not significant.
- the recording medium 31 is allowed to be shifted, displaced, and tilted relative to the selected object 21 and an original or desired projection plane 37 .
- a fiducial reference having at least seven degrees of freedom is needed to solve the system.
- a fiducial reference comprising at least four point-size reference markers can be used to determine the position of the radiation source relative to the selected object 21 and the recording medium 31 .
- FIG. 7 yet another arrangement of the system of the present invention is depicted wherein the distance between the object 21 and the radiation source 27 is sufficiently large so that magnification can be ignored and wherein the recording medium 31 is free to shift laterally relative to the object 21 and the desired or original projection plane 37 .
- this arrangement there are four degrees of freedom (two translational degrees of freedom for the radiation source 27 and two translational degrees of freedom for the recording medium 31 ). Therefore, a fiducial reference having at least four degrees of freedom is necessary to completely determine the system. Accordingly, a fiducial reference comprising at least two point-size reference markers can be used to determine the position of the radiation source relative to the selected object 21 and the recording medium 31 .
- This relatively constrained system may be useful in three-dimensional reconstructions of transmission electron micrographs produced from video projections subtending various degrees of specimen tilt and exhibiting various amounts of arbitrary and unpredictable lateral shift due to intrinsic instability associated with the instrument's electron lenses.
- the radiation source 27 may be either a portable or a stationary X-ray source.
- the radiation source 27 is not limited to an X-ray source.
- the specific type of source 27 which is utilized will depend upon the particular application.
- the present invention can also be practiced using magnetic resonance imaging (MRI), ultrasound, visible light, infrared light, ultraviolet light, or microwaves.
- MRI magnetic resonance imaging
- the source 227 is a hand-held X-ray source, similar to that described above in reference to source 127 , except that a low power laser aiming device 250 and an alignment indicator 251 are provided to insure that the source 227 and the recording medium 231 are properly aligned.
- a radiolucent bite block 218 is provided to constrain the detector 231 relative to the object 221 , thereby constraining the system to three degrees of freedom (two translational and one displacement for the radiation source 227 relative to the object 221 and detector 231 ). Consequently, the fiducial reference 222 can be fixed directly to the bite block 218 .
- the source 227 When the source 227 is properly aligned with the recording medium 231 , radiation emanating from the aiming device 250 impinges on the recording medium 231 . In response to a measured amount of radiation impinging on the recording medium 231 , a signal is sent to activate the alignment indicator 251 which preferably produces a visible and/or auditory signal. With the alignment indicator 251 activated, the X-ray source 245 can be operated at full power to record a projected image.
- the source 227 can optionally comprise a collimator 247 to collimate the radiation from the X-ray source and/or a transparent scatter shield 252 to protect the operator from scattered radiation.
- the operator can stand behind a radiopaque safety screen when exposing the patient to radiation from the source 227 .
- a handle 248 and trigger 246 may be provided to facilitate the handling and operation of the source 227 .
- the source 227 is connected to a computer/high voltage source 228 and an amplifier 260 for controlling operation of the device.
- the aiming device 250 comprises an X-ray source operated in an ultra-low exposure mode and the projected image is obtained using the same X-ray source operated in a full-exposure mode.
- a real-time ultra-low dose fluoroscopic video display can be mounted into the handle 248 of the source 227 via a microchannel plate (MCP) coupled to a CCD.
- MCP microchannel plate
- the video display switches to a lower gain (high signal-to-noise) frame grabbing mode when the alignment is considered optimal and the trigger 246 is squeezed more tightly.
- the aiming device 850 comprises a laser source 857 and a radiolucent angled mirror 858 which produces a laser beam, illustrated by dashed line 859 , which is concentric with the radiation emanating from the source 827 .
- the alignment indicator 851 comprises a radiolucent spherical surface 861 which is rigidly positioned relative to the detector 831 by a C-arm 829 that is plugged into the bite block 818 .
- the fiducial reference 822 comprises a radiolucent spacer containing a fiducial pattern that is affixed to the detector 831 .
- a central ring area 863 can be designated at the center of the spherical surface 861 such that aiming the laser beam 859 at the central ring area 863 assures an essentially orthogonal arrangement of the source 827 and the detector 831 .
- the concentric laser source 857 with a laser source that produces two laser beams that are angled relative to the radiation emanating from the source 827 permits the distance between the source 827 and the detector 831 to be set to a desired distance, provided that the two laser beams are constrained to converge at the spherical surface 861 when the desired distance has been established.
- the recording medium 31 is provided for recording the projected object image 40 of the selected object 21 and the projected reference images, 39 and 139 , of the reference markers 23 and 123 .
- the recording medium 31 may be in the form of a photographic plate or a radiation-sensitive, solid-state image detector such as a radiolucent charge-coupled device (CCD).
- CCD radiolucent charge-coupled device
- the recording medium 331 comprises a CCD having a top screen 200 , a bottom screen 206 positioned below the top screen 200 , and a detector 210 positioned below the bottom screen 206 .
- the top screen 200 is monochromatic so that a projected image projected onto the top screen 200 causes the top screen 200 to fluoresce or phosphoresce a single color.
- the bottom screen 206 is dichromatic, so that the bottom screen 206 fluoresces or phosphoresces in a first color in response to a projected image projected directly onto the bottom screen 206 and fluoresces or phosphoresces in a second color in response to fluorescence or phosphorescence from the top screen 200 .
- the detector 210 is also dichromatic so as to allow for the detection and differentiation of the first and the second colors.
- the recording medium 331 may also comprise a radiolucent optical mask 202 to modulate the texture and contrast of the fluorescence or phosphorescence from the top screen 200 , a radiolucent fiber-optic spacer 204 to establish a known projection disparity, and a radiopaque fiber-optic faceplate 208 to protect the detector 210 from radiation emanating directly from the radiation source.
- FIGS. 20 and 23 Yet another embodiment is depicted in FIGS. 20 and 23 , wherein the detector 731 comprises a phosphor-coated CCD and the fiducial reference 722 comprises a radiopaque rectangular frame 725 .
- Both the detector 731 and the fiducial reference 722 are contained within a light-tight package 756 .
- the detector 731 and fiducial reference 722 are preferably positioned flush with an upper, inner surface of the package 756 .
- the dimensions of the frame 725 are selected such that the frame 725 extends beyond the perimeter of the detector 731 .
- Phosphor-coated strip CCDs 754 are also contained within the package 756 .
- the strip CCDs 754 are positioned below the frame 725 such that radiation impinging upon the frame 725 castes an image of each edge of the frame 725 onto one of the strip CCDs 754 .
- the positions of the frame shadow on the strip CCDs 754 is used to determine the projection geometry.
- the recording medium 431 is smaller than the projected image of object 521 .
- the present invention also relates to a method for creating a slice image through the object 21 of FIG. 1 from a series of two-dimensional projected images of the object 21 , as shown in FIG. 2 .
- the method of synthesizing the image slice starts at step 45 .
- Each step of the method can be performed as part of a computer-executed process.
- a fiducial reference 22 comprising at least two reference markers, 23 and 123 , is selected which bears a fixed relationship to the selected object 21 . Accordingly, the fiducial reference 22 may be affixed directly to the selected object 21 .
- the minimum required number of reference markers 23 is determined by the number of degrees of freedom in the system, as discussed above.
- the fiducial reference 22 comprises reference markers 23 of a finite size, the size and shape of the reference markers 23 are typically recorded.
- the selected object 21 and fiducial reference 22 are exposed to radiation from any desired projection geometry at step 49 and a two-dimensional projected image 38 is recorded at step 51 .
- the projected image 38 contains an object image 40 of the selected object 21 and a reference image, 39 and 139 , respectively, for each of the reference markers 23 and 123 of the fiducial reference 22 .
- step 53 it is determined whether additional projected images 38 are desired.
- the desired number of projected images 38 is determined by the task to be accomplished. Fewer images reduce the signal-to-noise ratio of the reconstructions and increase the intensities of component “blur” artifacts. Additional images provide information which supplements the information contained in the prior images, thereby improving the accuracy of the three-dimensional radiographic display. If additional projected images 38 are not desired, then the process continues at step 60 .
- the system geometry is altered at step 55 by varying the relative positions of (1) the radiation source 27 , (2) the selected object 21 and the fiducial reference 22 , and (3) the recording medium 31 .
- the geometry of the system can be varied by moving the radiation source 27 and/or the recording medium 31 .
- the source 27 and recording medium 31 , the selected object 21 and fiducial reference 22 are moved.
- the radiation source and recording medium produce images using visible light (e.g., video camera)
- the geometry of the system must be varied to produce images from various sides of the object in order to obtain information about the entire object. After the system geometry has been varied, the process returns to step 49 .
- a slice position is selected at step 60 .
- the slice position corresponds to the position at which the image slice is to be generated through the object.
- each projected image 38 is projectively warped onto a virtual projection plane 37 at step 65 .
- the warping procedure produces a virtual image corresponding to each of the actual projected images.
- Each virtual image is identical to the image which would have been produced had the projection plane been positioned at the virtual projection plane with the projection geometry for the radiation source 27 , the selected object 21 , and the fiducial reference 22 of the corresponding actual projected image.
- the details of the steps involved in warping the projection plane 37 are shown in FIG. 3 .
- the process starts at step 70 .
- a virtual projection plane 37 is selected. In most cases it is possible to arrange for one of the projected images to closely approximate the virtual projection plane position. That image can then be used as the basis for transformation of all the other images 38 .
- a plane which is parallel to the plane containing the co-planar reference markers 23 can be selected as the virtual projection plane 37 .
- the reconstruction yields a slice image which may be deformed due to variations in magnification. The deformation becomes more prominent when the magnification varies significantly over the range in which the reconstruction is carried out. In such cases, an additional geometric transformation to correct for differential magnification may be individually performed on each projected image 38 to correct for image deformation.
- One of the recorded projected images 38 is selected at step 74 and the identity of the reference images 39 cast by each reference marker 23 is determined at step 76 .
- assignment of each elliptical image 39 to a corresponding reference marker 23 can be accomplished simply by inspection. Under such conditions, the minor diameter of the elliptical image 39 is always larger the closer the reference marker 23 is to the radiation source 27 . This is shown most clearly in FIG.
- spherical reference markers 23 which are hollow having different wall thicknesses and hence, different attenuations can be used. Accordingly, the reference image 39 cast by each spherical reference marker 23 can be easily identified by the pattern of the reference images 39 . Analogously, spherical reference markers 23 of different colors could be used in a visible light mediated system.
- each reference image 39 cast by each reference marker 23 is measured at step 78 .
- the projected center 41 of the reference marker 23 does not necessarily correspond to the center 42 of the reference image 39 cast by that reference marker 23 . Accordingly, the projected center 41 of the reference marker 23 must be determined.
- One method of determining the projected center 41 of the reference marker 23 is shown in FIG. 16 .
- the variation in intensity of the reference image 39 associated with reference marker 23 along the length of the major diameter of the reference image 39 is represented by the brightness profile 43 . The method depicted in FIG.
- the projected center 41 always intersects the brightness profile 43 of the reference image 39 at, or very near, the maximum 44 of the brightness profile 43 . Accordingly, the projected center 41 of a spherical reference marker 23 produced by penetrating radiation can be approximated by smoothing the reference image 39 to average out quantum mottle or other sources of brightness variations which are uncorrelated with the attenuation produced by the reference marker 23 . An arbitrary point is then selected which lies within the reference image 39 . A digital approximation to the projected center 41 is isolated by performing a neighborhood search of adjacent pixels and propagating the index position iteratively to the brightest (most attenuated) pixel in the group until a local maximum is obtained. The local maximum then represents the projected center 41 of the reference marker 23 .
- the fiducial reference 22 comprises reference markers 23 of finite size
- the sizes of each image 39 cast by each reference marker 23 are also recorded.
- the lengths of the major and minor diameters of elliptical reference images cast by spherical reference markers 23 can be measured.
- Computerized fitting procedures can be used to assist in measuring the elliptical reference images 39 cast by spherical reference markers 23 .
- Such procedures which are well-known in the art, may be used to isolate the elliptical reference images 39 from the projected image 38 and determine the major and minor diameters of the reference images 39 .
- the projected minor diameter of resulting elliptical reference images 39 will be slightly smaller than that determined geometrically by projection of the reference marker's actual diameter.
- the amount of the resulting error is a function of the energy of the X-ray beam and the spectral sensitivity of the recording medium 31 . This error can be eliminated by computing an effective radiographic diameter of the reference marker 23 as determined by the X-ray beam energy and the recording medium sensitivity in lieu of the actual diameter.
- One method of obtaining the effective radiographic diameter is to generate a series of tomosynthetic slices through the center of the reference marker 23 using a range of values for the reference marker diameter decreasing systematically from the actual value and noting when the gradient of the reference image 39 along the minor diameter is a maximum.
- the value for the reference marker diameter resulting in the maximum gradient is the desired effective radiographic diameter to be used for computing magnification.
- each projected image can be scaled by an appropriate magnification.
- the minor diameter of the reference image 39 is preferably used to determine the magnification since the minor diameter does not depend on the angle between the source 27 and the recording medium 31 . Accordingly, the magnification of a spherical reference marker 23 can be determined from the measured radius of the reference marker 23 , the minor diameter of the reference image 39 on the recording medium 31 , the vertical distance between the center of the reference marker 23 and the recording medium 31 , and the vertical distance between the recording medium 31 and the virtual projection plane 37 .
- a projection transformation matrix representing a series of transformation operations necessary to map the selected projected image 38 onto the virtual projection plane 37 .
- the projection transformation matrix is generated by solving each projected image 38 relative to the virtual projection plane 37 .
- the positions of the co-planar reference markers 23 are used to determine the transformation matrix by mapping the position of the reference images 39 cast by each co-planar reference marker 23 in the projected image onto its corresponding position in the virtual projection plane.
- the fiducial reference comprises a radiopaque frame 25
- the positions of the reference-images 39 cast by the reference markers 23 formed at the corners of the frame 25 are mapped to a canonical rectangle having the same dimensions and scale as the frame 25 .
- This approach also serves to normalize the projective data. Depending on the number of degrees of freedom, the transformation operations range from complex three-dimensional transformations to simple planar rotations or translations.
- step 84 it is determined whether all of the projected images 38 have been analyzed. If all of the projected images 38 have not been analyzed, the process returns to step 74 , wherein an unanalyzed image 38 is selected. If no additional projected images 38 are to be analyzed, then the process proceeds through step 85 of FIG. 3 to step 90 of FIG. 2 .
- an image slice through the object 21 at the selected slice position is generated at step 90 .
- An algorithm such as that described in U.S. Pat. No. 5,359,637, which is incorporated herein by reference, can be used for that purpose.
- the position of the reference image cast by the alignment marker or markers 23 in each projected image 38 are used as the basis for application of the algorithm to generate the image slices.
- a true three-dimensional representation can be synthesized. Accordingly, it is determined whether an additional slice position is to be selected at step 92 . If an additional slice position is not desired, the process proceeds to step 94 . If a new slice position is to be selected, the process returns to step 60 .
- the entire set of image slices is integrated into a single three-dimensional representation at step 94 .
- Alternative bases for interactively analyzing and displaying the three-dimensional data can be employed using any number of well-established three-dimensional recording and displaying methods.
- the source 627 is an unconstrained point source and the detector 631 is completely constrained relative to the object 621 . Accordingly, the system has three degrees of freedom (two translational and one displacement for the radiation source 627 relative to the object 621 and detector 631 ).
- a beam collimator 647 can be positioned between the source 627 and the object 621 to collimate the radiation from the source 627 .
- the detector 631 comprises a primary imager 632 and a secondary imager 634 positioned a known distance below the primary imager 632 . In one embodiment, both the primary and secondary imagers, 632 and 634 , are CCD detectors.
- the fiducial reference 622 comprises a radiopaque shield 633 with a ring-shaped aperture 636 of known size positioned between the primary imager 632 and the secondary imager 634 .
- Radiation from the source 627 passes through collimator 647 , irradiates object 621 , and produces an object image on the primary imager 632 .
- Radiation from the source 627 which impinges upon the radiopaque shield 633 passes through the aperture 636 to produce a circular, or elliptical, reference image of the aperture 636 on the secondary imager 634 .
- the secondary imager 634 can be a low quality imager such as a low resolution CCD.
- a lower surface of the primary imager 632 can be coated with a phosphorescent material 635 , so that radiation impinging upon the primary imager 632 causes the phosphorescent material 635 to phosphoresce.
- the phosphorescence passes through the aperture 636 to produce the reference image on the secondary imager 634 .
- the reference image produced using the system depicted in FIG. 19 can be used to determine the position of the source 627 relative to the object 621 and the detector 631 .
- a circle, or ellipse is fitted to the projected reference image.
- the position of the center of the fitted circle, or ellipse, relative to the known center of the aperture 636 is determined.
- the angle ⁇ of a central ray 637 radiating from the source 627 relative to the object 621 and the detector 631 can then be determined.
- the length of the minor diameter of the projected reference image is determined and compared to the known diameter of the aperture 636 to provide a relative magnification factor.
- the relative magnification factor can then be used to determine the distance of the source 627 from the object 621 .
- the center of the fitted circle can be determined as follows.
- a pixel or point on the secondary imager 634 that lies within the fitted circle is selected as a seed point.
- the center pixel of the secondary imager 634 can be selected, since the center point will typically lie within the fitted circle.
- a point R is determined by propagating from the seed point towards the right until the fitted circle is intersected.
- a point L is determined by propagating from the seed point towards the left until the fitted circle is intersected. For each pixel along the arc L-R, the average of the number of pixels traversed by propagating from that pixel upwardly until the fitted circle is intersected and the number of pixels traversed by propagating from that pixel downwardly until the fitted circle is intersected is determined.
- This average represents the row address of the fitted circle's center.
- the entire reference image is rotated by 90° and the process is repeated.
- the row address and column address together represent the position of the center of the fitted circle.
- the present invention is equally applicable to images produced using a variety of technologies, such as visible light, ultrasound, or electron microscopy images.
- technologies such as visible light, ultrasound, or electron microscopy images.
- ENM intermediate voltage electron microscope
- the present invention can also be used to reconstruct three-dimensional images of objects which either emit or scatter radiation.
- the present invention allows cellular changes to be detected and quantified in an efficient and cost-effective manner. Quantitation of three-dimensional structure facilitates comparison with other quantitative techniques, such as biochemical analysis. For example, increases in the Golgi apparatus in cells accumulating abnormal amounts of cholesterol can be measured and correlated with biochemically measured increases in cellular cholesterol.
- the present invention can be applied to construct topological images of geological structures by recording images of the structure created by the sun.
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Medical Informatics (AREA)
- Heart & Thoracic Surgery (AREA)
- Surgery (AREA)
- High Energy & Nuclear Physics (AREA)
- Theoretical Computer Science (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Optics & Photonics (AREA)
- Pathology (AREA)
- Radiology & Medical Imaging (AREA)
- Biomedical Technology (AREA)
- General Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Biophysics (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Dentistry (AREA)
- Oral & Maxillofacial Surgery (AREA)
- Apparatus For Radiation Diagnosis (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
- Image Processing (AREA)
- Magnetic Resonance Imaging Apparatus (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
A system for constructing image slices through a selected object, the system comprising an identifiable fiducial reference in a fixed position relative to the selected object, wherein the fiducial reference comprises at least two identifiable reference markers. A source of radiation is provided for irradiating the selected object and the fiducial reference to form a projected image of the selected object and the fiducial reference which is recorded by a recording medium.
Description
- This application is a continuation of U.S. application Ser. No. 09/034,922, filed on Mar. 5, 1998, still pending, the subject matter of which is incorporated herein by reference.
- The present invention relates to a method and system for creating three-dimensional displays or images from a multiplicity of two-dimensional projections and, more specifically, to a method and system for use in computed tomography systems in which random relative positional geometries between the source of radiation, the object of interest, and the recording means may be used for recording radiographic images for tomosynthesis.
- A wide range of tomosynthetic imaging techniques has previously been demonstrated to be useful in examining three-dimensional objects by means of radiation. These imaging techniques differ in the size and configuration of the effective imaging aperture. At one extreme, the imaging aperture approaches zero (i.e., a pinhole) and the resulting display is characterized by images produced from a single transmission radiograph. This yields an infinitely wide depth of field and therefore no depth information can be extracted from the image. At the other extreme, the aperture approaches a surrounding ring delimiting an infinite numerical aperture resulting in projection angles orthogonal to the long axis of the irradiated object. This yields an infinitely narrow depth of field and hence no information about adjacent slices through the object can be ascertained. It therefore follows that a “middle ground” approach, which provides the ability to adapt a sampling aperture to a particular task, would be highly advantageous.
- The key to achieving the full potential of diagnostic flexibility lies in the fact that perceptually meaningful three-dimensional reconstructions can be produced from optical systems having any number of different aperture functions. That fact can be exploited since any aperture can be approximated by summation of a finite number of appropriately distributed point apertures. The key is to map all incrementally obtained projective data into a single three-dimensional matrix. To accomplish this goal, one needs to ascertain all positional degrees of freedom existing between the object of interest, the source of radiation, and the detector.
- In the past, the relative positions of the object, the source, and the detector have been determined by fixing the position of the object relative to the detector while the source of radiation is moved along a predetermined path, i.e. a path of known or fixed geometry. Projective images of the object are then recorded at known positions of the source of radiation. In this way, the relative positions of the source of radiation, the object of interest, and the detector can be determined for each recorded image.
- Previously, a method and system has been described which enables the source of radiation to be decoupled from the object of interest and the detector. This is accomplished by fixing the position of the object of interest relative to the detector and providing a fiducial reference which is in a fixed position relative to the coupled detector and object. The position of the image of the fiducial reference in the recorded image then can be used to determine the position of the source of radiation.
- However, none of the existing techniques can be used in the most general application wherein the radiation source, the object of interest, and the detector are independently positioned for each projection. In such systems, there are nine possible degrees of freedom: 2 translational and 1 displacement degrees of freedom for the radiation source relative to the selected object and 2 translational, 1 displacement, 2 tilting, and 1 rotational degrees of freedom for the recording medium relative to the selected object. It is highly desirable to have a system and a method for constructing a three-dimensional radiographic display from two-dimensional projective data wherein the source of radiation, the object of interest, and the detector are all allowed to independently and arbitrarily vary in position relative to each other.
- The present invention relates to an extension of tomosynthesis which facilitates three-dimensional reconstructions of an object from any number of arbitrary plane projections of the object produced from any number of arbitrary angles. The information required to produce the three-dimensional reconstructions is derived from fiducial analysis of the projection themselves or from analyses of functional relationships established through known fiducial constraints. In accordance with the present invention, a system and methods are provided for creating three-dimensional images using tomosynthetic computed tomography in which the system and methods significantly simplify the construction of image slices at selected slice positions through an object. Following a one-time transformation of a series of projected images, only simple offset and averaging operations are required in selected embodiments of the invention for a variety of subsequent reconstructions of a volumetric region within which projective variations may be considered negligible.
- The system comprises an identifiable fiducial reference located in a fixed position relative to the object. The fiducial reference comprises at least two reference markers which are in a fixed geometry relative to each other. One of the reference markers may be used as an alignment marker during construction of a tomosynthetic slice through the object. The other reference marker or markers may be used to projectively warp or transform a projected image from an actual projection plane to a virtual projection plane. Each reference marker may be small enough to be considered point-size or, alternatively, may be finite in size. However, there are advantages to using markers of a known geometry such as spherical markers with a measurable diameter. In one embodiment, the fiducial reference comprises five point-size or finite reference markers that are arranged so that four of the reference markers are co-planar and no three or more reference markers are collinear.
- A radiation source is provided for irradiating the object with the fiducial reference in a fixed position relative to the object. The preferred radiation source depends upon the particular application. For example, the present invention may be practiced using x-rays, electron microscopy, ultrasound, visible light, infrared light, ultraviolet light, microwaves, or virtual radiation simulated by manipulation of magnetic fields (magnetic resonance imaging (MRI)).
- A recording medium or detector is used to record a series of projected images. Each projected image may include an object image of the object and a reference marker image for each of the reference markers. The recording medium may be in the form of a photographic plate or a radiation-sensitive, solid-state image detector such as a charge-coupled device (CCD), or any other system capable of producing two-dimensional projections or images suitable for digitization or other analysis.
- In operation, the system of the present invention is used to synthesize a three-dimensional reconstruction of the object to obtain, for example, an image slice through the object, at a selected slice position through the object, from a plurality of projected-images detected at the recording medium. The simplification of the construction method is achieved by warping, i.e. transforming or mapping, a series of projected images onto a virtual projection plane to yield modified images that would match those that would have been generated had the detector been in a fixed position relative to the object. By warping the projected images onto the virtual projection plane, the computation required for each image slice construction is greatly reduced. In addition, the solution of the projective transformations can be performed via a direct method that is both efficient and computationally robust. Further, magnification differences can be compensated for by appropriate scaling of the images.
- A series of two-dimensional projected images of an object with an associated fiducial reference is recorded. The fiducial reference markers are coupled in fixed position relative to the object. The projected images can be recorded with (i) the source, (ii) the recording medium, and (iii) the fiducial reference markers coupled to the object, in various or arbitrary projection geometries. Further, the projection geometry preferably varies from projected image to projected image. Some variation is required to produce a finite depth of field.
- The virtual projection plane may preferably correspond to the position of a plane through at least one of the reference markers in real space or to a plane defined by one of the existing projected images. Imaging systems that use projective geometries, which include optical and radiographic systems, can be appropriately warped using a projective transformation matrix. The projective transformation matrix is generated by solving each projected image relative to the virtual projection plane.
- The resulting transformations compensate for magnification and/or projective differences between the various images. Such differences are introduced when the source is sufficiently close to the object and/or the source moves in a direction which is not parallel to the projection plane.
- Once the projected images are warped and scaled to compensate for projective artifacts, construction of an image slice of the object at a selected slice position is performed based on techniques used in single reference marker applications. An example of such a technique is described in U.S. Pat. No. 5,359,637, which is incorporated herein by reference. Accordingly, the single reference point projection required by this technique may be abstracted from characteristics known to be associated with the object being projected, or from one or more fiducial reference markers either attached to or otherwise functionally related to the irradiated object.
- The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the accompanying drawings, in which:
-
FIG. 1 is a schematic representation of a system for creating three-dimensional radiographic displays using computed tomography in accordance with the present invention; -
FIG. 2 is a flow chart showing the steps involved in creating three-dimensional radiographic displays using computed tomography in accordance with the present invention; -
FIG. 3 is a flow chart showing details of a method of projectively warping or transforming a projected image from an actual plane of projection onto a virtual projection plane; -
FIG. 4 is a schematic representation of a system having nine degrees of freedom in which a source is shifted and displaced relative to an original projection plane and in which a projection plane of a recording medium is shifted, rotated, displaced, and tilted relative to the original projection plane; -
FIG. 5 is a schematic representation showing an arrangement of reference markers in accordance with the an embodiment of the present invention, wherein five spherical reference markers are positioned at five of the eight vertices of a cube; -
FIG. 6 is a schematic representation of a system having seven degrees of freedom in which an infinite point source is shifted relative to an original projection plane and in which a projection plane of a recording medium is shifted, displaced, and tilted relative to the original projection plane; -
FIG. 7 is a schematic representation of a system having four degrees of freedom in which an infinite point source is shifted relative to an original projection plane and in which a projection plane of a recording medium is shifted relative to the original projection plane; -
FIG. 8 is an exploded, schematic representation of a charge-coupled device (CCD) for use as a recording medium; -
FIG. 9 is a schematic representation of an embodiment of the present invention wherein the recording medium is smaller than the projected image of the object; -
FIG. 10 is a schematic representation of an embodiment of the present invention wherein the source is a hand-held X-ray source with a laser aiming device; -
FIG. 11 is a schematic representation of an embodiment of the present invention wherein the reference markers of the fiducial reference are positioned at the vertices of a square pyramid; -
FIG. 12 is a schematic representation of an embodiment of the present invention wherein the source is a hand-held X-ray source which is constrained relative to the recording medium by a C-arm; -
FIG. 13 is an enlarged schematic representation of the object of interest and the recording medium depicted inFIG. 14 ; -
FIG. 14 is a schematic representation of an embodiment of the present invention wherein the reference markers of the fiducial reference are positioned at the centers of the faces of a parallelepiped; -
FIG. 15 is a schematic representation of an embodiment of the present invention wherein the corners of a frame define four reference markers; -
FIG. 16 is a schematic representation of a reference image cast by a spherical reference marker showing the resulting brightness profile; -
FIG. 17 is a schematic representation of the parameters associated with a system comprising three spherical, non-collinear reference markers wherein the orthogonal distance between the radiation source and the recording medium is fixed at a distance short enough so that the images cast by the reference markers are magnified relative to the size of the actual reference markers; -
FIG. 18 is a schematic representation of the relevant parameters associated with a reference image associated with a spherical reference marker; -
FIG. 19 is a schematic representation of an embodiment of the present invention wherein the fiducial reference comprises a radiopaque shield with a ring-like aperture; -
FIG. 20 is a schematic, perspective view of an embodiment of the present invention, wherein the detector comprises a charge-coupled device (CCD) and the fiducial reference comprises a frame, shown with the front and a section of the top removed; -
FIG. 21 is a sectional view of the embodiment depicted inFIG. 22 taken along the 23-23 line; -
FIG. 22 is an alternate embodiment of a laser aiming device in accordance with the present invention; -
FIG. 23 is a graph of the projection angle, q, versus the major diameter of the reference image, dp; -
FIG. 24 is a graph of the distance from the center of a reference marker to the source, ap, versus the major diameter of the reference images, a; -
FIG. 25 is a graph of the projection angle, θ, versus the major diameter of the reference images, a; -
FIG. 26 is a graph of the offset correction distance, delta, versus the projection angle, q; -
FIG. 27 is a graph of an ellipse showing the variables x, y, b/2, and a/2; and -
FIG. 28 is a graph of a plot of y versus x for the equation of the ellipse shown inFIG. 27 . - The present invention generally relates to a
system 20, as depicted schematically inFIG. 1 , for synthesizing an image of anobject 21 at a selectedslice position 35 through theobject 21 from a plurality of radiographic projectedimages 38 of the selectedobject 21. Afiducial reference 22 is held in a fixed position relative to the selectedobject 21, for example, by directly attaching thefiducial reference 22 to theobject 21. The fiducial reference comprises two finite sized, identifiable reference markers, 23 and 123, which are maintained coupled together in a fixed geometry relative to each other by aradiolucent bar 24. However, thefiducial reference 22 may comprise various numbers and arrangements ofreference markers 23. Aradiation source 27 is provided to irradiate theobject 21 along with thefiducial reference 22. Irradiation of theobject 21 casts a projectedimage 38 onto arecording medium 31. The projectedimage 38 comprises anobject image 40 of theobject 21 and reference images, 39 and 139, of the reference markers, 23 and 123, respectively. - In general, the pattern of
source 27 positions does not need to be in any fixed geometry or position. Indeed, the position of thesource 27 may be totally arbitrary in translation and displacement relative to theobject 21. Likewise, therecording medium 31 may also be arbitrarily movable relative to theobject 21 by translation, displacement, tilting, or rotation. The only requirement is that for every degree of freedom in the system resulting from movement of thesource 27 or therecording medium 31 relative to theobject 21, thefiducial reference 22 must include sufficient measurable or defined characteristics, such as size, shape, or numbers ofreference markers 23, to account for each degree of freedom. - The minimum number of reference markers required to completely determine the system depends on the constraints, if any, imposed on the relative positions of (1) the radiation source, (2) the object and fiducial reference, and (3) the recording medium. The system may have a total of nine possible relative motions (2 translations and 1 displacement for the radiation source relative to a desired projection plane and 2 translations, 1 displacement, 2 tilts, and 1 rotation for the recording medium relative to the desired projection plane). Each of these possible relative motions must be capable of analysis either by constraining the system and directly measuring the quantity, by providing a sufficient number of reference markers to enable the quantity to be determined, or by estimating the value of the quantity. Each unconstrained relative motion represents a degree of freedom for the system. For a system to be completely determined, the total number of degrees of freedom in the system must be less than or equal to the total number of degrees of freedom associated with the fiducial reference.
- More than the minimum number of reference markers can be used. In such cases, the system is overdetermined and least squares fitting can be used to improve the accuracy of the resulting image slices. If, however, less than the minimum number of reference markers is used, then the system is underdetermined and the unknown degrees of freedom must either be estimated or measured directly.
- Although the reference markers can be essentially any size and shape, spherical reference markers of known diameter may be used. When using spherical reference markers of a finite size, a single reference marker can account for up to five degrees of freedom. When a spherical reference marker is projected obliquely onto the recording medium, the reference image cast by the spherical reference marker is elliptical and is independent of any rotation of the reference marker. Determining the position of the reference image in the projection plane (X- and Y-coordinates) and the magnitudes of the major and minor diameters of the elliptical image accounts for four degrees of freedom. Further, when the distance between the radiation source and the reference marker is sufficiently short, the reference image will be magnified relative to the actual size of the reference marker, thereby accounting for an additional degree of freedom. In contrast, only two degrees of freedom (the X- and Y-coordinates) are typically associated with the reference image of a point-size reference marker.
- The most complex, yet most generally applicable, arrangement is depicted in
FIG. 4 , wherein theradiation source 27 and therecording medium 31 are completely unconstrained and uncoupled from the selectedobject 21. In this arrangement, there are nine degrees of freedom: 2 translational (ΔX and ΔY) and 1 displacement (AZ) degrees of freedom for theradiation source 27 relative to an original or desiredprojection plane recording medium 31 relative to the original or desired projection plane. Accordingly, a fiducial reference system sufficient to solve a projection system having nine degrees of freedom is needed to completely determine the system. - One embodiment of the present invention that permits this general arrangement to be realized conveniently involves two-dimensional projected images from a system comprised of a fiducial reference having five point-size or finite reference markers. This approach conveniently facilitates three-dimensional reconstructions when exactly four reference markers are coplanar and no three or more reference markers are collinear. Under these conditions, only the projection from the non-coplanar marker need be distinguished from the other four because the projections from the latter always bear a fixed sequential angular arrangement relative to each other which simplifies identification of homologous points in all projections. For example, the reference markers can be placed at five contiguous vertices of a cube as shown in
FIG. 5 .Fiducial reference 122 comprises five reference markers, 23, 123, 223, 323, 423, positioned contiguously at five vertices of a cube. Theobject 121 is preferably positioned within the cube. The four co-planar reference markers, 23, 123, 223, and 323, then can be used for projectively warping or transforming the projected images onto a desired projection plane while the remainingreference marker 423 serves as the alignment marker required to determine the normalized projection angle as described in U.S. Pat. No. 5,359,637. - The most general reconstruction task requiring information sufficient to determine all nine possible degrees of freedom requires computation of separate projective transformations for each projected image in each and every slice. However, by limiting the region of interest to a subvolume constrained such that the magnification across and between its slices may be considered constant, it is possible to generate veridical three-dimensional images within the volume much more efficiently. The increase in efficiency under these conditions results from the fact that all projections within this region can be mapped by a single fixed transformation, and that associated slice generation can be accomplished by simple tomosynthetic averaging of laterally shifted projections as described in U.S. Pat. No. 5,359,637.
- Another useful arrangement of the fiducial reference comprising five reference markers is shown in
FIG. 11 , wherein afiducial reference 222 employing a pyramidal distribution ofreference markers 323 is used. Thefiducial reference 222 comprises fivereference markers object 221. As was the case inFIG. 5 , four of the reference markers, 23, 123, 223, and 323, lie in a plane that can be used to establish the desired projection plane. Here, they define the four corners of the base of a pyramid. Thefifth reference marker 423 is positioned to define the apex of the pyramid and serves as the means for determining the projection angles relative to the desired projection plane as described in U.S. Pat. No. 5,359,637. In use, thefiducial reference 222 may be attached or fixed relative to theobject 221 such that the base of the pyramid is proximate to the recording medium and the apex of the pyramid is proximate to the source. - In
FIG. 15 , afiducial reference 322 having an alternative arrangement of reference markers in a pyramidal distribution is shown. In this arrangement, thefiducial reference 322 comprises aradiopaque frame 25 having a radiolucent central window. The four inside corners of theradiopaque frame 25 define four reference markers, 23, 123, 223, and 323, at the base of the pyramid. Thefifth reference marker 423 is positioned at the apex of the pyramid. Preferably, theobject 321 is positioned between theframe 25 and thereference marker 423. - In
FIG. 14 , afiducial reference 422 which is also useful for solving a system with nine degrees of freedom is shown.Fiducial reference 422 comprises arectangular parallelepiped 33 with radiopaque reference markers, 23, 123, 223, 323, 423, and 523, centered on each of the six faces of theparallelepiped 33. The reference markers, 23, 123, 223, 323, 423, and 523, are marked with distinguishable indicia, such as X, Y, Z, {circle around (X)}, {circle around (Y)}, and {circle around (Z)} so that the reference images cast by the markers, 23, 123, 223, 323, 423, and 523, can be identified easily and distinguished from one another. Alternatively or additionally, two or more of the edges of theparallelepiped 33 may be defined byradiopaque bars 26 such that the intersections of thebars 26 provide additional reference markers, such asreference marker 623 located at the intersection of the three bars labeled 26 in FIG. 14.[HRt] Reducing the uncertainty of the projection geometry through the constraint of one or more degrees of freedom reduces the complexity of the resulting reconstruction. An arrangement of the system of the present invention which is somewhat constrained is depicted inFIGS. 12 and 13 , wherein a hand-held X-ray source is provided such that the orthogonal distance between theradiation source 127 and therecording medium 131 is fixed by a C-arm 129 at a distance short enough so that the image cast by thefiducial reference 122 is magnified relative to the size of the actualfiducial reference 122. Preferably, the C-arm 129 is connected to therecording medium 131 by aconcentric swivel collar 149 to allow the C-arm 129 to be rotated relative to therecording medium 131. A disposable and crushableradiolucent foam cushion 130 may be attached to the surface of therecording medium 131 to permit comfortable customized stable adaptation of thedetector 131 to theobject 121. The other end of the C-arm 129 is attached to apotted X-ray source 145 so that radiation emanating from the pottedX-ray source 145 impinges upon therecording medium 131. Atrigger 146 is provided for operating thesource 127. Thesource 127 optionally comprises acircular beam collimator 147 for collimating radiation emanating from thesource 127. Thecollimator 147 may provide a relatively long focal-object distance to provide nearly affine projection geometries. Preferably, ahandle 148 is also provided to enable the operator to more easily maneuver thesource 127. The hand-heldX-ray source 127 is connected to a computer/high voltage source 128 for controlling operation of the device. In addition, a disposableplastic bag 132 can be positioned around thedetector 131 for microbial isolation. Thesource 127 can optionally comprise a rotatable transparent radiopaqueplastic cylinder 119 and a transparentradiopaque shield 152 to protect the operator from scattered radiation. In this arrangement, there are 3 degrees of freedom (two translational and one displacement for the radiation source 127). Accordingly, a fiducial reference compensating for at least three degrees of freedom is necessary to completely describe or analyze the system. One convenient embodiment for solving the system depicted inFIGS. 12 and 13 employs afiducial reference 122 comprising a single radiopaque sphere of finite diameter. Under those conditions, the length of the minor axis of the resulting elliptical shadow plus two translational measurements are sufficient to define the projection geometry completely. - The computational steps involved in synthesizing a three-dimensional image using three spherical, non-linear reference markers in a system wherein the orthogonal distance between the radiation source and the recording medium is fixed at a distance short enough so that the images cast by the reference markers are magnified relative to the size of the actual reference markers (i.e., a system with eight degrees of freedom as depicted in
FIGS. 12 and 13 ) can be derived with reference toFIGS. 17 and 19 . In the drawings, c is the fixed distance between the source and the projection plane; Ps is the orthogonal projection of the source onto the projection plane; B, M, and T are the reference markers; r is the radius of the reference markers; ap is the distance from the center of a reference marker to the source; φ is the angle subtended by the center of a reference marker relative to a line orthogonal to the projection plane through the source; φ is the angle at the apex of an isosceles triangle having a base of length r and a height of length ap; Bs, Ms, and Ts are the reference images associated with the reference markers; a (or, alternatively, dp) is the major diameter of the reference images; b is the minor diameter of the reference images; x is the length of a section of an arc associated with a reference image measured from the projection of the center of the corresponding reference marker onto the projection plane along the major diameter, b, in a direction toward Ps; y is the length of an arc associated with a reference image through the projection of the center of the corresponding reference marker onto the projection plane and parallel to the minor diameter of the reference image; and ds is the major diameter of a reference image in a virtual projection plane. The derivation of the solution to the system depicted inFIGS. 17 and 18 is attached hereto as Chart A and accompanyingFIGS. 23-28 .FIG. 25 illustrates a graph of the solution for the projection angle, theta, andFIG. 26 illustrates a graph of the solution for the offset correction distance, delta. -
-
-
-
Solving # 2 for w and substituting the result into #1 yields:
-
-
-
-
Solving # 3 for dp yields:
-
-
-
- Solving #7 for d and substituting the result into #8 yields:
-
-
-
Solving # 9 for f/2 yields:
-
-
-
- Substituting #10 into #4 yields:
-
-
- Solving #11 for q . . . .
- Guess value: q:=1
- Given
- Solving #11 for q . . . .
-
-
-
-
- Angle(dp, ds, c):=Find(q)
- Example:
- dp:=10, 11 . . . 100
- ds:=10
- c:=100
-
-
- The result is shown in the graph of
FIG. 23 . -
dp Angle(dp, ds, c) 10 2.776 · 10−5 11 0.306 12 0.42 13 0.5 14 0.563 15 0.615 16 0.658 17 0.696 18 0.729 19 0.758 20 0.784 21 0.808 22 0.83 23 0.849 24 0.868 25 0.885 26 0.9 27 0.915 28 0.929 29 0.941 30 0.954 31 0.965 32 0.976 33 0.986 34 0.996 35 1.005 36 1.014 37 1.022 38 1.03 39 1.038 40 1.045 41 1.052 42 1.059 43 1.065 44 1.072 45 1.078 46 1.083 47 1.089 48 1.094 49 1.1 50 1.105 51 1.11 52 1.114 53 1.119 54 1.123 55 1.122 56 1.132 57 1.136 58 1.14 59 1.144 -
-
- Substituting #3 into 52 yields:
-
-
- Substituting #4 into #1 yields:
-
-
-
Solving # 5 for x yields:
-
-
-
-
- Equation of an ellipse expressed in terms of x, y, a, & b:
-
-
-
-
Solving # 1 for positive values of y yields:
-
-
-
- Let:
- x:=0, 0, 1 . . . 2
- a:=4
- b=2
- as shown in
FIG. 27 .
Plotting y as a function of x, as shown inFIG. 28 , yields:
- Let:
-
x 0 0 0.1 0.312 0.2 0.436 0.3 0.527 0.4 0.6 0.5 0.661 0.6 0.714 0.7 0.76 0.8 0.8 0.9 0.835 1 0.866 1.1 0.893 1.2 0.917 1.3 0.937 1.4 0.954 1.5 0.968 1.6 0.98 1.7 0.989 1.8 0.995 1.9 0.999 2 1 - Derivation of ap in Terms of Observable Quantities
-
-
-
Solving # 1 for f/2 yields:
-
-
-
- Substituting #3 into #2 yields the following implicit equation:
-
-
-
- Guess value: ap:=20
- Given
-
-
-
- ap(a, q, r, c):=Find(ap)
- Example:
- a:=50, 51 . . . 100
-
-
-
- r:=9
- c:=82
-
- The solution for these values is plotted in
FIG. 24 . - Augmented Complex General Sphere Derivation
-
-
- Substituting #2 into #1 yields:
-
-
- Solving #4 for ds and substituting the result into #3 yields:
-
-
- Substituting #6 into #5 and simplifying yields:
-
-
- From the ellipse derivation . . .
-
-
- Substituting #8 into #7 yields:
-
-
- From the derivation of x . . .
-
-
- Solving #10 for ds yields:
-
-
- Substituting #11 into #3 yields
-
-
- Substituting the first solution of #13 into #9 yields:
-
-
- Substituting the first solution of #13 Into #15 and simplifying yields:
-
-
- Solving #14 for q
- Guess value:
- Given
-
- In
FIG. 6 , another arrangement of the system of the present invention is depicted wherein theradiation source 27 is located at a fixed distance from the selectedobject 21 and sufficiently far so that magnification is not significant. However, therecording medium 31 is allowed to be shifted, displaced, and tilted relative to the selectedobject 21 and an original or desiredprojection plane 37. In this arrangement, there are seven degrees of freedom (two translational degrees of freedom for theradiation source object 21 and therecording medium 31. - In
FIG. 7 , yet another arrangement of the system of the present invention is depicted wherein the distance between theobject 21 and theradiation source 27 is sufficiently large so that magnification can be ignored and wherein therecording medium 31 is free to shift laterally relative to theobject 21 and the desired ororiginal projection plane 37. In this arrangement, there are four degrees of freedom (two translational degrees of freedom for theradiation source 27 and two translational degrees of freedom for the recording medium 31). Therefore, a fiducial reference having at least four degrees of freedom is necessary to completely determine the system. Accordingly, a fiducial reference comprising at least two point-size reference markers can be used to determine the position of the radiation source relative to the selectedobject 21 and therecording medium 31. This relatively constrained system may be useful in three-dimensional reconstructions of transmission electron micrographs produced from video projections subtending various degrees of specimen tilt and exhibiting various amounts of arbitrary and unpredictable lateral shift due to intrinsic instability associated with the instrument's electron lenses. - Referring to
FIG. 1 , theradiation source 27 may be either a portable or a stationary X-ray source. However, theradiation source 27 is not limited to an X-ray source. The specific type ofsource 27 which is utilized will depend upon the particular application. For example, the present invention can also be practiced using magnetic resonance imaging (MRI), ultrasound, visible light, infrared light, ultraviolet light, or microwaves. - In the embodiment shown in
FIG. 10 , thesource 227 is a hand-held X-ray source, similar to that described above in reference tosource 127, except that a low powerlaser aiming device 250 and analignment indicator 251 are provided to insure that thesource 227 and therecording medium 231 are properly aligned. In addition, aradiolucent bite block 218 is provided to constrain thedetector 231 relative to theobject 221, thereby constraining the system to three degrees of freedom (two translational and one displacement for theradiation source 227 relative to theobject 221 and detector 231). Consequently, thefiducial reference 222 can be fixed directly to thebite block 218. When thesource 227 is properly aligned with therecording medium 231, radiation emanating from the aimingdevice 250 impinges on therecording medium 231. In response to a measured amount of radiation impinging on therecording medium 231, a signal is sent to activate thealignment indicator 251 which preferably produces a visible and/or auditory signal. With thealignment indicator 251 activated, theX-ray source 245 can be operated at full power to record a projected image. In addition, thesource 227 can optionally comprise acollimator 247 to collimate the radiation from the X-ray source and/or atransparent scatter shield 252 to protect the operator from scattered radiation. In lieu of thescatter shield 252, the operator can stand behind a radiopaque safety screen when exposing the patient to radiation from thesource 227. Ahandle 248 and trigger 246 may be provided to facilitate the handling and operation of thesource 227. Thesource 227 is connected to a computer/high voltage source 228 and anamplifier 260 for controlling operation of the device. - In one embodiment, the aiming
device 250 comprises an X-ray source operated in an ultra-low exposure mode and the projected image is obtained using the same X-ray source operated in a full-exposure mode. Alternatively, a real-time ultra-low dose fluoroscopic video display can be mounted into thehandle 248 of thesource 227 via a microchannel plate (MCP) coupled to a CCD. The video display switches to a lower gain (high signal-to-noise) frame grabbing mode when the alignment is considered optimal and thetrigger 246 is squeezed more tightly. - An alternate embodiment of an aiming device in accordance with the present invention is shown in
FIG. 22 . The aimingdevice 850 comprises alaser source 857 and a radiolucentangled mirror 858 which produces a laser beam, illustrated by dashedline 859, which is concentric with the radiation emanating from thesource 827. Thealignment indicator 851 comprises a radiolucentspherical surface 861 which is rigidly positioned relative to thedetector 831 by a C-arm 829 that is plugged into thebite block 818. When the aimingdevice 850 is aimed such that thelaser beam 859 impinges upon thespherical surface 861, the specular component of thelaser beam 859 is reflected by thespherical surface 861. Accordingly, proper alignment of thesource 827, theobject 821, and thedetector 831 is obtained when the reflected portion of thelaser beam 859 is within a small solid angle determined by the position of the aimingdevice 850. Direct observation of the reflected portion of thelaser beam 859 by a detector orobserver 862 can be used to verify the alignment. As shown in the figure, thefiducial reference 822 comprises a radiolucent spacer containing a fiducial pattern that is affixed to thedetector 831. Further, acentral ring area 863 can be designated at the center of thespherical surface 861 such that aiming thelaser beam 859 at thecentral ring area 863 assures an essentially orthogonal arrangement of thesource 827 and thedetector 831. In addition, replacing theconcentric laser source 857 with a laser source that produces two laser beams that are angled relative to the radiation emanating from thesource 827 permits the distance between thesource 827 and thedetector 831 to be set to a desired distance, provided that the two laser beams are constrained to converge at thespherical surface 861 when the desired distance has been established. - Referring again to
FIG. 1 , therecording medium 31 is provided for recording the projectedobject image 40 of the selectedobject 21 and the projected reference images, 39 and 139, of thereference markers recording medium 31 may be in the form of a photographic plate or a radiation-sensitive, solid-state image detector such as a radiolucent charge-coupled device (CCD). - In one particular embodiment depicted in
FIG. 8 , therecording medium 331 comprises a CCD having atop screen 200, abottom screen 206 positioned below thetop screen 200, and adetector 210 positioned below thebottom screen 206. Thetop screen 200 is monochromatic so that a projected image projected onto thetop screen 200 causes thetop screen 200 to fluoresce or phosphoresce a single color. In contrast, thebottom screen 206 is dichromatic, so that thebottom screen 206 fluoresces or phosphoresces in a first color in response to a projected image projected directly onto thebottom screen 206 and fluoresces or phosphoresces in a second color in response to fluorescence or phosphorescence from thetop screen 200. Thedetector 210 is also dichromatic so as to allow for the detection and differentiation of the first and the second colors. Therecording medium 331 may also comprise a radiolucentoptical mask 202 to modulate the texture and contrast of the fluorescence or phosphorescence from thetop screen 200, a radiolucent fiber-optic spacer 204 to establish a known projection disparity, and a radiopaque fiber-optic faceplate 208 to protect thedetector 210 from radiation emanating directly from the radiation source. - Yet another embodiment is depicted in
FIGS. 20 and 23 , wherein thedetector 731 comprises a phosphor-coated CCD and thefiducial reference 722 comprises a radiopaquerectangular frame 725. Both thedetector 731 and thefiducial reference 722 are contained within a light-tight package 756. Thedetector 731 andfiducial reference 722 are preferably positioned flush with an upper, inner surface of thepackage 756. The dimensions of theframe 725 are selected such that theframe 725 extends beyond the perimeter of thedetector 731. Phosphor-coatedstrip CCDs 754 are also contained within thepackage 756. Thestrip CCDs 754 are positioned below theframe 725 such that radiation impinging upon theframe 725 castes an image of each edge of theframe 725 onto one of thestrip CCDs 754. The positions of the frame shadow on thestrip CCDs 754 is used to determine the projection geometry. In the embodiment shown inFIG. 9 , therecording medium 431 is smaller than the projected image ofobject 521. Provided that the reference images, 39 and 139, corresponding to the reference markers, 23 and 123, can be identified on all the projected images, image slices extending across the union of all the projected images can be obtained. This is illustrated schematically inFIG. 9 , wherein the reference images, 39 and 139, are taken with thesource 27 and therecording medium 431 in the image positions indicated by the solid lines. Similarly, the dashed images, 39′ and 139′, are taken with thesource 27′ and therecording medium 431′ in the positions indicated by the dashed lines. Accordingly, image slices of an object which casts an object image that is larger than therecording medium 431 can be synthesized. Further, by using multiple fiducial references spaced in a known pattern which are all linked to the object of interest, additional regions of commonality can be identified between multiple overlapping projection geometries, so that a region of any size can be propagated into a single, unified reconstruction. Thus, it is possible to accommodate an object much larger than the recording medium used to record individual projection images. - The present invention also relates to a method for creating a slice image through the
object 21 ofFIG. 1 from a series of two-dimensional projected images of theobject 21, as shown inFIG. 2 . The method of synthesizing the image slice starts atstep 45. Each step of the method can be performed as part of a computer-executed process. - At
step 47, afiducial reference 22 comprising at least two reference markers, 23 and 123, is selected which bears a fixed relationship to the selectedobject 21. Accordingly, thefiducial reference 22 may be affixed directly to the selectedobject 21. The minimum required number ofreference markers 23 is determined by the number of degrees of freedom in the system, as discussed above. When thefiducial reference 22 comprisesreference markers 23 of a finite size, the size and shape of thereference markers 23 are typically recorded. - The selected
object 21 andfiducial reference 22 are exposed to radiation from any desired projection geometry atstep 49 and a two-dimensional projectedimage 38 is recorded atstep 51. Referring toFIG. 1 , the projectedimage 38 contains anobject image 40 of the selectedobject 21 and a reference image, 39 and 139, respectively, for each of thereference markers fiducial reference 22. - At
step 53, it is determined whether additional projectedimages 38 are desired. The desired number of projectedimages 38 is determined by the task to be accomplished. Fewer images reduce the signal-to-noise ratio of the reconstructions and increase the intensities of component “blur” artifacts. Additional images provide information which supplements the information contained in the prior images, thereby improving the accuracy of the three-dimensional radiographic display. If additional projectedimages 38 are not desired, then the process continues atstep 60. - If additional projected
images 38 are desired, the system geometry is altered atstep 55 by varying the relative positions of (1) theradiation source 27, (2) the selectedobject 21 and thefiducial reference 22, and (3) therecording medium 31. The geometry of the system can be varied by moving theradiation source 27 and/or therecording medium 31. Alternatively, thesource 27 andrecording medium 31, the selectedobject 21 andfiducial reference 22 are moved. When the radiation source and recording medium produce images using visible light (e.g., video camera), the geometry of the system must be varied to produce images from various sides of the object in order to obtain information about the entire object. After the system geometry has been varied, the process returns to step 49. - After all of the desired projected images have been recorded, a slice position is selected at
step 60. The slice position corresponds to the position at which the image slice is to be generated through the object. - After the slice position has been selected, each projected
image 38 is projectively warped onto avirtual projection plane 37 atstep 65. The warping procedure produces a virtual image corresponding to each of the actual projected images. Each virtual image is identical to the image which would have been produced had the projection plane been positioned at the virtual projection plane with the projection geometry for theradiation source 27, the selectedobject 21, and thefiducial reference 22 of the corresponding actual projected image. The details of the steps involved in warping theprojection plane 37 are shown inFIG. 3 . The process starts atstep 70. - At
step 72, avirtual projection plane 37 is selected. In most cases it is possible to arrange for one of the projected images to closely approximate the virtual projection plane position. That image can then be used as the basis for transformation of all theother images 38. Alternatively, as shown for example inFIG. 4 , if thefiducial reference 22 comprises more than twoco-planar reference markers 23, a plane which is parallel to the plane containing theco-planar reference markers 23 can be selected as thevirtual projection plane 37. When thevirtual projection plane 37 is not parallel to the plane containing theco-planar reference markers 23, although the validity of the slice reconstruction is maintained, the reconstruction yields a slice image which may be deformed due to variations in magnification. The deformation becomes more prominent when the magnification varies significantly over the range in which the reconstruction is carried out. In such cases, an additional geometric transformation to correct for differential magnification may be individually performed on each projectedimage 38 to correct for image deformation. - One of the recorded projected
images 38 is selected atstep 74 and the identity of thereference images 39 cast by eachreference marker 23 is determined atstep 76. In the specialized case, such as the one shown inFIG. 1 , wherespherical reference markers 23 of the same radius are used and the relative proximal distance of eachreference marker 23 to theradiation source 27 at the time that theimage 38 was recorded is known, assignment of eachelliptical image 39 to acorresponding reference marker 23 can be accomplished simply by inspection. Under such conditions, the minor diameter of theelliptical image 39 is always larger the closer thereference marker 23 is to theradiation source 27. This is shown most clearly inFIG. 17 wherein the minor diameter of reference image Bs corresponding to reference marker B is smaller than the minor diameter of reference image Ts corresponding to reference marker T. Alternatively, when applied to radiation capable of penetrating the fiducial reference 22 (i.e., X-rays),spherical reference markers 23 which are hollow having different wall thicknesses and hence, different attenuations can be used. Accordingly, thereference image 39 cast by eachspherical reference marker 23 can be easily identified by the pattern of thereference images 39. Analogously,spherical reference markers 23 of different colors could be used in a visible light mediated system. - The position of each
reference image 39 cast by eachreference marker 23 is measured atstep 78. When aspherical reference marker 23 is irradiated bysource 27, the projectedcenter 41 of thereference marker 23 does not necessarily correspond to thecenter 42 of thereference image 39 cast by thatreference marker 23. Accordingly, the projectedcenter 41 of thereference marker 23 must be determined. One method of determining the projectedcenter 41 of thereference marker 23 is shown inFIG. 16 . The variation in intensity of thereference image 39 associated withreference marker 23 along the length of the major diameter of thereference image 39 is represented by thebrightness profile 43. The method depicted inFIG. 16 relies on the fact that the projectedcenter 41 always intersects thebrightness profile 43 of thereference image 39 at, or very near, the maximum 44 of thebrightness profile 43. Accordingly, the projectedcenter 41 of aspherical reference marker 23 produced by penetrating radiation can be approximated by smoothing thereference image 39 to average out quantum mottle or other sources of brightness variations which are uncorrelated with the attenuation produced by thereference marker 23. An arbitrary point is then selected which lies within thereference image 39. A digital approximation to the projectedcenter 41 is isolated by performing a neighborhood search of adjacent pixels and propagating the index position iteratively to the brightest (most attenuated) pixel in the group until a local maximum is obtained. The local maximum then represents the projectedcenter 41 of thereference marker 23. - Returning to step 78 of
FIG. 3 , when thefiducial reference 22 comprisesreference markers 23 of finite size, the sizes of eachimage 39 cast by eachreference marker 23 are also recorded. For example, the lengths of the major and minor diameters of elliptical reference images cast byspherical reference markers 23 can be measured. Computerized fitting procedures can be used to assist in measuring theelliptical reference images 39 cast byspherical reference markers 23. Such procedures, which are well-known in the art, may be used to isolate theelliptical reference images 39 from the projectedimage 38 and determine the major and minor diameters of thereference images 39. - Because the attenuation of a
spherical reference marker 23 to X-rays approaches zero at tangential extremes, the projected minor diameter of resultingelliptical reference images 39 will be slightly smaller than that determined geometrically by projection of the reference marker's actual diameter. The amount of the resulting error is a function of the energy of the X-ray beam and the spectral sensitivity of therecording medium 31. This error can be eliminated by computing an effective radiographic diameter of thereference marker 23 as determined by the X-ray beam energy and the recording medium sensitivity in lieu of the actual diameter. - One method of obtaining the effective radiographic diameter is to generate a series of tomosynthetic slices through the center of the
reference marker 23 using a range of values for the reference marker diameter decreasing systematically from the actual value and noting when the gradient of thereference image 39 along the minor diameter is a maximum. The value for the reference marker diameter resulting in the maximum gradient is the desired effective radiographic diameter to be used for computing magnification. - Further, each projected image can be scaled by an appropriate magnification. For
fiducial references 22 comprisingspherical reference markers 23, the minor diameter of thereference image 39 is preferably used to determine the magnification since the minor diameter does not depend on the angle between thesource 27 and therecording medium 31. Accordingly, the magnification of aspherical reference marker 23 can be determined from the measured radius of thereference marker 23, the minor diameter of thereference image 39 on therecording medium 31, the vertical distance between the center of thereference marker 23 and therecording medium 31, and the vertical distance between therecording medium 31 and thevirtual projection plane 37. - Returning to
FIG. 3 with reference toFIG. 1 , a projection transformation matrix, representing a series of transformation operations necessary to map the selected projectedimage 38 onto thevirtual projection plane 37, is generated atstep 80. The projection transformation matrix is generated by solving each projectedimage 38 relative to thevirtual projection plane 37. In one embodiment, the positions of theco-planar reference markers 23 are used to determine the transformation matrix by mapping the position of thereference images 39 cast by eachco-planar reference marker 23 in the projected image onto its corresponding position in the virtual projection plane. For example, when the fiducial reference comprises aradiopaque frame 25, the positions of the reference-images 39 cast by thereference markers 23 formed at the corners of theframe 25 are mapped to a canonical rectangle having the same dimensions and scale as theframe 25. This approach also serves to normalize the projective data. Depending on the number of degrees of freedom, the transformation operations range from complex three-dimensional transformations to simple planar rotations or translations. Once the projective transformation matrix has been generated, the matrix is used to map the projectedimage 38 onto thevirtual projection plane 37 atstep 82. - At
step 84, it is determined whether all of the projectedimages 38 have been analyzed. If all of the projectedimages 38 have not been analyzed, the process returns to step 74, wherein anunanalyzed image 38 is selected. If no additional projectedimages 38 are to be analyzed, then the process proceeds throughstep 85 ofFIG. 3 to step 90 ofFIG. 2 . - After each image has been warped onto the virtual projection plane, an image slice through the
object 21 at the selected slice position is generated atstep 90. An algorithm, such as that described in U.S. Pat. No. 5,359,637, which is incorporated herein by reference, can be used for that purpose. The position of the reference image cast by the alignment marker ormarkers 23 in each projectedimage 38 are used as the basis for application of the algorithm to generate the image slices. - By generating image slices at more than one slice position, a true three-dimensional representation can be synthesized. Accordingly, it is determined whether an additional slice position is to be selected at
step 92. If an additional slice position is not desired, the process proceeds to step 94. If a new slice position is to be selected, the process returns to step 60. - If image slices at multiple slice positions have been generated, the entire set of image slices is integrated into a single three-dimensional representation at
step 94. Alternative bases for interactively analyzing and displaying the three-dimensional data can be employed using any number of well-established three-dimensional recording and displaying methods. - In the embodiment shown in
FIG. 19 , thesource 627 is an unconstrained point source and thedetector 631 is completely constrained relative to theobject 621. Accordingly, the system has three degrees of freedom (two translational and one displacement for theradiation source 627 relative to theobject 621 and detector 631). Abeam collimator 647 can be positioned between thesource 627 and theobject 621 to collimate the radiation from thesource 627. Thedetector 631 comprises aprimary imager 632 and asecondary imager 634 positioned a known distance below theprimary imager 632. In one embodiment, both the primary and secondary imagers, 632 and 634, are CCD detectors. Thefiducial reference 622 comprises aradiopaque shield 633 with a ring-shapedaperture 636 of known size positioned between theprimary imager 632 and thesecondary imager 634. - Radiation from the
source 627 passes throughcollimator 647, irradiatesobject 621, and produces an object image on theprimary imager 632. In addition, radiation from thesource 627 which impinges upon theradiopaque shield 633 passes through theaperture 636 to produce a circular, or elliptical, reference image of theaperture 636 on thesecondary imager 634. Since thesecondary imager 634 is not used to record object images, thesecondary imager 634 can be a low quality imager such as a low resolution CCD. Alternatively, a lower surface of theprimary imager 632 can be coated with aphosphorescent material 635, so that radiation impinging upon theprimary imager 632 causes thephosphorescent material 635 to phosphoresce. The phosphorescence passes through theaperture 636 to produce the reference image on thesecondary imager 634. - In operation, the reference image produced using the system depicted in
FIG. 19 can be used to determine the position of thesource 627 relative to theobject 621 and thedetector 631. A circle, or ellipse, is fitted to the projected reference image. By fitting a circle, or ellipse, to the reference image, the effect of dead areas and/or poor resolution of thesecondary imager 634 can be eliminated by averaging. The position of the center of the fitted circle, or ellipse, relative to the known center of theaperture 636 is determined. The angle α of acentral ray 637 radiating from thesource 627 relative to theobject 621 and thedetector 631 can then be determined. In addition, the length of the minor diameter of the projected reference image is determined and compared to the known diameter of theaperture 636 to provide a relative magnification factor. The relative magnification factor can then be used to determine the distance of thesource 627 from theobject 621. - The center of the fitted circle can be determined as follows. A pixel or point on the
secondary imager 634 that lies within the fitted circle is selected as a seed point. For convenience, the center pixel of thesecondary imager 634 can be selected, since the center point will typically lie within the fitted circle. A point R is determined by propagating from the seed point towards the right until the fitted circle is intersected. Similarly, a point L is determined by propagating from the seed point towards the left until the fitted circle is intersected. For each pixel along the arc L-R, the average of the number of pixels traversed by propagating from that pixel upwardly until the fitted circle is intersected and the number of pixels traversed by propagating from that pixel downwardly until the fitted circle is intersected is determined. Any statistical outliers from the averages can be discarded and the average of the remaining values calculated. This average represents the row address of the fitted circle's center. To obtain the column address, the entire reference image is rotated by 90° and the process is repeated. The row address and column address together represent the position of the center of the fitted circle. - Although the above embodiments have been described in relation to projected images of objects produced using X-rays, the present invention is equally applicable to images produced using a variety of technologies, such as visible light, ultrasound, or electron microscopy images. Specifically, intermediate voltage electron microscope (IVEM) images can be used to provide quantitative three-dimensional ultrastructural information. Further, the present invention can also be used to reconstruct three-dimensional images of objects which either emit or scatter radiation.
- When IVEM images are used, the present invention allows cellular changes to be detected and quantified in an efficient and cost-effective manner. Quantitation of three-dimensional structure facilitates comparison with other quantitative techniques, such as biochemical analysis. For example, increases in the Golgi apparatus in cells accumulating abnormal amounts of cholesterol can be measured and correlated with biochemically measured increases in cellular cholesterol.
- When photographic images are used, it is possible to create a true three-dimensional model of a diffusely illuminated fixed scene from any number of arbitrary camera positions and angles. The resulting three-dimensional image permits inverse engineering of structural sizes and shapes, and may be expressed as a series of topographic slices or as a projective model that can be manipulated interactively. This capability is particularly useful in retrofitting existing structures or quantifying three-dimensional attributes using non-invasive methods. In addition, the present invention can be applied to construct topological images of geological structures by recording images of the structure created by the sun.
- It will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.
Claims (9)
1-23. (canceled)
24. A computer program product, comprising a computer usable medium having a computer readable program code embodied therein, the computer readable program code adapted to be executed to implement a method for synthesizing an image slice through a selected object at a selected slice position through the object from a plurality of projected images of the object comprising the steps of:
a. receiving the plurality of projected images of a region of interest of a selected object and a fiducial reference, the images recorded at different arbitrary relative positions between (1) a source of radiation, (2) the selected object and fiducial reference, and (3) a recording means; and
b. synthesizing an image slice of the selected object at a selected slice position through the object from the projected images.
25. The computer program product according to claim 24 , the computer readable program code adapted to be executed to implement a method for synthesizing an image slice through a selected object at a selected slice position through the object from a plurality of projected images of the object comprising the step of computing the effective magnification of each projected image by determining a radiographic diameter of the projected image of a reference marker of the fiducial reference, and scaling each projected image to the same magnification.
26. The computer program product according to claim 25 , wherein computing the effective magnification of each projected image comprises determining when the gradient along a minor diameter of the image of the reference marker is a maximum.
27. The computer program product according to claim 26 , wherein computing the minor diameter comprises generating a series of tomosynthetic slices through the center of the reference marker using a range of values for the reference marker diameter decreasing systematically from the actual value.
28. The computer program product according to claim 24 , wherein the step of synthesizing an image slice comprises aligning the projected images based on parameters related to a first marker of the fiducial reference displayed in the plurality of images and projectively warping a projected image from an actual projection plane to a virtual projection plane using parameters related to a second reference marker of the fiducial reference displayed in the plurality of images.
29. The computer program product according to claim 24 , the computer readable program code adapted to be executed to implement a method for synthesizing an image slice through a selected object at a selected slice position through the object from a plurality of projected images of the object comprising the step of generating a projected transformation matrix.
30. The computer program product according to claim 29 , wherein the step of generating the projected transformation matrix comprises mapping the position of a reference marker of the fiducial reference displayed in the projected image onto a corresponding position of the reference marker in a virtual projection plane.
31. The computer program product according to claim 24 , wherein the step of synthesizing an image of the selected object at a selected slice position through the object includes the steps of:
a. projectively warping each projected image onto a virtual projection plane;
b. generating an image slice through the object at a selected slice position.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/885,910 US20110092812A1 (en) | 1998-03-05 | 2010-09-20 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/034,922 US6289235B1 (en) | 1998-03-05 | 1998-03-05 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US09/862,006 US6810278B2 (en) | 1998-03-05 | 2001-05-21 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US10/972,887 US7110807B2 (en) | 1998-03-05 | 2004-10-25 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US11/505,255 US7801587B2 (en) | 1998-03-05 | 2006-08-16 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US12/885,910 US20110092812A1 (en) | 1998-03-05 | 2010-09-20 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/505,255 Continuation US7801587B2 (en) | 1998-03-05 | 2006-08-16 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110092812A1 true US20110092812A1 (en) | 2011-04-21 |
Family
ID=21879481
Family Applications (5)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/034,922 Expired - Fee Related US6289235B1 (en) | 1998-03-05 | 1998-03-05 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US09/862,006 Expired - Fee Related US6810278B2 (en) | 1998-03-05 | 2001-05-21 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US10/972,887 Expired - Fee Related US7110807B2 (en) | 1998-03-05 | 2004-10-25 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US11/505,255 Expired - Fee Related US7801587B2 (en) | 1998-03-05 | 2006-08-16 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US12/885,910 Abandoned US20110092812A1 (en) | 1998-03-05 | 2010-09-20 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
Family Applications Before (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/034,922 Expired - Fee Related US6289235B1 (en) | 1998-03-05 | 1998-03-05 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US09/862,006 Expired - Fee Related US6810278B2 (en) | 1998-03-05 | 2001-05-21 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US10/972,887 Expired - Fee Related US7110807B2 (en) | 1998-03-05 | 2004-10-25 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US11/505,255 Expired - Fee Related US7801587B2 (en) | 1998-03-05 | 2006-08-16 | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
Country Status (8)
Country | Link |
---|---|
US (5) | US6289235B1 (en) |
EP (1) | EP1059877B1 (en) |
JP (1) | JP4816991B2 (en) |
AT (1) | ATE499043T1 (en) |
AU (1) | AU2884699A (en) |
CA (1) | CA2322462C (en) |
DE (1) | DE69943214D1 (en) |
WO (1) | WO1999044503A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130113897A1 (en) * | 2011-09-25 | 2013-05-09 | Zdenko Kurtovic | Process and arrangement for determining the position of a measuring point in geometrical space |
WO2020186066A1 (en) * | 2019-03-12 | 2020-09-17 | Amdt Holdings, Inc. | Monoscopic radiographic image and three-dimensional model registration methods and systems |
US11463681B2 (en) | 2018-02-23 | 2022-10-04 | Nokia Technologies Oy | Encoding and decoding of volumetric video |
Families Citing this family (182)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6289235B1 (en) * | 1998-03-05 | 2001-09-11 | Wake Forest University | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US6081577A (en) | 1998-07-24 | 2000-06-27 | Wake Forest University | Method and system for creating task-dependent three-dimensional images |
EP1204369A1 (en) * | 1999-08-16 | 2002-05-15 | Super Dimension Ltd. | Method and system for displaying cross-sectional images of a body |
US6545790B2 (en) * | 1999-11-08 | 2003-04-08 | Ralph W. Gerchberg | System and method for recovering phase information of a wave front |
US8256430B2 (en) | 2001-06-15 | 2012-09-04 | Monteris Medical, Inc. | Hyperthermia treatment and probe therefor |
US6671349B1 (en) | 2000-11-13 | 2003-12-30 | Olganix Corporation | Tomosynthesis system and registration method |
SE518620C2 (en) * | 2000-11-16 | 2002-10-29 | Ericsson Telefon Ab L M | Stage construction and camera calibration with robust use of "cheers" |
EP1346322A1 (en) * | 2000-12-22 | 2003-09-24 | Koninklijke Philips Electronics N.V. | Stereoscopic viewing of a region between clipping planes |
SE0100728D0 (en) * | 2001-03-05 | 2001-03-05 | Sidec Technologies Ab Karolins | New method |
FR2822273B1 (en) * | 2001-03-13 | 2003-07-11 | Ge Med Sys Global Tech Co Llc | CALIBRATION PROCESS FOR THE RECONSTRUCTION OF THREE-DIMENSIONAL MODELS FROM IMAGES OBTAINED BY TOMOGRAPHY |
FR2823057B1 (en) * | 2001-03-28 | 2003-07-04 | Ge Med Sys Global Tech Co Llc | METHOD FOR DETERMINING THE MAGNIFICATION FACTOR OF A RADIOGRAPHIC IMAGE, IN PARTICULAR VASCULAR |
JP4157302B2 (en) * | 2002-01-10 | 2008-10-01 | 株式会社日立メディコ | X-ray CT system |
DE10206190A1 (en) * | 2002-02-14 | 2003-09-04 | Siemens Ag | Method and device for generating a volume data set |
US7640050B2 (en) * | 2002-03-14 | 2009-12-29 | Netkiser, Inc. | System and method for analyzing and displaying computed tomography data |
AU2003261073A1 (en) * | 2002-05-16 | 2003-12-02 | Barbara Ann Karmanos Cancer Institute | Combined diagnostic and therapeutic ultrasound system |
US20030228044A1 (en) * | 2002-06-05 | 2003-12-11 | Canon Kabushiki Kaisha | Radiographic marker location |
WO2004006745A2 (en) * | 2002-06-11 | 2004-01-22 | Macrotron Process Technologies Gmbh | System and method for performing tomosynthesis of an object |
US6756619B2 (en) | 2002-08-26 | 2004-06-29 | Micron Technology, Inc. | Semiconductor constructions |
JP3836060B2 (en) * | 2002-09-09 | 2006-10-18 | 三菱重工業株式会社 | Radiation generation apparatus and radiation irradiation direction calibration apparatus |
AU2003295507A1 (en) * | 2002-11-13 | 2004-06-18 | Digitome Corporation | Ray tracing kernel calibration |
US7616801B2 (en) | 2002-11-27 | 2009-11-10 | Hologic, Inc. | Image handling and display in x-ray mammography and tomosynthesis |
US7577282B2 (en) | 2002-11-27 | 2009-08-18 | Hologic, Inc. | Image handling and display in X-ray mammography and tomosynthesis |
US8571289B2 (en) | 2002-11-27 | 2013-10-29 | Hologic, Inc. | System and method for generating a 2D image from a tomosynthesis data set |
US10638994B2 (en) | 2002-11-27 | 2020-05-05 | Hologic, Inc. | X-ray mammography with tomosynthesis |
US8565372B2 (en) | 2003-11-26 | 2013-10-22 | Hologic, Inc | System and method for low dose tomosynthesis |
US7123684B2 (en) | 2002-11-27 | 2006-10-17 | Hologic, Inc. | Full field mammography with tissue exposure control, tomosynthesis, and dynamic field of view processing |
US7433507B2 (en) * | 2003-07-03 | 2008-10-07 | Ge Medical Systems Global Technology Co. | Imaging chain for digital tomosynthesis on a flat panel detector |
US20050080332A1 (en) * | 2003-10-10 | 2005-04-14 | Shiu Almon S. | Near simultaneous computed tomography image-guided stereotactic radiotherapy |
US20050084147A1 (en) * | 2003-10-20 | 2005-04-21 | Groszmann Daniel E. | Method and apparatus for image reconstruction with projection images acquired in a non-circular arc |
US8768026B2 (en) | 2003-11-26 | 2014-07-01 | Hologic, Inc. | X-ray imaging with x-ray markers that provide adjunct information but preserve image quality |
US7120283B2 (en) * | 2004-01-12 | 2006-10-10 | Mercury Computer Systems, Inc. | Methods and apparatus for back-projection and forward-projection |
US7693318B1 (en) | 2004-01-12 | 2010-04-06 | Pme Ip Australia Pty Ltd | Method and apparatus for reconstruction of 3D image volumes from projection images |
WO2005119174A1 (en) * | 2004-05-26 | 2005-12-15 | Werth Messtechnik Gmbh | Coordinate measuring apparatus and method for measuring an object |
US7576737B2 (en) * | 2004-09-24 | 2009-08-18 | Konica Minolta Medical & Graphic, Inc. | Image processing device and program |
US8189002B1 (en) | 2004-10-29 | 2012-05-29 | PME IP Australia Pty, Ltd. | Method and apparatus for visualizing three-dimensional and higher-dimensional image data sets |
US7778392B1 (en) | 2004-11-02 | 2010-08-17 | Pme Ip Australia Pty Ltd | Method of reconstructing computed tomography (CT) volumes suitable for execution on commodity central processing units (CPUs) and graphics processors, and apparatus operating in accord with those methods (rotational X-ray on GPUs) |
JP2006132995A (en) * | 2004-11-02 | 2006-05-25 | Shiyoufuu:Kk | Optical coherence tomograph and measuring head |
US7662082B2 (en) | 2004-11-05 | 2010-02-16 | Theragenics Corporation | Expandable brachytherapy device |
JP4512471B2 (en) * | 2004-11-10 | 2010-07-28 | 株式会社日立ハイテクノロジーズ | Scanning electron microscope and semiconductor inspection system |
EP2602743B1 (en) | 2004-11-15 | 2014-11-05 | Hologic, Inc. | Matching geometry generation and display of mammograms and tomosynthesis images |
EP1816965B1 (en) | 2004-11-26 | 2016-06-29 | Hologic, Inc. | Integrated multi-mode mammography/tomosynthesis x-ray system |
US7609884B1 (en) | 2004-12-23 | 2009-10-27 | Pme Ip Australia Pty Ltd | Mutual information based registration of 3D-image volumes on GPU using novel accelerated methods of histogram computation |
US9204116B2 (en) * | 2005-02-24 | 2015-12-01 | Brainlab Ag | Portable laser projection device for medical image display |
US7635848B2 (en) * | 2005-04-01 | 2009-12-22 | San Diego State University Research Foundation | Edge-on SAR scintillator devices and systems for enhanced SPECT, PET, and compton gamma cameras |
US7623732B1 (en) | 2005-04-26 | 2009-11-24 | Mercury Computer Systems, Inc. | Method and apparatus for digital image filtering with discrete filter kernels using graphics hardware |
US7991242B2 (en) | 2005-05-11 | 2011-08-02 | Optosecurity Inc. | Apparatus, method and system for screening receptacles and persons, having image distortion correction functionality |
US20090174554A1 (en) | 2005-05-11 | 2009-07-09 | Eric Bergeron | Method and system for screening luggage items, cargo containers or persons |
GB2427339A (en) * | 2005-06-15 | 2006-12-20 | Stereo Scan Systems Ltd | X-ray stereoscopic screening apparatus |
DE102005030607A1 (en) * | 2005-06-30 | 2007-01-04 | Siemens Ag | Interventional instrument with marker element |
US7505554B2 (en) * | 2005-07-25 | 2009-03-17 | Digimd Corporation | Apparatus and methods of an X-ray and tomosynthesis and dual spectra machine |
US7298816B2 (en) * | 2005-08-02 | 2007-11-20 | The General Hospital Corporation | Tomography system |
US7245694B2 (en) | 2005-08-15 | 2007-07-17 | Hologic, Inc. | X-ray mammography/tomosynthesis of patient's breast |
US7885378B2 (en) * | 2005-10-19 | 2011-02-08 | The General Hospital Corporation | Imaging system and related techniques |
US7465268B2 (en) | 2005-11-18 | 2008-12-16 | Senorx, Inc. | Methods for asymmetrical irradiation of a body cavity |
WO2007083376A1 (en) * | 2006-01-19 | 2007-07-26 | Shofu Inc. | Light coherence tomography device and measuring head |
US8532745B2 (en) | 2006-02-15 | 2013-09-10 | Hologic, Inc. | Breast biopsy and needle localization using tomosynthesis systems |
US20070249928A1 (en) * | 2006-04-19 | 2007-10-25 | General Electric Company | Method and system for precise repositioning of regions of interest in longitudinal magnetic resonance imaging and spectroscopy exams |
US7899232B2 (en) | 2006-05-11 | 2011-03-01 | Optosecurity Inc. | Method and apparatus for providing threat image projection (TIP) in a luggage screening system, and luggage screening system implementing same |
US8121361B2 (en) | 2006-05-19 | 2012-02-21 | The Queen's Medical Center | Motion tracking system for real time adaptive imaging and spectroscopy |
US8494210B2 (en) | 2007-03-30 | 2013-07-23 | Optosecurity Inc. | User interface for use in security screening providing image enhancement capabilities and apparatus for implementing same |
US20080037703A1 (en) * | 2006-08-09 | 2008-02-14 | Digimd Corporation | Three dimensional breast imaging |
EP2074383B1 (en) * | 2006-09-25 | 2016-05-11 | Mazor Robotics Ltd. | C-arm computerized tomography |
US8000522B2 (en) * | 2007-02-02 | 2011-08-16 | General Electric Company | Method and system for three-dimensional imaging in a non-calibrated geometry |
US7916834B2 (en) * | 2007-02-12 | 2011-03-29 | Thermo Niton Analyzers Llc | Small spot X-ray fluorescence (XRF) analyzer |
US8870771B2 (en) | 2007-05-04 | 2014-10-28 | Barbara Ann Karmanos Cancer Institute | Method and apparatus for categorizing breast density and assessing cancer risk utilizing acoustic parameters |
US10201324B2 (en) | 2007-05-04 | 2019-02-12 | Delphinus Medical Technologies, Inc. | Patient interface system |
US8323694B2 (en) * | 2007-05-09 | 2012-12-04 | Nanoprobes, Inc. | Gold nanoparticles for selective IR heating |
US8019151B2 (en) * | 2007-06-11 | 2011-09-13 | Visualization Sciences Group, Inc. | Methods and apparatus for image compression and decompression using graphics processing unit (GPU) |
US8392529B2 (en) | 2007-08-27 | 2013-03-05 | Pme Ip Australia Pty Ltd | Fast file server methods and systems |
US7630533B2 (en) | 2007-09-20 | 2009-12-08 | Hologic, Inc. | Breast tomosynthesis with display of highlighted suspected calcifications |
CN101126725B (en) * | 2007-09-24 | 2010-12-15 | 舒嘉 | Method for realizing image reconstruction by adopting X ray dimension photograph |
FR2923054B1 (en) * | 2007-10-24 | 2009-12-11 | Centre Nat Rech Scient | METHOD AND DEVICE FOR RECONSTRUCTING THE VOLUME OF AN OBJECT FROM A SEQUENCE OF CUT IMAGES OF SAID OBJECT |
US8040595B2 (en) * | 2007-11-02 | 2011-10-18 | Wavefront Analysis, Inc. | Light microscope with novel digital method to achieve super-resolution |
US9904969B1 (en) | 2007-11-23 | 2018-02-27 | PME IP Pty Ltd | Multi-user multi-GPU render server apparatus and methods |
US9019287B2 (en) | 2007-11-23 | 2015-04-28 | Pme Ip Australia Pty Ltd | Client-server visualization system with hybrid data processing |
US8548215B2 (en) | 2007-11-23 | 2013-10-01 | Pme Ip Australia Pty Ltd | Automatic image segmentation of a volume by comparing and correlating slice histograms with an anatomic atlas of average histograms |
US8319781B2 (en) | 2007-11-23 | 2012-11-27 | Pme Ip Australia Pty Ltd | Multi-user multi-GPU render server apparatus and methods |
US10311541B2 (en) | 2007-11-23 | 2019-06-04 | PME IP Pty Ltd | Multi-user multi-GPU render server apparatus and methods |
FR2927525B1 (en) * | 2008-02-19 | 2011-04-15 | Owandy | DENTAL RADIOGRAPHY DEVICE AND X-RAY SENSOR |
WO2009147671A1 (en) | 2008-06-03 | 2009-12-10 | Superdimension Ltd. | Feature-based registration method |
US8218847B2 (en) | 2008-06-06 | 2012-07-10 | Superdimension, Ltd. | Hybrid registration method |
DE202008017355U1 (en) * | 2008-07-30 | 2009-07-09 | Middelmann, Heinrich, Dipl.-Ing. Dr. med. dent. | Dental medical product for the evaluation of radiographs of areas to be diagnosed within the oral cavity of a patient and use of a dental product |
EP2245986B1 (en) * | 2008-08-22 | 2013-10-16 | BrainLAB AG | Arrangement of x-ray markers in the form of a pyramid |
US7991106B2 (en) | 2008-08-29 | 2011-08-02 | Hologic, Inc. | Multi-mode tomosynthesis/mammography gain calibration and image correction using gain map information from selected projection angles |
KR20110063659A (en) | 2008-09-04 | 2011-06-13 | 홀로직, 인크. | Integrated multi-mode mammography/tomosynthesis x-ray system and method |
US9248311B2 (en) | 2009-02-11 | 2016-02-02 | Hologic, Inc. | System and method for modifying a flexibility of a brachythereapy catheter |
US9579524B2 (en) | 2009-02-11 | 2017-02-28 | Hologic, Inc. | Flexible multi-lumen brachytherapy device |
US8170320B2 (en) | 2009-03-03 | 2012-05-01 | Hologic, Inc. | Mammography/tomosynthesis systems and methods automatically deriving breast characteristics from breast x-ray images and automatically adjusting image processing parameters accordingly |
US10207126B2 (en) | 2009-05-11 | 2019-02-19 | Cytyc Corporation | Lumen visualization and identification system for multi-lumen balloon catheter |
DE102009031165A1 (en) * | 2009-06-30 | 2011-01-05 | Siemens Aktiengesellschaft | Method and device for recording x-ray images for three-dimensional image reconstruction |
RU2542588C2 (en) * | 2009-09-08 | 2015-02-20 | Конинклейке Филипс Электроникс Н.В. | Measurement system of image generation with print matrix of photodetectors |
CN102481146B (en) | 2009-10-08 | 2016-08-17 | 霍罗吉克公司 | The aspiration biopsy system of breast and using method thereof |
US20110123452A1 (en) * | 2009-11-25 | 2011-05-26 | Nanoprobes, Inc. | Metal oligomers and polymers and their use in biology and medicine |
US8615127B2 (en) * | 2010-01-15 | 2013-12-24 | Vanderbilt University | System and method for point-based rigid registration with anisotropic weighting |
EP3407261A3 (en) | 2010-02-01 | 2019-02-20 | Covidien LP | Region-growing algorithm |
WO2011100691A1 (en) | 2010-02-12 | 2011-08-18 | Delphinus Medical Technologies, Inc. | Method of characterizing the pathological response of tissue to a treatmant plan |
CN102869301B (en) | 2010-02-12 | 2016-06-29 | 戴尔菲纳斯医疗科技公司 | The method characterizing the tissue of patient |
US8535337B2 (en) | 2010-04-26 | 2013-09-17 | David Chang | Pedicle screw insertion system and method |
DE102010019632A1 (en) * | 2010-05-06 | 2011-11-10 | Siemens Aktiengesellschaft | Method for recording and reconstructing a three-dimensional image data set and x-ray device |
JP5600272B2 (en) * | 2010-07-16 | 2014-10-01 | 富士フイルム株式会社 | Radiation imaging apparatus and method, and program |
US9352172B2 (en) | 2010-09-30 | 2016-05-31 | Hologic, Inc. | Using a guide member to facilitate brachytherapy device swap |
EP2624761B1 (en) | 2010-10-05 | 2021-07-14 | Hologic, Inc. | Upright x-ray breast imaging with a ct mode, multiple tomosynthesis modes, and a mammography mode |
WO2012071429A1 (en) | 2010-11-26 | 2012-05-31 | Hologic, Inc. | User interface for medical image review workstation |
US10342992B2 (en) | 2011-01-06 | 2019-07-09 | Hologic, Inc. | Orienting a brachytherapy applicator |
US9020579B2 (en) | 2011-03-08 | 2015-04-28 | Hologic, Inc. | System and method for dual energy and/or contrast enhanced breast imaging for screening, diagnosis and biopsy |
EP2510878B1 (en) | 2011-04-12 | 2014-02-26 | Marcus Abboud | Method for generating a radiological three dimensional digital volume tomography image of part of a patient's body |
US9606209B2 (en) | 2011-08-26 | 2017-03-28 | Kineticor, Inc. | Methods, systems, and devices for intra-scan motion correction |
JP6025849B2 (en) | 2011-09-07 | 2016-11-16 | ラピスカン システムズ、インコーポレイテッド | X-ray inspection system that integrates manifest data into imaging / detection processing |
US8976926B2 (en) * | 2011-09-24 | 2015-03-10 | Southwest Research Institute | Portable 3-dimensional X-ray imaging system |
JP2014534042A (en) | 2011-11-27 | 2014-12-18 | ホロジック, インコーポレイテッドHologic, Inc. | System and method for generating 2D images using mammography and / or tomosynthesis image data |
EP3315072B1 (en) | 2012-02-13 | 2020-04-29 | Hologic, Inc. | System and method for navigating a tomosynthesis stack using synthesized image data |
US8989843B2 (en) * | 2012-06-05 | 2015-03-24 | DePuy Synthes Products, LLC | Methods and apparatus for estimating the position and orientation of an implant using a mobile device |
WO2014003855A1 (en) | 2012-06-27 | 2014-01-03 | Monteris Medical Corporation | Image-guided therapy of a tissue |
US9763641B2 (en) | 2012-08-30 | 2017-09-19 | Delphinus Medical Technologies, Inc. | Method and system for imaging a volume of tissue with tissue boundary detection |
US9305365B2 (en) | 2013-01-24 | 2016-04-05 | Kineticor, Inc. | Systems, devices, and methods for tracking moving targets |
US9717461B2 (en) | 2013-01-24 | 2017-08-01 | Kineticor, Inc. | Systems, devices, and methods for tracking and compensating for patient motion during a medical imaging scan |
US10327708B2 (en) | 2013-01-24 | 2019-06-25 | Kineticor, Inc. | Systems, devices, and methods for tracking and compensating for patient motion during a medical imaging scan |
WO2014120734A1 (en) | 2013-02-01 | 2014-08-07 | Kineticor, Inc. | Motion tracking system for real time adaptive motion compensation in biomedical imaging |
US10123770B2 (en) | 2013-03-13 | 2018-11-13 | Delphinus Medical Technologies, Inc. | Patient support system |
US9275769B2 (en) * | 2013-03-14 | 2016-03-01 | Pcc Structurals, Inc. | Marking template for radiography |
WO2014151646A1 (en) | 2013-03-15 | 2014-09-25 | Hologic Inc. | Tomosynthesis-guided biopsy in prone |
US11183292B2 (en) | 2013-03-15 | 2021-11-23 | PME IP Pty Ltd | Method and system for rule-based anonymized display and data export |
US9509802B1 (en) | 2013-03-15 | 2016-11-29 | PME IP Pty Ltd | Method and system FPOR transferring data to improve responsiveness when sending large data sets |
US10540803B2 (en) | 2013-03-15 | 2020-01-21 | PME IP Pty Ltd | Method and system for rule-based display of sets of images |
US8976190B1 (en) | 2013-03-15 | 2015-03-10 | Pme Ip Australia Pty Ltd | Method and system for rule based display of sets of images |
US11244495B2 (en) | 2013-03-15 | 2022-02-08 | PME IP Pty Ltd | Method and system for rule based display of sets of images using image content derived parameters |
US10070839B2 (en) | 2013-03-15 | 2018-09-11 | PME IP Pty Ltd | Apparatus and system for rule based visualization of digital breast tomosynthesis and other volumetric images |
JP6523265B2 (en) | 2013-10-09 | 2019-05-29 | ホロジック, インコーポレイテッドHologic, Inc. | X-ray chest tomosynthesis to improve spatial resolution including flattened chest thickness direction |
FI130432B (en) * | 2013-11-29 | 2023-08-28 | Planmed Oy | Tomosynthesis calibration in connection with mammography |
ES2943561T3 (en) | 2014-02-28 | 2023-06-14 | Hologic Inc | System and method for generating and visualizing tomosynthesis image blocks |
US9700342B2 (en) | 2014-03-18 | 2017-07-11 | Monteris Medical Corporation | Image-guided therapy of a tissue |
US10675113B2 (en) | 2014-03-18 | 2020-06-09 | Monteris Medical Corporation | Automated therapy of a three-dimensional tissue region |
US9492121B2 (en) | 2014-03-18 | 2016-11-15 | Monteris Medical Corporation | Image-guided therapy of a tissue |
US10004462B2 (en) | 2014-03-24 | 2018-06-26 | Kineticor, Inc. | Systems, methods, and devices for removing prospective motion correction from medical imaging scans |
EP3188660A4 (en) | 2014-07-23 | 2018-05-16 | Kineticor, Inc. | Systems, devices, and methods for tracking and compensating for patient motion during a medical imaging scan |
US10285667B2 (en) | 2014-08-05 | 2019-05-14 | Delphinus Medical Technologies, Inc. | Method for generating an enhanced image of a volume of tissue |
JP6528386B2 (en) * | 2014-11-04 | 2019-06-12 | 富士通株式会社 | Image processing apparatus, image processing method and image processing program |
WO2016073445A1 (en) | 2014-11-07 | 2016-05-12 | Hologic, Inc. | Pivoting paddle apparatus for mammography/tomosynthesis x-ray system |
US10143532B2 (en) | 2015-02-11 | 2018-12-04 | Cmt Medical Technologies Ltd. | Tomographic scan |
US10327830B2 (en) | 2015-04-01 | 2019-06-25 | Monteris Medical Corporation | Cryotherapy, thermal therapy, temperature modulation therapy, and probe apparatus therefor |
US10163262B2 (en) | 2015-06-19 | 2018-12-25 | Covidien Lp | Systems and methods for navigating through airways in a virtual bronchoscopy view |
US11599672B2 (en) | 2015-07-31 | 2023-03-07 | PME IP Pty Ltd | Method and apparatus for anonymized display and data export |
US9984478B2 (en) | 2015-07-28 | 2018-05-29 | PME IP Pty Ltd | Apparatus and method for visualizing digital breast tomosynthesis and other volumetric images |
US9943247B2 (en) | 2015-07-28 | 2018-04-17 | The University Of Hawai'i | Systems, devices, and methods for detecting false movements for motion correction during a medical imaging scan |
US9649078B2 (en) * | 2015-07-28 | 2017-05-16 | Dental Imaging Technologies Corporation | Hybrid X-ray system with detachable radiation shield |
US10702226B2 (en) | 2015-08-06 | 2020-07-07 | Covidien Lp | System and method for local three dimensional volume reconstruction using a standard fluoroscope |
DE102015115060A1 (en) * | 2015-09-08 | 2017-03-09 | Biotronik Se & Co. Kg | Method, computer program and system for determining the spatial course of a body, in particular an electrode, based on at least one 2D X-ray image of the electrode |
US10716515B2 (en) | 2015-11-23 | 2020-07-21 | Kineticor, Inc. | Systems, devices, and methods for tracking and compensating for patient motion during a medical imaging scan |
US10302807B2 (en) | 2016-02-22 | 2019-05-28 | Rapiscan Systems, Inc. | Systems and methods for detecting threats and contraband in cargo |
US11353326B2 (en) * | 2016-03-06 | 2022-06-07 | Arizona Board Of Regents On Behalf Of The University Of Arizona | Traverse and trajectory optimization and multi-purpose tracking |
EP3445247B1 (en) | 2016-04-22 | 2021-03-10 | Hologic, Inc. | Tomosynthesis with shifting focal spot x-ray system using an addressable array |
DE102016211766A1 (en) * | 2016-06-29 | 2018-01-18 | Siemens Healthcare Gmbh | Generation of a picture sequence |
HUP1600469A2 (en) * | 2016-07-27 | 2018-01-29 | Peter Teleki | Method for determining the geometric parameters and/or material state of a specimen based on in-situ radiographic imaging |
AU2017340607B2 (en) | 2016-10-05 | 2022-10-27 | Nuvasive, Inc. | Surgical navigation system and related methods |
US10888292B2 (en) | 2016-11-08 | 2021-01-12 | Hologic, Inc. | Imaging with curved compression elements |
US10830712B2 (en) * | 2017-03-27 | 2020-11-10 | KUB Technologies, Inc. | System and method for cabinet x-ray systems with camera |
US11445993B2 (en) | 2017-03-30 | 2022-09-20 | Hologic, Inc. | System and method for targeted object enhancement to generate synthetic breast tissue images |
EP3600051B1 (en) | 2017-03-30 | 2024-05-01 | Hologic, Inc. | Method for synthesizing low-dimensional image data from high-dimensional image data using an object grid enhancement |
US11399790B2 (en) | 2017-03-30 | 2022-08-02 | Hologic, Inc. | System and method for hierarchical multi-level feature image synthesis and representation |
WO2018204705A1 (en) | 2017-05-03 | 2018-11-08 | Turner Innovations, Llc. | Three dimensional x-ray imaging system |
WO2018236565A1 (en) | 2017-06-20 | 2018-12-27 | Hologic, Inc. | Dynamic self-learning medical image method and system |
US10699448B2 (en) | 2017-06-29 | 2020-06-30 | Covidien Lp | System and method for identifying, marking and navigating to a target using real time two dimensional fluoroscopic data |
JP2020530346A (en) | 2017-08-11 | 2020-10-22 | ホロジック, インコーポレイテッドHologic, Inc. | Breast compression paddle with inflatable jacket |
EP3664713A4 (en) | 2017-08-11 | 2021-04-28 | Hologic, Inc. | Breast compression paddle with access corners |
US11707244B2 (en) | 2017-08-16 | 2023-07-25 | Hologic, Inc. | Techniques for breast imaging patient motion artifact compensation |
EP3449835B1 (en) | 2017-08-22 | 2023-01-11 | Hologic, Inc. | Computed tomography system and method for imaging multiple anatomical targets |
EP3457353B1 (en) * | 2017-09-18 | 2020-11-25 | Siemens Healthcare GmbH | Method and system for obtaining a true shape of objects in a medical image |
US10909679B2 (en) | 2017-09-24 | 2021-02-02 | PME IP Pty Ltd | Method and system for rule based display of sets of images using image content derived parameters |
US10893843B2 (en) | 2017-10-10 | 2021-01-19 | Covidien Lp | System and method for identifying and marking a target in a fluoroscopic three-dimensional reconstruction |
WO2019082029A1 (en) * | 2017-10-27 | 2019-05-02 | King Abdullah University Of Science And Technology | An apparatus and method for fiducial marker alignment in electron tomography |
KR101856426B1 (en) * | 2017-11-27 | 2018-06-20 | 세종대학교산학협력단 | 3D geometry enhancement method and apparatus thereof |
US10893842B2 (en) | 2018-02-08 | 2021-01-19 | Covidien Lp | System and method for pose estimation of an imaging device and for determining the location of a medical device with respect to a target |
US10905498B2 (en) | 2018-02-08 | 2021-02-02 | Covidien Lp | System and method for catheter detection in fluoroscopic images and updating displayed position of catheter |
US10743822B2 (en) * | 2018-06-29 | 2020-08-18 | Carestream Health, Inc. | Fiducial marker for geometric calibration of bed-side mobile tomosynthesis system |
US11090017B2 (en) | 2018-09-13 | 2021-08-17 | Hologic, Inc. | Generating synthesized projection images for 3D breast tomosynthesis or multi-mode x-ray breast imaging |
CA3126986A1 (en) * | 2019-02-06 | 2020-08-13 | William E. Butler | Spatiotemporal reconstruction of a moving vascular pulse wave from a plurality of lower dimensional angiographic projections |
EP3832689A3 (en) | 2019-12-05 | 2021-08-11 | Hologic, Inc. | Systems and methods for improved x-ray tube life |
US11380006B2 (en) * | 2020-01-22 | 2022-07-05 | Wisconsin Alumni Research Foundation | Size measurement using angle-constrained radiographic imaging |
JP2023511416A (en) | 2020-01-24 | 2023-03-17 | ホロジック, インコーポレイテッド | Horizontally Displaceable Foam Breast Compression Paddle |
US11471118B2 (en) | 2020-03-27 | 2022-10-18 | Hologic, Inc. | System and method for tracking x-ray tube focal spot position |
US11786191B2 (en) | 2021-05-17 | 2023-10-17 | Hologic, Inc. | Contrast-enhanced tomosynthesis with a copper filter |
WO2023101980A1 (en) * | 2021-11-30 | 2023-06-08 | Qsa Global Inc. | Systems and methods for compensating magnification and overlaying images in digital radiographic imaging |
Citations (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4205375A (en) * | 1977-01-31 | 1980-05-27 | Tokyo Shibaura Electric Co., Ltd. | Method and apparatus for performing computed tomography |
US4662379A (en) * | 1984-12-20 | 1987-05-05 | Stanford University | Coronary artery imaging system using gated tomosynthesis |
US4722056A (en) * | 1986-02-18 | 1988-01-26 | Trustees Of Dartmouth College | Reference display systems for superimposing a tomagraphic image onto the focal plane of an operating microscope |
US4920491A (en) * | 1988-05-16 | 1990-04-24 | General Electric Company | Enhancement of image quality by utilization of a priori information |
US4941164A (en) * | 1987-10-29 | 1990-07-10 | The Governors Of The University Of Alberta | Method and apparatus for improving the alignment of radiographic images |
US5008947A (en) * | 1988-10-13 | 1991-04-16 | Kabushiki Kaisha Toshiba | Method and apparatus for correcting extension rates of images |
US5051904A (en) * | 1988-03-24 | 1991-09-24 | Olganix Corporation | Computerized dynamic tomography system |
US5070454A (en) * | 1988-03-24 | 1991-12-03 | Olganix Corporation | Reference marker orientation system for a radiographic film-based computerized tomography system |
US5081577A (en) * | 1989-12-22 | 1992-01-14 | Harris Corporation | State controlled device driver for a real time computer control system |
US5227969A (en) * | 1988-08-01 | 1993-07-13 | W. L. Systems, Inc. | Manipulable three-dimensional projection imaging method |
US5299254A (en) * | 1989-11-24 | 1994-03-29 | Technomed International | Method and apparatus for determining the position of a target relative to a reference of known co-ordinates and without a priori knowledge of the position of a source of radiation |
US5359637A (en) * | 1992-04-28 | 1994-10-25 | Wake Forest University | Self-calibrated tomosynthetic, radiographic-imaging system, method, and device |
US5389101A (en) * | 1992-04-21 | 1995-02-14 | University Of Utah | Apparatus and method for photogrammetric surgical localization |
US5642293A (en) * | 1996-06-03 | 1997-06-24 | Camsys, Inc. | Method and apparatus for determining surface profile and/or surface strain |
US5694530A (en) * | 1994-01-18 | 1997-12-02 | Hitachi Medical Corporation | Method of constructing three-dimensional image according to central projection method and apparatus for same |
US5751787A (en) * | 1996-09-05 | 1998-05-12 | Nanoptics, Inc. | Materials and methods for improved radiography |
US5755725A (en) * | 1993-09-07 | 1998-05-26 | Deemed International, S.A. | Computer-assisted microsurgery methods and equipment |
US5828722A (en) * | 1996-05-17 | 1998-10-27 | Sirona Dental Systems Gmbh & Co., Kg | X-ray diagnostic apparatus for tomosynthesis having a detector that detects positional relationships |
US5872828A (en) * | 1996-07-23 | 1999-02-16 | The General Hospital Corporation | Tomosynthesis system for breast imaging |
US5878104A (en) * | 1996-05-17 | 1999-03-02 | Sirona Dental Systems Gmbh & Co. Kg | Method for producing tomosynthesis exposures employing a reference object formed by a region of the examination subject |
US5926557A (en) * | 1997-02-26 | 1999-07-20 | Acuity Imaging, Llc | Inspection method |
US6081577A (en) * | 1998-07-24 | 2000-06-27 | Wake Forest University | Method and system for creating task-dependent three-dimensional images |
US6118845A (en) * | 1998-06-29 | 2000-09-12 | Surgical Navigation Technologies, Inc. | System and methods for the reduction and elimination of image artifacts in the calibration of X-ray imagers |
US6120180A (en) * | 1997-10-17 | 2000-09-19 | Siemens Aktiengesellschaft | X-ray exposure system for 3D imaging |
US6122541A (en) * | 1995-05-04 | 2000-09-19 | Radionics, Inc. | Head band for frameless stereotactic registration |
US6249568B1 (en) * | 1998-06-19 | 2001-06-19 | Commissariat A L'energie Atomique | Process for improving a signal/noise ratio of the image of a moving object |
US6289235B1 (en) * | 1998-03-05 | 2001-09-11 | Wake Forest University | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US20030026469A1 (en) * | 2001-07-30 | 2003-02-06 | Accuimage Diagnostics Corp. | Methods and systems for combining a plurality of radiographic images |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE6933094U (en) | 1969-08-20 | 1969-12-11 | Bs Metallverarbeitungsgmbh | CABINET WALL |
DE2810608A1 (en) | 1978-03-11 | 1979-09-20 | Philips Patentverwaltung | PROCESS FOR LOW-DISTURBANCE LAYER REPRESENTATION OF SPATIAL OBJECTS BY USING DIFFERENT PERSPECTIVE IMAGES |
JPS55141097A (en) | 1979-04-20 | 1980-11-04 | Toshiba Corp | Diagnosis x-ray apparatus |
US4554676A (en) | 1983-03-16 | 1985-11-19 | The S. S. White Company | Dental aiming device |
JPS6175284A (en) * | 1984-09-19 | 1986-04-17 | Toshiba Corp | Radiation detector |
JPS63140907A (en) | 1986-12-04 | 1988-06-13 | Toshiba Corp | Measuring method for equipment installation position |
JPS63230151A (en) * | 1987-03-20 | 1988-09-26 | 株式会社 日立メデイコ | Measuring phantom for radiation image pickup apparatus |
JP2615820B2 (en) | 1988-04-28 | 1997-06-04 | 株式会社モリタ東京製作所 | Tooth X-ray image receiving device |
JP2679104B2 (en) | 1988-04-28 | 1997-11-19 | 株式会社モリタ東京製作所 | Tooth X-ray inspection system |
JPH0284984A (en) | 1988-09-22 | 1990-03-26 | Toppan Printing Co Ltd | Traveling sheet for self-traveling toy vehicle |
JPH02279141A (en) | 1989-04-20 | 1990-11-15 | Fuji Photo Film Co Ltd | Radiation image recorder |
JPH03132748A (en) | 1989-10-19 | 1991-06-06 | Fuji Photo Film Co Ltd | X-ray tomographic device |
DE4112966A1 (en) * | 1991-04-20 | 1992-10-22 | Hoechst Ag | POSITIVELY WORKING RADIATION-SENSITIVE MIXTURE AND PRODUCTION OF RADIATION-SENSITIVE RECORDING MATERIAL THEREFOR |
AU738399B2 (en) | 1992-04-28 | 2001-09-20 | Wake Forest University | Self-calibrated tomosynthetic, radiographic-imaging system, method, and device |
JPH08509144A (en) * | 1993-04-22 | 1996-10-01 | ピクシス,インコーポレイテッド | System to locate relative position of objects |
DE4327229A1 (en) | 1993-08-13 | 1995-02-16 | Abb Patent Gmbh | Device for setting at least one manipulated variable related to a specific manipulated variable in a motion detector |
JPH08124507A (en) * | 1994-10-25 | 1996-05-17 | Hitachi Ltd | Sample mounting base and device using the same |
US5782828A (en) * | 1996-12-11 | 1998-07-21 | Irvine Biomedical, Inc. | Ablation catheter with multiple flexible curves |
JP3439614B2 (en) * | 1997-03-03 | 2003-08-25 | 株式会社日立製作所 | Transmission electron microscope and element distribution observation method |
JPH1154079A (en) * | 1997-08-04 | 1999-02-26 | Ikegami Tsushinki Co Ltd | Electron microscopic operation-interlocking television camera |
-
1998
- 1998-03-05 US US09/034,922 patent/US6289235B1/en not_active Expired - Fee Related
-
1999
- 1999-02-26 AT AT99909697T patent/ATE499043T1/en not_active IP Right Cessation
- 1999-02-26 JP JP2000534116A patent/JP4816991B2/en not_active Expired - Fee Related
- 1999-02-26 CA CA002322462A patent/CA2322462C/en not_active Expired - Fee Related
- 1999-02-26 DE DE69943214T patent/DE69943214D1/en not_active Expired - Lifetime
- 1999-02-26 WO PCT/US1999/004435 patent/WO1999044503A1/en active Application Filing
- 1999-02-26 EP EP99909697A patent/EP1059877B1/en not_active Expired - Lifetime
- 1999-02-26 AU AU28846/99A patent/AU2884699A/en not_active Abandoned
-
2001
- 2001-05-21 US US09/862,006 patent/US6810278B2/en not_active Expired - Fee Related
-
2004
- 2004-10-25 US US10/972,887 patent/US7110807B2/en not_active Expired - Fee Related
-
2006
- 2006-08-16 US US11/505,255 patent/US7801587B2/en not_active Expired - Fee Related
-
2010
- 2010-09-20 US US12/885,910 patent/US20110092812A1/en not_active Abandoned
Patent Citations (36)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4205375A (en) * | 1977-01-31 | 1980-05-27 | Tokyo Shibaura Electric Co., Ltd. | Method and apparatus for performing computed tomography |
US4662379A (en) * | 1984-12-20 | 1987-05-05 | Stanford University | Coronary artery imaging system using gated tomosynthesis |
US4722056A (en) * | 1986-02-18 | 1988-01-26 | Trustees Of Dartmouth College | Reference display systems for superimposing a tomagraphic image onto the focal plane of an operating microscope |
US4941164A (en) * | 1987-10-29 | 1990-07-10 | The Governors Of The University Of Alberta | Method and apparatus for improving the alignment of radiographic images |
US5070454A (en) * | 1988-03-24 | 1991-12-03 | Olganix Corporation | Reference marker orientation system for a radiographic film-based computerized tomography system |
US5319550A (en) * | 1988-03-24 | 1994-06-07 | Olganix Corporation | High resolution digital image registration |
US5051904A (en) * | 1988-03-24 | 1991-09-24 | Olganix Corporation | Computerized dynamic tomography system |
US4920491A (en) * | 1988-05-16 | 1990-04-24 | General Electric Company | Enhancement of image quality by utilization of a priori information |
US5227969A (en) * | 1988-08-01 | 1993-07-13 | W. L. Systems, Inc. | Manipulable three-dimensional projection imaging method |
US5008947A (en) * | 1988-10-13 | 1991-04-16 | Kabushiki Kaisha Toshiba | Method and apparatus for correcting extension rates of images |
US5299254A (en) * | 1989-11-24 | 1994-03-29 | Technomed International | Method and apparatus for determining the position of a target relative to a reference of known co-ordinates and without a priori knowledge of the position of a source of radiation |
US5081577A (en) * | 1989-12-22 | 1992-01-14 | Harris Corporation | State controlled device driver for a real time computer control system |
US5389101A (en) * | 1992-04-21 | 1995-02-14 | University Of Utah | Apparatus and method for photogrammetric surgical localization |
US5359637A (en) * | 1992-04-28 | 1994-10-25 | Wake Forest University | Self-calibrated tomosynthetic, radiographic-imaging system, method, and device |
US5668844A (en) * | 1992-04-28 | 1997-09-16 | Webber; Richard L. | Self-calibrated tomosynthetic, radiographic-imaging system, method, and device |
US5755725A (en) * | 1993-09-07 | 1998-05-26 | Deemed International, S.A. | Computer-assisted microsurgery methods and equipment |
US5694530A (en) * | 1994-01-18 | 1997-12-02 | Hitachi Medical Corporation | Method of constructing three-dimensional image according to central projection method and apparatus for same |
US6122541A (en) * | 1995-05-04 | 2000-09-19 | Radionics, Inc. | Head band for frameless stereotactic registration |
US5878104A (en) * | 1996-05-17 | 1999-03-02 | Sirona Dental Systems Gmbh & Co. Kg | Method for producing tomosynthesis exposures employing a reference object formed by a region of the examination subject |
US5828722A (en) * | 1996-05-17 | 1998-10-27 | Sirona Dental Systems Gmbh & Co., Kg | X-ray diagnostic apparatus for tomosynthesis having a detector that detects positional relationships |
US5642293A (en) * | 1996-06-03 | 1997-06-24 | Camsys, Inc. | Method and apparatus for determining surface profile and/or surface strain |
US5872828A (en) * | 1996-07-23 | 1999-02-16 | The General Hospital Corporation | Tomosynthesis system for breast imaging |
US5751787A (en) * | 1996-09-05 | 1998-05-12 | Nanoptics, Inc. | Materials and methods for improved radiography |
US5926557A (en) * | 1997-02-26 | 1999-07-20 | Acuity Imaging, Llc | Inspection method |
US6120180A (en) * | 1997-10-17 | 2000-09-19 | Siemens Aktiengesellschaft | X-ray exposure system for 3D imaging |
US6810278B2 (en) * | 1998-03-05 | 2004-10-26 | Wake Forest University | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US6289235B1 (en) * | 1998-03-05 | 2001-09-11 | Wake Forest University | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US20010034482A1 (en) * | 1998-03-05 | 2001-10-25 | Webber Richard L. | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US7110807B2 (en) * | 1998-03-05 | 2006-09-19 | Wake Forest University Health Sciences | Method and system for creating three-dimensional images using tomosynthetic computed tomography |
US6249568B1 (en) * | 1998-06-19 | 2001-06-19 | Commissariat A L'energie Atomique | Process for improving a signal/noise ratio of the image of a moving object |
US6118845A (en) * | 1998-06-29 | 2000-09-12 | Surgical Navigation Technologies, Inc. | System and methods for the reduction and elimination of image artifacts in the calibration of X-ray imagers |
US6081577A (en) * | 1998-07-24 | 2000-06-27 | Wake Forest University | Method and system for creating task-dependent three-dimensional images |
US6801597B2 (en) * | 1998-07-24 | 2004-10-05 | Wake Forest University Health Sciences | Method and system for creating task-dependent three-dimensional images |
US6549607B1 (en) * | 1998-07-24 | 2003-04-15 | Wake Forest University | Method and system for creating task-dependent three-dimensional images |
US20050059886A1 (en) * | 1998-07-24 | 2005-03-17 | Webber Richard L. | Method and system for creating task-dependent three-dimensional images |
US20030026469A1 (en) * | 2001-07-30 | 2003-02-06 | Accuimage Diagnostics Corp. | Methods and systems for combining a plurality of radiographic images |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130113897A1 (en) * | 2011-09-25 | 2013-05-09 | Zdenko Kurtovic | Process and arrangement for determining the position of a measuring point in geometrical space |
US11463681B2 (en) | 2018-02-23 | 2022-10-04 | Nokia Technologies Oy | Encoding and decoding of volumetric video |
WO2020186066A1 (en) * | 2019-03-12 | 2020-09-17 | Amdt Holdings, Inc. | Monoscopic radiographic image and three-dimensional model registration methods and systems |
CN113795866A (en) * | 2019-03-12 | 2021-12-14 | Amdt控股公司 | Single-view-field radiological image and three-dimensional model registration method and system |
Also Published As
Publication number | Publication date |
---|---|
US6289235B1 (en) | 2001-09-11 |
US20050113682A1 (en) | 2005-05-26 |
JP4816991B2 (en) | 2011-11-16 |
DE69943214D1 (en) | 2011-04-07 |
EP1059877A1 (en) | 2000-12-20 |
CA2322462A1 (en) | 1999-09-10 |
EP1059877B1 (en) | 2011-02-23 |
CA2322462C (en) | 2009-09-29 |
US20010034482A1 (en) | 2001-10-25 |
US6810278B2 (en) | 2004-10-26 |
WO1999044503A1 (en) | 1999-09-10 |
EP1059877A4 (en) | 2002-09-11 |
JP2002505437A (en) | 2002-02-19 |
AU2884699A (en) | 1999-09-20 |
US20070165922A1 (en) | 2007-07-19 |
US7801587B2 (en) | 2010-09-21 |
US7110807B2 (en) | 2006-09-19 |
ATE499043T1 (en) | 2011-03-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7801587B2 (en) | Method and system for creating three-dimensional images using tomosynthetic computed tomography | |
US6549607B1 (en) | Method and system for creating task-dependent three-dimensional images | |
EP0268488B1 (en) | Method and apparatus for utilizing an electro-optic detector in a microtomography system | |
US5812629A (en) | Ultrahigh resolution interferometric x-ray imaging | |
US7412024B1 (en) | X-ray mammography | |
US7535986B2 (en) | Method and CT system for detecting and differentiating plaque in vessel structures of a patient | |
US4736396A (en) | Tomosynthesis using high speed CT scanning system | |
EP0234922B1 (en) | Producing tomographic images | |
JPH0228818B2 (en) | ||
US10638997B2 (en) | Echo-scintigraphic probe for medical applications and relevant diagnostic method | |
JPH0815182A (en) | Method for compensating for radiation scattering in x-ray imaging system | |
Rao et al. | The modulation transfer functions of x-ray focal spots | |
US20070268999A1 (en) | Apparatus and method for creating tomosynthesis and projection images | |
US20040069949A1 (en) | Method, apparatus and program for restoring phase information | |
US20070064869A1 (en) | Laminography apparatus | |
JP2005532532A (en) | Laser pointer device for identifying the location of radiation in the body | |
JP2988995B2 (en) | Storage phosphor, X-ray diffraction apparatus and X-ray diffraction method | |
JPS62290445A (en) | X-ray tomographic imaging apparatus | |
Makela | Dental x-ray image stitching algorithm | |
Mäkelä | Limittäiset hammasröntgenkuvat yhdistävä algoritmi | |
JPH0461851A (en) | Photographing of tomography image by radioactive ray and device therefor | |
JPS60181639A (en) | Computer-tomography of industrial sample by radiation | |
JPS59120139A (en) | Radiation tomographic apparatus | |
JPS62278730A (en) | Sample surface scanning type analyzer |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |