WO1988001485A1 - Systeme et procede de formation d'images a radiations infrarouges - Google Patents

Systeme et procede de formation d'images a radiations infrarouges Download PDF

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Publication number
WO1988001485A1
WO1988001485A1 PCT/US1987/002102 US8702102W WO8801485A1 WO 1988001485 A1 WO1988001485 A1 WO 1988001485A1 US 8702102 W US8702102 W US 8702102W WO 8801485 A1 WO8801485 A1 WO 8801485A1
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Prior art keywords
light rays
rays
accordance
bundle
transmitted
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Application number
PCT/US1987/002102
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English (en)
Inventor
Jerome R. Singer
Original Assignee
Singer Jerome R
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Publication of WO1988001485A1 publication Critical patent/WO1988001485A1/fr

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A61B5/0073—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence by tomography, i.e. reconstruction of 3D images from 2D projections

Definitions

  • This invention relates to three-dimensional imaging, and particularly to an infrared radiation based imaging system and method.
  • the invention is of particular interest in the use of infrared radiation for the study of human and animal bodies for analysis, diagnosis, and pharmaceutical investigations and studies.
  • DPG diaphanography
  • IR infrared
  • Benign and carcinomic tumors tend to absorb more visible and more IR light. These will generally appear as darkened areas in DPG.
  • arteries and veins are readily visualized in the DPG procedure.
  • DPG is utilized as a screening procedure. If a suspicious region is observed, further diagnostic procedures may include ultrasonic imaging. X-ray imaging. Magnetic Resonance Imaging or CT scanning.
  • a hand-held torch providing a suitable light source . for DPG is now commercially manufactured. Sinus Medical Equipment AB, Norrlandsgaten 31-33, 11143 Sweden.
  • the torch consists of a tungsten filament bulb, a xenon flash tube, and a cooling fan.
  • D.J. Watmough A light torch for the transillumination of female breast tissues, British J. of Radiology, 55. 142-146 (1982) , has shown that using such a light torch with some improvements, one can image a lesion of diameter down to 6 mm. Both IR sensitive photographic film and a silicon vidicon television camera were utilized in these observations.
  • X-rays X-rays
  • ultrasonic scans X-rays
  • Magnetic Resonance Imaging (MRI) CT scans
  • Nuclear scans X-rays
  • MRI Magnetic Resonance Imaging
  • Ultrasonic Imaging systems are believed to be harmless to the patient, however these systems do not provide good resolution relative to either the MRI or the CAT scanners. Ultrasonic imagers are utilized widely because they are inexpensive and can rapidly provide images. The low resolution of such scanners does -4- limit their usefulness in many medical diagnoses.
  • the Magnetic Resonance I ager (MRI) has become a very significant medical diagnostic system. MRI has the advantage of providing no ionizing radiation to the patient, and produces medical images which resolve tissue images to approximately two to three millimeters diameter.
  • the disadvantages of MRI are the substantial cost, the fact that one cannot image patients with internal magnetic prosthetic devices, the substantial space requirements, and the extensive maintenance needs.
  • the Computer Assisted Tomography scanner (the CAT scanner) , provides good tissue resolution, but does have the disadvantage of using X-rays which, along with all other ionizing radiation, can, cause tissue damage.
  • Nuclear Medicine Scanners are limited to the diagnoses of a few special diseases, where they are very valuable. They employ io' izing radiation, and are not used for general imaging studies.
  • imaging is achieved by illuminating an object with a bundle of light rays consisting of electromagnetic radiation within the near infrared range; separating out the transmitted rays which are not the result of scattering; individually detecting these transmitted rays in a manner specific to their cross-sectional location in the bundle; and repeating the process at different angles of incidence to generate a signal combination capable of manipulation by computerized tomography techniques to form tomographic images.
  • the bundle of light rays may range from a continuous beam, in which the rays are defined as contiguous geometrical sections of the beam, to a cluster of discrete rays of small cross-section separated from each other by gaps.
  • the bundle is a two-dimensional array of parallel rows of light rays capable of generating a plurality of tomographic images simultaneously.
  • the invention has application to internal imaging of almost all non-metallic objects, with a wide range of utility and types of information generated, including both medical and industrial applications.
  • the invention may be applied to integrated circuits for purposes of testing, analysis and quality control. It may also be used to control the quality, type and selection of such material as wood and plastics, by detecting porosity, blow holes, knot holes and other imperfections.
  • a further application is food grading, in which density may be determined and inhomogeneities detected. Similar determinations may be made in chemical and petroleum products in general. Medical imaging is the most important of the potential applications of the invention, where the images produced by the invention reflect different types of tissue structures in biological bodies in a diagnostically useful manner.
  • Figure 1 is a diagram of one example of an imaging system in accordance with the present invention.
  • Figures 2A, 2B and 2C are representations of alternative methods for converting a single incident beam into a series of parallel beams.
  • Figure 3 is a diagram of a second example of an imaging system in accordance with the present • invention.
  • Figure 4 is a diagram of a third example of an imaging system in accordance with the present invention.
  • Basic steps in the practice of the present invention include the formation of a light ray bundle; the transmission of the bundle through a subject body; the detection of rays transmitted through the body after removal of scattering; the rotation of the light ray bundle to repeat the transmission and detection at different angles of incidence; the storing of the detection signals after each transmission; and the combination of the stored signals in accordance with an algorithm to form images of tomographic slices of the body defined by the traversing rays.
  • the term "light ray” is intended to mean any b'eam of light whose intensity level averaged over its entire cross-sectional area translates into one picture element ("pixel") in the final image.
  • the size of the cross-section will determine the resolution of the image, and may be tailored accordingly to suit the type of body being studied and the size and shape of the irregularities or internal features expected to be found.
  • the size of each ray may thus vary widely. In medical applications, rays having a width or a diameter of about 4 mm or less, preferably about 3 mm or less, will provide the best results.
  • a single ray may comprise a spatial division of a single continuous beam, or in the alternative, may be discrete, i.e. , not connected or contiguous with neighboring rays. In the former case, the ray is the smallest cross-section of the beam which is resolved in the final image.
  • the wavelengths are in the near infrared range.
  • the optimal wavelength in each case will vary with the nature and quality of the material to be penetrated as well as the range of variations of transparency within the subject body. In general, wavelengths ranging from about 0.7 to about 5.0 microns will be used. For biological bodies, particularly human bodies, preferred wavelengths are those ranging from about 0.7 to about 1.6 microns. These are termed"near infrared or infrared waves.
  • the incident beam must be of sufficient intensity to penetrate and be transmitted through the body so that variations in the intensity of the transmitted light due to the different types of tissue or materials in the body transversed by the beam can be detected. This can vary widely, and will depend on the thickness and density of the body, the cross-sectional area of the body to which the beam is being exposed, and the sensitivity * of the detection medium. In most applications, an intensity of the entire bundle or beam ranging from about 0.5 watts to about 100 watts will provide the best results.
  • the term "bundle” is used to denote a group of rays in close proximity penetrating a subject body at the same time for simultaneous detection upon emergence.
  • the rays in the bundle may be contiguous or discrete, and form at least one straight row.
  • the bundle is a two-dimensional array of rays, most preferably rectangular, arranged in a series of parallel rows.
  • the bundle may be either of constant cross-section or fan-shaped.
  • Fan beams are those with a rectangular cross-section widening in the direction of transmission along the axis parallel to the rows. -9-
  • the bundle may be formed from rays emanating from individual sources. Most conveniently, however, the bundle is formed from a single ray which is separated into a multitude of rays by a combination, of reflection, refraction and transmission through mirrors, prisms and/or lenses.
  • a two-dimensional array may be formed by using two such arrangements in o series, one rotated 90 with respect to the other.
  • the light may be generated by any source which is capable of focusing a beam of the appropriate wavelength and intensity.
  • Light sources capable of producing a substantially monochromatic beam i..e. , one with a wavelength spread of approximately 1 Angstrom or less, are preferred.
  • Monochromatic beams are preferable for purpose of scatter filtering, and are particularly important where high resolution and tomographic techniques are used.
  • Lasers emitting radiation of the appropriate wavelength and intensity are particularly appropriate. Examples are crystal solid state, ion, gas and solid state diode lasers.
  • dye lasers and Nd:YAG and other gas and rare earth solid state lasers provide appropriate wavelengths.
  • Lasers with frequency doublers or tunable lasers such as some of the dye lasers are applicable to the present application.
  • the heat generated in the subject by absorption of the penetrating light may be sufficient to cause discomfort or tissue damage.
  • This may be alleviated by cooling to remove heat from the subject during the exposure. This may be done by conventional -means such as, for example, submersion in a cooling medium such as water or application of a protective skin preparation, which can also be made to serve the purpose of improving light transmission by matching the refractive indices at the interface.
  • the detection of emerging rays in accordance with the invention is substantially limited to rays passing straight through the subject body without reflection, refraction or scattering.
  • the emerging rays are thus collimated prior to reaching the detectors.
  • Small angle scattering may be included with the detected rays, depending on the ray and detector cross-sections and the length of transmission. All other transmissions are prevented from reaching or being detected by the detectors.
  • Collimation may be accomplished in any of several ways. Examples include: the use of non-reflecting light transmission pipes between the body and the detectors, each pipe corresponding to and sized to accommodate exactly one ray.
  • the pipes will generally have a square or rectangular cross-section; the use of aligned holes in two or more planes of light-absorbing material; separation of the light rays by one or more transverse planes between the body and the detectors; and the use of different wavelengths in adjacent rays.
  • the individual detectors may then be tuned to respond only to the wavelengths of the corresponding incident rays. This may be done by the use of filters or other conventional means.
  • Scattering may also be eliminated by the use of photodetectors programmed to accept light signals only at certain times or at certain modulation frequencies to correspond to source rays in direct alignment, thereby rejecting those rays impinging on them as the result of scattering from neighboring source rays.
  • the source rays are accordingly emitted at different times by rapid on/off switching between adjoining rays, or all modulated by the use of shutters, Pockels cells or similar devices capable of periodic on/off switching or intensity variations. In the latter case, adjoining rays are distinguished by differing modulation frequencies as are the corresponding photodetectors.
  • the detection system is comprised of a series of individual elements, arranged in an array corresponding to the incident bundle.
  • this is a two-dimensional array of photodetectors, which may include conventional photoconductive and photovoltaic detectors sensitive to infrared radiation. Examples include photomultipliers, silicon photodiodes, transistors, avalanche photodiodes, charge coupled devices, gallium arsenide photocathodes, detectors based on compounds of silicon, phosphor, germanium, antimony, or bismuth, and other vacuum and semiconductor photodetectors well known in the art. -12-
  • the imaging subject may be conceived as being divided into a set of hundreds of parallelepipeds with each parallelepiped being traversed by a single ray.
  • the difference in ray transmission through adjoining parallelepipeds determines the resolution of borders or irregularities within the subject. Therefore, detection of adjoining ray intensity differences is particularly important in obtaining high resolution images.
  • Lasers are not intrinsically constant in intensity over time. Therefore several means can be provided to stabilize the laser intensity over time.
  • One method is to use an intensity stabilizer which senses the beam intensity with a photodetector, amplifies the sensed voltage and provides a feedback signal to the ⁇ laser power source or a beam valve (such as a Pockels cell) to stabilize the laser intensity.
  • Another form of stabilization is to switch the laser rays rapidly so as to traverse neighboring parallelepipeds in the subject and thereby average out the intensity fluctuations.
  • the switching of the beam also provides another advantage which is that ray scatter from one parallelepiped to the neighboring parallelepiped will be rejected by the detection photodetector because such scatter will occur in different time periods.
  • a third method of correcting for laser intensity fluctuations is to use a comparison between the incident radiation and the transmitted radiation. For example, a small fraction (about 1%) of light emanating from the source may be deflected and directed to an- adjoining photodetector, and the resulting signal combined with that from photodetectors preceding the transmitted rays to provide a difference.
  • transmission is repeated at a series of different angles of incidence in accordance with conventional tomographic procedures to obtain sets of signal data corresponding to each angle for ultimate combination and manipulation in the generation of images.
  • the angles generally differ from one another by small increments, preferably at most two degrees and most preferably at most one degree. Increments of one degree or one-half degree are particularly preferred.
  • the aggregate of the angles will preferably be approximately 180" .
  • Angle variation is generally achieved by rotating both the source of the incident bundle and the detector bank. Conventional equipment, such as a computer driven servomotor may be used.
  • Image construction may then be achieved by conventional computerized tomography techniques, including such manipulations as convolution, inverse Fourier transforms, back projections, and combinations of these.
  • FIG. 1 Light of appropriate wavelength originates in a source 10, which may be a laser or a bank of lasers. An intensity steadier system 11 is used to stabilize the laser intensity. A series of mirrors or prisms 12, 13, 14 direct the light to a beam expander 15, which may be a set of optical lenses which expand the beam cross-section and then recollimate the beam. The resulting beam is then intercepted by a beam attenuator 16 to control the beam intensity. In order to provide a wave front with a uniform energy density, a set of lenses 18 is placed in the beam path to smooth the wave front energy distribution. -14-
  • the beam emerging from the lenses 18 is then expanded and/or separated into a two-dimensional array of parallel rays. This is done by a pair of separators 20, 21 which expand the beam out along a pair of 5 perpendicular axes.
  • the first separator 20 separates the incoming beam into a vertical row of rays 22, while the second separator 21 expands each of these rays horizontally to form a two-dimensional array of parallel rays 23.
  • the separator is comprised of a stack 25 of glass plates oriented at a 45° angle to the incident beam 26.
  • One face 27 of each glass plate is slightly silvered to
  • the plates may be silvered to produce about 4% reflection.
  • the plates may be cemented together with a cement such as Canadian Balsam having an index of refraction approximately equal to that of the glass (generally
  • the reflected beams 28 from each of the slightly silvered surfaces form a linear array.
  • a series of glass plates 30 are slightly 25 silvered similarly to those of Figure 2A and positioned at a similar angle with respect to the incident beam 31 but separated by gaps.
  • the resulting reflected rays 32 are also separated by gaps, as one method of eliminating scattered rays from those 30 reaching the detectors.
  • a thick glass plate 34 has one surface fully silvered 35 for total internal reflection, while -15- the other surface 36 is partially silvered for approximately 95% reflection.
  • the incoming beam 37 is directed at a 45° angle of incidence at a transparent portion 38 of the upper surface. Due to refraction, the portion of the beam transmitted through the glass travels at a 28° angle, and is fully reflected off the bottom reflecting surface 35. Upon reaching the upper surface 36, a portion is transmitted outward 39 while the remainder 40 is again reflected internally. As this continues down the length of the plate, a parallel set of rays 41 emerges.
  • the two-dimensional ray bundle 23 produced by the beam separators is intercepted by a partially reflecting mirror 45 arranged at an angle with respect to the direction of transmission.
  • the mirror 45 reflects a portion 46 of the ray bundle through a lens 47 which focuses the reflected rays onto a bank of reference photoreceptors 48 for purposes of comparison with the rays transmitted through the subject body.
  • the incident rays 49 comprise a two-dimensional array consisting of a series of parallel rows.
  • the intersection of the subject body 50 with each row is a tomographic slice 51, of which only one is shown in the drawing. In reality, a plurality of such slices is defined, parallel and possibly contiguous, depending on whether or not the incident rays are separated by gaps.
  • the collimator 53 may consist of or incorporate an array of filters as described above for selectively passing rays of appropriate wavelength.
  • a lens 54 focuses the rays on a bank of photoreceptors 55.
  • Signals from both banks of photoreceptors are directed to a signal processor and analog/digital converter 56 which feeds a set of representative signals to a computer 57 for temporary storage.
  • the signals from both banks of photoreceptors are carefully indexed within the computer so that computations can be carried out using related intensity measurements. .
  • One such calculation is the determination of the - transmission level of a specific ray divided by the incident level of that same ray. The quotient gives the percentage of the ray intensity which is transmitted.
  • the computer can be programmed to emphasize transmission levels relative to the average incidence or average transmission, relative to nearest neighbor ray transmission, relative to a normalized level, or relative to other laser wavelengths which can be employed simultaneously (in adjoining regions) or in a sequence of imaging procedures. Use of such different wavelengths provides additional means of resolving and discriminating between elements of the imaged subject.
  • the computer 57 then directs motors such as servomotors to rotate the system around the stationary nonrotating subject as indicated by the arrows 58, 59, while data is collected at each of a plurality of -17- points along the way, preferably about 1° or 0.5° increments.
  • the servomotor 60 is this drawing is shown as having coordinates in two orthogonal directions 61, 62.
  • a display terminal 63 either displays or records the series of images produced by the computer 57 for each tomographic plane 51 in a subject body, utilizing each of the various angles of incidence. Conventional computerized tomography techniques are used in generating the image.
  • FIG. 3 A second type of arrangement for an overall plan for multi-plane imaging is shown in Figure 3.
  • a laser 71 is the source of an IR beam
  • reflectors 72, 73 direct the beam through a beam expander 74 which shapes the beam into the desired size.
  • the beam then passes through lens configurations 75 of types well known in the art to even out the power distribution over the beam area and thus render it uniform.
  • the intensity of the beam can be adjusted by a variable attenuator 76 which is computer controlled by a computer programmed signal 77.
  • the beam is then separated by a beam separator 78 which may consist of as many as 100 partially reflecting plates. The separator provides a set of parallel rays which decrease the scatter interference from the object due to their separation.
  • a servo or stepping motor 79 is - programmed through a computer directed signal 80 to move the beam separator 78 through a space sufficient to fill in the gaps in the parallel rays 81 produced by the beam separator.
  • the servomotor will generally have several steps programmed to fill in the several gaps. -18-
  • a negative cylindrical lens 82 spreads the rays into fan beams 83 which are then collimated and separated by the collimator 84. It is generally advantageous to introduce gaps in the fan beams 83 orthogonal to those
  • the collimator 84 can provide this separation either by blocking portions of the beam or by using lenses to redirect the beam so that the fan beam shows gaps.
  • the gaps can be provided either by blocking portions of the beam or by using lenses to redirect the beam so that the fan beam shows gaps.
  • the fan beam is now partially (a few percent) 15 reflected by a 95% transmission window 86.
  • the few percent sample of the beam then is converged by the .lens 87 to the set of photodetectors 88.
  • One photodetector element corresponds to each pixel.
  • the segmented fan beam 89 passing through the window 20 86 traverses the subject 90 to be imaged, which it intersects along a series of parallel planes 91. Within the subject 90 there is absorption, reflection, refraction, and transmissions of the IR light. In order to provide good reconstructions, it is best to 25 accept only the emergent rays which have passed straight through, -or have only undergone very small angular deviations from the straight-through paths. The acceptor of such rays is the collimator 92 which, rejects scattered rays which emerge at any significant 3.0 angular deviation from the straight-through paths.
  • the lens 93 converges the rays onto the photodetector array 94 wherein there is a photodetector element positioned to detect each ray element.
  • the photodetector array is connected by cable to the amplifiers, signal processors, and filters 95. After signal processing, the signals are converted to digital form by the analog to digital converter 96 and fed into the computer (not shown) for the tomographic computation.
  • the sampled input IR is connected from the photodetector array 88 to the signal processor 97 and the A/D converter 98.
  • the signal emerging from the latter provides the computer with information regarding both spatial variations and time fluctuations in the intensity of the input beam. The computer will then use this for comparison when manipulating the signals emerging from the transmission side A/D converter 96 to provide improved signal level information as to rays transmitted through,the subject 90.
  • the system of elements 72 through 94 is rotated approximately one or one-half degree and the scan information is then repeated. By carrying out approximately 180 or 360 such scans enough information is obtained to carry out a reconstruction algorithm in the computer as in the Figure 1 embodiment.
  • Such reconstruction algorithms generally utilize Fourier transforms, convolutions and back projections. These techniques are well known in the science and art of image reconstruction.
  • FIG. 4 Such a system is shown in Figure 4.
  • the only moving part is a servomotor driven reflector 101, which directs an IR beam from a laser 102 to a convex reflector 103 which is part of a bank 104 of such reflectors arranged in an arc.
  • the convex reflector 103 produces a fan beam 105 directed toward the subject 106 after being separated into spaced-apart rays by an array of electronically controlled slits 107.
  • the fan beam here as well as the one on Figure 3 has a cross-section which expands along one axis only, i.e. , the axis parallel to the image planes (in the embodiments shown, the horizontal axis) .
  • Rays transmitted 108 through the subject are collimated by collimating slits 109, and converted to electric signals by a bank of photoelectric detectors 110, arranged in an arc. These signals are in turn processed by a signal processor and analog-to-digital converter 111 which feeds information to a computer 112 and display terminal 113 as in the other embodiments. Transmissions and signals at various angles through the subject 106 are accomplished by rotating the reflector 101 to engage in the convex reflectors 103 one at a time.
  • the advantage is that some portions of the subject transmit better at some wavelengths than at others.
  • image subtraction, and/or division, multiplication, averaging, and normalizing techniques one can obtain emphasis upon desired features of the images by optimizing the resolution of the images within several different transmission ranges.

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Abstract

Formation d'images tomographiques de la structure interne d'un corps humain (50) se fondant sur les variations de transparence, consistant à éclairer le corps avec un faisceau de rayons de lumière (49) dans l'infrarouge proche, les rayons étant arrangés de préférence en une série de rangées parallèles, à traiter les rayons transmis (52) sortant du corps afin d'éliminer les effets de diffusion, à détecter (55) les rayons traités d'une manière spécifiques à leur emplacement dans la section transversale du faisceau, et à répéter ce procédé sous différents angles d'incidence pour produire des images tomographiques simultanées (43) grâce à des techniques tomographiques informatisées.
PCT/US1987/002102 1986-09-02 1987-09-01 Systeme et procede de formation d'images a radiations infrarouges WO1988001485A1 (fr)

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US90321786A 1986-09-02 1986-09-02
US903,217 1986-09-02

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Cited By (18)

* Cited by examiner, † Cited by third party
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EP0336208A1 (fr) * 1988-03-29 1989-10-11 Shimadzu Corporation Calcul de tomographe
EP0385608A1 (fr) * 1989-02-15 1990-09-05 Hitachi, Ltd. Procédé pour examiner optiquement le corps humain et appareil pour celui-ci
EP0387793A2 (fr) * 1989-03-13 1990-09-19 Krauss, Manfred, Prof., Dr.-Ing.habil. Procédé et dispositif pour présentation de structures
EP0561643A1 (fr) * 1992-03-19 1993-09-22 Hitachi, Ltd. Dispositif d'imagerie par tomographie optique
EP0585620A1 (fr) * 1992-07-31 1994-03-09 Fuji Photo Film Co., Ltd. Méthode et appareil pour obtenir des informations tri-dimensionnelles sur des échantillons
WO1994013194A1 (fr) * 1992-12-09 1994-06-23 Carl-Zeiss-Stiftung Handelnd Als Carl Zeiss Procede et dispositif de determination optique a resolution locale de la repartition de tissus biologiques de densites diverses
EP0614645A1 (fr) * 1992-08-31 1994-09-14 Hitachi, Ltd. Appareil de tomographie optique informatisee
WO1998010698A1 (fr) * 1996-09-13 1998-03-19 Non-Invasive Technology, Inc. Imagerie non vulnerante de tissu biologique
EP0837649A1 (fr) * 1995-06-07 1998-04-29 Richard J. Grable Appareil d'imagerie laser pour tomographie diagnostique
GB2350673A (en) * 1999-06-04 2000-12-06 Toshiba Res Europ Ltd Three dimensional imaging using terahertz or Far IR radiation
US6195580B1 (en) 1995-07-10 2001-02-27 Richard J. Grable Diagnostic tomographic laser imaging apparatus
GB2359716A (en) * 2000-02-28 2001-08-29 Toshiba Res Europ Ltd A terahertz imaging apparatus with phase comparison
US6397099B1 (en) 1992-05-18 2002-05-28 Non-Invasive Technology, Inc. Non-invasive imaging of biological tissue
US6662042B1 (en) 2000-08-22 2003-12-09 Richard J. Grable Diagnostic tomographic laser imaging apparatus
DE4303047B4 (de) * 1993-02-03 2004-03-25 Bilz, Dietrich, Dr. Verfahren zur Untersuchung mehrdimensionaler inhomogener Strukturen
US6828558B1 (en) 1999-06-04 2004-12-07 Teraview Limited Three dimensional imaging
US7152007B2 (en) 2000-02-28 2006-12-19 Tera View Limited Imaging apparatus and method
WO2019150333A1 (fr) * 2018-02-05 2019-08-08 Sensoriumlab Sp. Z O.O. Procédé de mesure d'épanchement pleural

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US4515165A (en) * 1980-02-04 1985-05-07 Energy Conversion Devices, Inc. Apparatus and method for detecting tumors
US4600011A (en) * 1982-11-03 1986-07-15 The University Court Of The University Of Aberdeen Tele-diaphanography apparatus
US4649275A (en) * 1984-06-25 1987-03-10 Nelson Robert S High resolution breast imaging device utilizing non-ionizing radiation of narrow spectral bandwidth

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4212306A (en) * 1978-05-18 1980-07-15 Khalid Mahmud Breast examination device and method
US4515165A (en) * 1980-02-04 1985-05-07 Energy Conversion Devices, Inc. Apparatus and method for detecting tumors
US4600011A (en) * 1982-11-03 1986-07-15 The University Court Of The University Of Aberdeen Tele-diaphanography apparatus
US4649275A (en) * 1984-06-25 1987-03-10 Nelson Robert S High resolution breast imaging device utilizing non-ionizing radiation of narrow spectral bandwidth

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4937451A (en) * 1988-03-29 1990-06-26 Shimadzu Corporation Computed tomograph
EP0336208A1 (fr) * 1988-03-29 1989-10-11 Shimadzu Corporation Calcul de tomographe
EP0385608A1 (fr) * 1989-02-15 1990-09-05 Hitachi, Ltd. Procédé pour examiner optiquement le corps humain et appareil pour celui-ci
US5148022A (en) * 1989-02-15 1992-09-15 Hitachi, Ltd. Method for optically inspecting human body and apparatus for the same
EP0387793A2 (fr) * 1989-03-13 1990-09-19 Krauss, Manfred, Prof., Dr.-Ing.habil. Procédé et dispositif pour présentation de structures
EP0387793A3 (fr) * 1989-03-13 1991-07-03 Krauss, Manfred, Prof., Dr.-Ing.habil. Procédé et dispositif pour présentation de structures
EP0561643A1 (fr) * 1992-03-19 1993-09-22 Hitachi, Ltd. Dispositif d'imagerie par tomographie optique
US6397099B1 (en) 1992-05-18 2002-05-28 Non-Invasive Technology, Inc. Non-invasive imaging of biological tissue
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EP0814334A2 (fr) * 1992-07-31 1997-12-29 Fuji Photo Film Co., Ltd. Méthode et appareil pour obtenir des informations tri-dimensionnelles sur des échantillons
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