JP2003527886A - Digital flat panel X-ray detector positioning in diagnostic radiology - Google Patents

Abstract

(57) Abstract The digital flat panel two-dimensional X-ray detector (34) has a reliable position in various positions for different X-ray protocols for standing, sitting or lying patients. Move safely and conveniently. The present system makes it practical to use the same detector for multiple protocols that may otherwise require different equipment and, for example, at high cost, such detectors Utilizes the desired properties of flat panel digital detectors while mitigating the effects of less desirable properties such as weight and fragility of the panel.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

This patent specification is in the field of radiography and, more particularly, in the field of X-ray equipment using digital flat panel detectors.

[0002]

[Prior art]

Medical diagnostic X-ray machines have long used X-ray film contained inside a light-tight cassette, the cassette being placed on one side of the patient and the X-ray source on the other side. During the exposure, the X-rays penetrate the desired body position and the X-ray film records a spatially varying X-ray exposure in the film. Over the years, medical experience has developed and optimized a variety of standard protocols for imaging different parts of the body, which place the film cassette in a position different from the patient. Need to be done. For example, chest x-rays are often performed with the patient standing and pressing the chest or back against a vertical film cassette. Imaging of bones in the hand may be done with the cassette placed horizontally on the surface and the hand placed on top of the cassette. In another procedure, the patient may support the cassette under the arm. A collection of such standard protocols is available in Mosby-Year Book, Inc. Published by P
hilip W. Ballinger, et. al. Merrill Atlas of Radiographic Locations and Procedures by Merrill's Atlas of
Radiographic Positions and Radiolog
ic Procedures), 9th edition. As a result of advances in digital X-ray sensor technology, we are developing arrays of sensors that generate electrical signals related to local X-ray exposure, eliminating film as a recording medium. One example is described in US Pat. No. 5,319,206,
And the current version is commercially available from the assignee of this patent specification. Such digital arrays are often referred to as flat panel x-ray detectors, or simply flat panel detectors, and offer certain advantages over x-ray film. There is no need to process the film as the images can be created and obtained from the cassette in electronic digital form and transferred directly to the computer. The digital format of the x-ray data makes the images easy to incorporate into a hospital recording system. Digital flat panel detectors or plates also provide improved dynamic range as compared to x-ray film and therefore may require multiple images of the same biological tissue to be taken. It is possible to eliminate the limitation of the exposure range. On the other hand, digital flat panel detectors currently have a higher capital cost than film cassettes and are more fragile. They often incorporate lead shields to protect radiation-sensitive electronics and can be heavy. If they are connected to the computer by cables, it is necessary to consider the handling of the cables when moving the cassette and / or the patient. On the other hand, the cassette is disclosed in, for example, US Pat.
It can be independent, as in 661,309, in which case it includes a power supply and storage of image information, increasing its weight and possibly size. Such detectors typically have suitable scatter removal or Bucky (
Bucky) used in systems with plates.

The high initial cost of digital detectors is to equip the X-ray chamber with multiple detectors pre-mounted in various positions, such as a vertically mounted unit for the chest and a horizontal unit under the bed. It may hinder things. The fragility, weight and initial cost of the unit make it difficult for the patient to use in procedures to support the detector. The unique characteristics of digital flat panel detectors can make them unusable when using conventional film cassette holders with flat panel detectors.

A number of proposals have been made for X-ray systems that use flat panel detectors. A C-arm arrangement is provided under the name Traumex by Fisher Imaging Corporation of Denver, Colorado with the participation of the assignee of the present specification. Another C-arm arrangement is S
It is believed that it is provided under the name ddRMuli-System by wissray, and the literature from Swissray is ddRCombi.
-System is scheduled for sale in early 2000 and ddRMMulti
-It states that it provides the same function as the System, but uses an existing third-party suspension system for the X-ray tube (the illustration in that is the X-ray tube mounted on the ceiling. It is believed to represent a detector arrangement or device mounted for vertical movement on a structure separate from the support). A vertically moving and rotating image intensifier is believed to be shown in FIG. 3 of US Pat. No. 4,741,014. U.S. Pat. No. 5,764,724 proposes yet another patient table and can be moved to multiple positions along the table edge.

Although numerous other proposals have been made for positioning X-ray film cassettes, the different physical characteristics and conditions of flat panel detector systems allow the film cassette positioning proposals to be directly applied. Not meant to be. For example, U.S. Pat. No. 4,365,344 proposes a system for placing film cassettes in a variety of positions and orientations relative to a floor mounted X-ray source support. U.S. Pat. No. 5,157,707 relates to a ceiling mounted x-ray tube support to enable taking AP (anterior-posterior) and lateral chest images of a patient sitting on a bed. It is proposed to move the film cassette to a different position. Swedish Patent Document (Utlaggnin
gsskrift [B]) 463237 (Application No. 8900580-5) shows a similar proposal and mounting of an X-ray cassette and an X-ray source on the same structure extending upwards from the floor. It seems to indicate. US Patent No. 4,
No. 468,803 proposes to clamp an articulated support for a film cassette on the patient's table, and US Pat. No. 5,920,606 allows the patient to ride and We propose a platform that allows you to insert a film cassette inside and image the foot that bears the weight.

[0006]

[Problems to be Solved by the Invention]

Given the unique characteristics and requirements of digital flat panel detector systems, there is a safe, reliable, convenient and effective way to position such systems for a variety of imaging protocols. It is believed that there is a need to propose, and this patent specification is to meet such a need.

[0007]

[Means for Solving the Problems]

An exemplary and non-limiting example comprises a digital flat panel two-dimensional X-ray detector system, which is not mechanically coupled to the movement of the X-ray source and is standard or To be able to safely and conveniently move to any one of a variety of positions for other X-ray protocols and to maintain the position safely selected for acquiring X-ray images. With a single digital flat panel detector for the X-ray protocol, which may otherwise require multiple detectors, such as a ceiling mounted source. It makes it possible to use standard X-ray sources in the radiology room.

One preferred embodiment, which is by way of example and not limiting the scope of the invention as claimed, is a digital flat panel X with no mechanical connection to an X-ray source. It has a detector that includes a line detector arrangement and a scatter removal grid. A base supported on the floor supports an articulated structure, which supports the detector and selectively moves the detector in at least five degrees of freedom, standing, sitting Positioned against any one of a variety of standard or other diagnostic x-ray protocols for a patient in a lying and lying position. In a non-limiting example, this degree of freedom includes at least two translational movements and three rotational movements. For example, the first translational motion involves moving the lower slide along a base, and the first rotational motion comprises a proximal end mounted on the lower slide. Rotating the lower arm about a vertical axis, the second rotational movement including rotating a post mounted at the distal end of the lower arm about another vertical axis. And the second translational motion involves moving the upper slide up and down the column, and the third rotational motion couples the distal end to the detector and the proximal end. Rotating an upper arm mounted on the upper slide about a horizontal axis. Further, the detector can be rotatably mounted on the distal end of the upper arm for rotation about an axis transverse to its plane for a sixth degree of freedom. . The detector can also be rocked to provide angulation for cross table oblique imaging, as is commonly done for hip axiolaterals. That is, it is possible to rotate about a vertical axis when oriented vertically. In the more general case, the detector can be rotated about an axis extending along its viewing surface and approximately parallel thereto.

For some X-ray protocols, it may be desirable to combine the vertical movement of the detector with the vertical movement of the patient table, and such measures are included within the system disclosed herein. There is. In order to make it easier to move and position the detector, movement in at least some of the degrees of freedom is constrained by a detent, which detent biases the movement into suitable steps. It is possible to bias and lock to prevent unwanted movement. It is possible to drive the motion in one or more degrees of freedom. Further, it is possible to computer control the movement in some or all of the degrees of freedom. A collision avoidance system can be provided to help prevent pinch points and collisions for motion in one or more degrees of freedom.
An encoder associated with a moving part can provide digital information about movement and position, and the information can be used by a computer programmed to control that movement in various ways. Is. For example,
The information can be used in pinch points and collision avoidance and / or in computer controlled movements to position the detector at selected positions and orientations.

The system disclosed herein is capable of driving a patient table up and down and moving the table along its length, and further allows for greater versatility of X-ray protocols. It can be used with a patient table on a pedestal that can be rotated about a horizontal and / or vertical axis to do so. The system can be used without a table for x-ray protocols involving, for example, standing patients or patients on beds or gurneys or wheelchairs. The detector may have a rectangular imaging area, in which case provision may be made to rotate the detector between landscape and portrait orientations. Furthermore, it is possible to provide equipment for automatically detecting the orientation state, for example by providing an exposure sensor that functions to provide orientation information.
The detector may be provided with a square imaging area, in which case it is not necessary to rotate between landscape and portrait orientation states, for example, the imaging Rotation can still be applied to image the limbs or some other structure along the diagonal of the area, or to align the scattered light removal grid with the desired orientation. Variations of the disclosed system can be adapted for use with a step stall for imaging weight-bearing extremities, in which case the detector stalls on which the patient stands. It moves in at least two degrees of freedom between a horizontal orientation below the section and a vertical orientation in equilibrium with the section of the stall. Another variation could be for an X-ray protocol that does not involve the upper body of the standing patient.

[0011]

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the main support 10 can be fixed to the floor of the X-ray room (or to a movable platform, not shown), and on top of which the lower slide 14 is attached to the x-axis. It has a truck 12 on it for traveling along. The sliding body 14 supports a base end or a near end of a substantially horizontal lower arm 16 via a bearing 18, which allows the arm 16 to rotate about an axis extending upward, for example, the z axis. Is possible. The distal or distal end of the lower arm 16 supports an upwardly extending, e.g. vertical, column 20 which is mounted via a bearing 17 to extend upwardly, e.g. to rotate about a vertical axis. There is. The column 20 has slots 20 along its length.
a. The upper slide 22 is engaged with the slot 20a, runs along the length of the post 20 and is supported by a cable or chain system 24, which includes pulleys 26 (at the top and bottom of the post 20). (Only the upper pulley is shown) and is connected to a counterweight 28 running inside the column 20 with its direction reversed. The upper sliding body 22 is a bearing arrangement (device) 32.
The upper arm 30 is supported via the upper arm 30, and the upper arm 30 can be rotated about a horizontal direction extending along the length of the upper arm 30, for example, a horizontal axis. Preferably, the bearing arrangement or device is located along the center of mass of the detector system, which may include accidental braking or detents that may cause the detector to rotate and strike the patient. It provides a safety feature in case of release. Upper arm 30 contains, for example, a two-dimensional digital flat panel detector array of the type described in the above-referenced U.S. Patents, and typically receives control and other signals and digital images and other images. It carries an x-ray detector 34 that also includes electronics for transmitting information via a cable (not shown) and / or in a different manner and a scattered light elimination grid. Detector 34
Is connected to the upper arm 30 via a bearing arrangement (device) 36 (FIG. 7) that allows the detector 34 to rotate about an axis perpendicular to the X-ray receiving surface of the flat panel detector. Is possible. This may be desirable if the imaging area of the detector 34 is rectangular, allowing it to be used in either portrait or landscape orientation, or such rotation is otherwise If so desired, for example, the diagonal of the detector is aligned with the patient's limbs or other biological tissue of interest. On the other hand, the bearing arrangement (device) 36 can be omitted. For example, 36 bearings
Handle 38 may be attached to detector 34, or otherwise directly attached to upper arm 30, and lock and unlock various movements, for example. It has a manual switch or other controller 38a for control purposes such as locking and / or controlling motorized movement.

The patient table 40 is supported on a telescoping post 42 which moves the table 40 up and down, eg along the z-axis, within a guide 44, which is mounted on the floor or Alternatively, it may be mounted on a movable support and may or may not be fixed to the main support 10. The table 40 is made of a material that minimizes the distortion of the spatial distribution of X-rays passing through it. If desired, the table 40 can be movable along the x-axis in a manner similar to a bed in the QDR-4500 Acclaim system commercially available from the assignee of this patent specification, and / or Or it may be tilted about one or more transverse axes, eg the x-axis and y-axis, and / or rotated about an upwardly extending axis, eg the z-axis. Is possible. A console and display unit 41 (FIG. 9) connects to the detector 34 by a table or otherwise to provide power and control signals and receive digital image data (and possibly other information) for processing and display. Is possible. The display in unit 41 may be, for example, on a CRT or flat panel display screen used in the usual manner, and images and other information may be recorded and / or recorded as appropriate as known in the art. Or it can be printed. Conventional image processing equipment can be provided in the unit 41, for example for level and window control of the displayed digital X-ray image, image magnification, zooming, cropping, annotating, etc. The cable can be run through the upper arm 30, column 20, and lower arm 16 to avoid interference with the motion of the articulated support structure between the main support 10 and the detector 34. . On the other hand, the detector 34 can be powered and controlled in other ways, and the image data can be extracted from it in some other way. For example, the detector 34 can be a stand-alone detector having an internal power supply and having a control switch on or in the detector 34 to control its operation. Detector 34 may further include storage for one or more x-ray image data. It is possible to retrieve the image data from the detector 34 by a wireless connection, or by temporarily connecting a cable when reading the image data, or in some other way. The detector 34 can include one or more exposure sensors (not shown), such as an ion chamber used as is known in the art to control x-ray exposure. Arrangement of five exposure sensors around detector 34 such that they are along the top of the detector for chest x-rays in either orientation of detector 34 and the orientation of detector 34 By providing a microswitch or some other sensor (not shown) to detect the, a signal is provided supporting the use of the three exposure sensors on top of the detector 34 at that time.

The detector 34 is typically used with a ceiling-suspended x-ray source 46 of the type typically found in x-ray rooms. Such x-ray sources are typically suspended through a retractable arrangement or device which allows the sources to be moved vertically and rotated about an axis, thus The x-ray beam shown at 46a can be aligned with film cassettes and x-ray receivers such as digital flat panel detectors when using the systems disclosed herein. Translational movements of source 46 may also be possible. Such x-ray sources typically have an optical arrangement that produces a light beam that represents where the collimated x-ray beam will strike when the x-ray tube is energized. , And has appropriate controls for beam collimation and x-ray technology factors.

The first embodiment disclosed herein uses five degrees of freedom for movement of the detector 34, and optionally rotates the detector 34 about an axis transverse to its plane. If so, use the sixth degree of freedom. The detector 34 has no mechanical connection to the movement of the x-ray source 46, so that all movement of the detector 34 is independent of the position or movement of the x-ray source. Further, the detector 34 is a table 40.
With no mechanical connection, and thus any movement of the detector 34 is independent of the position or movement of the patient table. However, as will be described below, it is possible to provide equipment for selectively coupling the vertical movement of the detector 34 and table 40 for a given procedure, and the detector 34 and table 4 may be provided.
It is possible to provide a facility for collision avoidance with its support structure comprising zero and / or x-ray source 46.

The first degree of freedom of the detector 34 is related to the translational movement of the slide 14 along the main support 10. The second degree of freedom is related to the rotation of the lower arm 16 about the bearing at 18. The third degree of freedom relates to the rotation of the column 20 around the bearing at 17. The fourth degree of freedom is associated with the up and down movement of the upper slide 22 along the column 20. The fifth degree of freedom is associated with the rotation of the upper arm 30 about the bearing at 32. Optionally, the sixth degree of freedom is associated with rotation of detector 34 about the bearing at 36 (FIG. 7).

Through the combination of the translational movement of the lower slide 14 along the base 10 and the rotational movement of the lower arm 16 around the bearing at 18, the detector 34 optionally includes a table 40.
Move along the length of and across it. The height of the detector 34 is adjusted by moving the slide 22 above or below the column 20. The orientation of the detector 34 is adjusted via rotation about the bearing at 22 and, if provided and desired, via rotation about the bearing at 36. The rotation of the column 20 about the bearing at 17 further contributes to the positioning and orientation of the detector 34.

The patient table 40 and its support structures 42 and 44 need not be used at all for many X-ray protocols, and can be omitted entirely from the embodiments of the system disclosed herein. Yes, in that case, the detector 34 and its articulated support structure would otherwise be identical to those shown in FIGS. 1-9, 11, 12. As previously described, the embodiment shown in Figure 10 does not use a patient table. The patient table 40 is suitable for moving it to an unobtrusive position for certain X-ray procedures, or because of the configuration of the X-ray chamber or for other reasons, such as over 90 degrees or more. It can be mounted to rotate around the column 42 through a bearing device (not shown). Additionally or alternatively, the table 40 can be mounted to pivot about a y-axis, eg, an axis at the top of the post 42, and / or for example about an x-axis at the top of the post 42. It can be mounted so as to rotate. The table 40 can also be mounted to pivot about a vertical z-axis. This pivoting movement can be over any desired angle that the mechanical arrangement allows. Of course, it is possible to provide an appropriate arrangement for locking the table 40 in place.

At the detector 34 position shown in FIG. 1, the x-ray protocol may be a standing patient's chest x-ray. In the case of this protocol, the sliding body 14 moves to the left side in the drawing, the lower arm 16 rotates to a point away from the base 10, and the pillar 2
0 rotates the upper arm so that it is oriented vertically with respect to the base 10 and the lower arm 16, and the upper arm 30 has the detector 34 oriented vertically and the x-ray source 46 is moved to the proper position. Or the optical device rotates to show proper alignment with the detector 34. The vertical position of the detector 34 is the upper slide 2 along the column 20.
Adjusted by sliding 2. If detector 34 has portrait and landscape orientations, it is rotated to the desired orientation and after setting the x-ray technology factor and positioning the patient as is known in the art. X-ray exposure is performed. In the embodiment using manual movement, the operator releases the articulated structure between the detector 34 and the base 10 to depress the appropriate button 38a on the handle 38 to effect the appropriate movement. , And at the end of its movement, depressing or releasing appropriate buttons to lock the structure in place for the X-ray procedure. It is possible to use a single button or other operator interface to unlock all parts of the articulated structure for movement and lock them for the x-ray procedure, or It is possible to use the respective buttons of the other interface devices for a small set of individual movements. If some or all of these movements are motor driven, the operator may unlock the movements and support the motorized movement, and then optionally lock the articulated structure in place. Use the buttons or other controls.

If a larger distance between the detector 34 and the table 40 is desired, the lower arm 16 is rotated transversely to the base 10, eg, perpendicular to the base 10. , And the post 20 is rotated so that the upper arm 30 maintains the orientation shown in FIG. Further, the table 40 can be moved to the far right in FIG. 1 to allow for x-axis movement, and / or can be rotated or tilted as previously described.

The position shown in FIG. 2 can be used for protocols such as imaging or imaging the foot of a standing patient or imaging a patient on a wheelchair or gurney. It is similar to the position shown in FIG. 1 and the detector 34 can be similarly moved except to a lower vertical position. Again, if a greater distance from the side of the table 40 is desired, the lower arm 16 can be angled transverse to the length of the base 10. The x-ray source 46, not shown in FIG. 2, is in a position to direct the x-ray beam to the detector 34 through the patient.

FIG. 3 shows a suitable position for a chest AP image of a lying patient, for example a patient in a supine position on the table 40. The table 40 can be lowered to make it easier for the patient to ride on it, and then raised, if desired. For this X-ray protocol, the detector 34 is moved to the underside of the patient table 40 in a horizontal orientation by moving the articulating support structure as previously described. If desired, the detector 34 and table 40 can be interlocked when in the position shown and then moved up or down together. The interlock is a clamp or pin (not shown) when the upper slide 30 is manually moved along the post 20.
Can be mechanical, according to
Is driven vertically by the motor-driven vertical motion of the. When the sliding body 30 is driven by a motor, the vertical movements of the sliding body 30 and the table 40 can be synchronized via known electronic control. The table 40 is shown in FIG.
Moved all the way to the left as shown in.

FIG. 4 also shows the detector 34 in a horizontally oriented position and facing up, but at the head or foot of the table 40 and substantially flush therewith. X-ray protocols such as imaging of the limbs or head of a patient lying on the table 40 can be performed at this position on the detector 34 and the table 40. The table 40 is moved to the right in this example as shown in FIG. The x-ray source 46, not shown in FIG. 4, is above the detector 34.

FIG. 5 illustrates suitable detector 34 and table 40 positions for X-ray protocols such as arm or hand imaging of a patient lying on table 40. For this protocol, the detector 34 has been moved to one side of the table 40 and is in a horizontal orientation and facing upwards. The detector 34 can be coplanar with the table 40, or it can be vertically offset therefrom by a selected distance. The disclosed system allows the detector 34 to be moved to either side of the table 40 and is positioned at any one of a number of locations along one side of the table 40 and laterally and at selected distances. It is possible to separate from the table 40 both vertically. The X-ray source 46 is above the detector 34, not shown in FIG.

FIG. 6 illustrates the location of the detector 34 suitable for protocols such as wheelchair, gurney, arm or hand imaging of a patient on or standing. The positioning of FIG. 6 is similar to that of FIG. 1 except that the detector 34 is vertically lower and horizontally oriented and is oriented upwards. Again, X
The line source 46 is above the detector 34, not shown in FIG.

FIG. 7 illustrates suitable detector 34 position for X-ray protocols such as a cross table lateral view of a patient lying or sitting on a table 40. For this protocol, the detector 34 is oriented vertically and faces the side of the table 40. Typically, the lower edge of the image area of detector 34 is at or higher than table 40. The X-ray source 46 in this case is on the opposite side of the table 40 and its X-ray beam is directed horizontally to the detector 34.

FIG. 8 shows the detector 34 in a position similar to that in FIG. 7, again in the vertical orientation, but via rotation of the lower arm 16 and / or the column 20 into the table. It is angled with respect to the side edges of 40. The x-ray source 46 is located across the table 40 from the detector 34, and the central ray of the x-ray beam is typically perpendicular to the imaging surface of the detector 34.

FIG. 9 shows the detector 34 in a position similar to that in FIG. 1, but shows a structure in which an X-ray source 46 is suspended from the ceiling, and the detector 34 and, if desired, Shown is a console 41 that is electrically and electronically coupled to an x-ray source 46 and is located behind a known x-ray protection screen.

FIG. 10 shows that for an X-ray protocol such as imaging the patient's foot when only two degrees of freedom can be used for the detector 34, but with weight bearing. And shows an appropriate example. The post 50 in this embodiment is similar to the post 20 previously described, but the post 50 need not be on the lower arm 16 and may be floor mounted or mounted on a moveable platform. It can be provided on a support 52 which can be The column body 50 is supported by the support body 5 via the bearing 54.
It is rotatably mounted on 2 and rotates about an axis extending upward, such as its longitudinal axis. An arm 56 is mounted, for example, on a sliding body 58 that moves along the post 50 via a chain and pulley arrangement or device 60 with the weight 62 as the counterweight. The arm 56 is mounted on a sliding body 58 via a bearing 57, and rotates, for example, around a horizontal axis in the horizontal direction. In use, the patient optionally grasps a floor or wall-mounted handrail 66, climbs stairs 64, and stands on a low platform 68 that is essentially transparent or transparent to x-rays. . The detector 34 can be positioned in a horizontal orientation, under the platform 68 and facing upward, as shown. The x-ray source 46 is above the patient's foot and the x-ray beam is directed downward toward the detector 34. By grasping the handle 69, the operator can move the arm 5
It is possible to withdraw the detector 34 from underneath the platform 68 by rotating the post 50 through 6, and then rotate the arm 56 around the bearing 57 to bring the detector 34 to the lateral image of the patient's foot. Due to the required X-ray protocol for lateral images, it is possible to move adjacent to and in alignment with the platform 60 or above it in a vertical orientation. The assembly unit consisting of the stairs 64, the platform 68, and the handrail 66 fixed to it, can be provided on wheels 71 so that it can be moved as required.

11 and 12 show a locking detent mechanism that can be used for one or more of the rotary movements described above. In the presently preferred embodiment, such detents are used for rotation of lower arm 16, post 20, upper arm 30, and detector 34 around bearing 36 (FIG. 7).
It can be used for any rotation of. Similar detents can be used for rotation of post 50 and arm 56 in the embodiment of FIG. As a typical example, the rotation of the lower arm 16 around the lower slide 14 is taken, and
1 and 12, plate 100 is fixed to or part of a component of a non-rotating element in sliding body 14 of this example, and cog wheel 70, or a segment of such cog wheel. Is fixed to a rotating component, which is the lower arm 16 in this example. The cogwheel 70 has a pattern of valleys 70a and teeth 70b. A cam wheel 72 is rotatably mounted on a lever 74, which is rotatably mounted on the plate 100 at a pivot point 76 and is biased towards a cog wheel 70 by a spring 77. (Fig. 12). When the lower arm 16 is rotated with a force sufficient to overcome not only inertia and friction but also the biasing force of the spring 77, the cam wheel 72 rides on the teeth of the cogwheel 70, but the lower arm 16 If the rotating force is less than the threshold, the mechanism pushes the cam wheel 72 into the valley 70a and thus the rotation of the lower arm 16 is about 15 degrees apart in the presently preferred embodiment. Stop at one of several suitable positions. When the lower arm 16 is in the desired position, the detent mechanism is locked by releasing the solenoid 78 and its spring forces the lever 80 into the position shown in FIG. , In which case it comes to the lower right side of the lever 74 to keep the cam wheel 72 in the valley and thus prevent rotation of the lower arm 16. In order to allow the arm 16 to rotate, the solenoid 78 must be biased to move the lever 80 to the position shown in FIG. 11, which is the case, for example, in the embodiment of FIGS. 1-9. Is a control button 38a on the handle 38 or the handle 38 in the embodiment of FIG.
This can be done by operating the button 38a 'on the'. While it is possible to use the same type of detent for each rotary movement, different configurations of cog teeth may be desirable. For example, rotation around bearing 36 is only 2
Three or three preferred positions C, portrait, landscape, diagonal orientation C
In some cases, the cogwheel may need only three troughs between the teeth. Other rotations may require different angular ranges, in which case the segments of cogwheel 79 used may have different interior angles.

On the other hand, electronic, electromechanical and / or mechanical brakes and clutches can be used to immobilize and release the connection between the parts that can move relative to each other. The use of such a brake and clutch allows an operator to manually move the detector 34 to a desired position and also securely fixes the detector 34 at a predetermined position for exposure. It is possible. For example, an operator can operate switch 38a to engage such clutch or clutches and / or brakes or brakes, thereby permitting movement, and It is possible to operate the switch in order to disengage the appropriate clutch and / or brake and thereby prevent movement. Such clutch and / or brake arrangements can be used for one or more of the movements described above. It is possible to use different such arrangements or devices for different movements.

Instead of manually moving the detector 34 to the desired position as described above, each electric or other motor is driven under the control of an operator to drive some or all of the above-described movements. It is possible to use. On the other hand, it is possible to automate some or all of the movements so that the operator can select one of several preset movement sequences, or It is possible to select vertical, horizontal and angular positions, and it is possible to supply motor control commands that require computer control. It is possible to use proximity and / or impact sensors on moving parts as a safety measure, especially when the movement is driven by electric power rather than by hand, and when the moving parts are too close to each other or on the object or patient. It is possible to generate a stop motion signal in the event of a collision with.

The detector 34 may include a flat panel detector, which uses a sensing layer containing selenium, silicon or lead oxide to directly direct X-rays into electrical signals representing an X-ray image. Convert. On the other hand, the detector 34 is a flat panel detector that uses a luminescent material layer that generates a light pattern when an X-ray is incident, and a plurality of detectors that generate an electric signal representing an X-ray image in response to the light pattern. It is possible to include an array of devices.

The system disclosed herein can be used for tomosynthesis, in which case the x-ray source and the detector move relative to each other and the patient or At least one of the source and the detector moves in either a continuous motion or a step-and-shoot manner.
It is possible to read out the image information acquired at each step (or each time increment) and the detector is reset for the image at the next step (or time increment). Alternative methods of performing tomographic synthesis can be used, in which the movement of the X-ray source and detector relative to the patient occurs as described above, but the overall movement sequence From which only one image is generated, which represents a composite image taken over all positions.

The system disclosed herein provides a large number of movements to accommodate a variety of imaging protocols, with the x-ray detector image plane rotating between vertical and horizontal and at intermediate angles. It can also be locked, the detector moving horizontally not only across the length of the patient table but also along the length of the patient table so that it can be located on either side of the table. Yes, the detector moves vertically and the detector is oriented for portrait orientation and landscape orientation for a non-square detector array and / or for a desired orientation of the array grid, even in the case of a square array. It is possible to move in and out of the states, and the detector may detect some or all of these movements in order to reach any desired position and orientation state. It is possible to combine all.

It is possible to improve safety by moving the detector by hand,
Therefore, the operator can observe all movements and ensure safety. A sensor can be provided for collision detection if either movement is motor driven. If either movement is motor driven, it is possible to use a motor that stops easily to improve safety. Further, if either movement is motor driven, an encoder can be provided to track the position of the moving component, and the output of the encoder can be used for tracking and collision avoidance control in software. It is possible to use. If the motion is motor driven, a preset motor control can be stored in the computer and used to drive the detector motion for a specified imaging or imaging protocol or sensing position. Therefore, the detector can be automatically moved to a preset position for a given imaging protocol. Clutch control, handbrake, counterbalance, and / or movement that help identify and maintain the desired detector position and orientation, and prevent grid vibration and focusing to grid misalignment. Undesired movements can be avoided or reduced by using stops.

13 to 27 show another embodiment. The articulated structure supporting the detector 34 in this embodiment has a main support 100 (FIGS. 26 and 27),
It is typically mounted on the floor, but it can also be mounted on a moving platform or some other support. Flexible support sleeve 100
Move up and down. The column 106 is rotatably mounted on the sleeve 104 to rotate about a horizontal axis, and the arm 108 runs along its length and on the column 106 to rotate about the horizontal axis. It is rotatably attached to. Support 110
Extends from the arm 108, and another arm 112 is rotatably fixed to the support 110 at a rotation shaft 114 (FIG. 27). The detector 34 is fixed to the other end of the arm 112 for pivoting about an axis 116 that is perpendicular to the detector imaging surface. Appropriate brakes, clutches, locks, detents and / or
Alternatively, a counterweight may be used to manually move some or all of the articulated structure or motorize some or all of these movements to provide a detector 34 for multiple x-ray protocols. It is provided to simplify the positioning of the. A patient table 120 (FIGS. 13-15) is provided for each main support 130.
Respective sleeves 126, 1 capable of expanding and contracting vertically on
Mounted on two cross members 122, 124 supported on 28. In this way, the table 120 can be moved up and down (see FIGS. 14 and 15).
(See the difference between FIGS. 13 and 14) and, for example, can be tilted in order to move it to an unobtrusive position with respect to the chest X-ray of the standing patient. Thus, this embodiment can be used with or without a patient table and its support for multiple X-ray protocols for a standing, sitting or lying patient. Is.

Yet another embodiment is shown in FIGS. 28-37. In this embodiment, the articulated structure supporting the detector 34 has a main support 150 mounted on a rail 152, which is railed toward or away from the patient table 154. Exercise along. A vertically retractable column, generally indicated at 156, moves up and down an arm 158 having one end mounted thereon for rotation of the column 156 about a vertical central axis. The detector 34 is mounted on the other end of the arm 158 for rotation about at least an axis parallel to its imaging surface, so that the detector 34 rotates between horizontal and vertical orientations. Is possible (compare FIGS. 28 and 29). Preferably, the detector 34 is mounted on the arm 158 to rotate about an additional axis perpendicular to the imaging surface for changing between portrait and landscape orientations or for other purposes. ing. In this embodiment, the patient table 154 is mounted on a retractable support, shown generally at 160. The table 154 moves up and down (comparing FIGS. 32 and 33) by the expansion and contraction movement of the column body 160, and rotates about the vertical axis (compare FIGS. 28 and 29). Furthermore, the arm 158 is standing,
Arms 158 can be telescoping to further facilitate positioning of detector 34 for different x-ray protocols for sitting and lying patients. (Figs. 36-38). 28-3 for use with only independently mounted x-ray sources in some of these positions.
It is shown in FIG.

As shown in FIGS. 39-41, the articulated support for the detector 34 is a table 15
It can be used for X-ray protocols that do not require a patient table such as 4. In FIGS. 39-41, a gurney 162 supports a patient and is wheeled relative to a support for a detector 34 which may be mounted on rails 152. The detector 34 in this embodiment can be positioned as shown in Figures 39-42 or in other positions, some of which are shown in Figure 28 for multiple standard X-ray protocols. It is shown in relation to -38.

Yet another embodiment is shown in FIGS. 42-45. In this embodiment, the detector 34 is mounted on a support 168 and pivots about a horizontal axis 169 between the detector's 34 horizontal and vertical orientations (compare FIGS. 42-43). Rail 16
Mounted for movement along and across 6. The patient table portion 170 is mounted on a support for pivoting about an axis parallel to the axis 169 at least between the positions shown in FIGS. 42 and 43. Detector 34 is capable of sliding across the length of rail 166 between the positions shown in FIGS. 44 and 45 on another set of rails (not shown). Thus, the detector 34 may include, but is not limited to, an X-ray of a standing patient or a patient in a wheelchair (FIG. 43), a patient lying on the table 170 (where the detector 34 is It can be used for a variety of protocols, including the underside, and body parts that extend to the sides of the table 170 (FIG. 45).

Another embodiment for positioning the detector 34 relative to the patient bed is shown in FIG.
It is shown at 50. In this embodiment, the detector 34 is secured to a patient platform 180 mounted at 182 for pivoting about a horizontal axis between the positions of at least FIGS. 48 and 49. Counterweight 184 facilitates this pivoting movement. The detector 34 includes rails (not shown) extending along the length of the platform and rails extending across the length of the platform for sliding movement along each set of rails. It is fixed to the platform 180 via (not shown). In this way, the detector 34 is capable of sliding under the platform along the length of the platform so that a patient lying on the platform can be, for example, a ceiling-supported X-ray. It is possible to emit X-rays with an independently supported X-ray source such as a source. Further, the detector 34 is capable of sliding across the length of the platform 180 so that it is disengaged from the platform (in plan view) and pivoted about its axis about its end. It is possible to assume a vertical orientation state, for example as shown at 46, near the platform. In the upright position of the patient platform 180, the patient may stand on a support 185 that may be configured to move up and down along the upright platform 180, for example, by a motorized movement. The detector 34 is shown in FIG.
And 49, it is clear that it is on the side of the platform opposite the patient.

The detector 34 can be provided on a revolute articulated support structure, as shown in FIGS. 51-53. In this example, the wheeled platform 200
Supports a vertical column 202 which supports an arm 204 movably up and down along the column 202 (compare FIGS. 51 and 52) and is rotatable about a horizontal axis. . The rotating structure is movable up and down on a retractable support 208 (compare FIGS. 51 and 52) and up and down along its length (see different positions of bed 206 shown in FIG. 52). Can be used together with. The detector support structure can be used without a patient bed, for example, for standing patient chest x-rays as shown in Figure 53, or for many other x-ray protocols. is there. A standard x-ray source 46 can be used.

In yet another embodiment, shown in FIGS. 54-59, the detector 34 may be supported on a structure shown generally at 250, which extends along the length of the patient table 252. It is supported for sliding movement (compare FIGS. 54 and 55) and rotation about a horizontal axis transverse to the length of the table 252 (compare FIGS. 54 and 55a). The table 252 is mounted on a vertically extending pedestal 254 on a rotating platform 256. As shown in FIG. 56, the detector 34 is mounted on an arm 258 that is articulated at 260 to rotate about an axis perpendicular to the imaging surface of the detector 34, which detector is It is possible to move between two illustrated positions, a position below the patient table 252 and a position lateral to the patient table. Further, as shown in FIG. 57, the arm 258 can rotate about an axis parallel to one of its sides into a vertical orientation and along the length of the patient table 252. It is possible to slide along the length of the support 250 to position the detector at all different points. 58 and 59 show the mounting of the arm 258 which rotates about the two axes of interest. In addition, the detector 34 can be mounted on the arm 250 for rotation between portrait and landscape orientations.

The system as described above can be enhanced in a variety of other ways to improve functionality and to take advantage of the flexibility of digital image generation.

When using x-ray film, the sharpest image typically occurs when the patient is positioned as close to the film as possible. This protocol also avoids object expansion and the file has a 1: 1 image, so geometric distances can be easily measured. In digital images, there is no requirement that the image be 1: 1 with respect to the object. Display monitors come in a variety of sizes. In a digital image, it is possible to calculate pixel dimensions in the object plane or object plane, and thus calibrate the distances on the image. Furthermore, the optimal object imaging detector distance (OID) for digital detectors is different than for film. In the case of film, the OID that maximizes the sharpness of the object in the object plane is 0, that is, the object plane is as close to the film as possible. In a digital detector, this optimal distance may be where the combined execution system resolution is minimal in the object plane due to focal spot blurring and pixel size.
This occurs for a non-zero OID, and in a flat panel system with a 139 micron pixel size and a 0.5 mm x-ray tube focal spot, the optimum OID is about 7 cm.

The calibration of pixel dimensions in the object plane depends on the magnification factor, which is a function of both source-imaging detector distance (SID) and OID. Once the magnification factor is determined, the effective pixel size is known and the magnification factor [M = SID / (SID-OID)] and / or the pixel size is specified in the patient record, for example in an appropriate field in the DICOM header. Can be inserted into. Display workstation software can use or display this information to establish metrics for pixel dimensions. On the other hand, the image can be re-mapped to one with a pixel size having a magnification factor of 1, which means that the image is printed on a hard copy and manual measuring means are used. Useful in cases. Determining the magnification factor requires knowing the SID and OID. One way is to measure SID and OID. In one embodiment of this, an encoder or sensor (not shown) can determine the SID and OID. In another embodiment, the SID and OID can be inferred from the harvesting protocol, eg, for standing chest images, the SID is known to be 72 inches. There is. In yet another embodiment, image processing of the acquired image comprises determining a magnification factor, for example, through measurement of a known reference phantom in the field of view, or through direct analysis of the acquired image. May be possible.

Collection parameters such as X-ray tube voltage kVd and power mAs and SID and / or O
The knowledge of the ID can be used to estimate the patient incident dose. In the preferred embodiment of the system, this incident dose information is inserted into the patient record or DICOM header.

In a digital flat plate system, the fact that the optimal OID is non-zero means that the means for keeping the object imaged at the optimal OID is a useful adjunct to the digital radiation system. Is implied. One example of this is a radiolucent frame (not shown in the drawing) that prevented imaging the patient closer than some predetermined distance.

Since the vertical position of the detector 34 can be positioned independently of the vertical position of the patient bed, the condition of positioning the detector below the bed may result in the detector erroneously Allows for the probability of being in a good position on the underside. This is
It may occur if the bed is raised without raising the detector over the vertical distances involved. Therefore, a system that prevents this inappropriate condition or alerts the operator would be useful. In one embodiment of this, an encoder or sensor (not shown) determines the detector to bed distance. This distance determination may be to automatically move the detector to the desired distance from the bed, or to alert the operator to an improper position to avoid unnecessary exposure, or It can be used to prevent exposure through an interlock until the detector is properly positioned. In another embodiment, the detector mechanically locks into the bed frame so it moves vertically along the patient bed.

As described in one preferred embodiment, the detector can be rotated from portrait to a landscape orientation that is particularly useful for non-square panels, or the diagonal of the panel during imaging. It is possible to rotate over 45 degrees or some other angle to align with the elongated object. When it is possible to rotate the detector, it is useful for the control system to know the orientation of the panel. This allows the up and down and left and right decisions on the image. One way to determine the orientation of a detector is to measure the orientation of the detector and send this information to a control system. Or by using a sensor (not shown in the drawing). Once determined, this information can be used in a variety of ways. Orientation state information can be inserted into the DICOM header file on the coordinate system of the patient record or acquired image. This information can be printed on the image itself. This information can also be used to control the automatic collimation of the x-ray source to minimize radiation exposure to patient areas not imaged on the detector. This information can also be used to readjust the image to a standard display format. For example, if a hand image was taken with a horizontally aligned finger bone, but the radiologist wants to see the hand image with the fingers vertically aligned,
Software can determine from the orientation of the detector that it is necessary to rotate the image by 90 degrees before storing or displaying.

In a variant of the above, which does not require the measurement of the orientation of the detector, the image can be analyzed by computer and the orientation of the imaged body part is determined by the image processing means. It is possible. The image can then be rotated prior to storage or display to provide the body part in a standard orientation.

Determining the detector orientation relative to the x-ray source is useful for other reasons. The X-ray source has a non-uniform emission pattern. In particular,
The so-called heel effect changes energy and flux depending on the relative angle of the detector with respect to the anode. In film screen imaging, the anode is positioned relative to the body to minimize this effect, and the high power side of the x-ray tube is positioned above the thicker body parts where possible. To produce more uniform illumination on the film. In digital imaging, it is possible to correct this heel effect. In one embodiment of this, the orientation of the detector relative to the x-ray source is used to correct the acquired image for non-uniformities due to the heel effect. Heel effect non-uniformities can be calculated, measured in a previous calibration procedure, or estimated from the image using image processing means.

The use of an anti-scatter grid is another reason for measuring the orientation of the detector and anti-scatter grid relative to the x-ray source. Anti-scatter grids often consist of thin strips of radiopaque material, such as lead, separated by spacer material that is somewhat radiolucent. These grids often cover the detector with non-uniform absorption of incident radiation, causing non-uniformities in the image. This non-uniformity often has a geometrical orientation to it, and may be more pronounced along a given axis. The strength of this non-uniformity also depends on the SID. In the preferred embodiment of the system,
Correct the image to remove the effects of modulation non-uniformity. In one embodiment of this correction method, the system uses a sensor to determine the orientation of the grid relative to the detector. This information is used in conjunction with a model of the grid's behavior to estimate and remove the effect of the grid on the acquired image. A sensor or other means of measuring the SID is used to vary the strength of the non-uniformity correction. If the grid can be removed from the system, disable the cutoff correction of the grid if an anti-scatter grid is present and enable it if it is present. It is possible to use microswitches or other sensor means for this.

Another embodiment of the anti-scatter grid correction method involves another pre-calibration of the effect of the anti-scatter grid on image non-uniformity. These calibrations involve imaging the detector at the descatter grid at various orientation states and different SIDs and storing these calibration tables for use in a correction algorithm. Access to the appropriate calibration table depending on the presence and orientation of the scatter removal grid for the detector and depending on the orientation and distance of the x-ray source to the detector and grid assembly. And can be used to correct the image.

In another embodiment of the present invention, the sensor means not only determines the presence and orientation of the scatter proof grid, but also the type of grid installed. This is useful for the installation conditions used when different types of anti-scatter grids are used. This image correction method can correct the characteristics of the particular grid being used.

The sensor signal representing the presence or absence of an anti-scatter grid is used to alert the user or prevent x-ray exposure when the protocol identifies the use or non-use of the grid. It is also possible and the system determines that the actual grid state is inconsistent with the desired grid state.

Still another embodiment of this scattered ray removal grid correction method involves image processing means. Computer analysis of the image can be used to extract and correct for the slowly varying non-uniformities produced by the descatter grid. The heel effect can be analyzed and similarly corrected.

The anti-scatter grid and detector need not maintain the specified orientation with respect to each other. The grid may be preferentially rotated 90 degrees or other angles relative to the detector to allow independent alignment of the grid and detector. The system, as described in this patent specification, can tolerate this possibility. Sensors, encoders or switches can be used to measure these parameters, and the system can utilize this information for control and correction means.

Under certain imaging protocols, the detector and the X-ray source are tilted relative to each other so that the central axis of the X-ray source is not perpendicular to the detector surface. If the stack of descatter grids is not properly oriented with respect to the X-ray source, known imaging artifacts and severe grid cutoffs may occur in the acquired image. This can render the image unusable, and the patient is exposed to radiation without any positive purpose. The sensors and measuring means described above for determining the presence or absence of a scatter removal grid and the orientation of the grid relative to the X-ray source,
It can be used by a control system to determine if the detector is misaligned. In this case, interlocking means can be used to prevent X-ray exposure, or an alert can be provided to the operator.

In another preferred embodiment, it is possible to move the x-ray source to the correct orientation and SID relative to the detector depending on the protocol selected by the operator. The detector is manually moved to the desired position. The position and orientation of the detector is determined by the sensor or encoder means and then the motor and encoder means move the x-ray source to the corresponding correct position relative to the detector. In another embodiment, both the x-ray source and the detector are automatically moved under motor control to the correct position for the procedure previously selected by the operator. Sufficient collision avoidance and collision detection mechanisms provide safety for people and equipment. The position and orientation of the x-ray source and detector can be determined by any of a number of known encoder and sensor technologies. One particular sensor embodiment that is particularly attractive is, for example, Polhemus Corporation or Asce.
wireless RF or electromagnetic tracking and digitizing systems currently manufactured by N. Technology Technology Corporation can be used. These systems measure sensor position and orientation in six degrees of freedom.

Scatter removal grids are often used in radiation imaging to reduce the image degradation properties of scattered radiation on the image. Stationary scatter removal grids can produce the known moiré pattern artifacts, which is especially troublesome in digital detectors. Some embodiments of the system disclosed in this patent provide reduction or correction of moire patterns. One embodiment uses mechanical means to reciprocate or move the grid relative to the detector during exposure to blur the moire pattern. This requires synchronizing the movement of the grid with the exposure signal. Reciprocating the grid assembly can be expensive and can generate unwanted vibrations, so methods of reducing moire patterns without grid movement are particularly attractive. One embodiment for a stationary grid uses image processing means to remove the periodic pattern produced by the spatial frequency beats of the scatter removal grid at spatial frequencies of pixel size repetition. This algorithm can use the grid sensor previously described to determine the type of grid being used and its orientation relative to the detector.

Other embodiments reduce moire patterns through the selective design of anti-scatter grids. For example, moire patterns do not occur or are suppressed in systems where the detector pixel pitch has a period that is exactly 1: 1 (or an integer multiple thereof) with respect to the period of the scatter-removing grid pitch. It has been known. One difficulty in such a design is that it is necessary to manufacture the grid with very precise dimensions, or else the pattern will occur. The anti-scatter grid is composed of alternating stacks and spacers, and, for example, different batches of spacers or stacks may have slightly different dimensions. If the anti-scatter grid is manufactured with a period P that is slightly smaller than the detector pixel pitch D (D = P + ε, where ε is small compared to P), this grid will be small above the front of the detector. The moiré pattern phenomenon occurs when mounted at a distance, and the optimum distance depends on the relative size of the pixel period and the grid period. This reduction of the moire pattern is given by D = NP + ε, where N is an integer.
It also occurs for the period of the grid and the detector having the relationship of. In another preferred embodiment, the detector housing may allow mechanical mounting of the grid at a small but adjustable distance above the plate. Refer to FIG. 60, which is a schematic diagram illustrating this. During calibration of the system, the optimum distance is determined and the mounting mechanism is adjusted by shims or other means to position the grid at the correct distance from the plate. Such a system allows the grid to have a greater insensitivity to the manufacturing tolerance of the detector pixels.

FIG. 60 illustrates a focusing scattered radiation removing grid. In these grids, the diaphragm pitch is different on the detector plane relative to the object plane. For these grids, the relevant grid pitch that determines the moire pattern is the pitch of the grid diaphragm facing the detector.

The system embodiments are desired or useful in digital systems. One preferred embodiment includes the ability of the system to perform a low illumination preview image prior to the final full illumination image. In this procedure, the patient is positioned as desired and a low-radiation scout shot is used.
) Is done. The resulting images are displayed and analyzed by the operator for proper positioning of the patient, detector and x-ray tube. If the alignment is reasonable, a second full exposure image is taken.

In some procedures, the patient may support an image receptor, as with film. One example of this is standing chest image AP
In that case, the patient optionally puts his or her arm around the detector.
Often, the patient also partially supports the weight with the detector. To facilitate this, the preferred embodiment of the system includes a handle on the detector housing for grasping by the patient. If there are controls on the detector housing that can be touched by the patient, it is desirable to be able to disable these controls to prevent accidental touch by the patient. In the case of standing chest imaging, where the patient partially supports its weight on the detector, it is possible to provide sufficient damping resistance to prevent accidental detector movement. Is. On-bed imaging protocols can also benefit from the patient handle. One example is when the image is acquired while the patient is standing on the bed. In some of the proposed embodiments, there is a vertical column supporting the detector, and the patient handle on the column is useful for the reasons of patient support described above. There is. Another use of vertical posts may be as a support stand for a display screen, which is useful for use in operator control.

Another important design criterion for this system is to protect against accidental ingress of body fluids, blood or other fluids that may spill on the detector. The penetration of these liquids into sensitive electronics can be detrimental by the system and can provide a cleaning challenge. In one preferred embodiment, the detector housing is designed for easy cleaning, for example with a flat front. A seam for the detector housing opening can be provided at the rear of the housing away from the front surface.
The flat front surface is easily cleaned, and the seams mounted on the back side are less likely to introduce liquid into the detector. The seam can be further sealed with an O-ring to prevent liquids. Simple draping of the detector housing with plastic may not be desirable. Because it may interfere with the cooling fan required for the electronics. Practical designs for the detector housing should take into account the heat generated by the electronics associated with flat panel detectors. Analog-to-digital converters, amplifiers and other components often have undesired temperature coefficients, so flat panels are optimally maintained at a given temperature. Thus, in the preferred embodiment, the detector housing may have means for maintaining a stable temperature, or at least may prevent the temperature from exceeding a certain limit.

Another advantage of digital flat panels arises from the digital nature of the image.
In one preferred embodiment, automatically controlling a computer system maintains a log of system and operator performance. The system includes a history of each exposure and its associated parameters, such as exposure time, x-ray tube current and kV, source-
Detector and Source-Measure and store patient distance. The system also maintains a record of the image recapture and the type of imaging protocol being used.
This database can be used to evaluate system and operator performance. In another embodiment, the system implements automatic quality control and calibration. For safety reasons, the x-ray tube output needs to be routinely verified by a doctor in the hospital. This makes it possible to prevent dangerous irradiation of the patient by means of defective devices. In film systems, the operator finds that the film exposure is not optimal and thus provides a useful warning regarding x-ray dysfunction. Digital systems have a greater dynamic range and allow greater variation in the x-ray output before problems are noticed by image degradation. Therefore, a useful check of system performance is an algorithm that determines whether the recorded image matches the predicted image based on the x-ray tube voltage and current. This analysis can be performed on images taken in a special quality control procedure or on normal patient images. Feedback is given to the user when the system displays a potential problem. Another preferred embodiment for quality control is a system that uses a stored calibration file such as pixel gain and offset and an automated procedure to verify that the bad pixel map is correct. This can include a system for exposing and testing the uniformity of the flood field. These calibrations can proceed essentially without user intervention and can be performed automatically on a daily basis.
In another preferred embodiment, the system is remotely controllable and accessible, such as via a modem or network link, thus system debugging and maintenance can be provided by a service company. It is possible to provide a quicker service response with and without requiring a field service visit. In this system, remote users can access and analyze images and calibration files and control the system to perform automated tests.

In the present system, the operator controls the exposure time and voltage and determines the correct SID for the procedure by selecting the desired protocol from a list containing the most commonly implemented protocols. There are literally hundreds of possible protocols, and convenient methods of quickly accessing what is desired are useful. In the preferred embodiment, a set of collection protocols can be organized into a hierarchical folder array. This hierarchy is most conveniently organized by body parts, with each lower level containing a list of more and more specific body regions. For example, the fingertip AP Oblique protocol is accessed via the following folder section:

Lower Limb Toe AP Oblique: Information regarding this collection protocol is also available in the DICO of the patient record or image file.
It can be automatically inserted in the M header.

At present, digital images have a greater dynamic range than that of display devices, and the images are typically processed prior to display to optimize their performance. . The image contains an area of x-ray exposure that varies significantly from just unexposed areas directly below the attenuating body area to areas exposed to the x-ray beam directly with a very large exposure. Preferably, the system determines the location of the area of interest and adjusts and maps the image to one that optimizes the display of the area. In one preferred embodiment, the operator displays an approximate area of the desired area on the image for analysis and the display is optimized for exposure in that area. The system can take the form of a mouse-controlled cursor, which is used to click on or contour or otherwise define the area. In another preferred embodiment, the computer can use knowledge of the protocol in use and perform image analysis to locate the body part of interest and optimize the display of that part. For example, in AP chest images, the display may depend on the image protocol to optimize the display of lungs, spine or other organs. Preferably, information about the mapping transformation is stored, or otherwise both the original image and the remapped image are stored, thus restoring the image to the original if desired by the operator, or It is possible to remap with different parameters.

Yet another preferred embodiment relates to a convenient way for an operator to access a performed image of a patient. Normally, a simple text list of research questions is displayed on a computer screen, and the operator must read through that list to select the desired image for display or transfer or storage. In this preferred system, a thumbnail image of the research question is displayed next to the textual information. This gives the operator a visual key and makes it easy to select the correct file.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a digital flat panel detector in a vertical orientation with respect to a chest x-ray of a standing patient, for example, using a ceiling mounted x-ray source.

FIG. 2 is a similar schematic showing the detector in a lower position, such as for a patient's chest x-ray on a wheelchair, gurney, or some other support, or for imaging a standing patient's foot, etc. Fig.

FIG. 3 is a similar schematic diagram showing the detector in a horizontal orientation under the patient table.

FIG. 4 is a similar schematic diagram showing the detector at the same level and in a horizontal orientation next to the head or foot of the patient table, for example for imaging the limbs of the patient.

FIG. 5 is a similar schematic diagram showing the detector in a similar horizontal orientation next to one side of the patient table, eg, for imaging the patient's arm or hand.

FIG. 6 is a similar schematic diagram showing the detector in a horizontal position spaced from the table for imaging the patient's arm, for example, without the use of the table.

FIG. 7 is a similar schematic diagram showing the detector in a vertical orientation next to and parallel to one side of the patient table.

FIG. 8 is a similar schematic diagram showing the detector on one side of the patient table, but in a vertical orientation with an angle relative to the sides of the table.

FIG. 9 is a schematic diagram showing a detector used in an X-ray room having a ceiling mounted X-ray source and further showing an operator's console for processing the detector output and controlling the X-ray examination. ..

FIG. 10 is a schematic diagram illustrating another embodiment suitable for x-ray examination of a weight-bearing foot or other biological tissue.

FIG. 11 is a schematic diagram showing a lock detent used when positioning the detector, the detent being in a predetermined position during the detector movement period.

FIG. 12 is a schematic view showing the detent in the locked position.

FIG. 13 is a schematic view showing another embodiment.

FIG. 14 is a schematic view showing another embodiment.

FIG. 15 is a schematic view showing another embodiment.

FIG. 16 is a schematic view showing another embodiment.

FIG. 17 is a schematic view showing another embodiment.

FIG. 18 is a schematic view showing another embodiment.

FIG. 19 is a schematic view showing another embodiment.

FIG. 20 is a schematic view showing another embodiment.

FIG. 21 is a schematic view showing another embodiment.

FIG. 22 is a schematic view showing another embodiment.

FIG. 23 is a schematic view showing another embodiment.

FIG. 24 is a schematic view showing another embodiment.

FIG. 25 is a schematic view showing another embodiment.

FIG. 26 is a schematic view showing another embodiment.

FIG. 27 is a schematic view showing another embodiment.

FIG. 28 is a schematic view showing still another embodiment.

FIG. 29 is a schematic view showing still another embodiment.

FIG. 30 is a schematic view showing still another embodiment.

FIG. 31 is a schematic view showing still another embodiment.

FIG. 32 is a schematic view showing still another embodiment.

FIG. 33 is a schematic view showing still another embodiment.

FIG. 34 is a schematic view showing still another embodiment.

FIG. 35 is a schematic view showing still another embodiment.

FIG. 36 is a schematic view showing still another embodiment.

FIG. 37 is a schematic view showing still another embodiment.

FIG. 38 is a schematic view showing still another embodiment.

FIG. 39 is a schematic view showing another embodiment.

FIG. 40 is a schematic view showing another embodiment.

FIG. 41 is a schematic view showing another embodiment.

FIG. 42 is a schematic view showing another embodiment.

FIG. 43 is a schematic view showing another embodiment.

FIG. 44 is a schematic view showing another embodiment.

FIG. 45 is a schematic view showing another embodiment.

FIG. 46 is a schematic view showing still another embodiment.

FIG. 47 is a schematic view showing still another embodiment.

FIG. 48 is a schematic view showing still another embodiment.

FIG. 49 is a schematic view showing still another embodiment.

FIG. 50 is a schematic view showing still another embodiment.

FIG. 51 is a schematic view showing a further embodiment.

FIG. 52 is a schematic view showing a further embodiment.

FIG. 53 is a schematic view showing a further embodiment.

FIG. 54 is a schematic view showing another embodiment.

FIG. 55 is a schematic view showing another embodiment.

FIG. 55A is a schematic view showing another example.

FIG. 56 is a schematic view showing another embodiment.

FIG. 57 is a schematic view showing another embodiment.

FIG. 58 is a schematic view showing another embodiment.

FIG. 59 is a schematic view showing another embodiment.

FIG. 60 is a schematic diagram showing the relationship between the anti-scatter grid and the pixels of a flat panel digital X-ray detector.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) A61B 6/10 351 A61B 6/10 351 353 353 (81) Designated country EP (AT, BE, CH, CY, (DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), AU, CA, CN, JP, KR (72) Inventor Stain, JA. United States, Massachusetts 02116, Boston, Dartmouth Street 314 (72) Inventor Wilson, Kevin E. United States, Massachusetts 02139, Cambridge, Putnan Avenue 474, Apartment 2 Bee (72) Inventor Cabreil, Richard E. USA, Massachusetts 01876, Touksbury, Chandler Street 990 (72) Inventor Rossi, Remo USA, Massachusetts 01564, Sterling, Redemption Rock Trail 421 (72) Inventor Miller, James Dee. 21903, Perryville, Maryland, United States, Owen Landing 21-Sea F term (reference) 4C093 AA30 CA15 CA33 CA36 CA37 CA38 DA03 EA12 EB05 EB13 EB17 EC02 EC03 EC15 EC21 EC30 EC57 ED06 EE01 FA11 FA36 FA42 FA43 FB12 FD01

Claims (61)

[Claims] 1. A system for positioning a digital detector of x-rays for diagnostic protocols, comprising no mechanical connection to an x-ray source and having a digital flat panel x-ray detector arrangement and an antiscatter grid. A detector, a floor-supported pedestal, a pedestal-supported and pedestal-supported detector and for any one of a variety of standard diagnostic X-ray protocols. An articulated structure for selectively moving the detector in at least four degrees of freedom relative to the base to position the detector. 2. The system according to claim 1, wherein the articulated structure selectively moves the detector relative to the base in at least five degrees of freedom. 3. The patient table of claim 1, including a releasable coupling arrangement for selectively coupling the detector to the patient table with respect to at least one of the degrees of freedom of movement of the detector. System. 4. The system of claim 1, including a detent that limits at least some of the detector motion degrees of freedom to a suitable intermediate position. 5. The system of claim 4, wherein at least one of the detents has a step detent that biases the detector into a selected position. 6. The locking detent of claim 4, wherein at least one of the detents selectively locks the detector to prevent its movement relative to at least one of the degrees of freedom. The system that is. 7. The system of claim 1, including a motorized driver for moving the detector in at least one of the degrees of freedom. 8. The system of claim 1, including a collision avoidance system coupled to the support structure to prevent collisions involving the structure and detector. 9. The system of claim 8, wherein the collision avoidance system includes a collision sensor and a circuit that blocks motions in response to causing a collision. 10. The encoder of claim 1, wherein the encoder is coupled to the structure to provide digital information about its movement, and the encoder is coupled to and uses the information to receive digital information therefrom. And a system having a computer programmed to control the movement. 11. The method according to claim 10, further comprising a motor type driver for moving the detector in at least some of the degrees of freedom, wherein the computer controls at least the motor type driver. A system for using the digital information to position the detector at a selected position via. 12. The system of claim 1, wherein the degrees of freedom include rotation about two vertical and one horizontal axes. 13. The system of claim 11, wherein the degrees of freedom further include translation along a horizontal axis. 14. The system of claim 13, wherein the degrees of freedom further include translation along a vertical axis. 15. A system for positioning a digital detector of x-rays for diagnostic protocols using an x-ray source and optionally a patient table, wherein a digital flat panel x-ray detector arrangement and scatter is provided. A detector including a line removal grid; supporting the detector in at least two translational and two rotational movements for positioning the detector with respect to any one of a variety of standard diagnostic x-ray protocols And a floor mounted articulated structure for selective movement, the movement being selectively independent of movements of the X-ray source and the patient table. 16. The system of claim 15, wherein the articulated structure selectively moves the detector in at least two translational motions and three rotational motions. 17. The system according to claim 15, including a patient table and a releasable coupling arrangement for selectively coupling the detector to the patient table with respect to one of the translational movements. 18. The system of claim 15, comprising at least one detent that limits at least one of the movements of the detector to a selected position. 19. The system of claim 15, including a collision avoidance system coupled to the support structure to prevent collisions involving the structure and detector. 20. A digital flat panel x-ray detector in a digital flat panel detector system for a diagnostic x-ray procedure using an independently mounted x-ray source and optionally a patient table. Various standard diagnostics for standing, sitting and lying patients with selective movement of the detector along the length of the table independently of the x-ray source and patient table A support structure coupled to the detector for rotating the detector to position the detector with respect to any one of the X-ray protocols. 21. The main support according to claim 20, wherein the support structure extends along the length of the patient table, and the support structure is mounted on the main support to the length of the patient table. A lower slide moving along it, a lower arm having a proximal end mounted on said lower slide for rotation about the lower arm axis, An upwardly extending column mounted on the far end of the lower arm for rotation, and moving the lower slide along the main support and Rotating one or both of the lower arm and the post selectively moves the detector along and across the length of the patient table. 22. The upper slide body according to claim 21, wherein the support structure is further mounted on the column body to move along the column body, and for rotation about an upper arm axis. An upper arm having a proximal end mounted on the upper slide, and selectively moving the upper slide along the column and rotating the upper arm. And a system for moving the detector up and down and rotating the detector. 23. The system of claim 22, wherein the detector is mounted at the distal end of the upper arm for rotation about the detector axis across which the detector crosses the upper arm axis. 24. The system of claim 22, including at least a patient table that selectively moves up and down, and a coupling arrangement that selectively couples the vertical motion of the table to the vertical motion of the detector. 25. The system of claim 22 having releasable detents for locking the lower and upper arms and the post in a selected rotational position. 26. At least one of the detents according to claim 25.
At least one sector of the cogwheel and a sufficient force causes a relative rotation between the cogwheel and a cam to enter a valley between the teeth of the cogwheel but the force is present. Otherwise, it has a cam that remains in one trough and is biased against the cogwheel to maintain a selected relative position between the cogwheel and the cam. System. 27. The system of claim 25, including a lock that selectively and releasably locks the cam into a trough of a cogwheel. 28. The system of claim 22, including a collision avoidance circuit coupled to at least the detector to prevent collision with an object. 29. The system of claim 22, including at least one collision sensor to alert at least a probable collision between the detector and the object. 30. The cam of claim 29, wherein the cam is selectively and disengaged into one trough of a cogwheel in response to a subsequent warning of a probable crash associated with the crash sensor. A system having at least one collision avoidance circuit for preventing such a collision avoidance lock that locks the. 31. A system for positioning a digital detector of X-rays for diagnostic protocols, wherein the detector is a digital flat panel X-ray detector, for any one of a variety of standard diagnostic X-ray protocols. An articulated structure for selectively moving and supporting the detector in five degrees of freedom for positioning the detector, the detector being mechanically coupled to an x-ray source for movement therewith. And a system in which there is no mechanical coupling with the patient table due to movement therewith. 32. The system of claim 31, wherein the patient table has a base and a platform mounted thereon for up and down movement. 33. The system of claim 32, wherein the patient table has a platform mounted on the base for horizontal movement. 34. The system according to claim 33, wherein the patient table has a platform mounted on the base for tilting about a horizontal axis. 35. The system of claim 33, wherein the patient table has a platform mounted on the base for rotation about a vertical axis. 36. A system for positioning a digital detector of X-rays for diagnostic protocols, wherein the detector has no mechanical connection to an X-ray source, a main support, mounted on the main support. And along the length of the main support and across the main support to position the detector relative to any one of a variety of standard diagnostic x-ray protocols. An articulated structure that supports and selectively moves the detector in a rotational direction relative to one another and between different orientations. 37. The articulated structure of claim 36, wherein the articulated structure extends above the lower slide, the proximal end, mounted on the main support for movement along its length. A lower arm having a proximal end mounted on the lower slide for rotation about an axis, a lower arm of the lower arm for rotation about an axis extending above the tip. A post mounted on the tip end, one of the movement of the lower slide along the length of the main support and the upwardly extending axis or A system in which rotation about both moves the detector either or both along and across the length of the main support. 38. The articulated structure according to claim 37, further comprising: an upper slide body mounted on the column body for moving along the column body, and rotating about an upper slide body axis. An upper arm having a proximal end mounted on the upper slide body for moving the upper slide body along the column body and around the upper slide body axis. Rotation of the upper arm moves the detector up and down and about a first detector rotation axis. 39. The method of claim 3, wherein the upper arm comprises a tip end and the detector traverses the first detector axis and one face of the detector. Two detectors mounted on it for rotation about the detector axis. 40. A system for positioning an x-ray digital detector for a diagnostic protocol, wherein the digital flat panel x-ray detector, a low stepped platform for a patient to climb and step on a portion thereof, Part of the stepped platform for an X-ray image of a patient standing on it in a lower horizontal orientation and part of the platform for an X-ray image of a patient standing on it A detector support structure for supporting and selectively moving the detector in at least two degrees of freedom to selectively position the detector in a vertically oriented state along the detector. A system with no mechanical connection to the X-ray source used for imaging the patient. 41. The system of claim 40, wherein the degrees of freedom include rotation and translation of the detector. 42. The support structure of claim 40, wherein the support structure is between a horizontal position below the portion of the lower platform and a vertical orientation on the side of the portion and at least partially above. And a system for selectively moving the detector. 43. The system of claim 36, including support rails for supporting a patient riding on and standing on the low platform. 44. A variety of standard diagnostic x-rays for a standing, sitting or lying patient with an x-ray detector including a digital flat panel detector arrangement and an anti-scatter grid. Supports and optionally supports the detector in at least four degrees of freedom independent of any x-ray source and patient support for positioning the detector with respect to any one of the protocols. Using the articulated structure to move. 45. The method of claim 44, wherein the step of using the articulated structure comprises moving the detector in at least five degrees of freedom. 46. The method of claim 44, comprising locking the articulated structure selectively and releasably with respect to movement. 47. The method of claim 44, wherein the step of using the articulated structure to move the detector comprises motorizing the structure. 48. Positioning a digitally supported flat panel detector on the floor in any one of a number of standard X-ray protocols for standing, sitting and lying patients. In order to move the detector relative to an X-ray source mounted on the ceiling for moving the detector in at least five degrees of freedom relative to the X-ray source. How you are. 49. The method of claim 48, comprising locking the detector selectively and releasably with respect to movement. 50. The method of claim 48, wherein the moving step comprises motorizing the detector for motion in at least one of the degrees of freedom. 51. A digital flat panel X-ray detector cassette and a positioning arrangement for said cassette, comprising: a digital flat panel two-dimensional X-ray detector cassette (34), an upper arm (30) supporting said cassette, laterally. A first slide body (22) to which the upper arm is rotatably fixed for rotation about an extending axis; the slide body is fixed to move along the height of a column A column body (20) extending upward, a lower arm (16) to which the column body is fixed, and a lower arm rotatably fixed for rotation about an axis extending upward. A second slide (14), a main support (10) comprising laterally extending tracks along which the second slide moves, extending along the length of the track. Long A patient table (40) having a dimension and located at a higher level than the track, wherein the first slide and the second slide move linearly and the upper arm and The lower arm pivotally moves to position the cassette relative to the table in any one of a number of positions relative to the table, and to provide an AP image of a patient lying on the table. On the underside of the table in a horizontal or tilted orientation, on the side of the table in a vertical or tilted orientation with respect to an image of the side of the patient lying on the table, on the cassette and on the table. Supported on the cassette adjacent the head or foot of the table in a horizontal or tilted orientation for an image of the head or lower limbs of a lying patient. On the side of the table in a horizontal or tilted orientation for the image of the limbs, and in a vertical or tilted orientation for the standing patient's image and away from the table, and a support other than the table. A digital flat panel x-ray detector cassette including a horizontal or tilted orientation for a patient image on the body and spaced from the table, and a positioning arrangement for the cassette. 52. Digital flat panel X-ray detector cassette and positioning arrangement for said cassette, digital flat panel two-dimensional X-ray detector cassette (34), upper arm (30) supporting said cassette, said upper arm. Has a first slide (22) fixed for movement therewith.
), An upwardly extending post (20) to which the slide is fixed for movement along the length of the post, wherein the cassette or the post relative to the upper arm Relatively rotating about a horizontal axis via a rotating movement of at least one of the upper arms, the pillar being fixed and along each of two mutually transverse directions and the pillar. Lower support (16, 14 or 48) for selectively moving the column to the length of the body
, 52, 54, 58), a main support (10 or 44) supporting the lower support, and a digital flat panel X-ray detector cassette and a positioning arrangement for the cassette. 53. The pivotal arrangement (3) according to claim 52, wherein the pivotal arrangement (3) between the arm and the post provides for pivoting of the cassette between different orientations.
2) A cassette having and a positioning arrangement. 54. A telescopic support (52) according to claim 52, wherein said lower support extends to the side of said main support (46) and moves said column along a substantially horizontal axis. 48) having a cassette and positioning arrangement. 55. The cassette and positioning arrangement of claim 54 including mounting the telescopic support for pivotal movement about an upwardly extending axis. 56. A cassette according to claim 52, wherein said lower support comprises a plate (54) mounted for sliding movement on said main support along a first direction; Positioning arrangement. 57. The cassette and positioning arrangement of claim 55, wherein the cassette is mounted for relative movement with the main support along a second direction transverse to the first direction. 58. The mounting of claim 56, wherein the mounting of the cassette for movement along the second direction mounts the post for sliding movement over the plate along the second direction. A cassette including positioning and a positioning arrangement. 59. The patient table of claim 52, comprising a patient table having a width extending along one of the transverse directions and a length extending along the other, The length and width of the table for X-ray exposure, wherein the first slide body moves along the column body and the cassette rotates and the column bodies move along the transverse direction. A cassette and a positioning arrangement for positioning the cassette in selected horizontal and vertical positions relative to. 60. A method of using a digital flat panel X-ray detector cassette, wherein the digital flat panel X-ray detector cassette is fixed to an upper arm and the upper arm is moved up and down in the direction of a column extending upward. Fixed to a moving first slide, said cassette to said upper arm and said first slide to pivot said cassette between a vertical orientation and a horizontal orientation when fixing Pivotally securing at least one of the upper arms, the post relative to the patient table for selective movement along the length of the table and along its width. Supporting a body, thereby moving the cassette into a selected vertical alignment relative to the patient table, pivoting movement of the first slide body along the post and A height selected by one or more of the movements of the columns along the length and width of the patient table, a selected vertical alignment with the patient table and a selected angle. Moving the cassette to an oriented state thereby positioning the cassette in a selected position and locking the cassette in the selected position for X-ray exposure. 61. The method according to claim 51, wherein the column body expands and contracts to move the first sliding body upward or downward.