US20020003854A1 - Fluoro-assist feature for a diagnostic imaging device - Google Patents

Abstract

A frame (A) of a diagnostic imaging device such as a CT scanner or an MRI device has a bore defining a patient examination region (12). A first x-ray source (B) is mounted to a frame (C) for rotation around the examination region (12). An arc of first radiation detectors (14) detects x-rays which have traversed the examination region. A first image reconstruction processor (18) reconstructs a tomographic image representation from signals generated by the first radiation detectors. A fluoroscopy device (D) is mechanically coupled to the diagnostic scanner for generating and displaying at least substantially real-time fluoroscopic projection image representations on a display monitor (60). A second x-ray source (32) transmits x-rays to an amorphous silicon flat panel radiation detector (36). A second image reconstruction processor (58) reconstructs the fluoroscopic projection image representations from signals generated by the flat panel radiation detector (36). A C-arm (30) supports the second x-ray source (32) and the flat panel radiation detector (36) in a plane offset from a plane of the C-arm. A movable mounting structure (E) is mechanically connected with the gantry (A) and the C-arm (30) to move the C-arm between a stored position and an operating position adjacent the bore.

Description

BACKGROUND OF THE INVENTION
• The present invention relates to the medical diagnostic imaging arts. It finds particular application in conjunction with a diagnostic imaging device such as a computerized tomographic (CT) scanner and a Magetic Resonace Imaging (MRI) apparatus, which includes a fluoro-assist device, and will be described with particular reference thereto. However, it should be appreciated that the present invention may also find application in conjunction with other multi-modality medical imaging systems such as nuclear medicine scanners, etc. where a fluoro-assist device may be useful.[0001]
• When performing minimally invasive or certain interventional procedures such as abscess drainages, CT arterial portography, TIPS, and catheter placement for organ assessment, catheters are typically placed or positioned in a patient in a fluoroscopy room or suite. The patient, with the catheter in place, is then moved to a CT suite where the procedure is then performed.[0002]
• A number of disadvantages exist when moving a patient between a fluoroscopy suite and a CT suite. For instance, the danger exists that the catheter may move or shift within the patient during transport from the fluoroscopy suite to the CT suite. Further, the scheduling and availability of both suites can be complicated. In other cases, when a lesion is diagnosed during a CT procedure, the patient must then be rescheduled for a needle biopsy, or the biopsy is performed with the CT scanner alone, which is complicated and takes a long time to perform.[0003]
• It is known to use a mobile C-arm fluoroscopy device to provide fluoro images during interventional procedures performed in a CT suite. However, mobile C-arm fluoroscopy devices are not always available when needed. In addition, known C-arm fluoroscopy devices, including mobile C-arm fluoroscopy devices, use large, cylindrical image intensifier tubes which are difficult to maneuver and position adjacent a CT gantry.[0004]
• Further, the interventionalist must stand beside the image intensifier tube to access the patient during an interventional procedure, which may be an awkward position for the interventionalist and which also increases the radiation dose to the interventionalist. It is also known that image intensifier tubes tend to introduce image distortion due to the glass curvature and magnetic effects. Present mobile C-arms are big and bulky, and because of their size, they are difficult to store, and are typically in the way when not in use.[0005]
• It is known to use a CT system to provide a fluoro image for interventional work. However, using the CT system for fluoro imaging requires a physician to work on the patient in the bore of the CT gantry which is awkward for the physician, and which generates a significantly higher radiation dose to both the patient and the surgeon. Further, the CT system can only produce fluoro images which are in the same plane as the CT system.[0006]
• It is also known to rotate, pivot, or swing a common patient support between a CT scanner and an angiographic (i.e., fluoroscopic) unit. However, the patient is still moved when the patient support is rotated between the two pieces of diagnostic equipment. In addition, linking a separate CT scanner with an angiographic unit via a common, rotatable, patient support is an expensive alternate solution.[0007]
• Accordingly, it has been considered desirable to develop a new and improved fluoro assist feature for an imaging system which meets the above-stated needs and overcomes the foregoing difficulties and others while providing better and more advantageous results.[0008]
SUMMARY OF THE INVENTION
• In accordance with one aspect of the present invention, a diagnostic imaging apparatus is disclosed. The diagnostic imaging apparatus includes a frame defining an examination region. A diagnostic imaging subsystem generates first diagnostic image representations of an object when the object is positioned within the examination region. A patient support is adapted for movement through the examination region. A fluoroscopic imaging subsystem generates fluoroscopic image representations of the object. The fluoroscopic imaging subsystem includes an x-ray source for transmitting x-rays, a flat panel image receptor for detecting the x-rays and generating signals indicative of the detected x-rays, and a support member for supporting the flat panel image receptor in a stored position remote from the patient support and an operating position proximate the patient support.[0009]
• In accordance with another aspect of the present invention, a diagnostic imaging apparatus is disclosed. The diagnostic imaging apparatus includes a frame defining an examination region, a diagnostic imaging subsystem for generating a first diagnostic image representation of an object when the object is positioned within the examination region, and a patient support adapted for movement through the examination region. A fluoroscopic imaging subsystem is mechanically coupled to the frame, and includes a flat panel image receptor which detects x-rays and generates signals indicative of the detected x-rays.[0010]
• In accordance with yet another aspect of the present invention, a method of generating fluoroscopic projection image representations with a diagnostic imaging apparatus, is disclosed. The diagnostic imaging apparatus includes a frame defining an examination region, a first diagnostic imaging subsystem for generating diagnostic image representations of an object when the object is positioned within the examination region, and a patient support adapted for movement through the examination region. The method includes moving a flat panel image detector that is mechanically coupled to the frame from a stored position remote from the patient support to an operating position proximate the patient support, the radiation detector panel detecting x-rays generated by an x-ray source and generating signals indicative of the radiation detected, and reconstructing the fluoroscopic projection image representations from the signals generated by the radiation detector panel.[0011]
• In accordance with a further aspect of the present invention, a fluoroscopy imaging device which generates at least one of a fluoroscopic image representation and a radiographic image representation of an object is disclosed. The fluoroscopy imaging device includes a mobile cart, an x-ray source for transmitting x-rays, a flat panel image receptor for detecting the x-rays and generating signals indicative of the detected x-rays, and a support member secured to the mobile cart for supporting the x-ray source and the flat panel image receptor.[0012]
• One advantage of the present invention is the provision of a fluoro-assist device for a CT scanner which is readily available when needed.[0013]
• Another advantage of the present invention is the provision of a fluoro-assist device for a CT scanner which permits real-time imaging of minimally invasive tools (catheters, needles, etc.) that are inserted in a CT suite.[0014]
• Yet another advantage of the present invention is the provision of a fluoro-assist device for a CT scanner where a interventionalist can work behind a flat panel image receptor which acts as a primary barrier to radiation exposure.[0015]
• Still another advantage of the present invention is the provision of a fluoro-assist device for a CT scanner which incorporates a flat panel image detector.[0016]
• Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.[0017]
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention.[0018]
• FIG. 1 is a perspective view of an exemplary diagnostic imaging device such as a CT scanner or a Magnetic Resonance Imaging (MRI) apparatus having an integrated fluoro-assist device with a C-arm shown in an operating position;[0019]
• FIG. 2 is a perspective view of the CT scanner of FIG. 1 with the C-arm shown in a stored position adjacent the CT gantry;[0020]
• FIG. 3 is a perspective view of the C-arm of FIGS. 1 and 2;[0021]
• FIG. 4 is a perspective of the CT scanner of FIG. 1 showing a C-arm take-up/tension control system;[0022]
• FIG. 5 is a cross section view of the C-arm taken along the line[0023]5-5 of FIG. 3;
• FIG. 6 is a top plan view of an image detector housing mounted to the C-arm;[0024]
• FIG. 7 is a perspective view of a second embodiment of an integrated fluoro-assist device having a C-arm mounted to an overhead track;[0025]
• FIG. 8 is a perspective view of a CT scanner with the overhead C-arm of FIG. 7 positioned in front of the CT gantry;[0026]
• FIG. 9 is a perspective view of a CT scanner with the overhead C-arm of FIG. 7 positioned behind the CT gantry;[0027]
• FIG. 10 is a perspective view of a third embodiment of an integrated fluoro-assist device having an annular support ring mounted to an overhead track;[0028]
• FIG. 11 is a perspective view of a CT scanner with the annular support ring of FIG. 10 positioned within the CT bore from behind the gantry;[0029]
• FIG. 12 is a side elevation view of the integrated CT-fluoro-assist scanner of FIG. 1l;[0030]
• FIG. 13 is a perspective view of a CT scanner having separate fluoroscopic and CT x-ray sources mounted within the gantry and incorporating an integrated fluoro-assist device having an annular ring mounted to an overhead track for supporting a flat panel fluoroscopic detector within a bore of the CT scanner;[0031]
• FIG. 14 is a side elevation view of the integrated CT-fluoro-assist scanner of FIG. 13;[0032]
• FIG. 15 is a perspective view of a CT scanner having an integrated fluoroscopic/CT x-ray source mounted within the gantry and incorporating an integrated fluoro-assist device having an annular ring mounted to an overhead track for supporting a flat panel fluoroscopic detector within the bore of a CT scanner;[0033]
• FIG. 16 is a side elevation view of the integrated CT-fluoro-assist scanner of FIG. 15;[0034]
• FIG. 17 is a perspective view of a CT scanner incorporating a sixth embodiment of an integrated fluoro-assist device with a track-mounted support arm positioned for fluoroscopic imaging in a coronal plane;[0035]
• FIG. 18 is a perspective view of the CT scanner of FIG. 17 with the track-mounted support arm positioned for fluoroscopic imaging in a sagittal plane;[0036]
• FIG. 19 is a perspective view of a CT scanner incorporating a seventh embodiment of an integrated fluoro-assist device;[0037]
• FIG. 20 is a perspective view of an eighth embodiment of a fluoro-assist device; and[0038]
• FIG. 21 is a side elevation view of the Magnetic Resonance Imaging (MRI) apparatus of FIG. 1 with the C-arm shown in the operating position.[0039]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• With reference to FIGS. 1 and 2, an exemplary[0040]diagnostic imaging system2, such as aCT scanner4, includes a floor-mounted, non-rotating frame member or gantry A whose position remains fixed during data collection. An x-ray tube B is rotatably mounted on a rotating frame member or gantry C. The stationary gantry A includes acylinder10 that defines apatient examination region12. An array ofradiation detectors14 are disposed concentrically around the patient receiving region. In the illustrated embodiment, the x-ray detectors are mounted on the stationary gantry portion such that an arc segment of the detectors receives radiation from the x-ray tube B which has traversed theexamination region12. Alternatively, an arc segment of radiation detectors can be mounted to the rotating gantry to rotate with the x-ray tube. The x-ray tube B andradiation detectors14 comprise a diagnostic imaging subsystem of the diagnostic scanner.
• A[0041]control console16 contains animage reconstruction processor18 for reconstructing an image representation out of signals from thedetector array14. Preferably, the image reconstruction processor reconstructs a volumetric image representation from radiation attenuation data taken along a spiral path through the patient. A video monitor20 converts selectable portions of the reconstructed volumetric image representation into a two-dimensional human-readable display. Theconsole16 includes tape and disk recording devices for archiving image representations, and also includes circuitry for performing image enhancements, selecting planes, 3D renderings, or color enhancements, and the like. Various scanner control functions such as initiating a scan, selecting among different types of scans, calibrating the system, and the like, are also performed at thecontrol console16.
• The x-ray tube B includes an oil filled housing that has an x-ray permeable window directed toward the patient receiving region. An evacuated envelope is disposed within the housing and contains a rotating anode, such as a 7-inch anode, and a cathode or other electron source. High voltages, on the order of 150 kV applied between the rotating anode and the cathode, cause the generation of x-rays. The x-rays pass through the x-ray permeable window and across the[0042]patient receiving region12.
• [0043]Appropriate x-ray collimators22 focus the radiation into one or more planar beams which span theexamination region12, as is conventional in the art. Theconsole16 includes circuitry for gating the x-ray source B to control patient dosage. A high voltage power supply is mounted on the rotating gantry for rotation with the x-ray tube.
• A fixed patient table[0044]24 is positioned adjacent the diagnostic scanner so as to extend from theexamination region12 in a first direction substantially along a central axis of thecylinder10. Apatient beam26 is secured to an upper surface of the patient table24. Apatient couch28 is slidably secured to thepatient beam26 for back and forth movement through theexamination region12 along thebeam26. It should be appreciated that at least the patient couch can be configured to pan laterally relative to a longitudinal axis of the gantry bore. The table24,beam26, andcouch28, cooperate to define a patient support which is adapted for movement through the examination region.
• An integrated fluoroscopy or fluoro-assist device D is secured to the gantry A for movement between an operating position (FIG. 1) and a stored position (FIG. 2). The fluoro-assist device includes a support member that is movably secured to either side of the gantry A via a mounting structure E. In the embodiment being described, the support member is a C-[0045]arm30.
• A fluoroscopic x-ray source or[0046]tube32 is secured proximate a first end of the C-arm30 via a cantileveredsupport bracket34. Likewise, an opposingx-ray detector36 is secured proximate a second end of the C-arm30 via a cantileveredsupport bracket38. Anupper counterweight39aextends from the first end of the C-arm and alower counterweight39bextends from the second end of the C-arm. Thex-ray source32 anddetector36 cooperate to define a fluoroscopic imaging subsystem of the diagnostic scanner.
• In the embodiment being described, the mounting structure E includes a first link or[0047]support arm40 having one end pivotally secured to the gantry A and the other end pivotally secured to a second link orsupport arm42. A firstupright support arm44 is movably secured to thesecond arm42 for substantial horizontal movement along atrack46 associated with thesecond arm42. A secondupright support arm48 is movably secured to the firstupright support arm44 for substantial vertical movement along a common longitudinal axis of theupright support arms44,48. The C-arm30 is rotatably supported by a bearingassembly50 associated with the secondupright support arm48 which permits thex-ray source32 anddetector36 to rotate about a geometric center of the C-arm through an arc of at least 180°.
• The mounting structure E permits the C-arm to be conveniently stored or parked along the side of the gantry when not in use, and, when needed, to be positioned in front of the gantry with the[0048]x-ray source32 placed directly under the patient table. In particular, thefirst support arm40 pivots approximately 180° around the gantry when moving the C-arm between the stored position and the operating position. Further, thesecond support arm42 pivots approximately 90° around thefirst support arm40 when moving the C-arm between the stored position and the operating position. However, it should be appreciated that the C-arm can be mounted to any other part of the gantry.
• The bearing[0049]assembly50 permits the C-arm30, and thus thex-ray source32 anddetector36, to be rotated around a longitudinal axis of the patient from the “under table” position shown in FIG. 1, to a lateral position on either side of the patient table. This provides a ±90°, or any angle in-between, movement of thex-ray source32 anddetector36 from the “under table” position to provide lateral imaging from both sides of the patient.
• The C-[0050]arm30 moves vertically as the secondupright support arm48 telescopically extends and retracts vis-a-vis the firstupright support arm44 to permit easier access to the patient and to adjust image magnification. The C-arm also moves laterally across the patient with the first and secondupright support arms44,48 vis-a-vis thetrack46 to allow lateral image panning across a patient's body. Longitudinal image panning (i.e. along a patient's body) is accomplished by automatically or manually driving thepatient couch28 in either or both directions along therail26. It should be appreciated that the bearingassembly50 could permit the plane of the C-arm to rotate or tilt from an orientation normal to an axis of the patient support (e.g. to a position with thex-ray source32 over the patient table and thedetector36 under the patient table). Thus, an operating position of the flat panel image detector is broadly defined herein as any position or orientation (i.e. above, below, adjacent, etc.) of thedetector36 relative to the patient support without regard to the position of the detector relative to the gantry bore (i.e., within the bore or proximate the bore). The stored position of thedetector36 is defined as a position which is remote from at least one of the patient support and the gantry bore.
• Referring now to FIG. 3, the[0051]x-ray source32 and thedetector36, and more particularly acenterline51 of the imaging system, is offset a distance F from a plane of the C-arm by the cantileveredsupport brackets34,38. A fluoroscopic examination region is defined between the x-ray source and detector substantially along thecenterline51. By offsetting the x-ray source and detector offset from the C-arm, interference caused by the C-arm during interventional procedures is minimized.
• The[0052]centerline51 of the imaging system intersects with the orbit axis G of the C-arm. As a result, both the geometric center of the C-arm30 and theimaging system centerline51 are positioned at iso-center during a fluoroscopic imaging procedure. Theimaging system centerline51 rotates around, but does not shift laterally relative to, iso-center when the C-arm is orbited.
• In contrast, with known C-arm systems, the centerline of the imaging system is laterally offset from the orbit axis of the C-arm. During an imaging procedure, the centerline of the imaging system is positioned at iso-center and the orbit axis of the known C-arm is laterally offset from iso-center. When the known C-arm is rotated about its orbit axis, the imaging system centerline shifts off iso-center. Thus, in order to maintain the imaging system centerline at iso-center when a known C-arm system is orbited, the whole C-arm must be laterally repositioned in addition to being orbited.[0053]
• Referring now to FIGS. 4 and 5, a cable take-up/tension control system F for the C-[0054]arm30 is shown. It should be appreciated that the C-arm is shown with one or more protective covers removed. One or more data/power cables52 connect thex-ray source32 anddetector36 to a fluoro-image reconstruction computer54 andpower supply56 housed in acabinet58 which is mounted to the side of the gantry. Afirst hose anchor60 secures an intermediate portion of thecable52 to thecabinet58. Asecond hose anchor62 secures another intermediate portion of the cable to the upper end of the C-arm. Acable guide64 is positioned on or above the secondupright support arm48 proximate the bearingassembly50. The cable guide includes an aperture through which thecable52 slidably passes. The portion of thecable52 extending between thecable guide64 and thefirst anchor60 forms a variablelength service loop66. A portion of thecable52 extending between thecable guide64 and thesecond anchor62 rests at least partially within anopen channel68 defined within an exterior surface of the C-arm. When the C-arm is rotated in a clockwise direction from the upright position shown in FIG. 4, a portion of thecable52 resting within thechannel68 passes through thecable guide64 and is taken up by theservice loop66. Likewise, when the C-arm is rotated in a counter-clockwise direction, a portion of thecable52 defining theservice loop66 passes through thecable guide64 and is guided into thechannel68.
• A portion of the[0055]cable52 extending past thesecond anchor62 wraps around theupper counterweight39aand passes through one or moreclosed channels70 forming an inner portion of the C-arm30. A portion of thecable52 within the C-arm channels70 pass through thesupport arms34,38 to connect to thex-ray source32 anddetector36, respectively.
• Referring now to FIG. 6, the[0056]detector36 includes ahousing72 which supports a flat panel image receptor or array74 (shown in phantom) of individual image receptors. A “flat panel image receptor” as used herein includes a planar substrate such as glass laminated with an array of sensors such as amorphous silicon crystals that convert x-ray energy to electrical signals. That is, the sensors emit an electronic potential when struck by photons of x-ray energy. The intensity of the potential is related to the intensity of the x-ray beam. The electrical signals can be read out from a row/column matrix and then converted to digital data.
• In the embodiment being described, an amorphous silicon flat panel image receptor includes a Cesium Iodide scintillating layer on an amorphous silicon glass substrate. The scintillating layer converts x-ray energy into light. An array of photodiodes on the glass substrate convert the light into electrical signals. The electrical signals are readout of a row/column matrix that is accessed using thin film transistor switches on the amorphous silicon substrate. The analog data is then converted to a digital format.[0057]
• The amorphous silicon flat panel image receptor is compact in size and weight and replaces the conventional image intensifier tube, thus reducing the size of the[0058]detector36. The mechanical support (i.e. support arm38) for thedetector36 is also reduced in size and weight. Further, the flat panel image receptor74 provides a rectangular image, eliminates the distortion of an image common to conventional image intensifier tubes, and provides constant image quality across the flat panel of the image receptor, thus minimizing the amount of panning typically required with conventional image intensifier tubes. It should be appreciated that the flat panel image receptor can be of any dimension such as 20 cm×25 cm, and the system can be easily upgraded to incorporate larger flat panel image receptors. It is contemplated that a fluoro-assist device having a conventional image intensifier or alternate technology can be mechanically coupled to an imaging system in the same or similar manner as described above.
• The[0059]housing72 includes two handles integrally formed therein. Afirst control panel76ais mounted at one end of thehousing72 adjacent one handle, and asecond control panel76bis mounted on the opposite end of the housing adjacent the other handle. Depending upon the particular orientation of the C-arm, eithercontrol panel76a,76bcan be used to adjust the position (i.e. rotate) the C-arm, depending upon which control panel is most accessible to the operator.
• When the C-[0060]arm30, and thus thex-ray source32 anddetector36, is rotated to a lateral position on either side of the patient table, a physician performing an interventional procedure may position himself/herself behind the offsetdetector housing72 to prevent direct exposure to the x-ray beam generated by thesource32, and to reduce exposure due to scattered radiation. The flat panel image receptor74 may incorporate a lead shielding layer or other radiation absorbing material therein to minimize radiation exposure to the medical personnel. Alternatively, a lead shield may be incorporated into thehousing72.
• As described above, the flat panel image receptor[0061]74 within thehousing72 is coupled to the fluoro-image processing computer54 housed in thecabinet58 mounted to the side of the gantry. The fluoro-image processing computer54 processes the acquired image from thedetector36 and permits an operator to adjust window and level functions of the displayed image. The fluoro-image generated by the fluoro-image reconstruction computer is displayed on an adjustable monitor78 (FIGS. 1 and 2) connected to the gantry via alateral support arm80. Alternatively, themonitor78 can be suspended from the ceiling, or located on a cart. Themonitor78 can be either a flat panel monitor or a standard CRT monitor. In addition, the fluoro-image output could go directly to a filming device. The fluoro-image output could also go to the diagnostic system and be displayed with the volumetric images on thedisplay20.
• The fluoro-assist device D may be activated and deactivated with a foot pedal[0062]82 (FIG. 1) in a conventional manner. When activated, the fluoro exposure can be either continuous or pulsed. In the pulsed mode, radiography procedures can be performed, such as CINE, Spot Film and DSA, thereby generating radiographic image representations. Thex-ray source32 can be gated on and off in the pulsed mode using a conventional grid control circuitry or a pulse fluoro high-voltage power supply.
• Referring now to FIGS.[0063]7-9, the C-arm can be a stand-alone device which is mounted near the gantry and which provides the same functions described above. In particular, a C-arm90 is suspended from a ceiling via a mounting structure such as an overhead track system G includingfirst rails92, andtransverse rails94 which are movable along the first rails92. Atrolley96 is movably secured to thetransverse rails94 in directions transverse to therails92. Atelescopic support arm98 extends from thetrolley96. Acantilevered beam100 extends from thetelescopic arm98 to support the C-arm90. To reduce the torque applied to thebeam100, the C-arm is secured to an upwardlyangled end portion102 of thebeam100 which reduces the separation between the C-arm and thetelescopic arm98.
• A fluoroscopic x-ray source or[0064]tube104 is secured to an upper free end of the C-arm90, and an opposingx-ray detector106 is secured to the lower free end of the C-arm90. As stated above, thex-ray source104 can include a fixed or rotating anode x-ray tube with an integral or separate high voltage supply, and thedetector106 includes an amorphous silicon flat panel image receptor orarray108.
• As shown in FIG. 8, the overhead track system G is oriented above the diagnostic scanner so that the C-[0065]arm90 may be positioned in a stored position remote from the gantry, and positioned in an operating position between the patient table24 and the front of the gantry A. In particular, the C-arm90 may be positioned with thedetector106 substantially adjacent thepatient rail26 so that thepatient couch28 may be driven between thex-ray source104 and thedetector106. Alternatively, as shown in FIG. 5, the C-arm90 may be positioned in an operating position adjacent the rear of the gantry A so that thepatient couch28 must be driven through the bore of the gantry before passing between thex-ray source104 and thedetector106.
• Referring now to FIGS.[0066]10-12, a support member such as aring110 is suspended from a mounting structure such as an overhead track system H which includesparallel rails112 and atrolley114 movably secured to therails112. Asupport arm116 is suspended from thetrolley114. Thesupport ring110 is secured to a cantilevered lower portion of thesupport arm116. Thesupport ring110 defines a tapered, annular side wall having a first diameter at anend edge118, and a second diameter greater than the first diameter, at anopposing end edge120.
• A fluoroscopic x-ray source or[0067]tube122 is secured to an upper portion of thesupport ring110 adjacent theend edge120. Anangled support124 is secured to a lower portion of thesupport ring110 adjacent theend edge120. An amorphous siliconflat panel detector126 is secured to a planar surface of thesupport124 substantially beneath thex-ray source122.
• The overhead track system H is oriented above the diagnostic scanner so that the[0068]support ring110 can be positioned in a stored position remote from the gantry and in an operating position at least partially within the bore of the gantry A. In particular, the tapered annular sidewall defining thesupport ring110 conforms to the mutually tapered sidewall defining the bore of the gantry to facilitate accurately and repeatably positioning thex-ray source122 and thedetector126 relative to thepatient couch28 which is driven through the bore. Thus, with the support ring positioned in the bore, thepatient couch28 may be driven through the gantry and between thex-ray source122 and thedetector126 which are positioned immediately adjacent the rear of the gantry.
• Referring now to FIGS. 13 and 14, an[0069]alternate support ring130 is suspended from the previously described overhead track system H for movement between a stored position remote from the gantry and an operating position. Thesupport ring130 is secured to the cantilevered lower portion of thesupport arm116 which is suspended from thetrolley114. Thesupport ring130 has a diameter which substantially conforms to a diameter of an intermediate portion of a tapered sidewall defining thecylinder10 within the gantry A. A plurality oftabs132 extend radially from thesupport ring130. The tabs also extend at an angle from a plane of the support ring, which angle substantially defines the taper of the cylinder sidewall proximate the support ring, when positioned within thecylinder10. Thetabs132 facilitate accurately and repeatably positioning the support ring at a desired operating position within thecylinder10.
• A[0070]platform134 is secured to a lower portion of thesupport ring130 and extends transverse to thesupport ring130. An amorphous siliconflat panel detector136 is secured to an upper surface of theplatform134. A fluoroscopic x-ray source ortube138 is mounted to the rotating gantry portion C, and is angularly offset from the x-ray source B. The overhead track system G is oriented above the diagnostic scanner so that thesupport ring130 can be positioned within thecylinder10 from the rear of the gantry A so that thedetector136 is positioned substantially beneath thex-ray source138 within thepatient examination region12. When the support ring is fully positioned within thecylinder10, thetabs132 contact the tapered sidewall defining thecylinder10 to accurately and repeatably position thedetector136 relative to thex-ray source138 andpatient couch28.
• The diagnostic scanner incorporates an indexing means for driving or rotating the low[0071]power x-ray source138 to a predetermined position (e.g. a twelve o'clock position) substantially opposite to that of thedetector136 prior to initiating a fluoroscopic imaging procedure. It should be appreciated that thex-ray source138 may also be mounted to the non-rotating gantry portion A in a position either radially or axially offset from the x-ray source B mounted on the rotating gantry portion C. Alternatively, as shown in FIGS. 15 and 16, thesupport ring130 may be used in conjunction with the x-ray source B mounted in the rotating gantry portion C. The x-ray source is operated in a reduced power, fluoroscopic mode when positioned opposite to thefluoroscopic detector136.
• Referring now to FIGS. 11 and 18, a[0072]fluoroassist device150 for a diagnostic scanner includes an overhead track system, for example the track system as shown in FIGS.3-11, which supports amovable trolley152. Atelescopic support arm154 extends from thetrolley152. A lowermost free end of the support arm has a fluoroscopic x-ray source ortube assembly156 pivotally secured thereto. An L-shapedimage detector frame158 includes a first amorphous siliconflat panel detector160 mounted to a first leg of the frame, and includes a second amorphous siliconflat panel detector162 mounted to a second leg of the frame. Thefirst detector160 extends substantially transverse to thesecond detector162.
• The[0073]first detector160 is oriented horizontally between thepatient beam26 and thepatient couch28, while thesecond detector162 extends substantially upright from thepatient beam26 adjacent thepatient couch28. When fluoroscopic imaging in a coronal plane is desired, thetrolley152 andsupport arm154 are adjusted to position thex-ray source assembly156 substantially above thefirst detector160, as shown in FIG. 17. Likewise, when fluoroscopic imaging in a sagittal plane is desired, thetrolley152 andsupport arm154 are adjusted to position thex-ray source assembly156 laterally across from thesecond detector162, as shown in FIG. 18. Operator graspable handles164 assist in the accurate positioning and aiming of the x-ray source.
• The[0074]image detector frame158 can also be used in conjunction with two discrete fluoroscopic x-ray sources, as shown in FIG. 19. In particular, afirst x-ray source170 is fixedly mounted to the front of the gantry A substantially above the first,detector160. Likewise, asecond x-ray source172 is mounted, movably or fixedly, to the front of the gantry A substantially lateral from thesecond detector162. In one mode, thex-ray sources170,172 are used separately to generate fluoroscopic images in each of the coronal or sagittal planes. In another mode, thex-ray sources170,172 are used together to generate volumetric or 3D fluoroscopic images in a known manner.
• Referring to FIG. 20, the fluoroscopy or fluoro-assist device D, as described above with reference to FIGS.[0075]1-6, can also be mounted to amobile cart180. In addition, with reference to FIG. 21, the fluoroscopy or fluoro-assist device D can be mounted to anMRI device200. The MRI device includes aframe202 housing amain magnet204 for generating a temporally constant main magnetic field through anexamination region206. A series of gradient coils208 in conjunction with gradient amplifiers (not shown) generate gradient magnetic fields across the examination region. The gradient amplifiers generate current pulses which result in corresponding gradient magnetic field pulses along the x-, y-, and z-axis for phase encoding, and read out or frequency encoding. A radio frequency coil210 and a radio frequency transmitter (not shown) generate RF excitation pulses for exciting magnetic resonance and inversion or other pulses for manipulating the magnetic resonance.
• The patient table[0076]24 is positioned adjacent the MRI device so as to extend from theexamination region206 in a first direction substantially along a central axis of a bore defining theexamination region206. The fluoroscopy device D is secured to theframe200 by the mounting structure E for movement between an operating position as shown in FIG. 21, and a stored position. Alternatively, the fluoroscopy device can be suspended from the overhead track system G or H as described above.
• The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.[0077]
• For instance, although the fluoro-assist device of the present invention was described as providing fluoroscopic images, the fluoro-assist device could, with increased power of the x-ray source, provide radiographic exposures in addition to fluoroscopic exposures.[0078]
• Further, the fluoro-assist device D, which incorporates an amorphous silicon flat panel image receptor, may also be mechanically coupled to other medical diagnostic imaging systems such as a nuclear medicine scanner, etc. in the same manner as described above. Thus, the fluoro-assist device of the present invention can at least provide pilot scans for other diagnostic imaging procedures.[0079]

Claims (46)

Having thus described the preferred embodiments, the invention is now claimed to be:

1. A diagnostic imaging apparatus, comprising:

a frame defining an examination region;

a diagnostic imaging subsystem for generating first diagnostic image representations of an object when the object is positioned within the examination region;

a patient support adapted for movement through the examination region;

a fluoroscopic imaging subsystem for generating fluoroscopic image representations of the object, the fluoroscopic imaging subsystem including:

an x-ray source for transmitting x-rays;

a flat panel image receptor for detecting the x-rays and generating signals indicative of the detected x-rays; and

a support member for supporting the flat panel image receptor in a stored position remote from the patient support and an operating position proximate the patient support.

2. The diagnostic imaging apparatus ofclaim 1, wherein the flat panel image receptor includes a scintillating layer which coverts x-rays into light, and an amorphous silicon glass substrate supporting a plurality of photodiodes which convert the light generated by the scintillating layer into electrical signals.

3. The diagnostic imaging apparatus ofclaim 1, wherein the flat panel image receptor is offset from a plane of the support member by a first cantilevered arm, and the x-ray source is offset from the plane of the support member by a second cantilevered arm which secures the x-ray source to the support member.

4. The diagnostic imaging apparatus ofclaim 1, wherein the support member includes a C-arm.

5. The diagnostic imaging apparatus ofclaim 4, further including a mounting structure for permitting the C-arm to rotate through an arc of at least 180°.

6. The diagnostic imaging apparatus ofclaim 1, further including a mounting structure secured to the frame for supporting the support member in the stored position and the operating position.

7. The diagnostic imaging apparatus ofclaim 6, where in the mounting structure includes:

a support arm having a longitudinal track associated therewith;

a first upright support arm movably secured to the support arm for substantial horizontal movement along the track;

a second upright support arm movably secured to the first upright support arm for substantial vertical movement along a common longitudinal axis of the first and second upright support arms, the support member beign rotatably supported by the second upright support arm.

8. The diagnostic imaging apparatus ofclaim 1, wherein:

the frame includes a stationary frame member having a bore therethrough which defines the examination region, and a rotating frame member rotatably supported by the stationary frame member for rotation about the examination region; and

the diagnostic imaging subsystem includes a second x-ray source for transmitting x-rays through the examination region, an arc of radiation detectors for detecting x-rays which have traversed the examination region and for generating signals indicative of the radiation detected, and an image reconstruction processor for reconstructing an image representation from the signals generated by the arc of radiation detectors.

9. The diagnostic imaging apparatus ofclaim 1, wherein:

the support member includes a C-arm attached to a mounting structure that is mechanically secured to the frame;

the C-arm includes an open channel extending longitudinally along an exterior surface of the C-arm; and

the mounting structure includes a hose guide for directing a cable extending from the frame at least partially into the open channel when the C-arm is orbited in a first direction and for guiding the cable into a service loop from the open channel when the C-arm is orbited in a second direction.

10. The diagnostic imaging apparatus ofclaim 1, wherein the support member includes a C-arm mounted to a mobile cart.

11. The diagnostic imaging apparatus ofclaim 1, wherein:

the support member includes a C-arm; and

a centerline extending between the x-ray source and the flat panel image receptor intersects an orbital axis of the C-arm.

12. The diagnostic imaging apparatus ofclaim 1, wherein the flat panel image receptor is mounted in a housing having a first control panel proximate one end thereof and a second control panel proximate a second end thereof.

13. The diagnostic imaging apparatus ofclaim 1, wherein the diagnostic imaging subsystem includes a Computerized Tomographic (CT) scanner.

14. The diagnostic imaging apparatus ofclaim 1, wherein the diagnostic imaging subsystem is a Magnetic Resonance Imaging (MRI) system.

15. The diagnostic imaging apparatus ofclaim 1, wherein the support member includes a ring.

16. The diagnostic imaging apparatus ofclaim 15, wherein the ring includes at least one tab to facilitate positioning the ring in the operating position.

17. The diagnostic imaging apparatus ofclaim 1, wherein the fluoroscopy imaging subsystem operates in a radiographic mode to generate radiographic image representations.

18. A diagnostic imaging apparatus including a frame defining an examination region, a diagnostic imaging subsystem for generating a first diagnostic image representation of an object when the object is positioned within the examination region, and a patient support adapted for movement through the examination region, wherein the improvement comprises:

a fluoroscopic imaging subsystem mechanically coupled to the frame and including a flat panel image receptor which detects x-rays and generates signals indicative of the detected x-rays.

19. The diagnostic imaging apparatus ofclaim 18, wherein the flat panel image receptor includes a scintillating layer which coverts x-rays into light, and an amorphous silicon glass substrate supporting a plurality of photodiodes which convert the light generated by the scintillating layer into electrical signals.

20. The diagnostic imaging apparatus ofclaim 18, further including a C-arm for supporting the flat panel image receptor.

21. The diagnostic imaging apparatus ofclaim 20, wherein:

the flat panel image receptor is offset from a plane of the C-arm by a first cantilevered support arm which secures the flat panel image receptor to the C-arm; and

further including an x-ray source which is offset from the plane of the C-arm by a second cantilevered support arm which secures the x-ray source to the C-arm.

22. The diagnostic imaging apparatus ofclaim 21, wherein a centerline extending between the x-ray source and the flat panel image receptor passes through an orbital axis of the C-arm.

23. The diagnostic imaging apparatus ofclaim 20, further including a mounting structure for permitting the C-arm to rotate about a geometric center thereof through an arc of at least 180°.

24. The diagnostic imaging apparatus ofclaim 20, further including a mounting structure secured to the frame for supporting the C-arm in a stored position remote from the patient support and an operating position proximate the patient support.

25. The diagnostic imaging apparatus ofclaim 24, wherein the mounting structure includes:

a support arm having a longitudinal track associated therewith;

a first upright support arm movably secured to the support arm for substantial horizontal movement along the track;

a second upright support arm movably secured to the first upright support arm for substantial vertical movement along a common longitudinal axis of the first and second upright support arms, the C-arm being rotatably supported by the second upright support arm.

26. The diagnostic imaging apparatus ofclaim 18, wherein:

the frame includes a stationary frame member having a bore therethrough which defines the examination region, and a rotating frame member rotatably supported by the stationary frame member for rotation about the examination region; and

the diagnostic imaging subsystem includes an x-ray source for transmitting x-rays through the examination region, an arc of radiation detectors for detecting x-rays which have traversed the examination region and for generating signals indicative of the radiation detected, and an image reconstruction processor for reconstructing an image representation from the signals generated by the arc of radiation detectors.

27. The diagnostic imaging apparatus ofclaim 18, wherein:

the C-arm is mounted to a mounting structure that is mechanically secured to the stationary gantry;

the C-arm includes an open channel extending longitudinally along an exterior surface of the C-arm; and

the mounting structure includes a hose guide for directing a cable extending from the frame at least partially into the open channel when the C-arm is orbited in a first direction and for guiding the cable into a service loop from the open channel when the C-arm is orbited in a second direction.

28. The diagnostic imaging apparatus ofclaim 18, wherein the flat panel image receptor is mounted in a housing having a first control panel proximate one end thereof and a second control panel proximate a second end thereof.

29. The diagnostic imaging apparatus ofclaim 18, wherein the diagnostic imaging subsystem is a Computerized Tomographic (CT) scanner.

30. The diagnostic imaging apparatus ofclaim 18, wherein the diagnostic imaging subsystem is a Magnetic Resonance Imaging (MRI) system.

31. The diagnostic imaging apparatus ofclaim 18, wherein the support member includes a ring.

32. The diagnostic imaging apparatus ofclaim 31, wherein the ring includes at least one tab to facilitate positioning the ring in the operating position.

33. The diagnostic imaging apparatus ofclaim 18, wherein the fluoroscopy imaging subsystem operates in a radiographic mode to generate radiographic image representations.

34. A method of generating fluoroscopic projection image representations with a diagnostic imaging apparatus including a frame defining an examination region, a first diagnostic imaging subsystem for generating diagnostic image representations of an object when the object is positioned within the examination region, and a patient support adapted for movement through the examination region, the method comprising:

moving a flat panel image receptor that is mechanically coupled to the frame from a stored position remote from the patient support to an operating position proximate the patient support;

the flat panel image receptor detecting x-rays generated by an x-ray source and generating signals indicative of the radiation detected when positioned in the operating position; and

reconstructing the fluoroscopic projection image representations from the signals generated by the radiation detector panel.

35. The method ofclaim 34, further including:

displaying at least one of the fluoroscopic projection image representations and the diagnostic image representations on a display monitor.

36. The method ofclaim 34, wherein the moving step includes:

pivoting at least a portion of a mounting structure to move a C-arm supporting the flat panel image receptor from the stored position.

37. The method ofclaim 36, wherein the mounting structure includes:

a support arm having a longitudinal track associated therewith;

a first upright support arm movably secured to the support arm for substantial horizontal movement along the track;

a second upright support arm movably secured to the first upright support arm for substantial vertical movement along a common longitudinal axis of the first and second upright support arms, the C-arm being rotatably supported by the second upright support arm.

38. The method ofclaim 36, wherein the flat panel image receptor is offset from a plane of the C-arm by a cantilevered arm.

39. The method ofclaim 34, wherein the flat panel image receptor includes a scintillating layer which coverts x-rays into light, and an amorphous silicon glass substrate supporting a plurality of photodiodes which convert the Light generated by the scintillating layer into electrical signals.

40. A fluoroscopy imaging device which generates at least one of a fluoroscopic image representation and a radiographic image representation of an object, the fluoroscopy imaging device including:

a mobile cart;

an x-ray source for transmitting x-rays;

a flat panel image receptor for detecting the x-rays and generating signals indicative of the detected x-rays; and

a support member secured to the mobile cart for supporting the x-ray source and the flat panel image receptor.

41. The fluoroscopy imaging device ofclaim 40, wherein the flat panel image receptor includes a scintillating layer which coverts x-rays into light, and an amorphous silicon glass substrate supporting a plurality of photodiodes which convert the light generated by the scintillating layer into electrical signals.

42. The fluoroscopy imaging device ofclaim 40, wherein the flat panel image receptor is offset from a plane of the support member by a first cantilevered arm, and the x-ray source is offset from the plane of the support member by a second cantilevered arm which secures the x-ray source to the support member.

43. The fluoroscopy imaging device ofclaim 40, wherein the support member includes a C-arm.

44. The fluoroscopy imaging device ofclaim 43, wherein the C-arm is secured to the mobile cart by a mounting structure which permits the C-arm to rotate through an arc of at least 180°.

45. The fluoroscopy imaging device ofclaim 43, wherein a centerline extending between the x-ray source and the flat panel image receptor intersects an orbital axis of the C-arm.

46. The fluoroscopy imaging device ofclaim 40, wherein the flat panel image receptor is mounted in a housing having a first control panel proximate one end thereof and a second control panel proximate a second end thereof.

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