![Llllllllllllllllll||||||L|| United States Patent [191 [11] Patent Number: 5,762,608 Wame Et A]](http://data.docslib.org/img/c67e2595fe2bfde0612970b481e14b89-1.webp)
lllllllllllllll||l||||l||||@?llllllllllllllllll||||||l|| United States Patent [191 [11] Patent Number: 5,762,608 Wame et a]. [45] Date of Patent: *Jun. 9, 1998
[541 SCANNING X-RAY IMAGING SYSTEM 4,503,854 3/1985 Jako. WITH ROTATING C-ARM 4,515,165 5/1985 Carrol ...... 128/664 4,543,959 10/1985 Sepponen ...... 128/653 [75] Inventors: James R. Warne. Washington. Pa.; Alvin Karlolf. Framingham; Edward J. (List continued on next page.) Botz. Winchester. both of Mass; FOREIGN PATENT DOCUMENTS Michael D. Dabrowski. North Grosvenordale. Conn. 0 253 742 7/1987 European Pat. O?". . 0 265 302 9/1987 European Pat. 01f. . [73] Assignee: Hologic, Inc..Wa1tham. Mass. 2238706 2/1974 Germany . 24 12 161.7 3/1974 Germany . [*1 Notice: The portion of the term of this patent 86/07531 12/1986 WIPO . 88/08688 11/1988 WIPO . subsequent to Jan. 22. 2008. has been 90/10859 9/1990 WIPO . disclaimed. OTHER PUBLICATIONS [21] Appl. No.: 337,995 Rutt. B.K.. et al.. “High Speed. High-Precision Dual Photon [22] Filed: Nov. 10, 1994 Absorptiometry”. Reprint of pester exhibited at meeting at the American Society of Bone and Mineral Research. Jun. Related US. Application Data 16. 1985. Washington. DC. Pearce. R.B.. “DPA Gaining Strength in Bone Scanning [60] Continuation of Ser. No. 980,531, Nov. 23, 1992, aban doned, which is a division of Ser. No. 360,347, Jun. 5, 1989, Debate”. Diagnostic Imaging (Jun. 1986). Pat No. 5,165,410, which is a continuation-in-part of Ser. Norland Corporation advertising brochure for OsteoStatus No. 204,513, Jun. 9, 1988, abandoned, which is a continu ation-in-pan of Ser. No. 50,726, May 15, 1987, abandoned. System pp. 1-8. [51] Int Cl.6 ...... A6111 6/00 (List continued on next page.) [52] US. Cl...... 600/425; 378/55; 378/197 [58] Field of Search ...... 128/6531; 378154-55. Primary Examiner—-Ruth S. Smith 378/89. 119. 146. 193. 195-198; 600/425 Attorney, Agent, or Firm-Hamilton. Brook. Smith & Reynolds. RC. [56] References Cited [571 ABSTRACT U.S. PATENT DOCUMENTS A multidiagnosn'c rectilinear scanner for conducting non Re. 34,511 1/1994 O’Neill et a1...... 128/6531 invasive diagnostic procedures of bodily tissue. Both trans 3,803,417 4/1974 Kok ...... 250/447 mission and emission studies are performed on a single 3,944,830 3/1976 Dissing 250/358 scanner utilizing software modules for each kind of study. 3,988,585 10/1976 O’Neill et. a1. .. 250/363 Dual energy x-ray and radioactive sources are used to 4,012,636 3/1977 Engdahl et a1. . 250/363 4,107,532 8/1978 MaCovski 250/360 perform radiographic and absorptiometry transmission mea 4,144,457 3/1979 Albert . 250/445 surements. A system and method of identifying regions of 4,259,585 3/1981 Novak ...... 250/456 interest within tissue being scanned and recording the loca 4,275,305 6/1981 Racz et a1. 250/445 tion of those regions provides an additional diagnostic 4,342,916 8/1982 Iatteau et a]...... 378/4 capability. 4,358,856 11/1982 Steivender et a1. .. 378/167 4,365,343 12/1982 Grady et a1. 378/181 4,495,645 1/1985 Ohhashi ...... 382/6 25 Claims, 14 Drawing Sheets 5,762,608 Page 2
U.S. PATENT DOCUMENTS Saddler et al.. “Multimodality Imaging of the Thyroid and Parathyroid Glands”; J. Nuclear Medicine 28(1):122—129 4,590,378 5/1986 Platz ...... 250/363
4.618.133 10/1986 Siczek ...... 269/323 (Jan. 1987). 4.649.560 3/1987 Grady et a1. 378/196 “Magna Scanner”. Equipment Description. Sec. 1. pp. 4-6. 4.651.732 3/1987 Frederick 128/303 “Radioisotope Scanners. The Total Scanning system". Ohio 4,653.083 3/1987 Rossi ...... 378/196 4,657,755 4/1987 Christensen et a1...... 424/1.1 Nuclear. Inc. 4,6712% 6/1987 Matsuk ...... 128/660 Raytheon Series 600 Nuclear Scanner Instruction Manual. 4,716,581 12/1987 Barud ...... 378/198 4,829,549 5/1989 Vogel et a1. . 378/55 pp. 1-6 and 1-11. (Feb. 25. 1972). 4,856,044 8/1989 Tanguy et a1. .. . 378/55 “Model 1735 PHO/DOT Medical Scanner Operation 4,887,286 12/1989 Seidenberg ...... 378/170 Manual”. Nuclear Chicago. pp. 1-2 to 2-7. 4,907,252 3/1990 Aichinger et a1...... 378/99 4,922,915 5/1990 Arnold et a1...... 128/653 Endo et al.. “Patient Beam Positioning System Using CT 4,947,414 8/1990 Stein ...... 378/55 Images”. Physics in Medicine & Biology, 27 (1982). 5,042,486 8/1991 Pfeiler et a1...... 128/653
5,050,608 9/1991 Watanabe et a1...... 128/653 Tremolieres. La Medicine Nucleaire. Electronique Applica
5,119,817 6/1992 Allen ...... 128/653 tions. No. 20. pp. 71-83. (1981). 5,165,410 11/1992 Wame et a1. 128/653 Kule et al.. ‘Transmission Scanning: A Useful Adjunct to 5,261,404 11/1993 Mick et a1...... 128/653 Conventional Emission Scanning for Accurately Keying OTHER PUBLICATIONS Isotope Deposition to Radiographic Anatomy". Dept. Radi ology 0f the School of Medicine, pp. 278.284 (Aug. 1966). A New Dimension in Dual-Photon Absorptiometry Novo Introduces the BMC-Lab 23. Light Years Ahead. Genant. 11.. “Assesing Osteoporosis: CI‘ ‘s Quantitative Lunar Radiation Corporation’s Users Manual for Lunar DP3 Advantage”. Diagnostic Imaging, (Aug. 1985). Dual Photon Scanner. Robb et al.. “An Operator-interative. Computer-controlled Brochure. “Osteotek Bone Densitometry". Medical & Sci System For High Fidelity Digitization And Analysis Of enti?c Enterprises. Inc. Biomedical Images" Zie Voar Titel Boek, De 2e Pagina, pp. Sartoris. DJ. et al.. "Trabecular Bone Density in the Proxi 12-26. mal Femur: Quantitative CT Assessment”. Radiology 160:707-712 (1986). Bone Densitometry Market Research (1986). Mazess. R.B.. et al.. “Spine and Femur Density Using Wahner et a1. “Assessment of Bone Mineral. Part 1" .1. Dual-Photon Absorptiomelry in US White Women". Bone Nuclear Medicine. 25(10):1134—1141 (1984). and Mineral, 2:211-219 (1987). Weissberger. M.A.. et al.. “Computed Tomography Scan Mazess. “Dual photon Absorptiometry and Osteoporosis ning for the Measurement of Bone Mineral in the Human Absorptiometric Instrumentation" Meting Publication. Spine”. Journal of Computer Assisted Tomography, .lacobsen. Final Progress Report. “Development of Dichro 2:254-262 (Jul. 1978). mography Techniques”. pp. 1-2 and 15-18 (May 31. 1968). US. Patent Jun. 9, 1998 Sheet 1 of 14 5,762,608
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m'GZw\romwzm momoom >omwzm.330 > mozwommmoaqmmwEDPm ZOEQEmZQmPmmEDPm US. Patent Jun. 9, 1998 Sheet 4 of 14 5,762,608 319. THYROID Scan F’ sourcezTcggm,I—l23,I-l3l,TL-2OI \ Uptake BRAIN Source:Tc99m,I— I23 HEART Source:Tc99m,-TL-2Ol LIVER, SPLEEN Source: Tc99m,Sulfur Colloid m, LUNG S0urce:Tc99m-MAA , Fgcussed BQNE / Fracture‘ tress .5 Source:Tc99m-MDP T R EMISSION _ \ urnczrrliet;1 ate STUDIES THORASIC BMD Soon "* MANDIBULA JOINT Source:Tc99m— MDP __ KIDNEY STOMACH SourcezTC99m S PLE E N Sou rcezTc99m PAN CREAS Source: Tc99m,Se Compound GALL BLADDER, HEPTOBILIARY SourcerTc99m Compound US. Patent Jun. 9, 1998 Sheet 5 of 14 5,762,608 US. Patent Jun. 9, 1998 Sheet 6 of 14 5,762,608 US. Patent Jun. 9, 1998 Sheet 7 0f 14 5,762,608 Test 7 _ BMD = 2.90 9cm2 Scan Profile (TOTAL IMAGE) BMC 2.0- l.8-- 75 1.2 ' |.O" /77 0.8 " 0.6" 0.4- | l I 1 i I I n v 1 2O 4O 6O DISTANCE 549.9 test 7 REGION OF INTEREST # Region Regior) BMD H1 Width 1 0.88 8 6 <— Height 8 Lengih 6 Z9, 10 US. Patent Jun. 9, 1998 Sheet 9 of 14 5,762,608 l'—‘| TELESCOPING DETECTOR 4O \ 8O Em 45 /9O ‘ vIDEO MONITOR SCANNER 92 J PC/AT T v _ ELECTRONIC COMPUTER CONTROLLER + 82/ KEYBOARD I V \s4 vIDEO lMAGER ALARM PRINTER (FILM RECORDER) \96 \ 98 Sé £9. 13 US. Patent Jun. 9, 1998 Sheet 10 of 14 5,762,608 N6 U4 122 L__._.______.______J:______.__/____: 14 /// US. Patent Jun. 9, 1998 Sheet 11 of 14 5,762,608 F W "820257. "oEoZ 1 “$2238 $2235; “$252 Q95:B5;E2603E250EEoixvm203% __un: +5%,._+ _ ABXSLAMQEBm// @163925m 336E US. Patent Jun. 9, 1998 Sheet 12 of 14 5,762,608 4 ISO"\ PERFORM SCAN l I52 SAVE SCAN DATA 7 '54\ PROCESS/DISPLAY SCAN DATA 7 ADD MARKER |56’\ TO DISPLAY/ SET ~ SCANNER POSITION 1 MOVE MARKER/SCANNER ——> MARKERSET 7 LI60 '62 TERMINATE MARKING '64“ SAVE MARKERS l. 25,. I6 US. Patent Jun. 9, 1998 Sheet 13 0f 14 5,762,608 P4 174 '73 ‘ \X Z :44\/qg /:72 . V / US. Patent Jun. 9, 1998 Sheet 14 of 14 5,762,608 5 .762.608 1 2 SCANNING X-RAY IMAGING SYSTEM SUMMARY OF THE INVENTION WITH ROTATING C-ARM The present invention relates to the use of rectilinear RELATED U.S. APPLICHI‘ ION scanners for performing emission and transmission studies to provide diagnostic non-invasive measurements of body This application is a continuation of application Ser. No. tissue. 07/980531 ?led Nov. 23. 1992 now abandoned. which is a Divisional of Ser. No. 07/360347 ?led Jun. 5. 1989 (U.S. The apparatus utilizes a housing that can be easily adapted Pat. No. 5.165.410). which is a Continuation-in-Part of Ser. for the use of different radiation sources to conduct these No. 07/204513 ?led Jun. 9. 1988 now abandoned. which is diagnostic studies. For example. both a dual energy radio a Continuation-in-Part of Ser. No. 07/050,726 ?led May 15. active source. such as gadolinium~l53. or an x-ray generator 1987 now abandoned. can be placed in the housing of the scanner assembly. The radioactive source can be used for conducting transmission BACKGROUND studies. and the x-ray source can be used for conducting both The present invention relates to the ?elds of radiology and transmission and ?uorescence studies. The x-ray source. in nuclear medicine. and in particular to the use of rectilinear analogy with the dual photon energy source commonly used scanners for the performing of a number of diagnostic in bone densitometry. can use two energy levels to provide studies of bodily tissue and organs. an x-ray bone densitometer. Alternatively. the detector. collimator and software package can be replaced to permit The ?elds of radiology and nuclear medicine have long the performing of emission scintigraphy studies. A number been concerned with the development of techniques for the 20 of interchangeable collimators are used having dilferent non-invasive diagnosis of medical conditions of human or focal lengths. and sensitivity and which are designed to animal tissue. Generally procedures involve the use of x-ray operate for emitting isotopes with di?erent energy levels. radiation that is passed through a body to provide static or The wall thickness of the collimator columns is altered to dynamic transmission studies. or alternatively. the use of compensate for differing energy levels. radiopharmaceuticals that are introduced into the patient such that their distribution or concentration can be viewed 25 As described in U.S. patent application Ser. No. 050.726 by the detection of the resulting gamma ray emissions of ?led on May 15. 1987. a rectilinear scanner can be mounted variable intensity. on an assembly which permits the radiation source and detector to be rotated about a patient so that scanning can be Initially these systems used an analog rectilinear scanner conducted at any angle without having to move the patient. to generate static images wherein a scintillation-type gamma This permitted improved bone densitometry studies of ray detector equipped with a focusing collimator was moved patients su?ering from bone degeneration. The present continuously. through a series of parallel sweeps. to scan the application discloses the use of this multidirectional capa region under study. bility for a number of other diagnostic studies for which Rectilinear scanners have more recently been used with a digital rectilinear scanners have not been used. dual energy radioactive source for conducting transmission 35 bone densitometry studies. Early analog devices have been These studies are used to generate images of speci?c bodily tissue and organs as well as provide quantitative used for conducting emission studies with an injected iso information regarding the volume of organs. tissue density. tope as referenced above. In either case rectilinear scanners bone turnover rate. and organ studies such as thyroid uptake. have seen very limited use due to the development of so-called “gamma camera” systems developed in the last Each study performed by the scanner is controlled by a decade. software package designed for that study. Because of the interest in performing dynamic studies The present invention also incorporates the use of a laser. such as myocardial perfusion. wall motion. lung perfusion or other light source or some mechanical means for identi and lung ventilation. systems were developed to view the fying a speci?c portion of tissue being scanned. The user can record a position of particular interest relative to the scan entire region of interest. These “gamma camera" systems 45 utilized a large diameter sodium iodide crystal in conjunc being conducted using the laser. The software can then tion with a matrix of photomultiplier tubes and a multi analyze detected characteristics of the tissue for the identi channel collimator to perform a large variety of emission ?ed region of interest. studies. The problem with gamma cameras using scintilla The scanner assembly also incorporates sensors that tion detector crystals is that the resolution is limited by both detect any obstruction to the movement of the detector the light coupler between the detector and the photomulti during scanning. or during rotation of the scanner assembly. plier and. more importantly. by the scattering of the radiation These sensors either deactivate the motor drive thereby emitted from the in vivo region of investigation. Even if the stopping any further motion. or they actuate an alarm to resolution of gamma cameras were adequate they do not inform the operator of some obstruction. This reduces the produce an image of the tissue of actual size. Gamma 55 risk of injury to the patient or damage to the system during camera systems are also extremely expensive. require a large operation. space to be used. and necessitate a relatively high level of A separate table is used to support the patient so that any operator training. In addition. the use of gamma cameras for region of the body can be positioned within the scanning performing static studies has tended to lower their cost area of the device. One embodiment utilizes a detector that effectiveness due to there use on these low revenue static is rotatable to permit emission studies to be performed on a studies. person in a sitting or supine position. As a result of these factors. there is a need for a relatively Emission studies utilize a zoom capability of the detector inexpensive. portable and easy to use rectilinear scanner that to obtain images of different focal planes within the tissue can be used for diagnostic applications requiring the gen being imaged. eration of static images. This will operate to free the gamma 65 The above and other features of the invention including camera systems for performing the high revenue dynamic various novel details of construction and combinations of studies for which they are intended. parts will now be more particularly described with reference 5 .762.608 3 4 to the accompanying drawings and pointed out in the claims. planar directional scanning of patients for only one type of It will be understood that the particular multidiagnostic study. i.e. either emission with a radionuclide or transmis rectilinear scanner systems embodying the invention are sion with a dual energy radioactive source. The following discloses the ?rst multi-diagnostic rectilinear scanner that shown by way of illustration only and not as a limitation of can conduct a variety of scans on one portable system. the invention. The principles and features of this invention Dual photon absorptiometry with the scanners described may be employed in varied and numerous embodiments herein has the capability to both quantitate and image all without departing from the scope of the invention. kinds of bodily tissue. not just bone density as described in BRIEF DESCRIPTION OF THE DRAWINGS the parent application referenced above. The present appli cation describes the many different diagnostic tools for FIG. 1 is a perspective view of a preferred embodiment of which absorptiometry from a dual energy radioactive source the present invention. can be utilized. FIG. 2 is a cross-sectional view of the radiation source The rectilinear scanner is also easily adapted to perform and detector of FIG. 1 for scanning in the anterior position. emission studies as well as the use of an x-ray source and FIG. 3 is a cross-sectional view of the apparatus of FIG. detector to perform both transmission and ?uorescence 1 rotated to the lateral position. radiography studies. FIG. 4 is a top sectional view of the drawer assembly. A rectilinear scanner used in a number of diagnostic FIGS. 5a and 5b schematically illustrate a number of applications is illustrated generally in FIG. 1. A table 10 on diagnostic scans that can be conducted with the rectilinear which the patient lies has a drawer assembly 11 which is pulled out from under the table on the side from which a scanner of the present invention. 20 FIG. 6 is a perspective view of a preferred embodiment of bracket 12 protrudes. The bracket 12 extends in a “C” shape the invention having a single axis of rotation along with a from the drawer assembly 11 to a detecting apparatus 13. separate table used in conjunction therewith. FIG. 2 shows. in a cross-sectional view. the relationship between the detector apparatus 13 and the contents of the FIG. 7 is a side view of the embodiment of FIG. 6 drawer assembly 11. illustrating the rotation of the detector to enable the per 25 forming of emission studies on a sitting patient. Aradiation source 14 is mounted on a moveable platform 15. The source 14 is rigidly aligned with the detector FIG. 8 is a side view of the scanner assembly of FIG. 6 apparatus 13 by bracket 12 to insure that radiation emitted that has been rotated to perform a study at an oblique angle. from the source is received by the detector regardless of the FIG. 9 is an illustration of an image generated from a angle to which the source-detector axis is rotated. The thyroid uptake procedure and a graphical representation of a source 14 may be either a dual energy radioactive source or measured characteristic of the tissue. a dual energy x-ray source depending upon the type of study FIG. 10 is another illustration of an image generated being conducted. The entire rotatable apparatus is mounted wherein a particular region of interest has been selected and on a tray assembly 17. The tray 17 is rotatably mounted onto a characteristic thereof listed in tabulated form. 35 the assembly plates 19. The plates 19 in one embodiment FIG. 11 is an illustration of an image generated from a constitute the side walls of a drawer which compactly bone densitometry study along with a graphical illustration houses the source and scanning apparatus. of the quanti?ed cumulative density. To rotate the apparatus from the anterior position shown FIG. 12 illustrates an image similar to that shown in FIG. in FIG. 2 to the lateral position shown in FIG. 3. the 11 along with a graphical depiction comparing the results of 40 following steps must be taken. The user releases a locking the scan to a norm. mechanism and pulls the arm horizontally to one side of the FIG. 13 is a schematic diagram illustrating the control table so that the tray 17 and plates 19 slide the source from system for the embodiment of FIG. 6. under the center of the table to avoid contact with the table FIG. 14 is a partially sectioned view of the detector during rotation. In one embodiment of the invention the assembly and the collirnators used in conjunction with the source is approximately one inch below the table during performing of transmission and emission studies. anterior scanning and thus cannot be rotated without lateral FIG. 14A is a partial cut away top view of the focusing movement. Source proximity to the table is desirable. as the collimator shown in FIG. 14. source and detector are preferably as close to one another as FIG. 15 illustrates the imaging employed for marking and possible to yield the best possible image. The drawer assem recording points of interest. 50 bly plates 19 telescope out along the glides 20 until the pivot FIG. 16 illustrates a processing sequence used in marking point 18 is astride the table 10. The plates 19 are then locked the points of interest. in position by a locking mechanism (not shown). The arm 12 and the attached source and tray assembly 17 are rotated FIG. 17 is a cross-sectional view of another preferred manually by the user about the axis 18 to the desired embodiment of a collimator used for performing simulta position. Note that the pivot axis location must be chosen so neous emission and transmission studies. 55 that the source and scanning apparatus are rotated into a FIG. 18 is a schematic perspective view illustrating a position just above the plane of the table. This insures that preferred embodiment utilizing a fan beam and a linear array objects positioned on the table can be fully scanned laterally. of detectors used to perform linear scans. The pivot location also a?ects the adjustment of the center FIG. 19 is a schematic perspective view of another of gravity as discussed below. In an alternative embodiment preferred embodiment utilizing a two dimensional array of of the invention. the lateral movement of the drawer assem detectors to perform studies at di?erent angles relative to the bly and/or the rotation may be automatically controlled by object being scanned. adding the necessary motor and control systems. Such an DETAILED DESCRIPTION OF THE embodiment is described below with reference to FIGS. 6-8 INVENTION 65 where there is a stationary axis of rotation. Existing rectilinear scanner assemblies used for the in FIGS. 2 and 3 also illustrate the presence of weights 21 vivo diagnosis of bodily tissue generally permit only uni and 24. After initial assembly of the apparatus. the center of 5,762,608 5 6 gravity of the rotating elements must be adjusted to assure diagnosing the glandular disorder of hyper-or hyothyroid ease of manual rotation. In a preferred embodiment of the ism. The thyroid scan and uptake test typically uses a thyroid invention. the center of gravity of the rotating elements is scan and an orally administered dose of a radioiodine. The located along the pivot axis 18. When the center of gravity iodine is actively trapped and organi?ed in the thyroid gland. is so situated the rotating elements will not accelerate under The amount of the radioiodine appearing in the thyroid their own weight when the bracket 12 is rotated to any gland at 12-24 hours after administration is an index of the chosen angle. stopped and released. rate of thyroid hormone production. FIG. 4 shows a top view of the drawer assembly 11 and The system can further be used for the detection of stress illustrates the location of the pivot axis 18. the glides 20 for fractures that are currently detected on gamma camera displacement of the plates 19. and the tracks 26 on which the 10 systems. By injecting technetium —99 m labelled methylene platform 15 rides. The platform 15. as well as the attached diphosphate (MDP). stress fractures located within a skel source 14. bracket 12. and detector apparatus 13. are moved eton can be detected and a static image generated. The in a plane perpendicular to the source-detector axis. The higher resolution of digital rectilinear scanners is particu driving mechanism for the scanning motion is a so-called larly important for this measurement. The system utilizes a “x-y” table 16. The scanning mechanism is comprised of zoom imaging feature for the close examination of the area threaded bars. one running along the longitudinal or “y” axis under study. Other emission studies including those for the 26 of the table. the second 25 running perpendicular to the brain. heart. liver. lung. kidney. stomach. spleen. pancreas ?rst across the width or “x” axis of the table. The platform and gallbladder are all depicted in FIG. 5b. The types of 15 has threaded housings which receive. and are driven by. radioisotopes typically used for these studies are also indi the two threaded bars. The threaded “x” bar 26 is rotated by 20 cated. the motor 22. When the scanning assembly is rotated along Another preferred embodiment of the invention is with the source and detector. this insures full scanning depicted in the perspective view of FIG. 6. This system has capability at any angle. In a preferred embodiment of the a single axis of rotation 30 where the scanner cradle 32 invention. the scanning mechanism is controlled automati rotates in the direction indicated to perform non-anterior 25 cally by feeding the scanning rate and the size of the area to scans. be scanned into a computer. which then triggers the radiation The patient is placed on a separate moveable table 50 source and coordinates the desired scan. The data received by the detector can be processed. stored. or used to provide having wheels 52 to permit easy positioning of the area to be images of the tissue under study. scanned relative to the source detector axis. Alternatively. as 30 shown in FIG. 7. the scanner can rotate about axis 30. and During initial rotation of the system from the vertical the detector mount 39 can be rotated at pivot point 54. to position. the Weight of the tray assembly 17 and enclosed permit emission studies to be performed on a patient in the elements controls the balancing of the bracket 12 and the sitting position. attached components. The weights 24 are added to the front The table 50 also has two rectangular notches 51 along wall of the saddle to adjust the center of gravity in the horizontal plane. The weight 21 is added to the detector 35 one side. Each notch or recess 51 is dimensioned to permit the scanner cradle 32 to be inserted into the notch when the system to adjust the center of gravity in the vertical plane. cradle 32 is partially or totally rotated. This permits the easy As the system is rotated through larger angles from the positioning of the area to be scanned. particularly during vertical (e.g. 45°-90°). the correct weighting of the bracket scans at oblique angles. FIG. 8 illustrates the nestling of the and detector by weight 21 becomes more important to cradle 32 into either recess 51. maintain ease of manual rotation. The scanner cradle 32 is supported by a base 34 mounted By rotating the detector arm. scanning of the lumbar spine on wheels 36. The cradle 32 contains an x-y table similar to in both the anterior and lateral projections is now possible that shown in FIG. 4. The cradle 32 also contains a dual without repositioning the patient The patient remaining in enagy radioactive or x-ray source. depending upon the type the supine position for both the lateral and anterior-posterior 45 of study being conducted. For emission studies a shutter projection maintains the correct alignment of both exposing the source is automatically closed. Fluorescence projections. permits direct correlation of the two studies. and anatomically is diagnostically correct. studies are also conducted wherein a dye introduced into the tissue of intmest. or the tissue itself. is made to fluoresce Performing the lateral image as the ?rst study may enable upon the suitable irradiation of the tissue. The software the physician to observe extra-osseous calci?cation in tissue system can be programmed to open the shutter only while overlaying the lumbar spine. In the anterior-posterior transmission and ?uorescence studies are being conducted. projections. such extra-osseous calci?cation cannot be dis The adjustable detector 40 mounted at the end 39 of the tinguished from bone. and could therefore interfere with arm 38 is ?tted with a light source 46 such as a laser operated accurate bone density measurements in that projection. The by switch 42 which generates a beam 44. The laser 46 or bone being studied may be examined in real time by 55 some other mechanical indicator permits the operator to amplifying the signal output from the detector and display locate the point under study at any time before. during or ing the black and White or colored image on a screen or after the study. This is particularly useful for the physician printing the image on film using as many as 64 shades of who wishes to examine a particular portion of tissue. By gray to obtain a highly detailed image. centering the light source over the portion of interest. the FIG. 5a illustrates the types of transmission and ?uores operator can then record the location by momentarily actu cence studies that can be performed using the scanner. The ating the switch 42. The system software will then record system can further be used for performing traditional thyroid that point relative to the entire scan that has been. or will be scans which are useful in the diagnosis of a number of taken. The indicator can be used in conjunction with both thyroid conditions. As shown in FIG. 5B. numerous emis transmission or emission studies. The operator can easily sion studies can be performed on the present system includ 65 maneuver the arm 38 by directional switches 43. Switches ing the performing of thyroid uptake tests that are normally 45 operate to lower or raise the detector 40 in telescoping performed on a so-called “uptake unit.” This test is used for fashion. 5 ,762.608 7 8 Alternatively. an image of the area under study can be detector assembly during the positioning or scanning generated on a monitor and points or regions of interest may thereof. or due to the rotation of the scanner cradle 32. The end 41 of the detector that receives radiation from the source be identi?ed which may not be palpably or visually detect is ?tted with a spring mounted cone 80. If there is some able. The software is then used to “label” or “mar “ this obstruction of the receiving end 41 of the detector the cone region or a number of such regions on the screen. On 80 is displaced relative to the receiving end 41 causing the command. the software can direct the detector to move over actuation of an electrical circuit within the controller 82 the precise point of the anatomy which has been identi?ed resulting in the shutdown of the motor drive within the on the monitor. cradle 32. A laser beam can now be used to illuminate the point The upper surface 45 of the cradle 32 is spring mounted identi?ed on the monitor and the user can mark the point on such that if the cradle 32 encounters some obstruction during the patient’s skin with a dye marker. FIG. 15 shows an image rotation. such as the table 50. the surface 45 is displaced in which a marker has been set and listed as a recorded causing the actuation of a second alarm circuit 56. The marker. A blinking marker designates the current location of circuit 56 will trigger an audible alarm to notify the operator the laser. The image on the screen can also be printed on ?lm and can optionally result in the shutdown of the drive motor with the point marked by the laser appearing as a white that rotates the cradle 32. crosshair. thereby identifying the precise anatomical loca The rotating scanner assembly on the PolyScan diagnostic tion. system includes the scan drive table and a lead-shielded If the physician seeks to scan an area he believes to be detector tube weighing about 100 pounds. It may be rotated abnormal. he ?rst identi?es the area by palpating the tissue from —30 deg to +90 deg to perform scans at different angles. with his ?ngers and marking the point either by the laser. or The rotation mechanism includes heavy duty gears driven ?rst with a pen or dye and then recording the point with the from an electric motor through a reinforced rubber belt with laser. An x-ray image can then be produced. for example. teeth. referred to as a timing belt. Due to the weight of the with a white crosshair marking the point of interest on the rotating assembly a simple mechanism has been incorpo rated that senses loss of tension in the belt in the event of belt screen or the ?lm. 25 The software for the laser marking system can have the failure and locks to prevent further rotation. processing sequence illustrated in FIG. 16. In this sequence The system consists of two spring loaded pawls that a scan 150 has been performed. the data stored 152 and then engage and stop the main gear from turning in case of a processed and displayed 154. Amarker can then be added to failure of the belt. The tension of the belt in normal operation holds the pawls away from the gear unless the belt breaks. the displayed image 156 and the marker is moved 158 to the 30 proper position over the point or region of interest. The Strong springs will drive the pawls into the teeth of the gear position is then marked 160 and further markers can then be if the belt tension is lost. stopping all gear motion almost added and recorded until the process is terminated 162 and instantly. one or more markers are permanently stored 164. A schematic diagram of the system is shown in FIG. 13 showing the relationship between the control circuitry 82. FIG. 9 illustrates the results of such a scan for a thyroid 35 uptake. If a physician were to feel a particular nodule as a the cone 80. the surface 45 of cradle 32 and the alarm 56. result of a physical examination of the thyroid. the nodule The controller 82 is interfaced with a computer 92 which could be identi?ed using the laser 46. The scan results could processes the information generated by the detector 40 and then establish whether a “hot spot” 60 of the scan corre generates an image on the monitor 90. a color print on sponds to the nodule formerly “labelled" by the laser. A printer 96. or a ?lm on the ?lm recorder/video imager 98. horizontal slice 70 is selected across the image of the FIG. 14 illustrates the detector 40 along with two types of thyroid. The number of counts for the slice is then graphi collimators used in conjunction therewith. The detector 40 cally displayed as a function of position. The hot spot 72 on has a sodium iodide crystal 122 coupled to a collimator on the right side 74 of the image generates a substantially larger one side and a photomultiplier tube 110 on the opposite side. peak 76 then the peak 77 for the left side 75 of the image. The tube 110 is surrounded by an internal radiation shield FIG. 10 further illustrates how a rectangular portion 62 120. The outer surface 118 is preferably a light aluminum can be selected such that a region of interest therein can be shield. An adjustable gain potentiometer 114 is positioned speci?cally studied. The image shown is the result of a adjacent a connector 116 on top of the detector 40. Not thyroid uptake using the system in FIG. 6. shown in this ?gure are the means for telescoping the The height and length of the region can be selected by the SO detector relative to the arm 38. operator and the count within the region can be calculated by The two collimators 124 and 126 are used for performing a subroutine and displayed on a table adjacent the image emission and transmission studies respectively. A third type being analyzed. A number of such regions can be sequen of collimator similar to 126 is used for thyroid uptake studies tially de?ned analyzed. and displayed. without the lead rings 136 and 140. and without the spacer FIGS. 11 and 12 illustrate the imaging of bone density 55 138 separating the rings. The angled columns 134 of colli studies along with graphical analyses showing cumulative mator 12A transmit light from a point 125 lying within a density as a function of position and the comparison of focal plane that is scanned by the detector. By telescoping acquired data relative to stored normative values. the collimator 124 relative to arm 38. the focal plane of the The table 50 on which the patient lies permits the cradle collimator can be vertically repositioned between scans. 32 to rotate under or astricle the table 50 so that studies can This permits the obtaining of an image along a number of be conducted at any number of angles. Lateral imaging can slices of the tissue intersecting the focal plane. A lead ring be conducted by rotating the cradle so that the source 130 de?nes the aperture of the collimator 124 which is detector axis is positioned above the table 50. covered with a thin aluminum plate. All three collimators A preferred embodiment of the invention incorporates incorporate an inner wall 128 which prevents stray radiation safety features that warn the operator of potentially danger 65 from penetrating into the detector 40. ous situations where the patient may be injured or the system The ability of the system to scan along dilferent focal damaged as a result of the automatic movement of the planes provides the capability for characterizing tumors in