RADIONUCLIDES IN RENAL TRANSPLANTATION

G. Hör,H. W. Pabst,K. J. Pfeifer,P. Heidenreich,H. Langhammer,and H. G. Heinze Nuk'earmedizinische Klinik und Poliklinik der Technischen Universität and Klinik und Poliklinik fürRadiologie der UniversitätMünchen,Munich, Germany

In the terminal stages of renal failure, renal trans plantation has become an effective means of treat TABLE1. RADIONUCLIDESIN RENAL ment (1,2) . Although survival rates have improved TRANSPLANTATION since the availability of adequate immunotherapy, Procedureo-1'@l-hippuricRadiopharmaceutical

present means of diagnosing the various forms of acid Isotoperenography Tubular renal complications leave much to be desired. Effective renal function Since 1966 180 kidney transplantations have been plasma flow @ lismIn ‘@Yb. Isotope renography Glomerular performed at the university clinics in Munich (2). EDTA, -DTPA Renal clearance function Encouraged by communications of other authors ‘°‘Hg-mersalyl Scanning Localization (3—9)we have begun to use procedures involving ra “@Hg-chlormerodrin Scanning Localization ‘311-flbrinogen Scanning Localization dioisotopes, and results were compared with nephro “Xeclearance Renal blood logical testing procedures ( 10—iS). flow vsmTcO@ Clinical diagnosis was based on the clinical course, Scintillation camera Vascular perfusion palpation of the transplant, urine volume, serum creatinine, creatinine clearance, sodium excretion, urinary osmolarity, and biopsy. Radiological procedures were usually confined to into the arterial branch of the exteriorized kidney abdominal x-ray when kidney size was of interest. which was mounted to the forearm of the patient. Drip infusion urography was used when extravasa Renal cortical blood flow (RCBF) was deter tion of urine (urinary fistula) was suspected, and mined by externally monitoring the 133Xe washout arteriography was performed to exclude arterial from the exteriorized kidney. Graphical analysis of stenosis or thrombosis. the radioxenon disappearance curve was performed using rapid component I , its half-time, and lambda METHODS as the partition coefficient of radioxenon between Several radionuclide procedures were chosen for kidney blood and parenchyma, dependent on the the evaluation of function and morphological dis hematocrit. RCBF was related to kidney weight. orders of the renal transplants. These are summarized Renal scanning. Renal scanning was performed in in Table 1. 62 patients using 203Hg-mersalyl, ‘97Hg-chlormero Renography. One hundred fifty-three followup drin, and lI3mIn..Fe..EDTA, with a Picker Magna studies were carried out with 1311-o-hippuric acid scanner 500. (OIH) to estimate glomerular and tubular function. Sequential scintigraphy. Sequential scintigraphy (Since OIH measures effective renal plasma flow, was carried out in another I 6 patients using 250 @Ci it is listed as tubular function in the tables and re of 169Yb-EDTA and a Picker Anger scintillation ferred to as such in the test that follows.) Thirty-two camera. patients were additionally investigated using fl3mIn@ Renal clearance studies. Renal clearance studies Fe-EDTA (In) to study glomerular function alone. were performed in 30 followup examinations. One 133Xe clearance. During preservation of an ex tracorporeal cadaver kidney transplant in a perfusion Received Jan. 10, 1972; original accepted May I 1, 1972. chamber (16), 200—500 @Ciof radioxenon dissolved For reprints contact: 0. Hör,Nuklearmed. Klin. d. TU, in 3—5ml of sterile saline were injected selectively Ismaningerstrasse, 8 München80, Germany.

Volume 13, Number 11 795 H@R, PABST, PFEIFER, HEIDENREICH, LANGHAMMER, AND HEINZE

the decline of radioactivity in the whole body, with the exception of kidney and bladder which were shielded by lead. Several plasma samples were drawn, and radioactivity (C1)Ifl$ma)was determined in the well counter. Clearance (Cl) was calculated @ according to the formula of Oberhausen (18) sepa A. L.ø rately for OIH and 169Yb-EDTA:

A Cf=@@dm/dt C p1a@ma

RESULTS In acute rejection crises the following criteria were found (Fig. 1): 1. OIH accumulation (lack of excretory segment) or prolonged secretory maximum (Tmax), fall in un nary osmolanity, lack of bladder activity, and mar @ —a *1 ginal filling defects in the scan (Fig. 1B). 2. There is a decrease in endogenous C-CR. Cor relation between parameters of radionuclide renog raphy and the level of serum creatinine is presented in Table 2. There is a positive correlation between serum creatinine and the elimination index of the OIH and In-Fe-EDTA renograms, and a negative correlation between serum creatinine and accumula tion index of renography. 3. Differentbehaviorbetweentubularand gb merular function was found in acute tubular necrosis of transplanted cadaver kidneys that were subject to prolonged ischemia time before transplantation. B

F1G. 1. (A)OlH renogramin acuterejection:OIH accumula tion. (B) Photoscan (‘°@Hg.mersalyl)in anuric rejection crisis (same patient): radioactivity in periphery (cortical area) reduced, no blad. 24270 20370 25370 der activity.

hundred fifty microcunies of OIH were given intra venously, followed by 250 @Ciof ‘69Yb-EDTA20 mm later for combined investigation of renal plasma flow (RPF), and glomerular filtration (GFR). The filtration fraction (GFR/RPF) was estimated (17). Renal clearance was calculated according to the . . . . FIG. 2. Followup study with OIH- and “mln.EDTA renography whole-body pnnciple (18) by externally monitoring in kidneytransplant:rejectioncrisison March20, 1970.

TABLE2. CORRELATiONBETWEENSERUM-CREATININE(MG%) AND ISOTOPERENOGRAPHY (KIDNEYTRANSPLANTS)

Tubular functionGlomerular function“3mIn.EDTA

max.Renography Accum. ratio‘@l.o.HippumnEIim. ratio Secret. max. Accum. ratio Elim. ratio Filtrat.

n 41 35 25 38 33 38 r —0.662 +0J63 +0.595 —0.502 +0.530 +0.572 0.11 0.037 0.267 0.164 0.0678 0.950 p <0.001 <0.001 <0.01 <0.01 <0.01 <0.01

Accumulation ratio (1 .5/0.5 mm-activity). Elimination ratio (20.0/0.5 mm-activity).

796 JOURNAL OF NUCLEAR MEDICINE @ :@*@

RADIONUCLIDESIN RENALTRANSPLANTATION

TABLE3. RENOGRAPHICFOLLOWUPSTUDIES OF CADAVERKIDNEYTRANSPLANTSWITH TUBULAR NECROSIS

Total ischaemiarenogram(mm)(daystimeNormalization of after)

239 19 203 16 159 5 155 8 115 5 109 3

As an example of differences in glomerular and tubular function in acute rejection crises see Fig. 2, second panel. Note the continuous OIH accumula tion without excretion but excellent excretion of llsmln..FeEDTA The OIH renogram became nor mal on March 25, 1970. 4. In acute tubular necrosis delayed transit time of OIH seems to depend on the duration of ischemia FIG.3. Colorscan(“mln-EDTA)inkidneytransplantwithdou time of the cadaver kidney before transplantation bled renal artery: obstruction of upper branch. Note retention of (Table 3). radioactivity in area of renal pelvis. 5. The ll3mInEDTA wasfoundto be rapidlyex @ creted by normally functioning transplant kidneys so - that this radiopharmaceutical is more suitable for tests by the scintillation camera (Fig. 3). Arterial @ ,z@: thrombosis or complete occlusion results in total loss @, ,@ of accumulation of radioactivity. 6. Rectilinear scans using 203Hg-mersalyl or 197Hg chbormerodninwere characterized by filling defects in the center, in the upper, or in the lower pole of the rejected kidney as has been reported by us pre 9-11' 6-8' 2-i' viously (11). 7. Sequentialscanningafter injection of 169Yb EDTA and/or OIH presented no characteristic pat 62 mI/mm tern in rejection of the kidney transplant and was of no predictive value (Fig. 4). 8. Renalclearancestudies,however,gaveaddi kjdney tional information concerning the functional state of the rejected transplant (Fig. 4) . Simultaneous de termination of the clearances of OIH and 169Yb EDTA showed disproportionate reduction of RPF compared with GFR, so that ifitration in rejection crises was elevated (Fig. 5). 9. In some cases determination of the washout of 133Xein the kidney before transplantation, while pre FIG.4. Serialscintiphotography(sequentialscintigraphy)and served in a perfusion chamber, proved to be of OIH-single shot clearance in acute rejection. prognosticvalue when RCBF has been found normal (Fig. 6). From our folbowup studies we conclude that pa rameters of OIH as well as of the fl3mIn@Fe@EDTA DISCUSSION renogram are generally in accordance with the level Radionuclide renography is now an acknowledged of serum creatinine. and easily performed diagnostic tool for elucidating Collins, et al (3), Sharpe, et al (8) , and Staab, complications following renal transplantation. et al (9) have also reported on the prognostic value

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H@R, PABST, PFEIFER, HEIDENREICH, LANGHAMMER, AND HEINZE

- 133 x.@ Oecrance of a transplanted Clearance kidney in the chamber 01 Lavender

@ 1@@@. ,,@/g. IRc8F@ @ 1@ “.“.PlOp) @ A . @v

10 A@02, :

131 J-Hippuran-Clearance

50 100 150 200 250 300 350 ml/'viln

F1G.5. Comparativeglomerularand tubularclearancein transplanted kidneys.

of radionuclide renography which may show patho logical changes before clinical alterations.

@ The most common pathologic type is the continu 2 0 PG )p 2. 2@ 30 34 31 42 46 50 ous OIH accumulation with the lack of the excre tory phase. This type of renogram was described FIG. 6. RCBFstudyusing“Xeclearance(cadaverkidney,pre served in perfusion chamber). as a sign of rejection by Mobley, et al (6) . Con tinuous OIH accumulation, however, is not pa thognomonic for rejection of kidney transplants. It technique is superior to conventional scanning, espe may be due to rejection crisis as well as to disorders cially when used in conjunction with a computer, of excretion on account of a necrosis of the ureter because it supplies both functional and morphological at the level of the anastomosis. data (20—23). Lubin, et al (19) demonstrated kidney scanning The following criteria were described in rejection with OIH as a complementary test to renography crises (20) : (A) reduced initial uptake of OIH, to locate sites of abnormal accumulation. In ure (B) delay in intrarenal transport of OIH, and (C) teral obstruction, for instance, most of the abnor decreased renal excretion. mally pooled radiopharmaceutical is found in the There are also differences in the radioactivity pat renal pelvis, whereas in rejection it is principally tern associated with acute tubular necrosis (reduced cortically reduced. Furthermore renal scanning by accumulation) and renal artery thrombosis (lack of itself may help in the differential diagnosis of accumulation). oliguria. In necrotic renal allografts obtained from Clearance procedures represent another step for cadaver donors no uptake of 203Hg-chlormerodrin ward in expanding diagnostic possibilities after renal is observed (4) . In total obstruction of the renal transplantation (7,1 7,24—26,31 ) . The superiority of artery due to complete stenosis or to thrombosis we these methods over scanning procedures is evident regularly observed a nephrectomy-typeof renogram. because renal functional impairment may be quanti Immediately after intravenous injection of OIH, tated. Comparative studies including the estimation radioactivity disappears over the kidney transplant of GFR and RPF, as carried out by us, demonstrated similar to the blood disappearance curve which is that in rejection crisis RPF is more severely reduced externally registered over the heart. Acute tubular than glomerular function. Similar observations were necrosis may be associated with accumulation as well published by Rosen, et al (27). as with nephrectomy type. In our hands, simultane Renal ‘33Xeclearance supplies information con ous performance of radionuclide renography using cerning cortical blood flow of the kidney transplant OIH and 1I3mInFeEDTA was valuable in differ (14,15,27—29). The practicability of this method, entiating between the onset of glomerular and tubu however, is very limited. Radioxenon has to be in lar function in cadaver kidneys. Similar observations jected selectively into each renal artery, so this clear were reported by zum Winkel, et al (20,21 ) using ance technique is applicable only to the Seldinger sequential scintigraphy with the Anger camera. This technique or during surgery (intraoperative xenon

798 JOURNAL OF NUCLEAR MEDICINE RADIONUCLIDES IN RENAL TRANSPLANTATION clearance) (29) , in cases of inevitable arteriography 2. ZENKER R, PICHLMAIERH, ERPENBECKR, et al: Erste (in arterial stenosis, thrombosis) , or, in accordance Erfahrungen mit der Transplantation von Leichennieren beim Menschen. München Med Wschr 109: 613, 1967 with our practice, in extracorporeal kidney tnans 3. COLLINS JJ, WILSON RE: Functional evaluation of plants preserved in a perfusion chamber (14,15). human kidney transplants with renograms. Ann Surg 161: This procedure offers the possibility of preserving 428—440, 1965 cadaver kidneys prior to transplantation until func 4. FIGUEROAJE, MAXFIELDWS, BATSONHM, et al : Ra tion and histocompatibility are tested (16) . RCBF dioisotope renal function studies in human renal allografts: may be determined using the most rapid component Value in the differential diagnosis of oliguria in the presence of obstructive disease with and without urinary extravasa (Fig. 6) , and progressive redistribution of blood tion. I Urol 100: 104—108,1968 flow is seen in rejection because of hypoperfusion of 5. LOKEN MK. STAAB EV, VERNIER RL, et al: Radioiso the renal cortex as has been shown by autoradiogra tope renogram in kidney transplants. I Nucl Med 5: 807— phy (27) . This reduction in RCBF is considered to 810, 1964 6. MOBLEYJE, SCHLEGELJU: Radiohippuran accumu be caused by immunological mechanisms and may lation in the transplanted kidney as a signal of rejection. play a role in the ensuing renal failure. Surgery58:815—818,1965 Single injection clearance of OIH has been pro 7. RöSLERH: Radionephrographische Funktionsstudien moted by Rösler(7), Blaufox, et al (24), and Gott, nach Nierentransplantationen. Z Ges Exp Med 143: 345, et a! (25) . The volume of distribution (V) of the 1967 8. SHARPE AR, KiNG ER, HUME DM. et al: Sequential injected 0TH, calculated from the injected dose response of the iodine- I 3 1 Hippuran renogram in renal divided by the zero intercept of blood disappearance homotransplantation. I Nucl Med 7: 556—563,1966 curve times the slope (k = 0.693/half-time) enables 9. STAABEV, KELLY WD, LOKEN MK : Prognostic value one to evaluate the clearance (Cl) of the kidney of radioisotope renograms in kidney transplantation. I Nuci transplant : Cl = V X K (one-compartment con Med 10:133—135,1969 10. HEIDENREICHP, HöRG, PABST HW, et al : Funk cept) . Renal clearances are reduced early in rejec tions und Lokalisationsdiagnostik mit dem ‘mlndium-Eisen tion crises, where, on account of the oligunia, urinary Athylendiamin-traacetat-Komplex (EDTA) nach Niere-n sodium excretion and urinary osmolarity are unob transplantationen. Langenbecks Arch Chir 328: 91, 1970 tamable. According to Rösler (7) simultaneous ap 11. HöRG, PABST HW. HAUBOLDU: Studies of localiza plication of radionuclide renography with OIH and tion after renal transplantation. In Medical Radioisotope Scintigraphy, vol 2, Vienna, IAEA, 1969, pp 209—217 single-injection clearance gives quantitative informa 12. HöRG, PABST HW, EDEL HH : Möglichkeiten nu tion concerning the total clearance of the kidney klearmedizinischer Diagnostik nach Nierentransplantationen. transplant. PvuiinchenMed Wschr 111: 1190,1969 Simplified clearance techniques based only on the /3. HöR 0, FREY KW, BöSSNER0, et al: Nuklear determinations of half-time of the blood disappear ,nedizinische and nephrologische Verlaufskontrollen nach Nierentranspiantation. Deutscher Rontgenkongress, Stutt ance curve (30) or on the one-compartment concept gart, G Thieme, 1972, pp 121—122 did not correlate with standard clearance procedures 14. PABST HW, HöRG: Nephrologie. In Nuklearmedizin (31 ) . At the present time we believe one cannot Funktionsdiagnostik, Emrich D, ed, Stuttgart, G Thieme, decide whether the single-injection clearance calcu 1971,pp 275—312 lated according to one-compartment, two-compart 15. PABSTHW, HöRG: Radionuclides in renal trans plantation. Paper presented at the International Symposium ment, or multicompartment models is best suited for on Radionuclides in Nephrology, New York, Jan 25—27, replacing conventional clearance procedures (14). 1971,p 418 A really new idea obviating the compartment idea 16. DOBBELSTEINH, EDEL HH: Diureticawirkung an der was developed by Oberhausen ( 18) in measuring the extrakorporalen transpiantierten Niere. In Renal Transport, total-body clearance of renal clearance substances. Thurau K. JahrmärkerH, eds, Berlin-Heidelberg-New York, SpringerVerlag,1969,pp 413—418 Up to the present time, however, experiences with 17. PFEIFER KJ, ROmE R, RICHERT J, et al: Tubuläre this technique in kidney transplants are limited. und glomeruläreClearance und Sequenzszintigraphie bei Reviewing our own results and those reported in transplantierten Nieren. In Radioisotope in Klinik und For the literature it seems justifiable to use radioisotopic schung, MUnchen, Berlin, Schwarzenberg procedures to determine function and morphology 18. OBERHAUSEN E, ROMAHN A: Bestimmung der Nieren clearance durch externe Gamma-strahlenmessung. In Ra of kidney transplants. Exact and comparable inter dionuklide in Kreislaufiorschung und Kreislaufdiagnostik, pretation of the results obtained so far will depend Stuttgart-New York, FK Schattauer Verlag, 1968, pp 323— however on standardizing examination procedures to 326 be performed by nuclear medicine personnel. 19. LUBIN E, LEWITUS Z, ROSENFELD J, et a!: Kidney scanning with Hippuran, a necessary complement for cor rect interpretation of renography in the transplanted kidney. REFERENCES In Medical Radioisotope Scintigraphy, vol 2, Vienna, IAEA, 1. STARZLTE, VANHOUTrEJJ, BROWNDW, et al: Radi 1969,pp 219—222 ology and organ transplantation. Radiology 95: 3—18,1970 20. ViM WINKEL K, HARBST H, SCHENCK P, et al : Se

Volume 13,Number 11 799 H@R, PABST, PFEIFER, HEIDENREICH, LANOHAMMER, AND HEINZE quential scintigraphy in renal transplantation. In Medical bution of intravenously injected 11-orthoiodohippurate. Radioisotope Scintigraphy, vol 2, Vienna, IAEA, 1969, pp Mayo Clin Proc 46: 524—531,1971 197—208 27. ROSEN SM, TRUNIGER BP, KiuEK HR, et al: Intra 21. ZUM WINKEL K, KLINKE JD: Radioisotopenunter renal distribution of blood flow in transplanted dog kidney: suchungen bei der Nierentransplantation. Wiederbelebung, effect of denervation and rejection. I Clin Invest 46: 1239— Organersatz, Intensivmedizin (Darmstadt) 6: 121, 1969 1253,1967 22. FREEDMAN GS, TREvES 5, LANGE RC, et al : Renal 28. LADEFOOEDJ : Measurements of the renal blood flow transplant evaluation using technetium-DTPA, a gamma in man with the Xenon-l33 wash-out technique. Scand J camera, and a small computer. I Nucl Med 11: 320, 1970 Clin Lab Invest 18: 299—315, 1966 23. WEIsS ER, BLARD WH, WINSTON MA, et al: Scintil 29. LEWIS DH, BERGENTZSE, BRUNIUSU, et al: Value lation camera in the evaluation of renal transplants. I Nucl of renal blood flow measurement with xenon-i 33 at the Med 11:69—77,1970 time of kidney transplantation. Ann Surg 166: 65—74,1967 24. BLAUFOX MD, MERRILL JP: Evaluation of renal 30. E*3LESTONTA, ACCHIARDOS, RODRIGUE.Z-ANTUNEZ transplant function by iodohippurate sodium I 131. JAMA A, et al: 19 Hippuran in the evaluation of transplanted kid 202:575—581,1967 neys.Radiology93: 1145—1148,1969 25. Gorr FS, PRITCHARD WH, YOUNG WR et al: Renal 31. HöRG, PABSTH, STEINHOFFH, et al: Untersuchun blood flow measurement from the disappearance of intra gen zur Clearance von ‘9-Hippuran, @Hg-Salyrgan,5Cr venously injected Hippuran. I Nucl Med 3: 480—486,1962 EDTA und 5Cr-Inulin. In Radioisotope in der Kreislauf 26. TAUXEWN, MAHERFT, TAYLORW: Effective renal forschung und Kreislaufdiagnostik, Stuttgart-New York, FK plasma flow: estimation from theoretical volumes of distri Schattauer Verlag, 1968, pp 327—334

Accepted Articles To Appear in Upcoming Issues

Optimization of Data in Lung and Brain Scans. Accepted 6/26/72. Radiation Dose to a Breast Feeding Child After Mother Has @mTc Suresh M. Brahmavar. Robert B. Groves, Edward V. Staab, Jon MAA Lung Scan. Accepted 8/1/72. J. Erickson, and A. Bertrand Brill R. A. Berke, E. C. Hoops, J. C. Kereiakes, and E. L. Saenger Graves' Disease with Functioning Nodules (Marine-Lenhart Syn Study of Availability of Iodine from Calcium lodate Employing 1@I@ drome) . Accepted 6/26/72. Labeled Salt. Accepted 8/1/72. N. David Charkes I. S. Shenolkar and B. S. Narasinga Rao Serum Tn lodothyronine Uptake Using Albumin Microspheres in the Performing 18F Bone Scans on the Gamma Camera (Letter to the Assessment of Thyroid Function. Accepted 6/27/72. Editor). Accepted 8/4/72. E. Rolleri, G. Buzzigoli, and G. Plassio M. V. Merrick Macroaggregation of an Albumin-Stabilized Technetium-Tin (II) Synthesis of 5-F1uorouracil-1@F. VII (Preliminary Note). Accepted Colloid (Concise Communication) . Accepted 6/28/72. 8/4/72. Max S. Lin and H. Saul Winchell J. S. Fowler, R. D. Finn, R. M. Lambrecht, and A. P. Wolf Whole Body Imaging and Count Profiling with a Modified Anger Calculating the Radiation Dose to an Organ (Concise Communica Camera. I. Principles and Application. Accepted 6/28/72. tion). Accepted 8/8/72. Michael Cooke and Ervin Kaplan Roger 3. Cloutier and Evelyn E. Watson Whole Body Imaging and Count Profiling with a Modified Anger Xenon-133 Ventilatory Studies in Alphai—Antitrypsin Deficiency. Camera. II. Implementation and Evaluation. Accepted 6/28/72. Accepted 8/8/72. Michael Cooke and Ervin Kaplan R. F. Fallat, M. R. Powell., F. Kueppers, and E. Lilker Splenic Displacement and Changes of Splenic Size (Letter to the Serendipity in Cisternography (Case Report) . Accepted 8/8/72. Editor). Accepted 7/6/72. P. Kirchner and K. A. McKusick Bruno Schober Arachnoid Cyst of the Posterior Fossa Demonstrated by Isotope Cis Reply to the Letter to the Editor. Accepted 7/6/72. ternography (Case Report). Accepted 8/11/72. Richard P. Spencer Lanny G. Goluboff lftmTc..EHDP : A Potential Radiopharmaceutical for Skeletal Imaging Increased Resolving Power from Scintillation Cameras Using Elec (Preliminary Note) . Accepted 7/7/72. tronic Signal Processing and a Movable Filter Plate. Accepted 8/21/72. G. Subramanian, J. G. McAfee, R. J. Blair, E. G. Bell, A. Mehter, Ronald J. Jaszcak and T. Connor Functional Pulmonary Imaging (Concise Communication) . Accepted Hepatic Scintigraphy in Clinical Decision Making. Accepted 7/7/72. 8/21/72. David E. Drum and Julia Sdougou Christacopoulos John A. Burdine, and Paul H. Murphy, Veerasamy Alagarsamy, Regional Cerebral Blood Flow with the Anger Camera. Accepted Linda A. Ryder, and William N. Carr 7/20/72. Correlation of Ultrasound and Collold Scintiscan Studies of the Nor B. Leonard Holman, Rex Hill, David 0. Davis, and E. James ma] and Diseased Liver. Accepted 8/23/72. Potchen B. Leyton, S. Halpern, G. Leopold and S. Hagen Accelerated Clearance of Radioactive Chelate from Cerebrospinal Gamma Camera Study of the Hepato-Billiary Excretion of 1MI@Thy@ Fluid in Experimental Meningitis. Accepted 7/20/72. roxine Glucuronide and llOI@Rose Bengal in the Rat. Accepted 8/23/72. Prantika Som. Fazle Hosain and Henry N. Wagner, Jr. C. H. Bastomsky, P. W. Horton, and J. Shimmins False-Positive Liver Scan Due to Lung Abcess (Case Report) . Ac Body Potassium Measurements by Whole Body Counting : Screening cepted 7/20/72. of Patient Populations. Accepted 8/23/72. Harry K. Genant and Paul B. HotTer Pierre A. Delwaide Gating Mechanism for Motion-Free Liver and Lung Scintigraphy System for Handling and Dispensing Xenon-133 (Concise Communi (Concise Communication). Accepted 7/20/72. cation) . Accepted 8/23/72. Frank H. DeLand and Walter Mauderli R. E. Snyder and T. R. Overton. Diagnostic and Therapeutic Implications of Long Term Radioisotope Collimator Performance for Scintillation Camera Systems. Accepted Scanning in the Management of Thyroid Cancer. Accepted 7/27/72. 8/23/72. G. T. Krishnamurthy and W. H. Blahd Valerie A. Brookeman and Thomas J. Bauer

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