Comparison of Early Postoperative Function of Liver and Renal Allografts With Radionuclide Imaging A. Aktas ¸ , A. Koyuncu, A. Dalgiç, and M. Haberal ABSTRACT Objectives. Radionuclide imaging is a valuable tool during the early posttransplantation period for evaluating the functional status of renal and liver allografts. The aim of this study was to compare the early postoperative function of renal and liver allografts with serial radionuclide imaging. Methods. Twenty-two renal and 22 liver allograft recipients were evaluated with serial radionuclide imaging. All grafts were from living related donors. For renal scintigraphy, recipients were injected with Tc-99m DTPA, and imaging was performed on postoperative days 3 and 7. Liver allograft recipients were evaluated with Tc-99m mebrofenin hepato- biliary scintigraphy within the first postoperative week and as required thereafter. The following parameters were computed for each scintigraphy: uptake, time to excretion of the radiopharmaceutical (T ex ), and retention of radioactivity at the end of the study. Results. Among 22 renal transplant recipients, 19 (86%) had normal uptake and T ex values on day 7 posttransplantation. Nine (41%) renal grafts exhibited retention. Among 22 liver transplant recipients, 7 (32%) had normal findings on the first hepatobiliary scan. All except eight liver grafts (64%) had a delay in T ex , and 15 (68%) had parenchymal retention on the first scan, with improvement of function observed on serial scintigraphies obtained during follow-up. Decreases in uptake were seen less frequently and correlated with a prolonged postoperative hospital stay. Conclusion. Renal transplant recipients are more likely than liver allograft recipients to have a normal scintigraphy in the early posttransplantation period. Retention of radioac- tivity at the end of the study was the most frequently observed abnormality for both renal and liver allografts. Most liver transplant recipients exhibited a delay in excretion, and parenchymal retention, of radioactivity on the first evaluation, with subsequent improve- ment on follow-up serial scintigraphy studies. T HE SHORTAGE of cadaveric organs has necessitated the use of living donor transplantation. Imaging pro- cedures are particularly important during the early post- transplantation period to assess early function and reveal any posttransplantation complications. Both the liver and kidney exhibit a dynamic function that can be assessed by labeling analogs of inherently excreted substances by these organs. Radionuclide imaging with Tc-99m-labeled agents is a valuable, noninvasive technique for visualizing perfusion, uptake, and excretion patterns of intravenously adminis- tered radiopharmaceuticals. In the case of the liver, evaluation of hepatocyte function is carried out by labeling iminodiacetic acid derivatives. Using this tech- nique, bile flow through the biliary channels can be assessed. In the case of the kidney, agents excreted through glomerular or tubular pathways are used to evaluate urine flow through the kidney. In addition, early posttransplantation complications such as biliary and urine leakage and collection of peritransplantation fluid can be evaluated. It has been reported that information From the Baskent University, Faculty of Medicine, Department of Nuclear Medicine (A.A., A.K.), and Faculty of Medicine, Department of General Surgery (A.D., M.H.), Ankara, Turkey. Address reprint requests to Ays ¸ e Aktas ¸ , Baskent University, Fevzi C ¸ ak Cad. 10.sk No: 45 Bahc ¸ elievler, Ankara, Turkey 06490. © 2005 by Elsevier Inc. All rights reserved. 0041-1345/05/$–see front matter 360 Park Avenue South, New York, NY 10010-1710 doi:10.1016/j.transproceed.2004.12.027 Transplantation Proceedings, 37, 355–358 (2005) 355