Purpose: The aims of this study were to assess quantitative indices of baseline renal transplant scintigraphy (RTS) with Tc-DTPA for evaluation of delayed graft function (DGF) and prediction of 1-year graft function and to describe a new inclusive index for RTS.
Patients and methods: A total of 179 patients to whom RTS with Tc-DTPA was performed within 2 days after kidney transplantation were analyzed retrospectively. Hilson perfusion index, perfusion time (ΔP), peak-to-plateau ratio, peak perfusion-to-iliac artery ratio, T½ of graft washout, peak perfusion-to-uptake ratio, and ratio of uptake at 20 to 3 minutes (R20/3) were obtained. In addition, we first described the following formula defined as graft index (GI): GI = (ΔP × arterial peak × plateau)/(perfusion peak × uptake at 3 minutes). At 1 year, a serum creatinine level of more than 1.5 mg/dL was considered to be abnormal. Mann-Whitney U, Spearman coefficient of correlation test, and receiver operating characteristic curve were used for statistical analyses. P < 0.05 was considered statistically significant.
Results: Mean values of all the indices were significant. The most accurate, sensitive, and specific index for both identification of DGF and prediction of 1-year serum creatinine level of more than 1.5 mg/dL was GI. Area under the curve of GI was 0.94 for identification of DGF and 0.79 for 1-year prediction.
Conclusions: The question is, "Which index is the best indicator?" This study demonstrated that the parameters of ΔP, plateau, arterial peak, perfusion peak, and uptake at 3 minutes of RTS could be assessed together by the formula of GI, which provides more accurate information to identify DGF and predict 1-year graft function.