Evaluation of scintigraphic data of renal transplants

Scintigraphic data obtained during 594 examinations of renal transplants were evaluated by an experienced physician. Each examination included both the measurement of a radioiodine hippurate uptake curve, and a technetium 99m diethylenetriamine pentaacetic acid (DTPA) time-activity curve describing renal perfusion. Features were extracted from both curves. Discriminant analysis of the features resulted in a computer classification of the grafts. This classification was compared with the physician's diagnosis. Congruence between the computer classification and the diagnosis supported the diagnosis, and revealed those features which were able to lead to the correct diagnosis. The analysis was used to assess graft function, and to identify acute tubular necrosis and acute, as well as chronic, rejection. The computer classification was in agreement with the diagnosis in about 80% of the acute rejections, in 86% of all instances of acute tubular necrosis, and in 80% of chronic rejections. The procedure can be used to mutually improve the diagnosis of both physician and computer.