The significance of poor renal transplant concentrating ability as assessed by I-131 Hippuran imaging

A pattern of very poor renal allograft concentration of I-131 Hippuran and good bladder activity has been observed by the authors. The kidneys are typically barely visualized and the renogram curve is flat. The significance of this particular finding has not been described in the literature. Accordingly, a retrospective review of all patients exhibiting this scan pattern was performed and the authors attempted to correlate it with clinical, laboratory, and pathological findings at the time of study. Of 11 patients exhibiting this scan pattern, three had very high urine outputs at the time of study. Of the remaining eight patients, five had chronic rejection. In the remaining three patients, the diagnosis was: one each, acute rejection, mixed acute and chronic rejection, and cyclosporine toxicity. The authors conclude that although this pattern is non-specific, if the patient is not in a high output state, it is usually related to chronic rejection.