Prospective study of the value of ultrasound measurements in the diagnosis of acute rejection following renal transplantation.

In this prospective study we have used ultrasonographic measurements of the cross-sectional area of transplanted kidneys, as an objective assessment of graft size, for diagnosis of acute rejection episodes. Sixty episodes of acute graft dysfunction (serum creatinine rise of greater than or equal to 30 mumol/l) were studied in 40 patients. Tru-Cut biopsy under ultrasound control was performed in all cases and 36 episodes of acute cellular rejection were identified. An increase in graft cross-sectional area of greater than or equal to 10 per cent was defined as a positive scan, indicative of an acute rejection episode. Using these criteria, ultrasound correctly diagnosed rejection in 29 out of 36 cases (sensitivity 81 per cent) and there were four false positive results (specificity 83 per cent). The investigation had a predictive value of 88 per cent when positive and 74 per cent when negative.