DIFFERENTIATION OF DELAYED KIDNEY GRAFT FUNCTION WITH GADOLINIUM-DTPA-ENHANCED MAGNETIC-RESONANCE-IMAGING AND DOPPLER ULTRASOUND

RATIONALE AND OBJECTIVES. The authors differentiate acute tubular necr osis from transplant rejection in patients with delayed kidney graft f unction using gadolinium (Gd)-DTPA enhanced magnetic resonance (MR) im aging. METHODS. Twenty-four patients after renal transplantation (10 w ith normal graft function, 14 with delayed graft function) underwent c onventional and Doppler sonography and MR imaging examination after bo lus application of Gd-DTPA. Within a time period of 512 seconds, 39 si ngle-slice MR images were obtained, Measurements of signal intensity i n three regions of interests (cortex, medulla, renal pelvis) resulted in a graphic description of the dynamics of the contrast enhancement, The time between the start of the scan and the peaks of the curves was measured, RESULTS. In patients with normal graft function the curves reached the peaks between 39 and 55 seconds (cortex), 44 and 61 second s (medulla), and between 161 and 318 seconds (renal pelvis), Six patie nts with acute tubular necrosis showed normal values for the curves 1 and 2 but markedly prolonged time for curve 3 (between 420 and 512 sec onds), In all patients with histologically proven transplant rejection , the peaks of all curves were not reached before the ends of the scan s. CONCLUSION. The authors' preliminary results suggest that MR imagin g seems to be a sensitive, noninvasive diagnostic boat to differentiat e acute tubular necrosis from transplant rejection in the critical ear ly postoperative period.