Assessment of acute renal allograft dysfunction by MRI diffusion techniques

Abstract

Aim: To assess the role of DW MRI and ADC in acute allograft renal dysfunction as a possible alternative for graft biopsy. Material & methods: This study included 31 renal transplant recipients divided into 2 groups A: (11 patients) with normal allograft function and group B: (20 patients) with allograft dysfunction. Color Doppler Ultrasound was done for both groups, MRI with contrast for groups A, non-contrast MRI for group B, DW MRI at b 600 & 1000 for both groups. Ultrasound-guided needle biopsy and histopathological examination for group B. Results: At b 600; ADC values of group B are significantly lower than group A (P = 0.047). In group B, ADC values of the cortex are lower than those of medulla. No significant difference was founded between ADC values of AR and ATI (P = 0.981). At b 1000; ADC values of group B was significantly lower than that of group A (P = 0.030). ADC values of cortex correlate better than those of medulla. ADC values of ATI are slightly lower than those with AR, no significant difference (P > 0.05) regarding ADC values between AR and ATI. Sensitivity, specificity, accuracy, PPV, NPV for ADC values at b 600 & b1000 were 60%, 90.91%, 70.97%, 92.3%, 55.6 and 85%, 54.55%, 74.79%, 77.3%, 66.7 respectively. Conclusion: DW MRI is a promising noninvasive tool for early detection graft dysfunction especially at higher b values. Keywords: Acute allograft dysfunction, MR diffusion techniques