[MR (1.5 T) in the evaluation of pancreas transplant rejection]

Graft rejection is the major cause of graft loss following pancreatic transplantation. Early detection of the rejection process is of great importance towards planning effective treatment when transplant recipients present with aspecific clinical findings suggesting rejection. Up to date, the demonstration of pancreatic transplant rejection has been attempted with nuclear medicine and sonography (US). The authors studied high-field (1.5 T) MR potentials in pancreatic transplantation and rejection and correlated MR findings with clinical and laboratory data. Eleven MR scans were obtained from 4 patients with suspected pancreatic graft rejection, and 9 MR images from 4 patients with normal pancreatic allografts. Qualitative image evaluation showed the pancreatic tissue of the patients diagnosed with rejection to be hypointense on T1-weighted scans and highly hyperintense on T2-weighted scans, as compared to normal grafts. Quantitative data were obtained by comparing the signal intensity of pancreatic grafts to that of the nearby muscle. On both T1- and T2-weighted images, pancreatic tissue/muscle signal-intensity ratios were significantly different, in rejecting transplants, from those of normal allografts (p less than 0.001). Our qualitative and quantitative findings suggest the use of MR imaging as a reliable means of detecting pancreatic graft rejection.