Sonographic criteria for renal allograft rejection.

In order to define sonographic criteria for acute rejection of renal allografts, the following sonographic criteria were evaluated: (a) parenchymal thickness, (b) index of maximal sagittal to maximal longitudinal diameter, (c) cortical echos, (d) sinus echo changes, and (e) the medullary pyramids. Thirteen kidneys were removed for rejection. All had ultrasound studies 24 hours preoperatively. The sonographic changes in rejected kidneys were compared to those in 21 normal allografts. We found that renal enlargement, enlarged medullary pyramids, and a reduction in or a disappearance of the sinus echos were seen in acute rejection but were not seen in normal renal transplants. We conclude that these criteria are early signs of acute rejection and may be helpful in diagnosis, particularly if control sonograms are available.