Ultrasound changes in the transplant kidney.

The purpose of this trial was to study the ultrasound changes that take place in a non-selected group of transplant kidneys in the post-operative period and to identify the ultrasound signs that most accurately identify episodes of acute rejection. It was found that in patients with no episodes of rejection or acute tubular necrosis the ultrasound appearances of the kidney progressed in a predictable way to reach a stable picture similar to the non-transplanted kidney after 2 weeks. Those patients who had episodes of early rejection, but subsequently 'settled down' to a stable state had a similar progress between rejection episodes but the ultimate stable appearance of the kidney varied greatly. Those patients with recurrent rejection episodes, leading to eventual failure of the transplanted kidney, had an unpredictable sequence of ultrasound changes. These findings demonstrate that early rejection episodes may permanently affect the appearance of the kidney and this makes interpretation of future scans difficult unless a baseline scan is available for comparison. The comparison of cortico-medullary echogenicity with a baseline scan makes ultrasound a more specific test than previously reported, but does not improve the poor sensitivity.