Value of sonography for follow-up examination after allogenic kidney transplantation

In 66 patients with renal transplants 246 sonographic examinations were performed. The patients were divided into two groups based on their immunosuppressive protocol. Group I was treated with Cyclosporin A (CsA) and group II with azathioprin. A compensatory hypertrophy with a volume increase of 20% could be seen in nearly all grafts. During acute tubular necrosis only minimal sonographic changes could be found. In each group 16 patients developed an acute rejection episode. Sonographic signs of acute rejection were: (1) a hypoechoic enlargement of the renal pyramides; (2) an increase in cortical echogenicity; (3) an increase in graft volume greater than compensatory hypertrophy; (4) an indistinct parenchyma-pelvic border; (5) dilation of the pelvis with a parenchyma-pelvic index greater than 2.3:1 (in group II cases). Chronic rejection is characterized by graft shrinkage. No specific signs were evident. The increasing use of CsA diminishes the value of sonography in follow-up of acute rejection after kidney transplantation. Nevertheless, it is of great value for follow-up examination concerning other complications.