Renal functional CT studies of patients with nephrolithotomy

Renal functions of 13 patients, who underwent nephrolithotomy, were examined by the functional CT study. The warm ischemic time was 41+/-10 (mean+/-SD). After the operation, the tissueplasma ratio of contrast enhancement values failed to improve satisfactorily compared to that of the nonischemic hydronephrosis patients. Parenchymal volume decreased as much as that in the non-ischemic patients. As a result, Renal Functional Index (RFI) decreased significantly after nephrolithotomy. As RFI does not usually change in non-ischemic hydronephrosis after release of obstruction, the postischemic decrease of RFI may be caused mainly by ischemic damage and the effects of parechymal incision may not be dominant. (author)