Investigation of the clinical value of assessing renal size on computed tomography in autosomal dominant polycystic kidney disease.

: We examined relationship between serum creatinine concentration (Scr) and renal size on CT scans on 32 occasions in 25 patients with autosomal dominant polycystic kidney disease (ADPKD). As a result, a significant correlation was observed when the Scr was less than 5 mg/dl, as shown by the correlation coefficient (r) and P values of 0.803 and 0.0001, respectively. However, these values changed to 0.482 and 0.0093, respectively when 2 cases with Scr 6.2 and 6.4 mg/dl were included, and further changed to 0.005 and 0.9775 when an additional 4 cases with Scr 7.8, 9.9, 11.1 and 20.1 mg/dl were included. Renal size is therefore thought to be a useful parameter of renal function when the Scr is less than 5 mg/dl in ADPKD, but not when the Scr exceeds 6 mg/dl, and is regarded as useless for predicting the time at which dialysis would be required.