Grayscale and Doppler Ultrasonographic Findings Reflecting Disease Severity in Autosomal Dominant Polycystic Kidney Disease

Background: The purpose of this study was to identify the ultrasonographic findings that reflected disease severity in patients with autosomal dominant polycystic kidney disease (ADPKD). Materials and Methods: In 72 patients with ADPKD, resistive indices (RIs) and the severity of ultrasonographic morphologic abnormalities, such as renal severity index (RSI), modified RSI and the sum of bilateral renal size, were measured and correlated with clinical and laboratory findings including the presence of hypertension and serum creatinine concentration. RSI was calculated as the sum of three components in both kidneys and included the number of cysts, the size of the largest cyst, and the percentage of normal renal parenchyma. Modified RSI was the sum of the RSI and the score according to the size of both kidneys. Results: Mean RI in all patients was 0.62 +/- 0.09 (mean +/- 1 standard deviation). RIs in hypertensive ADPKD patients (0.63 +/- 0.11) were higher compared with normotensive patients (0.58 +/- 0.05) (p < 0.05). Serum creatinine concentration representing renal function correlated significantly with RIs (r = 0.630, p < 0.01) and with RSIs (r = 0.344, p < 0.01). The correlation between renal size and serum creatinine concentration or RIs was relatively weak (r = 0.232, r = 0.298, respectively). Conclusion: RI and RSI were useful parameters in the quantitative evaluation of disease severity and may reflect renal functional status in patients with ADPKD.