Evaluation of renal cortical thickness by non-contrast-enhanced MR imaging with spatially selective IR pulses: Comparison between cirrhotic and noncirrhotic patients.

Objective: To compare renal cortical thicknesses between patients with and without cirrhosis with normal renal function based on serum creatinine using non-contrast- enhanced steady-state, free precession (SSFP) MRI with spatially selective inversion recovery (IR) pulses and to discuss the clinical implications of measuring renal cortical thickness in patients with cirrhosis. Methods: 40 patients with and without cirrhosis who had normal renal function based on serum creatinine and underwent non-contrast-enhanced SSFP imaging with spatially selective IR pulses were included. The renal cortical thickness, renal width, renal cortical width ratio, serum creatinine levels and estimated glomerular filtration rates (eGFRs) were compared between cirrhotic and non-cirrhotic groups. Results: The mean renal cortical thickness was significantly lower in the cirrhotic group (3.6 +/- 0.9 mm) than in the non-cirrhotic group (4.9 +/- 0.8 mm; p < 0.001). The mean renal cortical width ratio was significantly lower in the cirrhotic group (0.07 +/- 0.02) than in the non-cirrhotic group (0.10 +/- 0.02; p < 0.001). The mean serum creatinine and mean eGFR did not show significant differences between the two groups. Conclusion: Measurement of renal cortical thickness by means of non-contrast-enhanced SSFP MRI with spatially selective IR pulses may help evaluate renal function accurately in patients with cirrhosis, in whom it may be overestimated by serum creatinine and eGFR. Advances in knowledge: (1) The renal corticomedullary junction was clearly depicted by non-contrast-enhanced SSFP MRI with spatially selective IR pulses in all patients with and without cirrhosis. (2) The mean renal cortical thickness measured on the optimal SSFP image with spatially selective IR pulses was significantly lower in the cirrhotic group (3.6 +/- 1.0 mm) than in the non-cirrhotic group (4.9 +/- 0.8 mm) (p, 0.001), although the mean eGFR did not show a significant difference between the two groups.