Reliability of magnetic resonance imaging for measuring the volumetric indices in autosomal-dominant polycystic kidney disease: Correlation with hypertension and renal function

Background: The purpose of this study was to determine if renal volumetric indices can be accurately measured using MRI, and if these volumetric indices are associated with hypertension and renal function in patients with autosomal-dominant polycystic kidney disease (ADPKD). Methods: For testing the accuracy of the MRI-based volume measurements that we proposed for clinical trial, we designed phantoms to simulate cysts within the kidney. Fifty-six patients with ADPKD were included in this study, and their respiratory compensated T₂-weighted fast spin-echo images were acquired. The total kidney volume (Vt), cyst volume (Vc), and noncystic parenchymal volume (Vp) were measured and the percent cyst volume (Pc) was calculated. These volumetric indices were compared with the disease progression in the ADPKD patients. Results: The MRI measures of the phantoms were accurate. The Vt, Vc and Pc were significantly greater in the hypertensive group (n = 35) than in the normotensive group (n = 21) (p < 0.01). The Vt, Vc and Pc were significantly greater in the renal failure group (n = 23) than in the normal renal function group (n = 33) (p < 0.01). The Vt, Vc, and Pc were inversely correlated with the creatinine clearance. Conclusion: MRI is a reliable method to measure renal volumetric indices. The MRI-based volume measurements can be employed as useful markers for the progression of disease in ADPKD patients.