Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease

The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) was established to develop and implement studies to test whether imaging techniques can provide accurate and reproducible markers of progression of renal disease in patients with polycystic kidney disease. Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by gradual renal enlargement and cyst growth prior to loss of renal function; however, standard radiographic imaging has not provided the resolution and accuracy necessary to detect small changes in renal volume or to reliably measure renal cyst volumes. The CRISP cohort study longitudinally observed ADPKD individuals using high-resolution magnetic resonance (MR) imaging to determine if change in renal and cyst volumes can be detected over a short period of time, and if they correlate with decline in renal function early in disease.

Patients who were diagnosed with ADPKD and had a creatinine clearance of at least 70 mL/min were enrolled. Standardization studies were conducted at each participating clinical center. After, in the full-scale protocol, participants underwent standardized MR renal imaging, comprehensive clinical evaluation, evaluation of renal iothalamate clearance, and determination of 24-hour urinary albumin and electrolyte excretion. Stereology was used from T1-weighted images to quantify renal volume, and region-growing thresholding was used from T2-weighted images to determine cyst volume.

The CRISP cohort was also analyzed by molecular analysis. Given the high level of unclassified variants (UCV) in patients with ADPKD, the purpose of the molecular analysis was to systematically classify UCVs in the PKD1 and PKD2 genes.

The current data package contains data through the CRISP 3 cycle as well as CRISP allele frequency data.