Clinical Kidney Volume Measurement Accuracy Using NEFROVOL

In case of Autosomal Dominant Polycystic Kidney Disease, kidney volume provides an indicator of disease progression. To estimate such growth, ultrasound is a safe and low cost imaging technique, albeit limited to regular shape organs. We developed a new measurement method with skin silicon templates to obtain parallel and equidistant images of the kidney, as a series of transverse sections. With NEFROVOL software, nephrologists are able to contour kidney boundaries, reconstruct a 3D renal representation and calculate its volume, including extremely irregularly shaped. We conducted a phantom study with sweet potatoes, volunteers and patients with transplanted or enlarged kidneys. The volumetric error decreases from 22% to 15% as the number of sections increases from 4 or 5 to 6 or 9 for patients and potatoes respectively. Best precision was estimated with 9 sections for 15 cm sweet potatoes and 6 sections for 11 cm healthy kidneys. The best skin template is one with two positions for the internal frame, with one section every 1.5 cm.