Fig. 2From: Clinical utility of computed tomography Hounsfield characterization for percutaneous nephrolithotomy: a cross-sectional studyVisual distribution of HUC (1a), HUM (1b), ∆HU (1c), HUD (1d) evaluated in soft tissue (●) and bone (○) scans for all stone types. Legend: HUC = HU at the center of the stone; HUM = HU mean value; ∆HU = difference between HUC and HU at stone’s periphery; HUD = ratio between HUM and stone’s largest diameter at axial planeBack to article page