3D versus 2D ultrasound - Accuracy of volume measurement in human cadaver kidneys

RATIONALE AND OBJECTIVES. Comparison of the accuracy of 3D and 2D ultrasound in assessing the volume of human cadaver kidneys. MATERIALS AND METHODS. Before autopsy the volume of 22 kidneys was assessed from a 3D data set after manually tracing organ contours (3D volumetry) and by applying a 3D ellipsoid formula both on a 3D data set and 2D images. Measurements by water-displacement served as the gold standard. RESULTS. 3D volumetry showed a mean absolute deviation of 31 mL (18.5%) compared with the mean gold standard measurement (168 mL), yielding a concordance correlation (Lin's rho(c)) of 0.71. Calculation based on the ellipsoid formula revealed a mean absolute deviation of 37 mL (22.0%) when applied on the 3D data set (rho(c) = 0.65) and of 42 mL (25.0%) when applied on 2D images (rho(c) = 0.61), respectively. CONCLUSIONS. 3D volumetry showed a satisfactory concordance correlation and is superior to volume calculation based on the ellipsoid formula either applied to a 3D data set or to conventional 2D images in assessing the volume of human cadaver kidneys.