Accuracy and Reliability of Volume Measurements by 3D Ultrasound: A Prospective Study Performed by Novices

Abstract

Purpose: This study evaluates the accuracy and reliability of off-line volume measurement using virtual organ computer-aided analysis (VOCAL TM ) and two-dimensional (2D) ultrasound by novices.Methods: Thirty medical students, 15 sonographers and three experts were recruited to measure a liver, a gestational sac and a breast cancer lesion using 2D ultrasound and threedimensional (3D) VOCAL TM method. The VOCAL TM measurements produced by the experts were used as the gold standard for comparison. Accuracy and reliability were assessed by analysis of variance followed by a mean separation procedure. Results:The t-test revealed with statistical significance that in measuring the liver, students outperformed sonographers regardless of 2D or VOCAL TM methods; also, VOCAL TM generated more accurate measurements than 2D ultrasound in both groups. In regards to the gestational sac, students continued to perform well with both 2D and VOCAL TM while the sonographers were accurate by using VOCAL TM only. Both groups of novices were not accurate with measuring the breast lesion. VOCAL TM increased the novices' interobserver reliability but not intraobserver reliability. Conclusion:Students and sonographers can measure regularly shaped structures, such as the gestational sac accurately and reliably using VOCAL TM . VOCAL TM increased interobserver reliability in all groups of operators.