Semi-automatic 3-D Reconstruction Measurement of Muscle Volume with Magnetic Resonance Imaging

Abstract

Background and Objective: We aimed to assess and verify the measurement accuracy and feasibility of semi-automatic magnetic resonance imaging (MRI) volume of interest (VOI) method by comparing its measurements with actual skeletal muscle volumes and discuss the clinical significance. Material and Methods: A total of 18 muscles from 2 pigs were measured by drainage method, VOI method (VVOI), the summation method (Vsum), and maximum section method (Vmax) respectively after MRI scanning. All measurements were performed by 2 musculoskeletal radiologists and repeated at 6 different times, recording the consuming time (minutes) of every muscle. The average result of the 2 radiologists was adopted. Results: The 3-D structure of the skeletal muscles was distinct and vivid. A Friedman test and the inter-class correlation coefficient (ICC) indicated the VOI method had a high intra- and inter-reliability. The root mean square error (RMSE) over 6 time-points was 1.101 mL. A Bland-Altman plot represented a superior consistency. Pairwise Mann–Whitney U testing demonstrated that the consuming time to measure each muscle by VOI method was short. Conclusions: The VOI method could semi-automatically display the 3-D reconstruct of the skeletal muscle clearly, conveniently, with a great accuracy, and high repeatability.