The feasibility and preliminary application of deltoid muscle volume measurement using MR volume of interest method / 中华放射学杂志

ABSTRACT

Objective To explore the feasibility and repeatability of deltoid muscle volume measurement using MR volume of interest method, and discuss the clinical significance. Methods Seventy-eight subjects'' MR images were retrospectively reviewed including 33 normal shoulders, 22 rotator cuff tear (7 male, 15 female), 12 cases with labrum lesions (11 male, 1 female), and 2 long head of biceps tendon lesions. Routine axial 2D MR images of deltoid muscle were transported into post-processing work station, the matrix of all images were higher than 275 × 336, and the imaging field included the upper and lower margin of the deltoid muscle, and the three dimension shape of muscle was reconstructed by software based on MR volume of interest, then the muscle volume was calculated automatically. This process was independently performed by 2 operators, and operator 1 repeated this process 1 week later. Intra-class correlation coefficient and 95％confidence interval were used to analyze the reliability and repeatability of the measurement. Deltoid muscle volumes of different ages and different pathological processes were compared using stratified sampling method, one-way analysis of variance (ANOVA), least significant difference (LSD) multiple comparison method, and independent-samples t test. Results Three-dimensional shape of deltoid muscle were well demonstrated and corresponded well to the known anatomy. The measurement showed very good inter-and intra-observer consistency (ICC 0.983 and 0.995, respectively). There were statistical differences in deltoid muscle volume between group A and C [volume(382.39 ± 38.87) cm3 and (279.15 ± 63.65) cm3;P=0.000], group B and C [volume(358.49 ± 44.50) cm3 and (279.15 ± 63.65) cm3; P=0.000]. The normal participants were divided by gender into normal group 1 (9 males and 15 females) and normal group 2 (13 males and 1 female) using stratified random sampling method. The deltoid muscle volume of patients with rotator cuff tear was lower than the normal group 1 [volume(313.21±63.48) cm3 versus (359.08±57.98) cm3;t=-2.562, P<0.05], and there was no statistical difference in deltoid muscle volume between labrum-ligament complex lesions patients and the normal group 2 [volume (394.28 ± 33.67) cm3 versus (389.30 ± 22.14) cm3; t=0.385, P=0.704]. Conclusions Volume of interest measurement based on routine MR images could evaluate the deltoid muscle volume conveniently and directly, and which could be used as a preferred choice for muscle volume evaluation.