Fig. 2
(A) The areas of subscapular muscle (Ssc, red) and infraspinatus and teres minor muscles (Isp + TM, blue) in every axial image are delineated by applying semi-automatic segmentation tools. (B) The 3D models of Ssc and Isp + TM are separated by the Y-view plane (blue), Y + 2.5 cm plane (yellow), and Y + 5 cm plane (red) using the Dynamic Modeler module. Moreover, we implemented a cut off at the plane 3 cm inferior to the lower end of the glenoid labrum (green) to exclude the inferior margin of each muscle volume, because this area was usually out of range in our shoulder CT protocol. (C) For each 3D model of Ssc and Isp + TM muscles, three sections of 3D models were newly created (hence, we obtained six sectional muscle models): from the most lateral end of the muscles to the plane of Y-view (Y section), to the plane 2.5 cm medial to the Y-view (Y + 2.5 cm section), and to the plane 5 cm medial to the Y-view (Y + 5-cm section). For step A, we performed the whole muscle measurement as well.
