Fig. 1

Process for identifying, isolating, and measuring cysts included isolating the subchondral region of 7.5 mm from the subchondral surface (a), cyst identification on CT images (b), and segmenting individual cysts using semi-automatic region growing for larger cysts manual segmentation for smaller cysts (c). Segmented image volumes were then used to measure cyst parameters, and regional BMD excluding cysts which included total, lateral, and medial regions (d)