Figure 5.

Regions where automatic segmentation failed to delineate bone-cartilage and cartilage-saline boundaries. Upper left-shown at a posterior coronal slice, automatic segmentation did not properly identify the bone-cartilage boundary in regions of suspected low bone density and cartilage-saline boundary where saline failed to imbibe the joint space. Upper right-manual correction of the same coronal image in the upper left was used to better-define the bone and cartilage boundary. Lower left-shown at a sagittal image near the medial wall of the femur, an air bubble introduced into the anterior joint space prevented automatic segmentation of cartilage. Lower right-semi-automatic segmentation of the same sagittal image in the lower left panel corrected the site of the air bubble as indicated by the arrow. Page Width, Color.