Fig. 1

a Sagittal STIR (left), post-contrast T1 FS (T1 CE FS) (middle) and dynamic contrast enhanced MR images (DCE-MRI) (right) in one patient through the medial joint compartment with region of interests (ROIs) drawn in the weight-bearing femoral condyles. Computer assisted segmentation of BML on the STIR and T1 CE FS images is shown; the marked pixels represent areas above the threshold signal intensity, i.e., STIR-BML and CEA-BML, respectively. An area with rapid and steep enhancement (right image) is seen in the femoral condyle, yellow color. Pixels exhibiting a pathologic enhancement pattern within the ROI are visualized and segmented digitally. b Corresponding STIR (left) and T1 CE FS images (right) without ROI or pixel segmentation. (BML=bone marrow lesion, CEA-BML=contrast enhancing areas of bone marrow lesion)