Fig. 1-A Axial PD/T2-weighted MRI scan of the knee. Fig. 1-B Axial PD fat-suppressed MRI scan of the knee. The arrow indicates the patellar cartilage. Fig. 1-C Coronal PD fat-suppressed MRI scan of the wrist.
Fig. 2-A Sagittal PD MRI scan of the knee without fat saturation. Fig. 2-B Sagittal PD MRI scan of the knee with fat saturation. Note the conspicuity of the marrow edema and contrast medium. Fig. 2-C Sagittal MRI scan of the knee, performed with use of Dixon water excitation in a patient with traumatic injury, showing marrow edema in the posterior aspect of the lateral tibial plateau.
Figs. 3-A through 3-E GRE sequences. Fig. 3-A T1-weighted 3D sequence of the knees (VIBE). The articular cartilage appears hyperintense, and the joint fluid appears hypointense. Fig. 3-B bSSFP sagittal image of the ankle joint. The cartilage has low to intermediate signal intensity, and the joint fluid is hyperintense. Fig. 3-C DESS axial image of the right hip. The articular cartilage has intermediate signal intensity, and the joint fluid is hyperintense. Fig. 3-D DESS coronal image of the wrist. Fig. 3-E MEDIC coronal image of the wrist. The cartilage is hyperintense.
Fig. 5-A T2 map generated for the hip joint in a normal subject (anatomic image). Fig. 5-B Map depicting distribution of T2 values in each voxel. Fig. 5-C Sagittal T2 map for the tibiofemoral joint, showing early increased T2 (areas of red) in a patient with early osteoarthritis and normal cartilage thickness. Fig. 5-D Sagittal T2 map of the knee with Grade-III chondral lesion in the inferior medial patellar facet (arrow).
Fig. 6-A Sequence of events in cartilage degeneration, from macromolecular changes to cartilage thinning and focal defects. Biochemical assessment techniques are capable of detecting the macromolecular changes within the cartilage that occur very early on in the buildup to actual morphological changes. Figs. 6-B and 6-C Coronal (Fig. 6-B) and axial (Fig. 6-C) PD FS images of the knee in a patient with advanced OA, showing Grade-IV chondromalacia, marginal osteophytes, defects, subchondral changes (edema, cysts), and synovial thickening/joint effusion.