Figure 2
Use of MRI after ACI in joints. (a) The status of the whole knee (sample 7, sagittal T1-weighted spin echo, TR = 722, TE = 20, field of view = 20 cm). (b) Cartilage surface congruity and cartilage overgrowth (arrowhead, sample 3) and (c) cartilage filling a subchondral defect (arrowhead, sample 7) can be identified on 3D T1-weighted images with fat suppression. Similarly, the images can demonstrate changes in the bone, whether uneven bone profile (b) (dotted arrow), cysts in the underlying subchondral bone (d,e) (arrowheads), or artefacts (b) (asterisk). MRI is particularly suitable for longitudinal study of grafts such as can be seen in (d) and (e), which were taken at, respectively, 6 and 30 months after ACI treatment (sample 22, 3D dual excitation in the steady state with fat suppression). 3D = three-dimensional; ACI = autologous chondrocyte implantation; MRI = magnetic resonance imaging; TE = echo time; TR = repetition time.