Cartilage Repair Surgery: Outcome Evaluation by Using Noninvasive Cartilage Biomarkers Based on Quantitative MRI Techniques?

Figure 4

Upper row: dGEMRIC-MACI. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) of a 39-year-old male patient 24 months after MACI of the lateral femoral condyle (marked by arrows). Images (A) and (B) represent the raw images with the different flip angles on which the dGEMRIC-T1 map is based (C). The T1-dGEMRIC map shows slightly reduced GAG content in the repair tissue. Lower row: dGEMRIC-MFX. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) of a 42-year-old male patient 24 months after microfracture therapy of the patella cartilage (marked by arrows). Images (A) and (B) represent the raw images with the different flip angles on which the dGEMRIC-T1 map is based (C). The T1-dGEMRIC map showed a clearly reduced GAG content in the repair tissue. For T1-Gd mapping, we used a 3D gradient echo (GRE) sequence with a TR of 15 ms, a TE of 1.95 ms, and two flip angles of 5° and 18.6°. The field of view was 160 × 160 mm, the pixel matrix was 384 × 384, and the voxel size was 0.4 × 0.4 × 3.0 mm; the bandwidth was 480 Hz/pixel and 22 slices were assessed with a total acquisition time of 3:40 minutes.