T1ρ and T2 mapping of the proximal tibiofibular joint in relation to aging and cartilage degeneration

ObjectiveTo study the effects of aging and cartilage degeneration of the proximal tibiofibular- and femorotibial joint (PTFJ, FTJ) on the cartilage of the PTFJ using T1ρ and T2 mapping.Materials and methodsWe performed sagittal T1ρ and T2 mapping of the PTFJ and FTJ on 55 subjects with knee disorders. We placed 3 regions of interest (ROIs) on images of the cartilage in the PTFJ, medial femoral condyle (MFC), and medial tibia plateau (MTP). Correlation analysis was performed for the T1ρ and T2 values of each ROI and the patient age and the osteoarthritic grade of the PTFJ and FTJ.ResultsThe T1ρ and T2 values of the PTFJ were affected neither by aging nor the osteoarthritic grade of the FTJ. Values of the FTJ normalized to PTFJ values were correlated with the osteoarthritic grade of the FTJ in the MFC (r = 0.851 and 0.779, respectively) and the MTP (r = 0.635 and 0.762, respectively). There was a significant difference in the T1ρ but not the T2 value of the PTFJ and MFC between normal and mildly osteoarthritic cartilage of each joint.ConclusionWe document that the T1ρ and T2 values of PTFJ cartilage were not affected by aging or cartilage degeneration in the FTJ. The T1ρ value of the PTFJ may represent a useful internal standard reference for evaluating early degeneration of the FTJ.