The value of adding T2 mapping sequence to the routine MRI protocol in the evaluation of cartilage lesions of the ankle joint

Abstract

Ankle joint cartilage injury is frequently associated with degenerative changes, even in the absence of symptoms. Earlier treatment of cartilage damage with joint preservation is clearly more successful. The main limitation of morphologic cartilage magnetic resonance imaging sequences is that they are not very sensitivity in the detection of early cartilage degeneration. Recent advances in biochemical magnetic resonance imaging have yielded sequences that are sensitive to molecular changes in the composition of cartilage matrix. This includes water- and collagen-sensitive T2\T2* mapping. The aim of this study was to determine the extent of improvement of the diagnostic performance of routine magnetic resonance imaging protocol in the evaluation of ankle joint articular cartilage lesions following the addition of a T2 mapping sequence. A total of 45 cases, 30 patients (12 male and 18 female) and 15 controls (10 male and 5 female) who underwent routine ankle magnetic resonance imaging with additional T2 mapping sequence, were included in the study. Out of 30 patients, four patients were misdiagnosed as being normal, while having changes of cartilage composition of early degenerative changes, discovered by T2 mapping sequence. The patients group as well as the-control groups had significantly higher T2-values in the superficial cartilage layer (P < 0.001) compared to the deep layer. When comparing between the medial and the lateral compartments at patients group, the T2-relaxation times were more pronounced in the medial talar cartilage compartment compared to the lateral talar cartilage compartment. Magnetic resonance imaging can observe not only the destruction of the structural integrity but also the change of the components in articular cartilage. In this study, the addition of a T2 mapping of the ankle cartilage sequence to a routine MR ankle protocol improved sensitivity and accuracy in the detection of early cartilage lesions within the ankle joint.