Role of MRI T2 mapping in assessment of articular Knee Cartilage in Osteoarthritis

Abstract

T2 mapping of hyaline cartilage is an imaging technique for the qualitative and quantitative detection of the cartilage providing convincing color mapping and quantitative detection of the cartilage mainly regarding architecture and changes in water content, proteoglycan, and collagen matrix ultra-structure associated with early cartilage degeneration. This work aims at elucidating the role of MRI complementary T2 mapping in assessment of articular knee cartilage for improving sensitivity of early detection of Osteoarthritis. Also, compare the articular cartilage T2 relaxation values in normal subjects and patients with osteoarthritis. The material of this study included sixty (60) subjects, divided into two groups, 50 patients (symptomatic group: 33 men and 17 women) with clinical evidence of osteoarthritis, and 10 normal control group (asymptomatic group 8 men and 2 women) were included in this study, with their ages ranged between 19-75 years. MR imaging was performed at 1.5 Tesla by using a routine protocol with the addition of a sagittal, coronal, or axial T2 mapping sequence or all. The standard imaging planes of the knee were evaluated with articular cartilage assessment as intact or not. Thereafter, these standard planes were evaluated together with T2 maps and articular cartilage was again assessed as of normal (<48 ms) or elevated (≥48 ms) T2 value in terms of milliseconds. Generalized estimating equation models were used to compare the sensitivity and specificity of the routine MR imaging protocol and T2 maps.