High resolution T2∗ mapping in assessment of knee articular cartilage on 3T MRI

• Published in: Journal of clinical orthopaedics and trauma Vol. 27; p. 101823
• Main Authors: Khandelwal, Rachit, Kharat, Amit, Botchu, Rajesh, Koganti, Deepak, Shah, Viraj P.
• Format: Journal Article
• Language: English
• Published: India Elsevier B.V 01.04.2022; Elsevier
• Subjects: 3T MRI; Articular cartilage; Degenerative; General Orthopaedics and Others; Knee joint; ROI areas; T2∗ mapping; Knee joint; Degenerative; 3T MRI; Articular cartilage; ROI areas; T2∗ mapping
• ISSN: 0976-5662; 2213-3445
• DOI: 10.1016/j.jcot.2022.101823

To evaluate the spectrum of T2∗ values in healthy cartilage of young asymptomatic adults on high resolution 3T MRI. A total of 50 asymptomatic adult volunteers with age ranging from 18 to 35 years were enrolled for the study with the purpose of assessing T2∗ values in healthy cartilage without any degenerative changes. The articular cartilage was assessed on two sections, one each through the medial and lateral compartments. The cartilage was segmented into 8 regions through the tibio-femoral and patella-femoral joints. Further post processing was done using multiple ROI placement to delineate ROI areas for calculation of full thickness and zonal (superficial and deep) T2∗ values. Thus, a total of 1200 ROI areas (50 volunteers, 8 segments, and 3 areas for each segment) were assessed. The results revealed a superior bulk T2∗ value of 29.2 ± 3.6 ms from the posterior medial femoral cartilage and 26.1 ± 3.1 ms from the patellar region. Intermediate values were obtained from posterior lateral femoral cartilage, central femoral cartilage, and trochlea. The tibial plateau cartilage had the lowest values – 19.6 ± 2.6 ms for the medial tibial plateau and 20.6 ± 2.8 ms for lateral tibial plateau. The study demonstrated substantial regional physiological variation existing in the T2∗ values across various regions of the knee joint, which could be attributed to varying amounts of shearing forces across the joint. No significant differences were noted in bulk T2∗ values between the two genders, with only the trochlear segment revealing significantly increased values in males (p = 0.007). All the cartilage segments revealed significantly increased T2∗ values in the superficial zone as compared to the deep zone. There is a significant regional difference in the bulk T2∗ values of articular cartilage in a normal physiological state across various joint segments. A zonal gradient with increasing values from the deep to the superficial zone also exists. These findings can prove invaluable in assessing changes in T2∗ values occurring in diseased/degenerative cartilage.