Quantitative MR evaluation of the infrapatellar fat pad for knee osteoarthritis: using proton density fat fraction and T2*relaxation based on DIXON

Authors：Chen, Yanjun; Zhang, Xintao; Li, Mianwen; Zhong, Lijie; Ding, Yukun; Zhang, Yaru; Du, Xueting; Mo, Xianfu; Chen, Jialing; Chen, Qianmin; Huang, Wenhua; Zhong, Shizhen^*; Zhang, Xiaodong^*

Source：European Radiology, 2022, 32(7): 4718-4727.

DOI：10.1007/s00330-022-08561-5

• Knee osteoarthritis
• Adipose tissue
• Magnetic resonance imaging
• Disease progression

Objectives To investigate the efficacy of fat fraction (FF) and T2* relaxation based on DIXON in the assessment of infrapatellar fat pad (IFP) for knee osteoarthritis (KOA) progression in older adults. Methods Ninety volunteers (age range 51-70 years, 65 females) were enrolled in this study. Participants were grouped based on the Kellgren-Lawrence grading (KLG). The FF and T2* values were measured based on the 3D-modified DXION technique. Cartilage defects, bone marrow lesions, and synovitis were assessed based on a modified version of whole-organ magnetic resonance imaging score (WORMS). Knee pain was assessed by self-administered Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire. The differences of FF and T2* measurement and the correlation with WORMS and WOMAC assessments were analyzed. Diagnostic efficiency was analyzed by using receiver operating characteristic (ROC) curves. Results A total of 60 knees were finally included (n = 20 in each group). The values were 82.6 +/- 3.7%, 74.7 +/- 5.4%, and 60.5 +/- 14.1% for FF is the no OA, mild OA, and advanced OA groups, and were 50.7 +/- 6.6 ms, 44.1 +/- 6.6 ms, and 39.1 +/- 4.2 ms for T2*, respectively (all p values < 0.001). The WORMS assessment and WOMAC pain assessment showed negative correlation with FF and T2* values. The ROC showed the area under the curve (AUC), sensitivity, and specificity for diagnosing OA were 0.93, 77.5%, and 100% using FF, and were 0.86, 75.0%, and 90.0% using T2*, respectively. Conclusions FF and T2* alternations in IFP are associated with knee structural abnormalities and clinical symptoms cross-sectionally and may have the potential to predict the severity of KOA.

• Institution
  广东医学院; 南方医科大学