Objective:To investigate the correlation between MRI signal for infrapatellar fat pad (IPFP) and pathological changes in knee osteoarthritis (KOA),and to analyze the role of IPFP in the development of knee osteoarthritis.Methods:A total of 114 subjects (without special knee disease) were enrolled for this study.The intensity of MRI signal for IPFP was determined by fat-suppressed proton-density-weighted turbospin-echo magnetic resonance imaging.Based on the cartilage defects and osteophytes of knee joint,the subjects were divided into a KOA group and a control group.The difference of MRI signal for IPFP between two groups was analyzed.Results:After excluding the potential confounders of age,gender and BMI,the intensity of MRI signal for IPFP was positively correlated with defections in patellar,medial femur,lateral tibial or knee joint (OR 1.333 to 2.168,P 0.006 to 0.023);the intensity of MRI signal for IPFP was also positively correlated with osteophytes in patellar,medial femur,lateral tibial or knee joint (OR 1.309 tol.781,P 0.004 to 0.046);the intensity of MR/signal for IPFP in the KOA group was significantly higher than that in the control group (P=0.028).Conclusion:The increase in the density of MRI signal for IPFP is an imaging manifestation for knee degeneration.IPFP inflammation and endocrine abnormalities may play an important role in KOA.

Purpose MRI is one of the most effective methods in examining anterior cruciate ligament (ACL),but probability of misdiagnose and missed diagnosis still might exist.This research aims to investigate the effect of oblique coronal MRI views in individualized bent-knee position on the imaging findings of ACL.Materials and Methods Seventy healthy volunteers recruited by the Third Xiangya Hospital,Central South University from September 2016 to March 2017 were involved in this prospective study.3-T MRI combined with independently designed knee joint dynamic imaging auxiliary instrument was employed to perform a dynamic scan in the sagittal plane;the optimal bentknee angle with ACL basically in straight layers (angle of the individualized bent-knee position) was measured.Afterwards,oblique coronal MRI views (PDWI+FS) in both regular extended-knee position and individualized bent-knee position were conducted.And their separate effects on ACL imaging findings in oblique coronal MRI views were compared.Results Oblique coronal MRI scan in extended-knee position and individualized bent-knee position were 92.9％ (65/70) and 45.7％ (32/70) respectively in displaying the imaging of the whole ACL.The former outperformed the latter,and the difference was statistically significant (P＜0.001).Conclusion In contrast to oblique coronal MRI scan in extended-knee position,the scan in individualized bent-knee position elevates the performance of whole ACL imaging.