Magnetic Resonance Imaging Prospective Study Of Transplanted Cartilage With Biomechanical Indexes

Objective：To evaluate the value of T2mapping in monitoring the repaired cartilageafter matrix-associated autologous chondrocyte transplantation（MACT）.Methods：9patients （16plug cartilages）were examined four times with MR T2mapping at1，3，6and12months after MACT. In each time point quantitative(full-thickness) T2values were calculated in the transplanted area and control cartilage.Paired t-test was used to compare the T2values in every time point betweentransplanted and control cartilage. For longitudinal analysis of T2values, one-wayanalyse of variance (ANOVA) was performed.Results： The T2values of the repaired area at1，3，6and12months after MACT were82.00±17.73ms、71.56±12.33ms、57.30±6.13ms and49.74±5.15ms, respectively.T2values of transplanted area were longer than that of normal area in each time pointafter MACT, there were significant differences between the transplanted and controlcartilage at1and3months (p <0.05) after MACT, but not at6or12months(p=0.065、0.204). The T2values of transplanted area between1and6months、1and12months、3and6months、3and12months showed significant diffenrence (P<0.05)；but no between1and3months、6and12months (p=0.185,0.527); For controlcartilage, T2values hadn’t significant difference at each time point after MACT (P>0.05).Conclusion：T2mapping can be used to monitor the progression of repaired cartilagenoninvasively and dynamically, which show effective in evaluating the development ofthe transplanted cartilage. Objective：To evaluate the value of delayed Gadolinium-enhanced MRI of cartilage inmonitoring the repaired cartilage after matrix-associated autologous chondrocytetransplantation（MACT）.Methods：9patients （16plug cartilages） were examined four times with delayedgadolinium-enhanced MRI of cartilage at1，3，6and12months after MACT. In eachtime point, the precontrast T1（T1pre）、postcontrast T1（T1post） and△R1(△R1=1/T1post-1/T1pre) were measured in transplanted area and control cartilage. Paired t-testwas used to compare the△R1values between transplanted area and control cartilagein each time point. For longitudinal analysis of△R1values, one-way analyse ofvariance (ANOVA) was performed.Results：The△R1values of the transplanted area at1,3,6and12months after MACTwere2.28±0.38s-1，1.93±0.31s-1，1.53±0.36s-1and1.08±0.15s-1, respectively. The△R1values of the transplanted area were significantly higher than that of controlcartilage at the four time points (P＜0.05). Besides,△R1value of the transplantedarea was gradually close to control cartilage over time. The△R1values showedsignificant differences between1and6months、1and12months、3and6months、3and12months、6and12months at transplanted area (P＜0.05)，but not between1and3months (P=0.55). For control cartilage, R1values had significant difference at thedifferent time points after MACT (P＞0.05).Conclusion：dGEMRIC can quantitatively reflect the biochemical composition ofrepair cartilage, which has important clinical value in the follow-up of the repairedcartilage.