MRT2图评价膝关节软骨的初步探讨

The pilot study of MR T2 mapping in the cartilage evaluation of knee joint

目的探讨MRT2图（T2 mapping）评价膝关节软骨生物组织构成变化的应用价值。方法对20名健康志愿者运动前后双膝关节、19例骨性关节炎（OA）患者的患膝行矢状面SE序列8回波扫描。测量关节软骨各感兴趣区的T2值，比较志愿者运动前后及运动前浅、深层，以及志愿者与OA患者之间T2值的差异。原始图像经后处理后获得相应的T2图。运动前后T2值的比较采用配对t检验，运动前浅、深层及志愿者与OA患者间T2值的比较采用独立样本t检验。结果志愿者运动前膝关节胫骨面软骨浅、深层的T2值分别为（48．8±6．3）ms、（44．3±5．7）ms；运动后分别为（43．4±5．0）ms、（40．3±6．1）ms，运动前后差异有统计学意义（t值分别为6．004和5．037，P值均〈0．05）；运动前胫骨面软骨浅、深层T2值差异有统计学意义（t=3．148，P〈0．01）。运动前股骨面软骨浅、深层的T2值分别为（52．1±5．7）ms、（47．7±5．3）ms；运动后分别为（47．2±4．5）ms、（43．6±4．1）ms；运动前后差异有统计学意义（t值分别为6．169和5．957，P值均〈0．05）；运动前股骨面软骨浅、深层T2值差异有统计学意义（t=3．384，P〈0．01）。相应的T2图显示了T2值变化的空间分布趋势。OA患者膝关节胫骨面关节软骨T2值为（56．0±9．1）ms，较志愿者要高，两组间比较差异有统计学意义（t=-3．446，P〈0．01）。结论MRT2图可用于评价运动前后、OA时关节软骨生物组织构成的变化，对关节软骨退变诊断具有一定的临床指导价值。

Objective To discuss the value of MR T2 mapping in the research of the biomechanics and function of cartilage of knee joint. Methods Knees of 20 healthy adults before and after jogging and 19 osteoarthritis patients were examined with sagittal 8-echo SE sequence. The T2 value of cartilage was selected and calculated. The T2 values in the superficial and deep cartilage of femoral and tibial joint before and after jogging were compared, so did between the osteoarthritis patients and healthy adults. The source images were sent to the workstation to get T2 mappings. The T2 value of cartilage between before and after jogging was compared with paired-samples t test. The T2 value between superficial and deep cartilage before jogging was compared with independent-samples t test, so did between the osteoarthritis patients and healthy adults. Results The T2 values in the superficial and the deep tibial cartilage were （48. 8 ± 6. 3 ） ms, （44. 3 ± 5.7） ms before jogging and （43.4 ± 5.0） ms, （40. 3 ± 6. 1 ） ms after jogging. The T2 values were significantly different between before and after jogging （ t = 6. 004 and t = 5.037, P 〈 0. 05 ）. There was a significant difference between superficial and deep tibial cartilage before jogging （ t = 3. 148 ,P 〈 0. 01 ）. The T2 values in the superficial and deep femoral cartilage were （52. 1 ± 5.7） ms, （47. 7 ± 5.3 ） ms before jogging and （47. 2 ±4.5 ） ms, （43.6 ± 4. 1 ） ms after jogging. The T2 values were significantly different between before and after jogging（ t = 6. 169 and t = 5. 957, P 〈 0. 05 ）. There was a significant difference between superficial and deep femoral cartilage before jogging（t = 3. 384 ,P 〈0.01 ）. The T2 mapping showed those changes. The mean T2 value in the tibial cartilage of osteoarthritis patients was （56.0 ±9. 1 ） ms and was higher than that of healthy adults. There was a significent difference between osteoarthritis patients and healthy adults （ t = - 3.446, P 〈 0. 01 ）. Conclusion T2 mapping can be used in the research of biomechanics and function of cartilage and has a prelimilary value in the diagnosis of cartilage degeneration.