基于磁共振分区的健康膝关节软骨T2图

T2 Mapping of Articular Cartilage in the Healthy Knee Using A Magnetic Resonance Segmentation

目的在磁共振分区的基础上,探讨T2图在健康膝关节软骨不同区域的表现和运用。方法将77名健康人胫股关节按年龄分为H1组（〈40岁）和H2组（≥40岁）,计算体重指数并行T2图成像,按照全器官磁共振成像评分分区测量关节软骨10个亚区的T2值,比较各亚区组间、组内各亚区间及性别间T2值的差异、T2值与体重指数及年龄的相关性,并评价T2值测量的观察者间和观察者内信度。结果健康人胫股关节软骨各亚区T2值为40.3~53.5 ms。除股骨外侧后区外,H2组各亚区T2值显著高于H1组（P≤0.032）。组内T2值在各亚区间差异具有统计学意义（P〈0.001）。除H2组胫骨内侧后区（P=0.048）外,组内其余各亚区T2值性别差异均无统计学意义。除H2组胫骨外侧中区（P=0.050,R=0.308）外,组内其余各亚区T2值与体重指数均无相关性。T2值在H1组胫骨内侧前区（P=0.004,R=-0.467）、胫骨外侧前区（P=0.024,R=-0.375）、H2组胫骨各亚区（除胫骨外侧前区）以及股骨内侧中区（P=0.004~0.015,R=0.376~0.437）与年龄具有相关性。观察者内和观察者间具有可信度（R〉0.809,P≤0.005）。结论以全器官磁共振成像评分分区为基础的膝关节软骨T2图加强了对功能承重区的关注,有效反映了T2值的变化和与危险因素间的关系。

Objective To evaluate T2 mapping of the healthy knee articular cartilage in different subregions using a magnetic resonance segmentation.Methods T2 mapping was performed to 77 healthy tibiofemoral cartilages,which were divided into group H1（40 years old） and group H2（≥40 years old）.T2 values of cartilage in 10 subregions based on the Whole-Organ Magnetic Resonance Imaging Score（WORMS） segmentation and body mass index（BMI） were calculated.T2 values of cartilage in 10 subregions were compared.The association between T2 value and BMI/age was analyzed.The intra-and inter-observer reproducibility of measurement was calculated.Results The T2 values of all the subregions ranged 40.3-53.5 ms.T2 values of group H2 were significantly higher than those in group H1（P≤0.032） except in posterior lateral femoral subregion.The inter-subregion differences within group were significant（P0.001）.The inter-gender differences were significant only in posterior medial tibial subregion of group H2（P=0.048）.No correlation of T2 values with BMI was found except in cetral lateral tibial subregion of group H2（P=0.050,R=0.308）.T2 values were correlated with age in anterior medial（P=0.004,R=-0.467） and anterior lateral（P=0.024,R=-0.375） tibial subregions of group H1,and in all tibial subregions except anterior lateral tibial subregion of group H2,and central medial femoral subregion of group H2（P=0.004~0.015,R=0.376~0.437）.The correlation coefficients for intra-and inter-observer of measurement showed good reproducibility（R0.809,P≤0.005）.Conclusion T2 mapping of the healthy knee articular cartilage based on the WORMS segmentation can effectively reflect the changes and correlations of T2 values with risk factors by focusing on the functional weight-bearing subregions.