不同勾画方法及参数定量评估DLS患者椎旁肌退行性改变的MRI特点

MRI features of paraspinal muscle degeneration in DLS patients quantitatively evaluated by different delineation methods and parameters

目的使用两种不同的椎旁肌勾画方法及多参数定量评估退行性腰椎侧凸(DLS)患者多裂肌、竖脊肌、腰大肌退行性改变的MRI特点。方法收集2019年8月至2022年3月于该院确诊为DLS的患者33例作为试验组,同期招募健康志愿者35例作为对照组,行腰椎常规序列和多回波Dixon-vibe序列MRI检查。在第4腰椎至第5腰椎椎间盘(L 4/5)中心层面的水脂相图中分别对多裂肌、竖脊肌的总肌肉横截面积(TCSA)、纯肌肉横截面积(PCSA)进行勾画测量。采用组内相关系数评估两种勾画方法的一致性,分析两组受试者椎旁肌各参数差异,受试者工作特征(ROC)曲线比较椎旁肌有差异参数的曲线下面积(AUC)。结果TCSA、PCSA在DLS患者多裂肌和竖脊肌中一致性较好(ICC>0.75,P<0.05)。试验组多裂肌和竖脊肌的总肌肉脂肪浸润(TMFI)、纯肌肉脂肪浸润(PMFI)均明显大于对照组(P<0.05),但腰大肌TMFI差异不明显(P>0.05);试验组多裂肌相对PCSA(RPCSA)、相对TCSA(RTCSA)、相对功能面积(RFCSA)均明显小于对照组(P<0.05),但在竖脊肌和腰大肌中仅RTCSA差异明显(P<0.05);两组多裂肌PMFI不对称性(AR PMFI)、TCSA不对称性(AR TCSA),竖脊肌TMFI不对称性(AR TMFI)、PCSA不对称性(AR PCSA),腰大肌AR TCSA比较差异有统计学意义(P<0.05)。多裂肌TMFI、竖脊肌AR PCSA、腰大肌RTCSA在3种肌肉各参数的AUC较大(0.7619、0.7108、0.7126)。结论多回波Dixon-vibe序列对DLS患者多裂肌和竖脊肌的两种勾画方法具有较好的一致性。在L 4/5层面多裂肌的退行性改变表现最突出,肌肉内外受脂肪浸润严重,相对的功能面积减小;竖脊肌表现为纯肌肉面积的不对称程度明显增大;腰大肌相对的横截面积表现出明显减小。

Objective To quantitatively evaluate the MRI features of multifidus,erector spinae and psoas muscle degeneration in patients with degenerative lumbar scoliosis(DLS)using two different paraspinal muscle delineation methods.Methods A total of 33 patients diagnosed with DLS in the hospital from August 2019 to March 2022 were collected as the experimental group,and 35 healthy volunteers were recruited as the control group during the same period.Routine lumbar spine sequence and multi-echo Dixon-vibe sequence MRI were performed.The total muscle cross-sectional area(TCSA)and pure muscle cross-sectional area(PCSA)of the multifidus muscle and erector spinae muscles were measured in the water-fat phase diagram at the 4/5 center level of the lumbar intervertebral disc(L 4/5).The intra-group correlation coefficient was used to evaluate the consistency of the two different delineation methods.The differences of paraspinal muscle parameters between the two groups were analyzed.The receiver operating characteristic(ROC)curve was used to compare the area under the curve(AUC)of the paraspinal muscle with different parameters.Results TCSA and PCSA had good consistency in multifidus and erector spinae in DLS patients(ICC>0.75,P<0.05).The total muscle fat infiltration(TMFI)and pure muscle fat infiltration(PMFI)of multifidus and erector spinae in the experimental group were significantly higher than those in the control group(P<0.05),but there was no significant difference in TMFI of psoas major(P>0.05).The relative PCSA(RPCSA),relative TCSA(RTCSA)and relative functional area(RFCSA)of multifidus muscle in the experimental group were significantly lower than those in the control group(P<0.05),but only RTCSA parameters were significantly different in erector spinae and psoas major(P<0.05).There were significant differences in PMFI asymmetry(AR PMFI),TCSA asymmetry(AR TCSA),erector spinae TMFI asymmetry(AR TMFI),PCSA asymmetry(AR PCSA),and psoas major AR TCSA between the two groups(P<0.05).The AUC of multifidus muscle TMFI,erector spinae muscle AR PCSA and psoas major muscle RTCSA were larger in the three muscles(0.7619,0.7108,0.7126).Conclusion The multi-echo Dixon-vibe sequence has good consistency with the two delineation methods of multifidus and erector spinae in DLS patients.At the L 4/5 level,the degenerative changes of the multifidus muscle were the most prominent,the fat infiltration inside and outside the muscle was serious,and the functional area was reduced.The erector spinae showed a significant increase in the asymmetry of the pure muscle area,while the relative cross-sectional area of the psoas major showed a significant decrease.