肌肉脂化率主观评分法的稳定性与可靠性研究

The study of stability and reliability of subjective semi-quantitative grading method for leg muscle fatty infiltration in dystrophinopathy

目的：比较3位阅片者肌肉脂化率主观评分结果的一致性,分析主观评分法与客观评分法的相关性,评价抗肌萎缩蛋白病中肌肉脂肪浸润主观评分法的稳定性及可靠性。方法：搜集本院2012年1月-2015年8月抗肌萎缩蛋白病患者194例,行双下肢横轴面T1WI及IDEAL-Quant序列扫描。在横轴面T1WI图像中,由3位不同阅片者分别对所有患者下肢肌肉脂肪浸润程度进行两次主观盲法评分;在IDEAL-Quant脂肪图中测量得出肌肉脂化率。利用kappa检验分析各位阅片者自身及不同阅片者之间主观评分结果的一致性,使用spearman相关模型分析主观评分与IDEALQuant序列脂化率定量结果的相关性。结果：在对所有大腿肌肉脂肪浸润的主观半定量评估中,三位阅片者两次阅片评分结果自身比较Kappa值分别为0.75、0.54、0.55;三位阅片者之间阅片评分结果 Kappa值分别为0.54、0.23、0.22。主观评分结果与客观定量结果相关（r=0.60~0.92,P〈0.05）。但主观评分估计的脂肪浸润程度高于客观定量结果。结论：主观评分法的结果相对稳定、可靠,但与临床经验有关;主观评分法会高估肌肉脂肪浸润程度。

Objective：To analyze the intra-observer and inter-observer agreement of subjective semi-quantitative grading scores.Then to compare subjective semi-quantitative grading method with objective fat quantification method in assessing leg muscle fatty infiltration in dystrophinopathy.Methods：One hundred and ninety-four boys with genetically and/or pathologically confirmed dystrophinopathy were recruited.The axial T1-weighted images and IDEAL-Quant fat fraction maps were obtained.The axial T1-weighted images were visually evaluated by three readers subjectively.The objective muscle fat fraction value could be automatically calculated on GE AW4.6workstation based on fat fraction maps of IDEALQuant sequence.The kappa analysis was used to analyze the intra-and inter-observer agreement.The Spearman correlation was used to compare the two methods.Boxplot diagrams were used to show the differences between them.Results：The average intra-observer agreement values for all the muscles were 0.75,0.54 and 0.55 respectively.The average inter-observer agreement values for all the muscles were 0.54,0.23 and 0.22 respectively.Significant positive correlation was shown between the semi-quantitative and quantitative methods of all the muscles with the correlation coefficient varied from 0.60to0.92（P0.05）,except for the internal obturator muscle and the adductor longus.However,the fat infiltration level evaluated by the semi-quantitative method was higher than the objective method.Conclusion：Subjective semi-quantitative grading method was reliable and stable in evaluating leg muscle fatty infiltration in dystrophinopathy.The Stability was correlated with observer＇s clinical experience.But the subjective semi-quantitative grading method can overestimate the fatty infiltration level.