目的 本研究旨在利用心脏磁共振（cardiac magnetic resonance， CMR）定量评估肌营养不良（muscular dystrophy， MD）相关心肌病患者心外膜脂肪组织（epicardial adipose tissue， EAT）体积，并探讨其与双能X线吸收法（dual-energy X-ray absorptiometry， DXA）测量的全身体成分之间的相关性。 方法 回顾性纳入了2018年1月至2023年12月期间于中山大学孙逸仙纪念医院同时接受3.0T CMR及全身DXA检查的MD相关心肌病确诊男性患儿（患病组），并以年龄、体质量指数（body mass index， BMI）匹配的健康男性儿童作为对照（健康对照组）。使用专用后处理软件于CMR短轴电影序列上手动勾画心包轮廓，计算EAT体积、前室间隔脂肪厚度、左、右房室间隔心外膜脂肪厚度。DXA用于测量全身脂肪质量（fat mass， FM）、全身脂肪分数（fat fraction，FF）以及全身瘦体质量（lean body mass，LBM）。上述所有参数，均除以身高的平方，以标准化得到相关指数，心外膜脂肪体积指数（epicardial adipose tissue volume index，EATVI），全身脂肪质量指数（fat mass index，FMI）、FF以及全身瘦体质量指数（lean body mass index，LBMI）。对比患病组与健康对照组间各参数的差异，通过Pearson相关性分析评估EAT指标与DXA指标之间的关联，通过多因素线性回归分析影响EAT的因素，运用ROC曲线下面积评估EATVI区分患病组与健康对照组的能力。 结果 共纳入55例患病组［年龄（12.42 ± 2.65）岁］和21例健康对照者［年龄（12.67 ± 2.15）岁］，均为男性儿童。患病组与健康对照组EATVI［（28.0 ± 3.3）mL/m²vs. （19.2 ± 2.9）mL/m²］，差异有统计学意义（P < 0.05）。两组前室间隔脂肪厚度指数［（2.75 ± 2.15）mm/m²vs. （2.27 ± 2.24）mm/m²］、左房室隔脂肪厚度指数［（2.83 ± 2.20）mm/m²vs. （2.78 ± 2.64）mm/m²，P > 0.05）］、右房室隔脂肪厚度指数［（4.97 ± 2.59）mm/m²vs. （4.42 ± 3.60）mm/m²］，差异均无统计学意义（P > 0.05）。两组间FMI［（3.93 ± 2.49）kg/m²vs. （2.73 ± 1.38）kg/m²，P < 0.05）］，FF百分比［（18 ± 8） vs. （16 ± 5），P > 0.05）］及LBMI［（14.59 ± 1.90）kg/m²vs. （15.99 ± 1.83）kg/m²，P < 0.05）］。相关性分析显示，EATVI与DXA测量的全身FMI（r = 0.62，P < 0.05）、全身FF（r = 0.47，P < 0.001），均呈正相关。EATVI与全身LBMI（r = - 0.61，P < 0.001）呈显著负相关。线性回归分析结果显示，在调整了其他变量的影响后，BMI、FMI、LBMI以及代谢性疾病状态与脂肪组织指数存在统计学显著关联。运用EATVI区分MD相关心肌病患者与健康对照组的ROC曲线下面积达到0.984。 结论 在MD相关心肌病患者中，基于CMR定量评估的EAT体积与基于DXA测量的躯干及全身脂肪含量密切相关，提示EAT的积累可能反映了MD患者特定的内脏脂肪分布模式。同时，EAT与肌肉萎缩程度相关，强调了在MD患者中脂肪代谢与肌肉消耗之间潜在的交互作用。

Objective The aim of this study was to quantitatively evaluate the volume of epicardial adipose tissue （EAT） in patients with muscular dystrophy（MD）-associated cardiomyopathy using cardiac magnetic resonance （CMR） and to explore its correlation with the total body composition measured by dual-energy X-ray absorptiometry （DXA）. Methods Male children diagnosed with MD-associated cardiomyopathy， who simultaneously underwent 3.0 T CMR and whole-body DXA at Sun Yat-sen Memorial Hospital from January 2018 to December 2023， were retrospectively included in this study. Healthy male children matched for age and body mass index （BMI） served as controls. The EAT volume， anterior septal fat thickness， and left and right atrial septal fat thickness were calculated by manually delineating the pericardium on CMR short-axis cine sequences using dedicated post-processing software. DXA was used to measure fat mass （FM）， fat fraction （FF）， and lean body mass （LBM）. All the above parameters were divided by the square of height and normalized to obtain relevant indexes， namely the epicardial adipose tissue volume index （EATVI）， whole-body fat mass index （FMI）， FF， and whole-body lean body mass index （LBMI）. Pearson correlation analysis was employed to assess the correlation between EAT and DXA. Results A total of 55 children with MD-associated cardiomyopathy ［age （12.42 ± 2.65） years］ and 21 healthy controls ［age （12.67 ± 2.15） years］ were recruited. There was a statistically significant difference in the epicardial adipose tissue volume index between children with MD-associated cardiomyopathy and healthy controls ［（28.0 ± 3.3） mL/m2 vs. （19.2 ± 2.9） mL/m2， P < 0.05］. For the anteroventricular septal fat thickness index ［（2.75 ± 2.15） mm/m2 vs. （2.27 ± 2.24） mm/m2， P > 0.05］， the left atrioventricular septal fat thickness index ［（2.83 ± 2.20） mm/m2 vs. （2.78 ± 2.64） mm/m2， P > 0.05］， and the right atrioventricular septal fat thickness index ［（4.97 ± 2.59） mm/m2 vs. （4.42 ± 3.60） mm/m2， P > 0.05］， no significant differences were found. There were significant differences in the total body fat mass index ［（3.93 ± 2.49） kg/m2 vs. （2.73 ± 1.38） kg/m2， P < 0.05］， the percentage fat fraction ［（18 ± 8） vs. （16 ± 5）， P > 0.05］， and the total body lean mass index ［（14.59 ± 1.90） kg/m2 vs. （15.99 ± 1.83） kg/m2， P < 0.05］. Correlation analysis indicated that the epicardial adipose tissue volume index was positively correlated with the body fat mass index （r = 0.62， P < 0.05） and the body fat fraction （r = 0.47， P < 0.001） measured by DXA. The epicardial adipose tissue volume index was negatively correlated with the total lean body mass index （r = -0.61， P < 0.001）. Conclusions In patients diagnosed with myodystrophic cardiomyopathy， the volume of EAT quantified via CMR exhibits a strong correlation with the trunk and whole-body fat content measured by DXA. This implies that the accumulation of EAT might mirror a distinct visceral fat distribution pattern among patients with MD. Furthermore， the EAT volume was found to be correlated with muscle atrophy， which underscores a potential interplay between the impaired fat metabolism and muscle wasting in these patients.