为了评估非酒精性脂肪肝患者中骨骼肌脂肪浸润（肌脂肪症）与肝细胞癌（HCC）的关联性，在横断面队列研究中，对72例组织学证实的非酒精性脂肪肝病（NAFLD）患者（其中38例为非酒精性脂肪性肝炎；NASH），其中20例经活检诊断为HCC，我们使用MRI中的质子密度脂肪分数（PDFF）来评估骨骼肌中的肌脂肪症（平均脂肪分数和基于一阶辐照学的模式），在第三腰椎水平即在牵脊肌（ES）、腰方肌（QL）、腰肌、斜肌和腹直肌中。PDFFES在患有HCC的患者中比没有HCC的患者高出70%（分别为9.6 ±5.5%和5.7 ±3.0%，p＜0.001）。在多元逻辑回归中，不受年龄、性别、内脏脂肪面积和肝纤维化阶段的影响，PDFFES是HCC存在的显著预测因子（AUC = 0.72，95% CI 0.57-0.86，p = 0.002）。PDFFES与HCC之间的关系在NASH患者中加剧（AUC = 0.79，95% CI 0.63-0.86，p = 0.006）。在NASH患者中，异质性的放射学特征，如牵脊肌（ES）、腰方肌（QL）或腰肌中的能量和熵，是HCC的独立预测因子。能量ES识别了NASH人群中患有HCC的患者（n = 13），其AUC = 0.92（95% CI 0.82-1.00，p＜0.001）。在NAFLD患者中，特别是NASH患者中，肌脂肪症的程度和异质性与HCC独立关联，无论肝纤维化阶段如何。我们的数据表明，肌脂肪症可以作为日益扩大的NAFLD人群中HCC的生物标志物，并为进一步的纵向研究打下基础。• 非酒精性脂肪肝病患者中，尤其是非酒精性脂肪性肝炎患者中，HCC与寰椎旁骨骼肌的严重脂肪浸润（肌脂肪症）独立相关。• 肌脂肪症与HCC的关联与肝纤维化阶段无关。• 肌脂肪症的直方图辐照学特征预测了非酒精性脂肪性肝炎患者中HCC的风险。© 2023年，作者（专有许可）授权给欧洲放射学协会（European Society of Radiology）。

To evaluate the association between fat infiltration in skeletal muscles (myosteatosis) and hepatocellular carcinoma (HCC) in patients with non-alcoholic fatty liver disease (NAFLD).In a cross-sectional cohort of 72 histologically proven NAFLD patients (n = 38 with non-alcoholic steatohepatitis; NASH), among which 20 had HCC diagnosed on biopsy, we used proton density fat fraction (PDFF) at MRI to evaluate myosteatosis in skeletal muscles (mean fat fraction and first order radiomic-based pattern) at the third lumbar level, namely in erector spinae (ES), quadratus lumborum (QL), psoas, oblique, and rectus muscles.PDFFES was 70% higher in patients with HCC when compared to those without HCC (9.6 ± 5.5% versus 5.7 ± 3.0%, respectively, p < 0.001). In multivariate logistic regression, PDFFES was a significant predictor of the presence of HCC (AUC = 0.72, 95% CI 0.57-0.86, p = 0.002) independently from age, sex, visceral fat area, and liver fibrosis stage (all p < 0.05). The relationship between PDFFES and HCC was exacerbated in patients with NASH (AUC = 0.79, 95% CI 0.63-0.86, p = 0.006). In patients with NASH, radiomics features of heterogeneity such as energy and entropy in any of the paraspinal muscles (i.e., ES, QL, or psoas) were independent predictors of HCC. EnergyES identified patients with HCC (n = 13) in the NASH population with AUC = 0.92 (95% CI 0.82-1.00, p < 0.001).In patients with NAFLD, and more specifically in those with NASH, the degree and heterogeneity of myosteatosis is independently associated with HCC irrespective of liver fibrosis stage.Our data suggest that myosteatosis could be used as a biomarker of HCC in the ever-expanding NAFLD population and pave the way for further investigation in longitudinal studies.• HCC in patients with non-alcoholic fatty liver disease, and more specifically in those with non-alcoholic steatohepatitis, is independently associated with severe fatty infiltration (myosteatosis) of paravertebral skeletal muscles. • Association between myosteatosis and HCC is independent from liver fibrosis stage. • Histogram-based radiomics features of myosteatosis predicts the risk of HCC in patients with non-alcoholic steatohepatitis.© 2023. The Author(s), under exclusive licence to European Society of Radiology.