肌肉减少是肌肉衰弱的已知特征，并预示着不良临床预后。虽然肌肉指标可以从常规计算机断层扫描（CT）图像中得出，但缺乏针对多个椎体水平以及广泛年龄范围的性别特异参考值。本研究的目标是提供社区为基础的弗雷明翰心脏研究队列中胸部和腹部CT扫描中骨骼肌肉质量和密度的参考值，以协助识别肌肉衰弱。该前瞻性试验的二次分析描述了在2002年至2011年期间至少进行过1次CT扫描且无癌症病史的弗雷明翰心脏研究参与者的肌肉指标按年龄和性别进行分析。利用2个先前验证过的机器学习算法，随后进行人工质量保证，对每个级别的单个轴向CT图像上的骨骼肌进行分析，包括第5、第8、第10胸椎和第3腰椎的横断面肌肉面积（cm²）、平均骨骼肌放射性衰减（SMRA，以霍恩斯菲尔德单位表示）、骨骼肌指数（SMI，以cm²/m²表示）以及骨骼肌测量（SMRA·SMI）。测量结果按年龄组（<45岁、45-54岁、55-64岁、65-74岁、≥75岁）、性别和椎体水平进行总结。已创建了能够计算年龄、性别和椎体水平特异性参考值的模型，并嵌入开放访问的在线网络应用程序中。这个队列包括3804名参与者（1917名[50.4%]男性；平均年龄55.6±11.8岁；范围33-92岁）和7162份CT扫描。肌肉指标在年龄增长和女性上呈定性减少。本研究建立了基于胸椎和腰椎水平CT的肌肉指标的年龄和性别特异参考值。这些值可用于未来研究探讨肌肉质量和密度在健康和疾病中的作用，以及识别肌肉衰弱。 版权所有©2023 Wolters Kluwer Health，Inc. 保留所有权利。

Loss of muscle mass is a known feature of sarcopenia and predicts poor clinical outcomes. Although muscle metrics can be derived from routine computed tomography (CT) images, sex-specific reference values at multiple vertebral levels over a wide age range are lacking.The aim of this study was to provide reference values for skeletal muscle mass and attenuation on thoracic and abdominal CT scans in the community-based Framingham Heart Study cohort to aid in the identification of sarcopenia.This secondary analysis of a prospective trial describes muscle metrics by age and sex for participants from the Framingham Heart Study without prior history of cancer who underwent at least 1 CT scan between 2002 and 2011. Using 2 previously validated machine learning algorithms followed by human quality assurance, skeletal muscle was analyzed on a single axial CT image per level at the 5th, 8th, 10th thoracic, and 3rd lumbar vertebral body (T5, T8, T10, L3). Cross-sectional muscle area (cm2), mean skeletal muscle radioattenuation (SMRA, in Hounsfield units), skeletal muscle index (SMI, in cm2/m2), and skeletal muscle gauge (SMRA·SMI) were calculated. Measurements were summarized by age group (<45, 45-54, 55-64, 65-74, ≥75 years), sex, and vertebral level. Models enabling the calculation of age-, sex-, and vertebral-level-specific reference values were created and embedded into an open access online Web application.The cohort consisted of 3804 participants (1917 [50.4%] males; mean age, 55.6 ± 11.8 years; range, 33-92 years) and 7162 CT scans. Muscle metrics qualitatively decreased with increasing age and female sex.This study established age- and sex-specific reference values for CT-based muscle metrics at thoracic and lumbar vertebral levels. These values may be used in future research investigating the role of muscle mass and attenuation in health and disease, and to identify sarcopenia.Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.