Dual-energy X-ray absorptiometry (DEXA) is the gold standard for osteoporosis screening and diagnosis. However, abdominal conventional computed tomography (CT) scan is widely available and multiple studies validated its use as a screening tool for osteoporosis compared to DEXA. The aim of this study was to determine the reliability of measuring core muscle size at the L3–L4 intervertebral disk space and estimate the relationship between core muscle size and bone mineral density (BMD) measured by DEXA. Retrospective chart review was performed on patients who underwent a DEXA scan for osteoporosis and a conventional abdominal CT scan within one-year apart. Total cross-sectional area (CSA) and Hounsfield Unit (HU) density of core muscles (psoas, paraspinal, and abdominal wall muscles) were measured. The association between psoas, paraspinal, abdominal, and central muscle CSA and Bone Mineral density (BMD) at L3, L4, total Lumbar Spine (LS), and right (R) and left (L) hip was estimated in crude and adjusted for age and sex linear regression models. Sixty patients (37 females, 23 males) met the inclusion criteria. The average interval between DEXA and abdominal CT scans was 3.6 months (range 0.1–10.2). Psoas muscle density was significantly positively associated with R hip BMD in both crude and adjusted models (β = 20.2, p = 0.03; β = 18.5, p = 0.01). We found a significant positive linear association between psoas muscle CSA and HU density with BMD of LS, R, and L hip in both crude and adjusted models. The strongest significant positive linear association was observed between total abdominal CSA and R hip BMD in crude and age and sex adjusted (ß = 85.3, p = 0.01; ß = 63.9, p = 0.02, respectively). CT scans obtained for various clinical indications can provide valuable information regarding BMD. This is the first study investigating association between BMD with central muscle density and CSA, and it demonstrated their significant positive the association.

双能 X 射线吸收测定法 (DEXA) 是骨质疏松症筛查和诊断的金标准。然而，腹部常规计算机断层扫描 (CT) 扫描广泛可用，多项研究验证了与 DEXA 相比，它作为骨质疏松症筛查工具的用途。本研究的目的是确定在 L3-L4 椎间盘空间测量核心肌肉大小的可靠性，并估计核心肌肉大小与 DEXA 测量的骨矿物质密度 (BMD) 之间的关系。对在相隔一年内接受骨质疏松症 DEXA 扫描和常规腹部 CT 扫描的患者进行回顾性图表审查。核心肌肉（腰大肌、脊柱旁肌和测量腹壁肌肉）。L3、L4、总腰椎(LS) 和右 (R) 和左 (L) 臀部的腰大肌、脊柱旁、腹部和中央肌肉 CSA 与骨矿物质密度 (BMD) 之间的关联以粗略估计并针对年龄和性别线性回归模型。60 名患者（37 名女性，23 名男性）符合纳入标准。DEXA 和腹部 CT 扫描之间的平均间隔为 3.6 个月（范围 0.1-10.2）。在原始模型和调整后的模型中，腰大肌密度与右髋 BMD 显着正相关（β = 20.2， p  = 0.03；β = 18.5， p = 0.01）。我们发现腰大肌 CSA 和 HU 密度与原始模型和调整模型中 LS、R 和 L 髋关节的 BMD 之间存在显着的正线性关联。在原始和年龄和性别调整后的总腹部 CSA 和 R 髋 BMD 之间观察到最强的显着正线性关联（分别为 ß = 85.3，p  = 0.01；ß = 63.9，p  = 0.02）。针对各种临床适应症获得的 CT 扫描可以提供有关 BMD 的宝贵信息。这是第一项调查 BMD 与中心肌肉密度和 CSA 之间关联的研究，它证明了它们之间的显着正关联。