基于胸部CT机会性筛查的骨质疏松评估研究 进展

Research Progress in Osteoporosis Assessment Based on Opportunistic Screening with Chest CT

摘要: 老年人群骨质疏松症的患病率较高，但是早期诊断率偏低。依靠常规影像学检查开展骨质疏松的机会性筛查，有助于实现疾病的早期发现与干预，减轻社会及医疗负担。双能X线吸收测定法(dual-energy X-ray absorptiometry, DXA)是骨质疏松症诊断的金标准之一，但是存在测量易受干扰、设备普及率低、患者依从性差等缺点。传统定量CT (quantitative CT, QCT)虽然可以测量体积骨密度，但是扫描时需要同时放置外部校准模体，不能对已经完成的常规CT数据进行回顾性分析，限制了它在机会性筛查中的应用。自体模定量CT (phantomless quantitative CT，自体模QCT)用体内组织作内参照，不需要外部校准模体就可以从常规胸部CT中提取骨密度信息，支持回顾性分析，是机会性筛查的重要技术途径。胸部CT在中老年人群中应用广泛，且覆盖有松质骨的胸椎节段，比腹部CT更具机会性筛查优势。但是以往的研究大多集中在腹部CT上，胸部CT在节段标准化、诊断阈值本土化及体成分联合评估等方面还缺乏系统性研究。本文对自体模QCT技术原理、测量层面选择、不同技术路径比较以及体成分联合评估的潜在价值进行了系统的梳理，确定了T11、T12椎体作为测量节段的可行性，提出了“骨密度–肌肉–脂肪”联合评估的策略。未来急需开展以中国人群为对象的多中心研究来建立胸部CT机会性筛查的诊断阈值，推动自动化分析工具的开发，把机会性筛查纳入到骨质疏松的防治指南中，实现大规模早期筛查和综合健康管理。

Abstract: Osteoporosis is highly prevalent in older adults, yet early detection rates remain suboptimal. Opportunistic screening for osteoporosis using routine imaging examinations may enable earlier identification and intervention, thereby alleviating societal and healthcare burdens. Dual-energy X-ray absorptiometry (DXA), one of the diagnostic gold standards for osteoporosis, has notable limitations, including susceptibility to measurement artifacts, limited equipment availability, and poor patient adherence. Although conventional quantitative computed tomography (QCT) can quantify volumetric bone mineral density (vBMD), it requires the concurrent placement of an external calibration phantom during scanning and therefore cannot be applied retrospectively to previously acquired routine CT data, which restricts its utility for opportunistic screening. Phantomless quantitative CT (phantomless QCT; internal-calibration QCT) uses in vivo tissues as internal references, allowing bone density information to be extracted from routine chest CT without an external phantom and enabling retrospective analyses; thus, it represents an important technical approach for opportunistic screening. Chest CT is widely performed in middle-aged and older populations and covers thoracic vertebral segments rich in trabecular bone, offering advantages over abdominal CT for opportunistic screening. However, prior studies have largely focused on abdominal CT, and systematic research on chest CT remains limited with respect to standardized vertebral level selection, localization of diagnostic thresholds, and integrated assessment with body composition. This review systematically summarizes the principles of phantomless QCT, measurement level selection, comparisons among technical pathways, and the potential value of combined body composition assessment. We confirm the feasibility of using the T11 and T12 vertebral bodies as measurement levels and propose a “bone density-muscle-fat” integrated evaluation strategy. Future multicenter studies in Chinese populations are urgently needed to establish diagnostic thresholds for chest CT-based opportunistic screening, accelerate the development of automated analysis tools, and incorporate opportunistic screening into osteoporosis prevention and management guidelines to enable large-scale early screening and comprehensive health management.