Rea J A, Li J, Blake G M, Steiger P, Genant H K, Fogelman I
Osteoporosis Screening and Research Unit, Guy's Hospital, London, UK.
Osteoporos Int. 2000;11(8):660-8. doi: 10.1007/s001980070063.
The accurate identification of prevalent vertebral fractures is important in both the clinical and research setting as they are associated with increased risk of further fracture and irreversible clinical consequences. This study reports a direct comparison of prevalent vertebral deformity identification using X-ray absorptiometry (XA) scans, acquired on a dual-energy X-ray absorptiometry (DXA) machine, and conventional radiographs in a diverse group of 161 postmenopausal women, ranging from healthy subjects with normal bone mineral density (BMD) to osteoporotic subjects with multiple vertebral deformities. Deformities were identified by a trained operator by visual assessment of the XA scans (VXA) and semiquantitatively by an experienced radiologist on the conventional radiographs (XSQ). Subjects were recruited prospectively and were triaged according to their VXA results into normal, equivocal and definite deformity groups. VXA and XSQ demonstrated good agreement (96.3%, K = 0.79) in classifying vertebrae as normal or deformed in the 1978 of 2093 vertebrae deemed analyzable on both the XA scans and conventional radiographs. VXA showed good sensitivity (91.9%) in the identification of moderate/severe XSQ deformities and an excellent negative predictive value (98.0%) was produced when VXA was used to distinguish subjects without vertebral deformities from those with possible or definite deformities on a per subject basis. The majority of disagreement between the two methods resulted from different classification of mild wedge and endplate deformities and the poor visualization of upper thoracic vertebrae on the XA scans. Agreement improved, particularly on a per subject basis, when analysis was restricted to the vertebral levels from L4 to T7. Visual triage of XA scans by a trained operator would seem to be swift, convenient and cost-effective method, with excellent negative predictive value, to distinguish subjects with very low risk of vertebral deformities from those with possible deformities. These 'normal' subjects can then be excluded prior to performing conventional radiographs and further time-consuming and costly methods of vertebral deformity assessment such as XSQ by an experienced radiologist and/or quantitative morphometry. VXA may prove useful in the clinical evaluation of patients at risk of osteoporosis as an adjunct to BMD scans or in the selection of subjects for osteoporosis-related clinical trials.
准确识别常见的椎体骨折在临床和研究环境中都很重要，因为它们与进一步骨折的风险增加和不可逆转的临床后果相关。本研究报告了在161名绝经后女性的不同群体中，使用双能X线吸收仪（DXA）机器上获得的X线吸收测定（XA）扫描和传统X线片对常见椎体畸形识别的直接比较，这些女性群体从骨密度（BMD）正常的健康受试者到有多个椎体畸形的骨质疏松受试者。由一名经过培训的操作人员通过对XA扫描进行视觉评估（VXA）来识别畸形，并由一位经验丰富的放射科医生在传统X线片上进行半定量识别（XSQ）。前瞻性招募受试者，并根据他们的VXA结果分为正常、可疑和明确畸形组。在XA扫描和传统X线片上均可分析的2093个椎体中的1978个椎体中，VXA和XSQ在将椎体分类为正常或畸形方面显示出良好的一致性（96.3%，K = 0.79）。VXA在识别中度/重度XSQ畸形方面显示出良好的敏感性（91.9%），并且当使用VXA在个体基础上区分无椎体畸形的受试者与可能或明确有畸形的受试者时，产生了出色的阴性预测值（98.0%）。两种方法之间的大多数分歧源于轻度楔形和终板畸形的不同分类以及XA扫描中上胸椎的可视化不佳。当分析仅限于L4至T7的椎体水平时，一致性有所提高，特别是在个体基础上。由经过培训的操作人员对XA扫描进行视觉分类似乎是一种快速、方便且具有成本效益的方法，具有出色的阴性预测值，可将椎体畸形风险极低的受试者与可能有畸形的受试者区分开来。然后可以在进行传统X线片以及由经验丰富的放射科医生进行进一步耗时且昂贵的椎体畸形评估方法（如XSQ）和/或定量形态测量之前排除这些“正常”受试者。VXA可能被证明在骨质疏松症风险患者的临床评估中作为BMD扫描的辅助手段有用，或者在骨质疏松症相关临床试验的受试者选择中有用。
