Synarc, Inc., San Francisco, CA 94105, USA.
Osteoporos Int. 2009 Jul;20(7):1199-205. doi: 10.1007/s00198-008-0806-9. Epub 2008 Dec 13.
The utility of vertebral fracture assessment (VFA) by DXA to detect prevalent vertebral fracture in a multicenter setting was investigated by comparison to conventional radiography. While limited by lower image quality, overall performance of VFA was good but had a tendency to miss mild prevalent fractures.
In osteoporosis clinical trials standardized spine radiographs are used to detect vertebral fractures as a study endpoint. Lateral spine imaging with dual X-ray absorptiometry (DXA) scanners, known as vertebral fracture assessment (VFA) by DXA, presents a potential alternative to conventional radiography with lower radiation dose and greater patient convenience.
We investigated in a multicenter setting the ability of VFA to detect fractures in comparison with conventional radiography. The study examined 203 postmenopausal women who had imaging of the spine by DXA and radiography. Three radiologists experienced in vertebral fracture assessment independently read the VFA scans and radiographs using the Genant semiquantitative method on two occasions.
Analyzing the data from all readable vertebrae, the kappa statistic, sensitivity, and specificity ranged from 0.64-0.77, 0.65-0.84, and 0.97-0.98, respectively. Considering only moderate and severe fractures improved the kappa statistic (0.80-0.91) and sensitivity (0.70-0.86). While image quality of VFA is inferior to radiography, the detection of vertebral fractures using visual scoring is feasible. However, VFA underperformed due to unreadable vertebrae and reduced sensitivity for mild fractures. Nevertheless, VFA correctly identified most moderate and severe vertebral fractures. Despite this limitation, VFA by DXA provides an important tool for clinical research.
本研究通过与常规放射摄影比较，调查了双能 X 线吸收法（DXA）的椎体骨折评估（VFA）在多中心环境中检测普遍存在的椎体骨折的效用。尽管受到图像质量较低的限制，但 VFA 的总体性能良好，但存在漏诊轻度普遍性骨折的趋势。
在骨质疏松症临床试验中，标准化的脊柱 X 光片用于检测作为研究终点的椎体骨折。双能 X 射线吸收仪（DXA）的侧位脊柱成像，称为 DXA 的椎体骨折评估（VFA），与常规放射摄影相比，具有潜在的替代方案，其具有较低的辐射剂量和更大的患者便利性。
我们在多中心环境中研究了 VFA 与常规放射摄影相比检测骨折的能力。该研究检查了 203 名绝经后妇女，她们通过 DXA 和放射摄影对脊柱进行了成像。三位具有椎体骨折评估经验的放射科医生在两次检查中使用 Genant 半定量方法独立读取 VFA 扫描和放射照片。
分析所有可读椎体的数据，kappa 统计量、敏感性和特异性分别为 0.64-0.77、0.65-0.84 和 0.97-0.98。仅考虑中度和重度骨折可提高 kappa 统计量（0.80-0.91）和敏感性（0.70-0.86）。虽然 VFA 的图像质量低于放射摄影，但使用视觉评分检测椎体骨折是可行的。然而，由于无法读取椎体和轻度骨折的敏感性降低，VFA 的性能下降。尽管存在这种局限性，但 DXA 的 VFA 为临床研究提供了重要工具。
