Imaging Division, Clinical Department of Radiological and Histocytopathological Sciences, University of Bologna, Sant'Orsola, Malpighi Hospital, Via G. Massarenti 9, 40138 Bologna, Italy.
Bone. 2012 Apr;50(4):836-41. doi: 10.1016/j.bone.2012.01.018. Epub 2012 Jan 31.
The aim of this study was to investigate the diagnostic performance of new dual-energy X-ray absorptiometry (DXA) technologies in the detection of vertebral fractures (VFs). Sixty-eight patients were submitted to DXA and conventional radiography (XR) on the same day. Lateral images of the spine were independently evaluated by three radiologists with different experience in skeletal imaging, in two sessions with 7 days between evaluations of the same anonymous images. The most expert physician repeated the analysis in a subsequent reading session after further 7 days. Results from expert XR evaluation were considered as gold standard. A semiquantitative approach was used to interpret images and morphometric analysis was performed when a VF was suspected. Seventy vertebrae (70/884, 7.9%) were excluded from the lesion-based analysis, as not evaluable: 11/70 (15.7%) missed by XR only, 56/70 (80.0%) missed by DXA only, 3/70 (4.3%) missed by both techniques (upper thoracic spine). Forty "true" fractures were detected (4.9% out of 814 vertebrae) in 26 patients (38.2% of the 68 studied patients). Twenty-five (62.5%) were mild fractures. DXA sensitivity and specificity were 70.0% and 98.3% on a lesion-based analysis, 73.1% and 90.5% on a patient-based analysis. Intra-observer agreement was excellent with no significant difference between the two techniques. Inter-observer agreement among the 3 observers was higher for XR (k=0.824 versus 0.720 in the detection of VFs, p=0.011). DXA accuracy was not influenced by radiologist experience; T4-L4 assessability as well as reproducibility and repeatability of the two techniques and accuracy of DXA were independent from sex, age, body mass index, grade of arthrosis. However DXA sensitivity was affected by mild VFs. Vertebral level did not affect the diagnostic performance with exception of vertebral body assessability. Latest improvements make VFs assessment by DXA competitive with traditional radiographic gold standard, providing consistent advantages and attractions. Few limitations still affect DXA performance and need to be overcome.
本研究旨在探讨新型双能 X 射线吸收法（DXA）技术在检测椎体骨折（VF）中的诊断性能。68 例患者于同日行 DXA 和常规 X 射线（XR）检查。脊柱侧位图像由 3 位具有不同骨骼成像经验的放射科医生分别进行评估，两次评估之间间隔 7 天，对相同匿名图像进行评估。最有经验的医生在随后的阅读会议中，在进一步 7 天后重复分析。专家 XR 评估结果被认为是金标准。采用半定量方法解读图像，当怀疑有 VF 时进行形态计量分析。70 个椎体（70/884，7.9%）因不可评估而被排除在病变分析之外：11 个椎体（15.7%）仅被 XR 漏诊，56 个椎体（80.0%）仅被 DXA 漏诊，3 个椎体（4.3%）两种技术均漏诊（胸椎上段）。在 26 名患者（68 名研究患者中的 38.2%）中发现了 40 个“真正”骨折（814 个椎体中有 4.9%）。25 个（62.5%）为轻度骨折。病变分析时，DXA 的敏感性和特异性分别为 70.0%和 98.3%，基于患者的分析分别为 73.1%和 90.5%。观察者内一致性极好，两种技术之间无显著差异。3 位观察者之间的观察者间一致性在 XR 中更高（VF 检测中 k=0.824 对 0.720，p=0.011）。DXA 的准确性不受放射科医生经验的影响；T4-L4 可评估性以及两种技术的可重复性和再现性以及 DXA 的准确性与性别、年龄、体重指数、关节炎程度无关。然而，DXA 的敏感性受到轻度 VF 的影响。椎体水平对诊断性能没有影响，但椎体可评估性除外。最新的改进使 DXA 评估与传统的放射学金标准具有竞争力，提供了一致的优势和吸引力。但仍有一些局限性影响 DXA 的性能，需要克服。
