From the Department of Diagnostic and Interventional Radiology, Lausanne University Hospital, Rue du Bugnon 46, 1011 Lausanne, Switzerland.
Radiology. 2018 Mar;286(3):948-959. doi: 10.1148/radiol.2017170325. Epub 2017 Nov 2.
Purpose To test the potential of Dixon T2-weighted fat-only sequences to replace T1-weighted sequences for the detection of bone metastases, with the hypothesis that diagnostic performance with an alternative magnetic resonance (MR) imaging protocol (sagittal spin-echo Dixon T2-weighted fat-only and water-only imaging) would not be inferior to that with the standard protocol (sagittal spin-echo T1-weighted and spin-echo Dixon T2-weighted water-only imaging). Materials and Methods A total of 121 consecutive whole-spine MR imaging examinations (63 men; mean age ± standard deviation, 61.4 years ± 11.8) performed for suspected vertebral bone metastases were included in this retrospective, institutional review board-approved study. Quantitative image analysis was performed for 30 randomly selected spine levels. Qualitative analysis was performed separately by two musculoskeletal radiologists, who registered the number of metastases for each spine level. Areas under the curve with the protocols were compared on the basis of nonparametric receiver operating characteristic curve estimations by using a noninferiority test on paired data, with a best valuable comparator as a reference. Interobserver and interprotocol agreement was assessed by using κ statistics. Results Contrast-to-noise ratio was significantly higher on the alternative protocol images than on the standard protocol images (181.1 [95% confidence interval: 140.4, 221.7] vs 84.7 [95% confidence interval: 66.3, 103.1] respectively; P < .001). Diagnostic performance was not significantly inferior with the alternative protocol than with the standard protocol for both readers in a per-patient analysis (sensitivity, 97.9%-98.9% vs 93.6%-97.9%; specificity, 85.2%-92.6% vs 92.6%-96.3%; area under the curve, 0.92-0.96 vs 0.95, respectively; all P ≤ .02) and a per-spine level analysis (all P < .01). Interobserver and interprotocol agreement was good to very good (κ = 0.70-0.81). Conclusion Dixon T2-weighted fat-only and water-only imaging provide, in one sequence, diagnostic performance similar to that of the standard combination of morphologic sequences for the detection of probable spinal bone metastases, thereby providing an opportunity to reduce imaging time by eliminating the need to perform T1 sequences. RSNA, 2017 An earlier incorrect version of this article appeared online. This article was corrected on November 6, 2017.
通过假设替代磁共振成像（MR）成像方案（矢状自旋回波 Dixon T2 加权脂肪仅和水仅成像）的诊断性能不劣于标准方案（矢状自旋回波 T1 加权和自旋回波 Dixon T2 加权水仅成像），来检验 Dixon T2 加权脂肪仅序列替代 T1 加权序列检测骨转移的潜力。材料与方法：本回顾性、机构审查委员会批准的研究共纳入 121 例连续行全脊柱 MR 成像检查（63 例男性；平均年龄±标准差，61.4 岁±11.8 岁）以疑诊脊柱骨转移。对 30 个随机选择的脊柱水平进行定量图像分析。两名肌肉骨骼放射科医师分别进行定性分析，对每个脊柱水平的转移瘤数量进行登记。基于配对数据的非参数接收器工作特征曲线估计，使用非劣效性检验比较两种方案的曲线下面积，以最佳有价值的比较器作为参考。通过 κ 统计量评估观察者间和协议间的一致性。结果：替代方案图像的对比噪声比显著高于标准方案图像（181.1[95%置信区间：140.4，221.7]与 84.7[95%置信区间：66.3，103.1]；P<0.001）。在每位患者的分析中，替代方案的诊断性能并不明显劣于标准方案（敏感度，97.9%-98.9%与 93.6%-97.9%；特异性，85.2%-92.6%与 92.6%-96.3%；曲线下面积，0.92-0.96 与 0.95；所有 P≤0.02）和每个脊柱水平的分析（所有 P<0.01）。观察者间和协议间的一致性良好至非常好（κ=0.70-0.81）。结论：Dixon T2 加权脂肪仅和水仅成像在一个序列中提供的诊断性能与形态序列标准组合相似，可用于检测可能的脊柱骨转移，从而有机会通过消除对 T1 序列的需求来减少成像时间。RSNA，2017
