Imaging & Therapy Systems Division, Healthcare Sector, Siemens Japan K. K., Tokyo, Japan.
Department of Biomedical Sciences and Morphological and Functional Imaging, University of Messina, Messina, Italy.
Invest Radiol. 2018 Jul;53(7):409-416. doi: 10.1097/RLI.0000000000000458.
The aim of this study was to evaluate the diagnostic performance of virtual noncalcium (VNCa) dual-energy computed tomography (DECT) reconstructions enabling visualization of bone marrow edema for characterization of incidental thoracolumbar compression fractures in routine thoracoabdominal staging computed tomography (CT).
We retrospectively analyzed 51 oncological patients without suspected fracture or indicative complaints presenting at least 1 thoracolumbar compression fracture on routine thoracoabdominal staging DECT who had been examined between October 2015 and June 2017 using third-generation dual-source CT, had a previous CT within 3 months before, and also had undergone additional magnetic resonance imaging within 14 days, which served as the standard of reference. Three independent and blinded radiologists initially evaluated all vertebrae on conventional grayscale DECT series; after at least 8 weeks, observers reevaluated all cases using grayscale and color-coded VNCa DECT images. The age of each fracture was determined as either acute, chronic, or inconclusive. Specificity, sensitivity, and intraobserver and interobserver agreements were calculated taking into account clustering.
A total of 98 vertebral compression fractures were detected in 51 patients (20 women, 31 men; median of 1 fracture per patient). The reference standard defined 45 as acute and 53 as chronic. For identification of only acute fractures (cutoff 1), the combination of grayscale and VNCa image series showed a higher sensitivity (91% vs 47%; P < 0.001) but equal specificity (both 100%) compared with analysis of grayscale images alone. When defining a positive finding as a fracture considered either acute or inconclusive (cutoff 2), combined analysis of grayscale and VNCa images showed similar sensitivity (96% vs 93%; P = 0.28) but significantly higher specificity (96% vs 75%; P < 0.001) compared with evaluation of grayscale images alone. Area under the curve analysis for detection of vertebral compression fractures showed superior results for reading of grayscale and VNCa image series (0.98) compared with analysis of grayscale images alone (0.89; P < 0.001).
Dual-energy CT-derived color-coded VNCa reconstructions substantially improve the characterization of incidental thoracolumbar compression fractures seen on routine thoracoabdominal staging DECT by allowing for visualization of bone marrow edema.
本研究旨在评估虚拟非钙（VNCa）双能量计算机断层扫描（DECT）重建在常规胸腹分期 CT 中用于诊断偶然发生的胸腰椎压缩性骨折的骨髓水肿的诊断性能。
我们回顾性分析了 2015 年 10 月至 2017 年 6 月期间在常规胸腹分期 DECT 中至少发现 1 个胸腰椎压缩性骨折且无骨折或提示性症状的 51 例肿瘤患者。所有患者均使用第三代双源 CT 进行检查，且在检查前 3 个月内有之前的 CT 检查，同时在 14 天内进行了额外的磁共振成像检查，作为参考标准。3 位独立且盲法的放射科医生最初对常规灰度 DECT 系列中的所有椎体进行评估；至少 8 周后，观察者使用灰度和彩色编码 VNCa DECT 图像重新评估所有病例。每个骨折的年龄确定为急性、慢性或不确定。考虑到聚类，计算了特异性、敏感性、观察者内和观察者间的一致性。
51 例患者中共检测到 98 个椎体压缩性骨折（20 例女性，31 例男性；每位患者中位数为 1 个骨折）。参考标准将 45 个定义为急性，53 个为慢性。对于仅识别急性骨折（截止值 1），灰度和 VNCa 图像序列的组合显示出更高的敏感性（91%对 47%；P<0.001），但特异性相同（均为 100%），与单独分析灰度图像相比。当将阳性发现定义为考虑为急性或不确定的骨折（截止值 2）时，灰度和 VNCa 图像的联合分析显示出相似的敏感性（96%对 93%；P=0.28），但特异性显著更高（96%对 75%；P<0.001），与单独分析灰度图像相比。用于检测椎体压缩性骨折的曲线下面积分析显示，阅读灰度和 VNCa 图像序列的结果优于单独分析灰度图像（0.98 对 0.89；P<0.001）。
双能 CT 衍生的彩色编码 VNCa 重建通过允许观察骨髓水肿，显著提高了常规胸腹分期 DECT 中偶然发生的胸腰椎压缩性骨折的特征描述能力。
