Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University, Yanta Western Road, Xi'an, Shaanxi 710061, China; Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China.
Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China.
Acad Radiol. 2019 Jul;26(7):967-973. doi: 10.1016/j.acra.2018.09.007. Epub 2019 Feb 22.
To investigate the influence of monoenergetic images of different energy levels in spectral computed tomography (CT) on the accuracy of computer aided detection (CAD) for pulmonary embolism (PE).
CT images of 20 PE patients who underwent spectral CT pulmonary angiography were retrospectively analyzed. Nine sets of monochromatic images from 40 to 80 keV at 5 keV interval were reconstructed and then independently analyzed for detecting PE using a commercially available CAD software. Two experienced radiologists reviewed all images and recorded the number of emboli manually, which was used as the reference standard. The CAD findings for the number of PE at different energies were compared with the reference standard to determine the number of true positives and false positives with CAD and to calculate the sensitivity and false positive rate at different energies.
There were 120 true emboli. The total numbers of CAD-detected PE at 40-80 keV were 48, 67, 63, 87, 106, 115, 138, 157, and 226. Images at low energies had low sensitivities and low false positive rates; images at high energies had high sensitivities and high false positive rates. At 60 keV and 65 keV, CAD achieved sensitivity at 81.67% and 84.17%, respectively and false positive rate at 7.55% and 12.17%, respectively to provide the optimum combination of high sensitivity and low false positive rate.
Monochromatic images of different energies in dual-energy spectral CT affect the accuracy of CAD for PE. The combination of CAD with images at 60-65 keV provides the optimum combination of high sensitivity and low false positive rate in detecting PE.
研究能谱 CT 不同能级单能量图像对肺栓塞（PE）计算机辅助检测（CAD）准确性的影响。
回顾性分析 20 例接受能谱 CT 肺动脉造影的 PE 患者的 CT 图像。以 5keV 为间隔重建 40keV-80keV 的 9 组单能量图像，然后使用商业 CAD 软件独立分析这些图像以检测 PE。两位有经验的放射科医师对所有图像进行了回顾，并手动记录了栓塞的数量，将其作为参考标准。比较不同能量 CAD 对 PE 数量的检测结果与参考标准，确定 CAD 检测到的真阳性和假阳性的数量，并计算不同能量的敏感性和假阳性率。
共发现 120 个真栓子。40keV-80keV 时 CAD 检测到的 PE 总数分别为 48、67、63、87、106、115、138、157 和 226。低能量图像的敏感性和假阳性率均较低；高能量图像的敏感性和假阳性率均较高。在 60keV 和 65keV 时，CAD 的敏感性分别为 81.67%和 84.17%，假阳性率分别为 7.55%和 12.17%，可获得高敏感性和低假阳性率的最佳组合。
双能能谱 CT 不同能量单能量图像影响 PE CAD 的准确性。CAD 与 60keV-65keV 图像相结合可在检测 PE 中获得高敏感性和低假阳性率的最佳组合。
