Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University.
Department of Diagnostic Radiology, Red Cross Kumamoto Hospital.
Circ J. 2020 Mar 25;84(4):636-641. doi: 10.1253/circj.CJ-19-0722. Epub 2020 Feb 27.
The aim of this study was to evaluate the quality and diagnostic performance of virtual monochromatic images (VMI) obtained with dual-layer dual-energy computed tomography (DL-DECT) during indirect CT venography (CTV) for deep vein thrombosis (DVT).
This retrospective study was approved by the Institutional Review Board, which waived the requirement for informed consent. We retrospectively enrolled 45 patients who underwent CTV with DL-DECT, and VMI were retrospectively generated. We compared the venous attenuation, noise, contrast, and contrast-to-noise ratio (CNR) between VMI with the highest CNR and conventional CT on paired t-test. Furthermore, we compared the pooled area under the curve (AUC) of each technique with Delong's test in 34 patients who underwent color Doppler ultrasonography. The 40-keV VMI had the best CNR. The noise was significantly lower on 40-keV (9.7±2.5 HU) than on 120-kVp VMI (10.5±2.5 HU; P<0.01). The contrast (120 kVp, 38.2±15.3 HU vs. 40 keV, 131.6±43.6 HU) and CNR (120 kVp, 3.8±1.7 vs. 40 keV, 14.4±6.1) were significantly higher in 40-keV VMI than in 120-kVp VMI (P<0.01). Furthermore, the pooled AUC was significantly higher for 40-keV (0.84) than for 120-kVp VMI (0.78; P=0.03).
In indirect CTV, 40-keV VMI obtained with DL-DECT offers better image quality and diagnostic performance for DVT than conventional CT.
本研究旨在评估双层双能 CT（DL-DECT）间接 CT 静脉造影（CTV）时虚拟单能量图像（VMI）在诊断深静脉血栓（DVT）中的质量和诊断性能。
本回顾性研究获得了机构审查委员会的批准，该委员会豁免了知情同意书的要求。我们回顾性地纳入了 45 例接受 DL-DECT 行 CTV 的患者，并且回顾性地生成了 VMI。我们通过配对 t 检验比较了 VMI 与常规 CT 之间的静脉衰减、噪声、对比和对比噪声比（CNR）。此外，我们对 34 例行彩色多普勒超声检查的患者，用 Delong 检验比较了每种技术的曲线下面积（AUC）。40keV 的 VMI 具有最佳 CNR。40keV 的噪声（9.7±2.5HU）显著低于 120kVp 的 VMI（10.5±2.5HU；P<0.01）。40keV 的对比度（120kVp，38.2±15.3HU 比 40keV，131.6±43.6HU）和 CNR（120kVp，3.8±1.7 比 40keV，14.4±6.1）显著高于 120kVp 的 VMI（P<0.01）。此外，40keV 的 AUC 明显高于 120kVp（0.84 比 0.78；P=0.03）。
在间接 CTV 中，DL-DECT 获得的 40keV VMI 提供了比常规 CT 更好的 DVT 图像质量和诊断性能。
