Department of Health Sciences, School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Department of Radiology, Saiseikai Fukuoka General Hospital, Fukuoka, Japan.
Eur Radiol Exp. 2021 Apr 27;5(1):18. doi: 10.1186/s41747-021-00217-1.
In this study, we investigated the influence of beam hardening on the dual-energy computed tomography (DECT) values of iodine maps, virtual monoenergetic (VME) images, and virtual non-contrast (VNC) images. 320-row DECT imaging was performed by changing the x-ray tube energy for the first and second rotations. DECT values of 5 mg/mL iodine of the multi-energy CT phantom were compared with and without a 2-mm-thick attenuation rubber layer (~700 HU) wound around the phantom. It was found that the CT density values UH, with/without the rubber layer had statistical differences in the iodine map (184 ± 0.7 versus 186 ± 1.8), VME images (125 ± 0.3 versus 110 ± 0.4), and VNC images (-58 ± 0.7 versus -76 ± 1.7) (p < 0.010 for all). This suggests that iodine mapping may be underestimated by DECT and overestimated by VME imaging because of x-ray beam hardening. The use of VNC images instead of plain CT images requires further investigation because of underestimation.
在这项研究中，我们调查了束硬化对碘图、虚拟单能量（VME）图像和虚拟非对比（VNC）图像的双能 CT（DECT）值的影响。通过改变第一和第二旋转时的 X 射线管能量来进行 320 排 DECT 成像。比较了多能量 CT 体模的 5mg/mL 碘的 DECT 值，有无缠绕在体模周围的 2mm 厚衰减橡胶层（~700HU）。结果发现，在碘图（184±0.7 与 186±1.8）、VME 图像（125±0.3 与 110±0.4）和 VNC 图像（-58±0.7 与-76±1.7）中，带有/不带有橡胶层的 CT 密度值 UH 存在统计学差异（p<0.010 所有）。这表明由于 X 射线束硬化，DECT 可能会低估碘图，而 VME 成像可能会高估碘图。由于低估，使用 VNC 图像代替普通 CT 图像需要进一步研究。
