Tian Shi-Feng, Liu Ai-Lian, Liu Jing-Hong, Sun Mei-Yu, Wang He-Qing, Liu Yi-Jun
Department of Radiology, First Affiliated Hospital of Dalian Medical University, Dalian, Shenyang 116011, China.
Chin Med J (Engl). 2015 Mar 5;128(5):610-4. doi: 10.4103/0366-6999.151656.
The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography (CT) virtual noncontrast (VNC) spectral imaging in a retrospective analysis.
Forty hepatic metastases patients underwent CT scans including the conventional true noncontrast (TNC) and the tri-phasic contrast-enhanced dual energy spectral scans in the hepatic arterial, portal venous, and equilibrium phases. The tri-phasic spectral CT images were used to obtain three groups of VNC images including in the arterial (VNCa), venous (VNCv), and equilibrium (VNCe) phase by the material decomposition process using water and iodine as a base material pair. The image quality and the contrast-to-noise ratio (CNR) of metastasis of the four groups were compared with ANOVA analysis. The metastasis detection rates with the four nonenhanced image groups were calculated and compared using the Chi-square test.
There were no significant differences in image quality among TNC, VNCa and VNCv images (P > 0.05). The quality of VNCe images was significantly worse than that of other three groups (P < 0.05). The mean CNR of metastasis in the TNC and VNCs images was 1.86, 2.42, 1.92, and 1.94, respectively; the mean CNR of metastasis in VNCa images was significantly higher than that in other three groups (P < 0.05), while no statistically significant difference was observed among VNCv, VNCe and TNC images (P > 0.05). The metastasis detection rate of the four nonenhanced groups with no statistically significant difference (P > 0.05).
The quality of VNCa and VNCv images is identical to that of TNC images, and the metastasis detection rate in VNC images is similar to that in TNC images. VNC images obtained from arterial phase show metastases more clearly. Thus, VNCa imaging may be a surrogate to TNC imaging in hepatic metastasis diagnosis.
在一项回顾性分析中，使用计算机断层扫描（CT）虚拟平扫（VNC）光谱成像对肝转移瘤进行定性和定量评估。
40例肝转移瘤患者接受了CT扫描，包括传统的真正平扫（TNC）以及肝动脉期、门静脉期和平衡期的三相对比增强双能量光谱扫描。通过以水和碘为基础物质对的物质分解过程，利用三相光谱CT图像获得三组VNC图像，包括动脉期（VNCa）、静脉期（VNCv）和平衡期（VNCe）。采用方差分析比较四组图像中转移瘤的图像质量和对比噪声比（CNR）。使用卡方检验计算并比较四个非增强图像组的转移瘤检出率。
TNC、VNCa和VNCv图像的图像质量无显著差异（P>0.05）。VNCe图像的质量明显低于其他三组（P<0.05）。TNC和VNC图像中转移瘤的平均CNR分别为1.86、2.42、1.92和1.94；VNCa图像中转移瘤的平均CNR显著高于其他三组（P<0.05），而VNCv、VNCe和TNC图像之间未观察到统计学显著差异（P>0.05）。四个非增强组的转移瘤检出率无统计学显著差异（P>0.05）。
VNCa和VNCv图像的质量与TNC图像相同，VNC图像中的转移瘤检出率与TNC图像相似。动脉期获得的VNC图像能更清晰地显示转移瘤。因此，VNCa成像可能是肝转移瘤诊断中TNC成像的替代方法。
