Sakane Makoto, Kim Tonsok, Hori Masatoshi, Onishi Hiromitsu, Nakamoto Atsushi, Tsuboyama Takahiro, Tatsumi Mitsuaki, Tomiyama Noriyuki
Department of Radiology, Osaka University Graduate School of Medicine, D1, 2-2, Yamadaoka, Suita, Osaka, 565-0871 Japan.
Springerplus. 2014 May 8;3:234. doi: 10.1186/2193-1801-3-234. eCollection 2014.
The purpose of this study was to compare the effects of high-concentration contrast material and low-voltage CT simulated by virtual monochromatic (VM) imaging on contrast enhancement at multiphasic CT of the upper abdomen.
This study included 72 patients who underwent CT during early arterial (EAP), late arterial and portal venous phases after 300-mgI/ml (Group A; 34 patients) or 350-mg/ml (Group B; 38 patients) contrast-material injection at the same volumetric rate (0.067 mL/sec/kg). VM images were generated at 50 and 65 keV. Contrast-to-noise ratios (CNRs) of aorta, portal vein, and liver parenchyma were calculated and statistically compared.
Mean CNRs for 50-keV VM images were significantly higher than 65-keV VM images of each organ at any phases (p < 0.05), except for hepatic parenchyma in EAP. Aortic CNRs in EAP on 65- and 50-keV images of Group B were significantly higher than Group A (p <0.05, respectively). Aortic CNR on 50-keV images of Group A and on 65-keV images of Group B were 11% and 21% higher than 65-keV images of Group A, respectively.
Low-voltage CT simulated by VM image improved contrast enhancement through any phases, while high-concentration contrast material increased only arterial contrast in EAP more effectively.
本研究旨在比较虚拟单色（VM）成像模拟的高浓度对比剂和低电压CT对上腹多期CT对比增强的影响。
本研究纳入72例患者，在以相同容积速率（0.067 mL/sec/kg）注射300 mgI/ml（A组，34例患者）或350 mg/ml（B组，38例患者）对比剂后，于动脉早期（EAP）、动脉晚期和门静脉期行CT检查。在50 keV和65 keV下生成VM图像。计算主动脉、门静脉和肝实质的对比噪声比（CNR）并进行统计学比较。
除EAP期肝实质外，各期50 keV VM图像的平均CNR均显著高于65 keV VM图像（p <0.05）。B组65 keV和50 keV图像EAP期的主动脉CNR显著高于A组（分别为p <0.05）。A组50 keV图像和B组65 keV图像的主动脉CNR分别比A组65 keV图像高11%和21%。
VM图像模拟的低电压CT在各期均改善了对比增强，而高浓度对比剂仅在EAP期更有效地增加了动脉期对比。
