1 Department of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194.
AJR Am J Roentgenol. 2014 Jan;202(1):W106-16. doi: 10.2214/AJR.13.10720.
The purpose of this study was to prospectively evaluate the contrast enhancement, vascular depiction, image quality, and radiation dose of low-tube-voltage whole-body CT angiography (CTA) performed with low-concentration iodinated contrast material.
Whole-body CTA was performed on 109 patients with a 64-MDCT scanner. Patients were randomized into three groups: CTA with 240-mg/mL contrast material at 80 kVp (240-80 group), 300-mg/mL at 80 kVp (300-80 group), and 370-mg/mL at 120 kVp (370-120 group). Signal-to-noise ratio (SNR), arterial depiction, image quality, and radiation dose were assessed. Figure of merit was computed to normalize signal-to-noise ratio, estimated effective dose, and iodine weight.
In the 240-80 group, the mean load of administered iodine was 21.6 g; for the 300-80 group, 26.8 g; and the 370-120 group, 34.0 g (p < 0.05). The ranges of mean vascular enhancement were 508-521 HU, 546-593 HU, and 435-442 HU (p < 0.05). Arterial depiction and image quality were comparable for the 240-80 and 370-120 groups and were greater for the 300-80 group than the other two groups in selected arteries (p < 0.05). Effective dose was higher (p < 0.05) in the 370-120 group (2.8-5.4 mSv) than in the others (2.3-4.3 mSv). The figure of merit in the 240-80 group was greater than (p < 0.05) or comparable to that in the 370-120 group.
Use of 240-mg/mL contrast material at 80 kVp seems appropriate for routine whole-body CTA and beneficial for reduction of iodine load and radiation dose, whereas use of 300-mg/mL contrast material may marginally improve delineation of selected small arteries.
本研究旨在前瞻性评估低浓度碘对比剂行低管电压全身 CT 血管造影（CTA）的对比增强、血管显示、图像质量和辐射剂量。
109 例患者使用 64 层 MDCT 扫描仪进行全身 CTA。患者随机分为三组：240mg/mL 对比剂 80kVp（240-80 组）、300mg/mL 对比剂 80kVp（300-80 组）和 370mg/mL 对比剂 120kVp（370-120 组）。评估信噪比（SNR）、动脉显示、图像质量和辐射剂量。计算优值以归一化信噪比、估算有效剂量和碘重量。
在 240-80 组中，注射碘的平均负荷为 21.6g；在 300-80 组中，为 26.8g；在 370-120 组中，为 34.0g（p<0.05）。平均血管增强范围分别为 508-521HU、546-593HU 和 435-442HU（p<0.05）。240-80 组和 370-120 组的动脉显示和图像质量相当，而 300-80 组在选定的动脉中优于其他两组（p<0.05）。有效剂量在 370-120 组（2.8-5.4mSv）较高（p<0.05），而在其他两组（2.3-4.3mSv）较低。240-80 组的优值大于（p<0.05）或与 370-120 组相当。
80kVp 时使用 240mg/mL 对比剂似乎适用于常规全身 CTA，有利于降低碘负荷和辐射剂量，而使用 300mg/mL 对比剂可能会略微改善选定小动脉的显影。
