Clinical Medical College, Yangzhou University, Radiology Department, Subei People's Hospital of Jiangsu Province, Yangzhou, China.
Clinical Medical College, Yangzhou University, Radiology Department, Subei People's Hospital of Jiangsu Province, Yangzhou, China.
Clin Radiol. 2014 Apr;69(4):e183-9. doi: 10.1016/j.crad.2013.12.001. Epub 2014 Feb 4.
To evaluate the feasibility of a low-dose contrast medium protocol for 64-detector row computed tomography angiography (CTA) of the neck using a low-tube-voltage/high-tube-current setting.
A phantom study was performed using 64-detector row spiral CT at multiple tube voltage and current settings. Iodine contrast medium attenuation curves were acquired by processing and used to select the best contrast medium-to-noise ratio (CNR). A prospective clinical study was then performed on 84 patients requiring neck CTA. Patients were randomly divided into two groups of 42. Group A was examined using the conventional imaging protocol (120 kV, 400 mAs) and group B was examined at 80 kV and 600 mAs along with a 50% reduction in contrast medium dose. The CT dose index-volume (CTDI(vol)), background noise (BN), and CNR were measured and statistically analysed. Various image quality criteria were evaluated by two senior radiologists using a qualitative five-point scale.
Comparing group B with A, CTDIvol decreased by 54% (B: 27.48 mGy, A: 59.11 mGy), however, the CNR increased by 50%. The mean attenuation, which was caused by venous streak artefacts, was significantly lower in group B than A. Qualitative image analysis found that all criteria were significantly better for group B than A.
At 64-detector row spiral CT, the low-tube-voltage/high-tube-current with low-dose contrast medium protocol was superior to the conventional protocol regarding radiation dose, venous streak artefacts, and image quality, and is feasible for CTA of the neck.
评估低管电压/高管电流设置下使用低剂量对比剂方案进行 64 排螺旋 CT 血管造影（CTA）颈部检查的可行性。
使用 64 排螺旋 CT 在多个管电压和电流设置下进行了体模研究。通过处理获得碘对比剂衰减曲线，用于选择最佳的对比噪声比（CNR）。然后对 84 例需要行颈部 CTA 的患者进行了前瞻性临床研究。患者随机分为两组，每组 42 例。A 组采用常规成像方案（120kV，400mAs）检查，B 组在 80kV 和 600mAs 下检查，并将对比剂剂量减少 50%。测量 CT 剂量指数容积（CTDIvol）、背景噪声（BN）和 CNR，并进行统计学分析。两位资深放射科医生使用定性五分制评估各种图像质量标准。
与 A 组相比，B 组 CTDIvol 降低了 54%（B 组：27.48mGy，A 组：59.11mGy），而 CNR 增加了 50%。B 组静脉条纹伪影引起的平均衰减明显低于 A 组。定性图像分析发现，B 组的所有标准均明显优于 A 组。
在 64 排螺旋 CT 上，低管电压/高管电流低剂量对比剂方案在辐射剂量、静脉条纹伪影和图像质量方面优于常规方案，适用于颈部 CTA。
