Ippolito D, Talei Franzesi C, Fior D, Bonaffini P A, Minutolo O, Sironi S
1 Department of Diagnostic Radiology, San Gerardo Hospital, Monza, Italy.
Br J Radiol. 2015 May;88(1049):20140140. doi: 10.1259/bjr.20140140. Epub 2015 Mar 18.
To assess the diagnostic quality of low dose (100 kV) CT angiography (CTA), by using ultra-low contrast medium volume (30 ml), for thoracic and abdominal aorta evaluation.
67 patients with thoracic or abdominal vascular disease underwent multidetector CT study using a 256 slice scanner, with low dose radiation protocol (automated tube current modulation, 100 kV) and low contrast medium volume (30 ml; 4 ml s(-1)). Density measurements were performed on ascending, arch, descending thoracic aorta, anonymous branch, abdominal aorta, and renal and common iliac arteries. Radiation dose exposure [dose-length product (DLP)] was calculated. A control group of 35 patients with thoracic or abdominal vascular disease were evaluated with standard CTA protocol (automated tube current modulation, 120 kV; contrast medium, 80 ml).
In all patients, we correctly visualized and evaluated main branches of the thoracic and abdominal aorta. No difference in density measurements was achieved between low tube voltage protocol (mean attenuation value of thoracic aorta, 304 HU; abdominal, 343 HU; renal arteries, 331 HU) and control group (mean attenuation value of thoracic aorta, 320 HU; abdominal, 339; renal arteries, 303 HU). Radiation dose exposure in low tube voltage protocol was significantly different between thoracic and abdominal low tube voltage studies (490 and 324 DLP, respectively) and the control group (thoracic DLP, 1032; abdomen, DLP 1078).
Low-tube-voltage protocol may provide a diagnostic performance comparable with that of the standard protocol, decreasing radiation dose exposure and contrast material volume amount.
Low-tube-voltage-setting protocol combined with ultra-low contrast agent volume (30 ml), by using new multidetector-row CT scanners, represents a feasible diagnostic tool to significantly reduce the radiation dose delivered to patients and to preserve renal function, while also maintaining adequate diagnostic quality images in assessment of aorta.
通过使用超低对比剂用量（30毫升）的低剂量（100千伏）CT血管造影（CTA）来评估胸主动脉和腹主动脉，以评价其诊断质量。
67例患有胸或腹部血管疾病的患者使用256层扫描仪进行多排CT检查，采用低剂量辐射方案（自动管电流调制，100千伏）和低对比剂用量（30毫升；4毫升/秒）。对升主动脉、主动脉弓、降主动脉、无名动脉分支、腹主动脉以及肾动脉和髂总动脉进行密度测量。计算辐射剂量暴露[剂量长度乘积（DLP）]。35例患有胸或腹部血管疾病的患者组成的对照组采用标准CTA方案（自动管电流调制，120千伏；对比剂，80毫升）进行评估。
在所有患者中，我们均正确显示并评估了胸主动脉和腹主动脉的主要分支。低管电压方案（胸主动脉平均衰减值为304亨氏单位；腹主动脉为343亨氏单位；肾动脉为331亨氏单位）与对照组（胸主动脉平均衰减值为320亨氏单位；腹主动脉为339亨氏单位；肾动脉为303亨氏单位）之间在密度测量上无差异。胸腹部低管电压研究的低管电压方案中的辐射剂量暴露（分别为490和324 DLP）与对照组（胸部DLP为1032；腹部DLP为1078）有显著差异。
低管电压方案可提供与标准方案相当的诊断性能，同时降低辐射剂量暴露和对比剂用量。
通过使用新型多排CT扫描仪，低管电压设置方案结合超低对比剂用量（30毫升）是一种可行的诊断工具，可显著降低输送给患者的辐射剂量并保护肾功能，同时在主动脉评估中保持足够的诊断质量图像。
