目的探讨东芝320排CT采用 自适应迭代剂量降低技术 ( A d a p t i v e Iterative Dose Reduction 3D AIDR 3D)、100kVp条件及低浓度对比剂碘克沙 醇(270mgI/mL)行头颈CTA的临床价值。 方法 收集我院60例临床怀疑头颈部血管 病变患者的头颈CTA资料，随机分成A、B 两组。A组管电压为100 kVp，采用Sure Exposure 3D三维智能剂量控制技术，对 比剂为碘克沙醇270mgI/mL，重建方法为 AIDR 3D。B组管电压120 kVp，对比剂为 优维显(370mgI/mL)，采用滤波反投影重 建(FBP)法。对图像质量进行分析并记录 每例患者接受的辐射剂量，对测量结果 行统计学分析。结果 A、B组的容积剂量 指数(CTDIvol)、剂量长度乘积(DLP)分 别为(5.3±0.9)mGy、(10.3±1.4)mGy及 (191.0±37.6)mGy×cm、(388.1±45.4) mGy×cm，A组较B组低约48.5%、50.8%， P<0.05，差异有统计学意义。A组各血 管CT均值及图像质量评分均高于B组(P ＜0.05)，B组主动脉SNR、CNR高于A组， P<0.05，差异有统计学意义；两组颈内动 脉、颈总动脉及大脑中动脉SNR及CNR差异 无统计学意义。结论 应用100kVp、低浓 度对比剂及AIDR 3D重建算法进行头颈CTA 扫描，可获得较好的图像质量，在不影响 诊断的前提下能大幅度降低患者辐射剂 量。

Objective To investigate the clinical value of low tube voltage (100kVp) , low concentration contrast medium(270mgI/mL) and Adaptive Iterative Dose Reduction 3D in cerebral-and-cervical CT angiography (CTA) with 320-slice CT scanner. Methods The cerebral-and-cervical CTA data of Sixty patients which were suspected as cerebral and cervical vascular disease were collected and the patients were divided into two groups randomly. Patients in group A were performed CTA by using low tube voltage (100 kVp), low concentration contrast medium(270mgI/mL), with the Sure Exposure 3D automatic exposure control system and AIDR 3D reconstruction. Patients in group B using 120 kVp tube voltage, contrast medium of Ultravist (370mgI/mL), with filter back projection (FBP) reconstruction. Statistic analysis was implemented with regard to the CT values, the image quality and the radiation dose values. Results The CTDIvol and DLP reduced 48.5%,50.8% respectively in group A (5.3±0.9)mGy vs 0.3±1.4)mGy ,(191.0±37.6) mGy×cm vs (388.1±45.4)mGy×cm, the differences had statistic significance (P<0.05). The subjective evaluation of the images and CT value of group A were higher than group B, and the differences were statistically significant (P<0.05). The SNR and CNR of the aorta were higher in group B than in group A, the differences were in statistic significance (P<0.05). There was no significant statistic difference between group A and group B for the SNR and CNR of the common carotid artery, the internal carotid artery and the middle cerebral artery. Conclusion Cerebral-and-cervical CTA with low tube voltage and low-concentration contrast by AIDR 3D reconstruction performs higher quality image, and reduces the radiation dose for the patients greatly without image affect for diagnosis.