能谱CT超双低剂量在头颈联合CTA中的应用价值  

Application of Energy Spectrum CT Double Low Dose Scanning in Cephalo-Cervical CT Angiography

作　　者：吕仁锋[1] 徐哲[1] 袁丽萍[1] 邴晶[1] 

机构地区：[1]大连市中心医院放射线科,116000

出　　处：《临床放射学杂志》2014年第4期616-619,共4页Journal of Clinical Radiology

摘　　要：目的研究能谱CT超低管电压结合超低浓度对比剂(超双低)对头颈联合CTA图像质量和辐射剂量的影响。方法选取我院行头颈联合CTA患者80例,随机分成A、B两组(各40例)。A组管电压80 kVp,对比剂为威视派克270 mgI/ml。B组管电压120 kVp,对比剂为欧乃派克350 mgI/ml。图像重建使用自适应统计迭代算法(ASiR),其他扫描参数不变。记录图像最佳对比噪声比,颈动脉CT均值和噪声均值,辐射剂量及平均碘摄入量。由两位放射医师用4分制评估图像质量,利用SPSS统计软件对数据进行t检验。结果 (1)A组图像对比噪声比高于B组(A组:16.34±2.21;B组:14.53±2.04,t=3.85,P<0.001)。(2)两组图像噪声和图像质量评分分别为9.45±1.04和3.64±0.49分、9.38±0.97和3.52±0.48分,差异无统计学意义(P均>0.05))。(3)A组颈动脉平均CT值[(444.30±40.2)HU]高于B组[(353.00±54.4)HU](t=8.54,P<0.001)。(4)A组辐射剂量明显低于B组,降低约68%(1.25±0.20 mSv和4.02±0.58 mSv),差异有统计学意义(t=28.55,P<0.001))。(5)A组人均对比剂碘摄入量[(230.42±5.04)mgI/kg]低于B组[(303.34±7.34)mgI/kg](t=52.08 P<0.001)。结论能谱CT头颈联合血管成像使用管电压80 kVp及超低浓度对比剂270 mgI/ml可以提供较好的图像对比噪声比,在保证诊断图像质量的同时明显降低了辐射剂量,同时减少了对比剂碘量的摄入,对潜在肾功能损害的患者是一个较好的选择。Objective To investigate the effect of energy spectrum CT scanning with super-low tube kV and super-low contrast concentration （double super-low） on the image quality and radiation dose in cephalo-cervical CT angiography （CTA）. Methods A total of 80 cases who received cephalo-cervical CTA at authors＇ hospital were collected. The pa- tients were randomly and equally divided into group A and group B. For patients of group A 80 KVp tube voltage and low- concentration contrast agent （Visipaque 270mgI/ml） were used in CTA, while for patients of group B 120 KVp tube voltage and usual-concentration contrast agent （Omnipaque 350mgl/ml） were employed in CTA. Using adaptive statistical iterative algorithm （ASiR） the images were reconstructed, the other scanning parameters were the same in both groups. The best contrast to noise ratio （CNR）, the mean CT value and noise of carotid artery, the radiation dose and the average intake of iodine were recorded. Using 4 points scale the image quality was evaluated by two radiologists. Using statistical software SPSS the results were statistically analyzed with t test. Results （ 1 ） The CNR of group A （ 16.34 ± 2.21 ） was higher than that of group B （ 14.53 ±2.04）, the difference was statistically significant （ t = 3.85, P 〈 0. 001 ）. （2） The image noise and image quality scores of group A and group B were （9.45 ± 1.04 and 3.64 ＋ 0.49） and （9.38 ± 0.97 and 3.52 ±0.48 ） respectively, the differences between the two groups were not significant （P 〉 0.05 ）. （3） The mean carotid CT value of group A was （444.30 ± 40.2） HU, which was significantly higher than that of group B （ 353 ± 54.4） HU, the difference between the two groups was significant （ t = 8.54, P 〈 0. 001 ）. （4） The radiation dose of group A was obviously lower than that of group B （ 1.25 ±0.20 mSv vs. 4.02 ±0.58 mSv） , the radiation dose of group A was approximately reduced by 68% when compared with group B. The difference was s

关 键 词：能谱 碘浓度 辐射剂量 迭代算法 

分 类 号：R816.1[医药卫生—放射医学]