100kVp条件下碘克沙醇(270mgI/mL)应用于头颈部CTA检查的可行性研究

Feasibility of CT angiography of head and neck using 100kVp as tube voltage with iodixanol(270mg I/mL)as contrast medium

目的:探讨100kVp条件下应用碘克沙醇(270mg I/mL)行头颈部CTA检查的可行性。方法:连续40例行头颈部CTA检查的患者,根据检查方案分为A、B两组进行评价。A组:使用碘帕醇(370mg I/mL),管电压120kVp,噪声指数(NI)13,共20例;B组:使用碘克沙醇(270mg I/mL),管电压100kVp,NI 11,共20例。读取CT剂量报告中的容积剂量指数(CTDIvol),计算体型特异性剂量估计(SSDE)值。图像质量主观评价:采用双盲法由两位具有3年以上CT诊断经验的医师采用5分法进行评价。图像质量客观评价:测量并分析两组中主动脉、颈总动脉、颈内动脉及大脑中动脉的CT值和标准差(SD)。结果:A、B组中患者年龄[分别为(64.55±8.76)岁和(63.65±14.06)岁]和BMI[(23.92±2.23)和(23.56±2.20)kg/m2]的差异无统计学意义(P>0.05)。A、B两组间CTDIvol[分别为(33.39±2.53)和(26.76±1.03)mGy]和SSDE[分别为(66.27±4.01)和(53.58±2.06)mGy]的差异有统计学意义(P<0.05)。A、B组间主观评分(分别为4.20±0.62和4.10±0.55)的差异无统计学意义(P>0.05)。客观评价:两组间主动脉、颈总动脉、颈内动脉和大脑中动脉的CT值及SD值的差异均无统计学意义(P>0.05)。结论:100kVp条件下、应用碘克沙醇(270mg I/mL)行头颈部CTA检查,在图像质量保持不变的情况下,可降低辐射剂量并减少对比剂使用量。

Objective：To evaluate the feasibility of using 100kVp as tube voltage and 270mg I/mL iodixanol as con- trast medium in head and neck CT angiography （CTA）. Methods： Forty consecutive patients underwent head and neck CTA. Patients were divided into group A and group B according to different CT protocols. Group A：20 patients, Iopamidol （370mg I/mL） as contrast medium, tube voltage 120kVp, noise Index 13 ; group B： 20 patients, Iodixanol （270mg I/mL） as contrast medium,tube voltage 100kVp,noise Index 11. CT dose index （CTDIvol） was recorded and size-specific dose estimate （SSDE） was calculated. The subjective evaluation of CTA image quality was obtained by 2 radiologists having more than three years experience of CT diagnosis, using double blind method with five scale score. CT attenuation and standard deviation of vessel lumen （including aorta, common carotid artery,internal carotid artery） were measured and used as objec tive evaluation of image quality. Results： There was no significant statistic difference in age [（64. 55 ± 8. 76）years vs （63.65±14.06） years,P〉0.05] and BMI [（23.92±2.23）kg/m^2 vs （23.56±2.20）kg/m^2 ,P〉0.05] of two groups. The mean values of CTDIvol [（33.39±2. 53）mGy vs （26. 76±1. 03）mGy,P〈0. 05] and SSDE [（66. 27±4. 01）mGy vs （53.58±2.06）mGy,P〈0.05] in Group A were higher than those of group B, with significant statistic difference. There was neither significant difference in subjectively evaluated image quality （4.2±0.69. vs 4.1±0.55 ,P〉0.05） ,nor in objectively evaluated image quality showing as CT values of blood vessel lumen between the 2 groups,as well as the standard deviation of CT value （P）0.05）. Conclusion： Head and neck CTA with tube voltage as 100kVp and Iodixanol （270mg I/mL） as contrast medium can reduce radiation dose and contrast medium load, providing satisfactory image quality for clinical application.