双源CT大螺距模式联合超低容量、低浓度对比剂及低X线剂量技术在颈动脉CTA中的临床应用价值  

The Clinical Value of Carotid CTA Using High-Pitch Mode with Ultra-Low Volume,Low Concentration Contrast Media and Low Voltage

作　　者：蓝文婷[1,2] 俞哲锋[1] 邝平定[1] 丁信法[1] 张敏鸣[1] LAN Wenting YU Zhefeng KUANG Pingding et al(Department of Radiology, the Secomd Affiliated of Zhejiang University Medical College, Hangzhou, Zhejiang Province 310009, P. R. China)

机构地区：[1]浙江大学医学院附属第二医院放射科,310009 [2]浙江大学宁波医院(浙江省宁波市第一医院)放射科

出　　处：《临床放射学杂志》2016年第11期1764-1769,共6页Journal of Clinical Radiology

摘　　要：目的探讨双源CT大螺距模式下超低容量(30 ml)、低浓度对比剂(270 mg I/ml)、低管电压(80 k V)技术用于颈部动脉CTA的可行性。方法选取60例颈动脉CTA患者,随机分成两组,双低实验组使用超低容量(30ml)、低浓度(270 mg I/ml)对比剂、低电压(80 k V),常规对照组为60 ml高浓度(370 mg/ml)对比剂、高电压(120k V),比较两组间图像质量,包括主观评分、颈动脉各段血管CT值,并计算对比噪声比(CNR)。辐射剂量比较两组的剂量长度乘积(DLP)、CT容积剂量指数(CTDIvol)、有效辐射剂量(ED)值。结果双低实验组与常规对照组各段血管内CT值均在300 HU以上,双低实验组的各段血管平均CT值均大于常规对照组;常规对照组的CNR较实验组稍高(91.8±8.1、69.6±6.3,P=0.045),但主观评分图像质量两组间无差异(3.5±0.2和3.7±0.1,P=0.59),不影响临床诊断结果。常规对照组和双低实验组的DLP分别为(396.2±56.4)m Gy·cm和(69.2±3.1)m Gy·cm;CTDIvol分别为(13.2±2.2)m Gy和(1.9±0.1)m Gy,ED分别为(11.8±1.4)m Sv和(2.1±0.3)m Sv,双低实验组较常规对照组分别降低85.6%、82.5%、82.2%,存在显著性差异;且总碘摄入量减少63.5%。结论双源CT大螺距模式下联合使用30 ml超低容量和270 mg I/ml低浓度对比剂、80 k V颈动脉CTA检查,能在满足临床诊断需要的同时大幅度减低对比剂使用量及X射线剂量,为高危患者尤其是肝肾功能不全者提供了一种安全性更好的检查方法。Objective To investigate the clinical value of carotid CTA using high-pitch mode and dual-low dose technology （ 30ml ultra-low contrast volume,270mgI/ml low concentration contrast media and 80kV low tube voltage）. Methods 60 consecutive carotid CTA examinations were randomly divided into two groups： a dual-low experimental group and a control group. We compared the radiation dosage （DLP, CTDIvol, ED, CNR） and image quality （CT values, contrast noise rate of carotid artery and subjective scores）. Results The CT values of all vascular segments of the two groups were all above 300 HU, meeting the diagnostic requirements. The CT values of the dual-low experimental group were higher than the control group. Dosage of the control and dual-low experimental groups ： DLP （era） of the two groups were （ 396.2 ± 56.4）mGy ·cm,（69.2 ±3.1）mGy · cm; CYDIvol was （13.2 ±2.2）mGy and （1.9 ±0.1）mGy; ED was （11.8 ±1.4） mSv and （2.1 ± 0.3） mSv respectively. Compared with the control group, DLP, CTDIvol, ED values of the dual-low experimental group were reduced by 85.6%. 82.5% , 82.2% respectively. The total iodine intake amount was reduced by 63.5%. For the image quality , the contrast noise rate （CNR） value of the control group was higher than the dual-low group （91.8 ± 8.1 vs 69.6 ± 6.3,P = 0. 045 ）, but the subjective scores showed no obvious difference（3.5 ± 0.2 vs 3.7 ± 0.1 P = 0.59） which doesnt influence the clinical diagnosis. Conclusion The dual：low dosage technology （ultra-low volume low concentration contrast, and low tube voltage）with high pitch mode can provide satisfactory images, meanwhile the radiation dosage can be slgnificantly reduced, moreover the iodine intake amount is decreased greatly. This technique is an ideal safer option for carotid CTA, especially for patients with renal dysfunction.

关 键 词：颈动脉CTA 辐射剂量 对比剂低容量 低浓度 低电压 大螺距 

分 类 号：R816.1[医药卫生—放射医学] R743[医药卫生—临床医学]