Objective To explore the application value of low tube voltage combined with individ‐ual iodine contrast agent in carotid CTA . Method 120 patients were enrolled and underwent GE Discov‐ery CT 750 HD . Following the study design ,the patients were divided into two groups ,the conventional group and the low dose group ,with 60 cases in each group . The conventional group used 120 kV tube voltage and filtered backprojection (FBP) . The low dose group used 100 kV tube voltage with 50% adap‐tive statistical iterative reconstruction (ASIR) . The rest of the scanning parameters were the same in both groups . In the conventional group ,flow rate for the was 5 mL/s ,and the amount of contrast agent was used by the method of empirical value . In the low dose group ,the flow rate was 4 mL/s ,and the dosage of iodine contrast agent w as individualized:Contrast agent dosage = (t test‐bolus peak time+2 s‐5 s) × injection velocity . The contrast agent ioversol (320 mgI/mL) was used in all tests . The data were uploaded to GE AW4 .5 workstation for reconstruction and analysis . Objective values including gen‐der ,age and other objective values were recorded ,combined with the subjective score for statistical analy‐sis . Data were analyzed by independent samples t test and non parametric test . Results The iodine contrast agent in the low dose group of iodine contrast agent (57 .67 ± 9 .44) mL was lower than that in the conventional group (68 .83 ± 12 .80) mL (P<0 .001) . The effective dose of ionizing radiation in the low dose group (1 .82 ± 0) mSv was lower than that in the conventional group (3 .08 ± 0 .19) mSv (P<0 .001) . The SNR value and CNR value of carotid artery in the low dose group(51 .60 ± 20 .50 ,64 .73 ± 24 .98) were higher than those in the conventional group(31 .24 ± 11 .18 ,39 .70 ± 13 .51)(P<0 .001) ,respectively . The SNR value and CNR value of aortic arch in the low dose group(46 .40 ± 18 .11 ,59 .53 ± 22 .57)were higher than those in the conventional group(27 .21 ± 8 .82 ,35 .67 ± 11 .11)(P<0 .001) ,respectively . There were no significant differences in gender ,age ,height ,weight ,CT value of carotid artery and the image quality between the two groups (P>0 .05) . Conclusion In carotid CTA ,using the tube voltage of 100 kV combined with individual iodine contrast agent not only can meet the needs of clinical diagnosis , but also can effectively reduce the radiation dose and the dosage of iodine contrast agent .%目的：探讨低管电压结合个体化碘对比剂应用方案在颈动脉CT血管成像（CTA）中的应用价值。方法前瞻性纳入在能谱C T行颈动脉C T A成像的受检者120例，采用序贯设计依次分为常规组和低剂量组，每组60例。常规组管电压120 kV ，滤波反投影重建（FBP ）；低剂量组管电压100 kV ，50％自适应统计迭代重建（ASIR）；余各项扫描参数均相同。常规组对比剂流速5 mL／s ，对比剂用量采用经验值法；低剂量组对比剂流速4 mL／s ，对比剂用量采用个体化方案：碘对比剂用量＝（Ttest‐bolus峰值时间＋2 s－5 s）×注射速率。所有受检者均采用碘佛醇对比剂（320 mgI／mL ）。数据上传至GE AW4．5工作站，行图像重建分析。记录受检者的性别、年龄等各项客观数值，计算信噪比（SNR）等数值，结合主观评分，行统计学分析。结果低剂量组碘对比剂用量（57．67±9．44）mL ，低于常规组（68．83±12．80）mL（P＜0．001）；低剂量组有效电离辐射剂量（1．82±0．00）mSv ，低于常规组（3．08±0．19）mSv（P＜0．001）；低剂量组颈动脉SNR、对比噪声比（CNR）（51．60±20．50，64．73±24．98）分别高于常规组颈动脉SNR、CNR（31．24±11．18，39．70±13．51）（P＜0．001）；低剂量组主动脉弓 SNR、CNR （46．40±18．11，59．53±22．57）分别高于常规组（27．21±8．82，35．67±11．11）（ P＜0．001）；2组性别、年龄、身高、体质量指数、颈动脉平均CT值和图像质量主观评分差别均无统计学意义（P＞0．05）。结论在颈动脉CTA成像中，管电压100 kV结合个体化碘对比剂应用方案，不仅能很好满足临床诊断需求，而且能有效降低电离辐射剂量及碘对比剂用量，具有较大应用优势。
展开▼
