双低扫描在头颈部CT血管造影中的应用价值

目的 研究低管电压及低对比剂用量对头颈部CTA血管造影图像质量及辐射剂量的影响。 方法 收集经太湖县人民医院行头颈部CTA扫描患者共75例,随机分为4组,每组人数及用药剂量为:A组20人,管电压100 kV,碘剂:1.0 ml/kg,0.9%生理盐水:1.2~1.0 ml/kg;B组19人,管电压100 kV,碘剂:0.8 ml/kg,0.9%生理盐水:1.2~0.8 ml/kg;C组18人,管电压80 kV,碘剂:1.0 ml/kg,0.9%生理盐水:1.2~1.0 ml/kg;D组18人,管电压80 kV,碘剂:0.8 ml/kg,0.9%生理盐水:1.2~0.8 ml/kg。分别记录各组的图像质量评分,辐射剂量长度乘积及有效辐射剂量,颈总动脉CT值,胸锁乳突肌CT值及对比剂用量等。 结果 4组的图像质量评分均达到诊断要求。C、D组的辐射剂量明显低于A、B组;B、D组的对比剂用量低于A、C组,C组颈总动脉CT值明显高于A、B组,4组的胸锁乳突肌CT值无明显差异。 结论 低管电压及低对比剂用量扫描可以用于头颈部CTA血管造影,并且可以在满足诊断要求的前提下,大大减少辐射剂量及碘摄入量。 

The value of low-tube voltage and low contrast agent concentration for head and neck CT angiography

Objective To evaluate the image quality and radiation dose of craniocervical CT angiography (CTA) using low-tube voltage and low volume of contrast material(CM). Methods A total of seventy-five patients who underwent craniocervical CTA in the Taihu county people's hospital were randomly assigned into four groups. The number and dosage of each group were as follows. Group A include 20 cases with 100 kV and 1.0 ml/kg iodine and (1.2-1.0)ml/kg 0.9% normal saline; Group B include 19 cases with 100 kV and 0.8ml/kg iodine and (1.2-0.8)ml/kg 0.9% normal saline; Group C include 18 cases with 80 kV and 1.0 ml/kg iodine and (1.2-1.0)ml/kg 0.9% normal saline; Group D include 18 cases with 80 kV and 0.8 ml/kg iodine and (1.2-0.8)ml/kg 0.9% normal saline; The imaging quality score, dose-length product(DLP), effective dose(ED), the CT value of carotid artery and the CT value of sternocleidomastoid and also the volume of contrast agent were recorded. Results The image quality score of the four groups all reached the diagnostic requirement. The radiation dose of group C and group D was significantly lower than that of group A and group B. The volume of contrast agent in group B and group D was lower than that of group A and C, and the CT value of total carotid artery in group C was significantly higher than those of group A and group B, and there was no significant difference in CT value of the sternocleidomastoid muscle in the four groups. Conclusion Using low-tube voltage and and low volume of CM not only provide images of diagnostic quality but also reduce both radiation dose and iodine intake in craniocervical CTA.