摘要
目的探讨多层螺旋CT颈部血管造影(CTA)低剂量扫描的可行性和合理性。资料与方法将常规行颈部CTA检查的患者60例随机分为A、B、C三组,每组20例。在其他扫描参数不变的情况下,A组采用常规剂量250 mAs、B组采用150 mAs、C组采用100 mAs条件行CTA扫描。以图像显示解剖结构及病变的情况为主要指标,比较B、C两种低剂量组扫描所得图像质量与常规剂量A组扫描图像质量的差异。结果当mA值由常规250mAs降低至150 mAs和100 mAs时,CT剂量加权指数(CTDI)由16.7 mGy分别降至10.0 mGy和6.7 mGy,下降40.1%和59.8%;剂量长度积(DLP)由(564.6±32.5)mGy分别降至(336.2±24.5)mGy和(204.3±33.7)mGy,下降40.5%和63.8%。B、C组与A组比较,剂量差异均有统计学意义(P<0.01);而B组图像质量与A组比较,差异无统计学意义(P>0.05);C组图像质量与A组比较,差异有统计学意义(P<0.05)。结论150 mAs可作为颈部CTA低剂量扫描的最佳mA值,适当降低管电流是一种切实可行的降低辐射剂量的CTA扫描方法。
Objective To study the rationality and possibility of muhi-slice spiral CT in the examination of the cervical arteries CT angiography at low-dose. Materials and Methods 60 cases by routine cervical arteries CT angiography were randomly divided into three groups,group A, group B and group C. With the others scanning parameters kept unchanged, the patients in group A were scaned with a routine dose of 250 mAs,the others in group B and C were scaned with a low （lose of 150 mAs and 100 mAs. Anatomic structures and lesions showed on images were chosen to evaluate and compare the difference in images quality of three groups. Results CT dose index（CTDI） was reduced from 16.7raCy to 10.0 mGy（ decreased 40.1% ） and 6.7 mGy（ decreased 59.8% ） when mAs decreased from 250 mAs to 150 mAs and 100 mAs. Dose lenth product（DLP） was reduced from （564.6±32.5）mGy to （336.2 ±24.5）mGy（decreased 40.5% ） and （204.3±33.7） mGy （decreased 63.8% ） when mAs decreased from 250 mAs to 150 mAs and 100 mAs. There was significant difference between group A and B （ P 〈 0.01 ）, while obvious difference could not be found in the quality of images obtained from group A and B（P 〉 0.05）. Conclusion It is a feasible CT angiography scanning method to decrease the radiation close by decreasing mAs appropriately, 150mAs was chosen.
出处
《临床放射学杂志》
CSCD
北大核心
2009年第2期254-256,共3页
Journal of Clinical Radiology
