16层螺旋CT颅颈联合CTA扫描参数的优化及规范化

目的 探讨16层螺旋CT颅颈联合CTA扫描参数的优化及规范化.方法 将60例接受颅颈联合CTA患者随机均分成Ⅰ、Ⅱ、Ⅲ三组,分别以100、150、180 HU作为监测阈值进行追踪触发扫描,比较三组间各点动静脉CT值及动脉显示差异.另将40例患者随机均分成A、B两组,采取不同层厚与螺距相匹配(层厚0.625 mm, 螺距1.375:1与层厚1.25 mm,螺距1.375:1)进行扫描,比较两组间动脉显示的差异.结果 Ⅰ、Ⅱ、Ⅲ组病例的颈部及颅内动脉均获得清晰显示,显示程度评分差异无统计学意义;颈总动脉及颈内动脉各点强化CT值在3组间差异无统计学意义(P＞0.05),而各点同层静脉CT值在3组间有统计学差异(P＜0.05);A、B 组病例在显示程度评分上无统计学差异.结论 16层螺旋CT颅颈联合CTA扫描最优参数为阈值100 HU,120 kV,280 mA,层厚1.25 mm,螺距1.375:1,0.5秒/周,准直宽度16×0.625 mm,为将以上参数规范化提供了参考.

Optimization and standardization of imaging parameters for 16-slice spiral CT angiography in intracranial and cervical arteries

Objective To explore the optimization and standardization of imaging parameters for 16-slice spiral CT angiography in intracranial and cervical arteries. Methods Sixty patients were randomly divided into three groups, and the automatic bolus tracking thresholds of 100, 150 and 180 HU in the descending aorta were used respectively. The CT values of artery and vein among three groups were compared. Other 40 patients were randomly divided into A and B group and underwent CTA with different slice thickness and pitch, and the difference in arterial display were compared. Results The carotid and intracranial arteries in all three groups were well displayed. No statistical difference was found in enhancement CT values of three points of common carotid artery and internal carotid artery among three groups (P>0.05), while the differences of CT values in same level vein among three groups were significant (P<0.05). There was no significant difference in the average score of display degree between group A and B. Conclusion Imaging parameters for 16-slice spiral CT angiography in intracranial and cervical arteries are recommended as follows:100 HU (threshold), 120 kV, 280 mA, 1.25 mm (thickness), 1.375:1 (pitch), 0.5 s/r and 16×0.625 mm (effective thickness).