不同扫描方向对头颈联合CT血管造影图像质量的影响

Impact of different scanning directions on image quality of united head and cervical arteries CT angiography

目的通过改变头颈联合CTA成像的扫描方向避免较重的颅内静脉回流伪影及锁骨下静脉注射伪影,从而获得高质量的诊断图像。方法选择在我院接受头颈联合CTA检查的患者200例,随机分成A、B两组(各100例),分别进行头向足方向及足向头方向扫描,其他扫描参数相同。对图像质量进行评分,记录升主动脉、颈总动脉、基底动脉CT值及对比剂注射侧锁骨下静脉CT值和升主动脉中心部噪声值,并进行统计学分析。结果①A组图像质量明显优于B组,差异有统计学意义(U=7.40,P<0.001)。②两组基底动脉、颈总动脉、升主动脉CT值比较,差异无统计学意义(P均>0.05)。③两组注射侧锁骨下静脉CT值差异有统计学意义(U=22.91,P<0.001)。④两组升主动脉中心部噪声值比较,差异有统计学意义(U=2.61,P<0.05)。结论头颈联合CTA成像,选用头向足方向扫描可以有效避免较重的颅内静脉回流伪影及注射侧锁骨下静脉残留对比剂的伪影,同时能够得到强化均匀的高质量诊断图像。

Objective To observe the impact of different scanning directions on image quality of united head and cervical arteries CT angiography,in order to avoid artifacts of intracranial venous reflux and artifacts in the subclavian vein with the arm injection.Methods Totally of 200 patients who underwent united head and neck CTA were randomly divided into Group A and B（each n=100）.Patients in Group A were scanned from cranial-caudal direction,while in Group B were scanned from caudal-cranial direction.The other parameters of scanning were the same.Image quality in the two groups were scored,CT value of the ascending aorta,common carotid artery,basilar artery,injection side subclavian vein and pattern noise value were recorded and statistically analyzed.Results ①The image quality of Group A was obviously better than that of Group B（U=7.40,P0.001）.②The differences of CT value of basilar artery,common carotid artery and aorta between the two groups were not statistically significant（all P0.05）.③CT value of injection side subclavian vein in the two groups were significantly different（U=22.91,P0.001）.④Pattern noise value of the two groups were significantly different（U=2.61,P0.001）.Conclusion Scanning from cranial-caudal direction in united head and neck CTA can effectively avoid heavy artifacts from intracranial venous reflux and the artifacts in the subclavian vein with the arm injection,and enhance the uniform imaging quality.