摘要
目的 :探讨多层螺旋CT颅颈联合动脉成像时准直与螺距的最佳匹配方案。方法 :扫描设备为飞利浦MX80 0 0四层螺旋CT机。采用追踪触发技术启动诊断扫描 (触发阈值设定为 75HU)。将 4 0例无头颈部动脉系统疾病的志愿者按扫描参数的不同随机分为A(准直 1.0mm ,螺距 1.75 0 )、B(准直 2 .5mm ,螺距 0 .6 2 5 ) 2组 ,探讨颅颈联合MSCTA时准直与螺距的恰当匹配。以最大强度投影和容积再现法重建动脉影像。统计方法采用四格表资料的 χ2 检验和成组设计的两样本均数t检验 (双侧 ,α=0 .0 5 )。结果 :A、B两组对Ⅰ～Ⅳ级血管的显示率无显著性差异 ;对Ⅴ级动脉分支的显示能力存在显著性差异 (χ2 =3.91,P <0 .0 5 ) ,A组的显示能力高于B组。动脉Ⅰ～Ⅴ级分支的图像质量A、B两组间均存在显著性差异 (P <0 .0 5 )。B组对Ⅰ -Ⅱ级动脉的成像质量优于A组。A组对Ⅲ～Ⅴ级动脉的成像质量优于B组。结论 :①颅颈联合MSCTA可系统显示头颈部血管 ,避免分段成像的遗漏或不必要的重复、追加扫描。②颅颈联合CTA采用准直1 0mm、螺距 1.75 0优于准直 2 .5mm、螺距 0 .6 2 5 ,这种匹配方式对小血管显示佳。
Objective:To explore the optimal match between collimation and pitch of MSCTA in intracranial and cervical arteries.Methods:CT scanning was performed with a PHLIPS MX8000 four-slice spiral unit. To explore the optimal match between collimation and pitch of MSCTA in intracranial and cervical arteries, forty volunteers with normal cerebral and carotid arteries were divided randomly into two groups and the scanning parameters were as follows.Group A: collimation 1.0mm, pitch 1.750.Group B: collimation 2.5mm, pitch 0.625. Three-dimensional cerebral and carotid arterial images were reconstructed with MIP and VR. Statistical significance was determined with the χ 2 test and t test(α=0.05).Results:There is no significant difference between group A and group B in revealing Ⅰ～Ⅳ grades artery structures. The difference of the revelation for the Ⅴ grades artery structures between the two groups is significant(χ 2=3.91,P<0.05). More small arteries were displayed in group A. Image quality of Ⅰ～Ⅴ grades artery structures differed significantly in group A and group B(P<0.05).Image quality of Ⅰ～Ⅱgrades artery structures of group B was superior to that of group A. Image quality of Ⅲ～Ⅴgrades artery structures of group A was superior to that of group B.Conclusion:1.MSCTA in intracranial and cervical arteries can display systematically the cerebral and carotid arteries and avoid the omission or further scan.2.On the basis of the same other parameters, the optimal scanning match is a collimation of 2.5mm with a pitch of 1.750.
出处
《医学影像学杂志》
2004年第7期573-577,共5页
Journal of Medical Imaging
