不同层厚对128层螺旋CT肺动脉显示率及伪影发生率的影响

背景：行螺旋CT肺动脉造影检查,肺动脉显示率与伪影发生率,对诊断准确性评价有着重要作用。目的：评价不同层厚对128层螺旋CT肺动脉显示率及伪影发生率的影响。方法：经螺旋CT肺动脉造影检查将疑似急性肺栓塞患者图像分别重建为不同层厚的4组：0.6,1.0,3.0,5.0mm,比较4组图像对栓塞肺动脉显示的清晰程度,并评价4组图像显示肺动脉各级分支的连续程度与伪影发生率。结果与结论：主肺动脉、左右肺动脉及叶动脉显示,4组间差异无显著性意义;段及亚段级肺动脉显示,0.6,1.0mm层厚组优于3.0,5.0mm组（P〈0.001）;第6级肺动脉显示,4组间差异均有显著性意义（P〈0.001）,且0.6mm组显示率最佳。1.0mm层厚图像在显示亚段级以上肺动脉分支方面与0.6mm层厚能力相近,且优于3.0,5.0mm层厚组;3.0,5.0mm组显示肺动脉各级分支连续程度低于0.6,1.0mm组。39例阴性患者部分容积伪影0.6mm组2例,1.0mm组5例,3.0mm组11例,5.0mm组17例,组间比较差异有显著性意义（P〈0.001）。提示,行螺旋CT肺动脉造影检查,采用3.0mm及以下层厚可较准确观察亚段肺动脉;采用0.6mm层厚可减少部分容积伪影,从而提高螺旋CT肺动脉造影图像质量。

Influence of different slice thickness on display rate of pulmonary arterial and incidence rate of artifacts by 128-slice spiral CT

BACKGROUND：The display rate of pulmonary artery and the incidence of artifact by CT pulmonary angiography （CTPA） play an important role in the evaluation of diagnostic accuracy.OBJECTIVE：To evaluate the effect of different thickness on the 128-slice spiral CT display rate of pulmonary artery and the incidence rate of artifact.METHODS：Patients with suspected acute pulmonary embolism were examined by CTPA,and images were divided into 4 groups according to different thickness：0.6,1.0,3.0 and 5.0mm.Display clarity of pulmonary embolism arteries of the images of 4 groups was compared to evaluate the continuous level of pulmonary artery branches and the incidence rate of artifact.RESULTS AND CONCLUSION：The main pulmonary artery and lobe pulmonary artery of two lungs showed no significant difference among the 4 groups;segmental and sub-segmental pulmonary artery showed 0.6mm and 1.0mm slice thickness were better than 3.0mm and 5.0mm thickness groups （P0.001）;for the 6th pulmonary artery,4 groups showed significant differences （P0.001）,and the display rate of 0.6 mm was the best.The ability that 1.0mm slice thickness images showed sub-segmental pulmonary artery branch level and above was similar to the 0.6mm,and better than 3.0mm and 5.0mm groups;3.0mm and 5.0mm slice thickness groups showed continuous pulmonary artery all branches lower than 0.6mm and 1.0mm slice thickness groups.Partial volume artifacts of 39 cases with negative were 2 cases from 0.6mm group,5 from 1.0mm group,11 from 3.0mm group,17 from 5.0mm group,showing significant differences among 4 groups （P0.001）.In CTPA examination,slice thickness at 3.0mm or less can observe sub-segmental pulmonary artery more accurately,while 0.6mm slice thickness can reduce the incidence of partial volume artifacts and improve images quality of CTPA.