Loubeyre P, Angelie E, Grozel F, Abidi H, Minh V A
Department of Radiology, Lyon-Sud Hospital, Pierre Benite, France.
Radiology. 1997 Oct;205(1):153-7. doi: 10.1148/radiology.205.1.9314977.
To evaluate a computed tomographic (CT) artifact that simulates aortic dissection.
Two groups of 65 patients underwent spiral CT of the chest for reasons other than suspected aortic dissection. In each group, two series of images (10-mm sections) were reconstructed with use of a 180 degrees or 360 degrees linear-interpolation algorithm. Series of images were read by two radiologists, and variance between interpretations was statistically measured.
Among series of images, artifacts were seen on 21-26 (32%-40%) with use of a 180 degrees algorithm and 41 (63%) and 44 (68%) with use of a 360 degrees algorithm. Concordance between reviewers was fair (kappa = 0.58, 0.59) or good (kappa = 0.65) with use of a 180 degrees algorithm and excellent (kappa = 0.92) with use of a 360 degrees algorithm. In one group, with use of a 180 degrees algorithm, two series of reconstructed images were separated by 5 mm; artifact was observed on seven (11%) CT studies (on both series of images) and was located along the left or left anterior side of the aorta.
To reduce the frequency of a spiral CT artifact that simulates aortic dissection, two series of segmented images can be reconstructed with a change of image position along the z axis of the aorta and use of a 180 degrees linear-interpolation algorithm.
评估一种模拟主动脉夹层的计算机断层扫描（CT）伪影。
两组各65例患者因疑似主动脉夹层以外的原因接受胸部螺旋CT检查。每组使用180度或360度线性插值算法重建两组图像（层厚10mm）。两组图像由两名放射科医生阅片，并对解读之间的差异进行统计学测量。
在图像系列中，使用180度算法时，21 - 26幅（32% - 40%）出现伪影，使用360度算法时，分别有41幅（63%）和44幅（68%）出现伪影。使用180度算法时，阅片者之间的一致性为中等（kappa = 0.58，0.59）或良好（kappa = 0.65），使用360度算法时为优秀（kappa = 0.92）。在一组中，使用180度算法时，两组重建图像在z轴上相差5mm；在7例（11%）CT检查中（两组图像均有）观察到伪影，位于主动脉左侧或左前侧。
为减少模拟主动脉夹层的螺旋CT伪影的发生频率，可沿主动脉z轴改变图像位置并使用180度线性插值算法重建两组分段图像。
