Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific St., Seattle, WA 98195-7115, USA.
AJR Am J Roentgenol. 2010 Mar;194(3):W263-71. doi: 10.2214/AJR.09.2788.
The purpose of this study was to evaluate the use of a triphasic contrast bolus for ECG-gated CT in the assessment of chest pain by measuring vascular luminal attenuation and determining the degree of contrast-related streak artifact.
We reviewed the images from 44 ECG-gated CT examinations performed with a coronary contrast bolus modified for imaging of the entire chest. Luminal attenuation achieved with the resulting triphasic bolus was measured at specified vascular locations in the right side of the heart, pulmonary arteries, coronary arteries, and thoracic aorta. The occurrence of contrast-related streak artifact was recorded, and artifact severity was scored on a subjective 4-point scale.
The mean attenuation values in the pulmonary arteries (345.3 +/- 136.7 HU), coronary arteries (340.8 +/- 82.5 HU), and thoracic aorta (386.4 +/- 67.2 HU) were above a diagnostic threshold of 200 HU. Although there was no significant difference between the mean arterial values, the right-heart attenuation (281.6 +/- 121.8 HU) was significantly lower than the attenuation in the other two locations. On a location basis, 92.2% of the 1,972 arterial measurements were above the 200-HU threshold. Streak artifacts were found in 21 examinations (47.7%), and none was scored as severe. Statistical analysis revealed that the occurrence of streak artifact increased with higher right-heart attenuation.
In this series, a triphasic contrast bolus for ECG-gated whole-chest CT consistently achieved arterial attenuation above a diagnostic threshold in the pulmonary arteries, coronary arteries, and aorta. Right-heart attenuation was simultaneously reduced, which is important for decreasing the prevalence and severity of streak artifacts.
本研究旨在通过测量血管内腔衰减并确定对比相关条纹伪影的程度,评估三相对比剂团注用于 ECG 门控 CT 评估胸痛的效果。
我们回顾了 44 例使用改良冠状动脉对比剂进行全胸部 ECG 门控 CT 检查的图像。在心脏右侧、肺动脉、冠状动脉和胸主动脉的指定血管位置测量三相对比剂团注后获得的内腔衰减值。记录对比相关条纹伪影的发生情况,并采用主观 4 分制评分法评估伪影严重程度。
肺动脉(345.3±136.7HU)、冠状动脉(340.8±82.5HU)和胸主动脉(386.4±67.2HU)的平均衰减值均高于 200HU 的诊断阈值。尽管平均动脉值之间无显著差异,但右心衰减值(281.6±121.8HU)明显低于其他两个部位的衰减值。基于部位,1972 个动脉测量值中有 92.2%高于 200HU 阈值。21 例(47.7%)检查中出现条纹伪影,无一例评为严重。统计学分析显示,条纹伪影的发生与较高的右心衰减值相关。
在本系列中,三相对比剂团注用于 ECG 门控全胸部 CT 可始终获得肺动脉、冠状动脉和主动脉的诊断阈值以上的动脉衰减值。同时,右心衰减值降低,这对于减少条纹伪影的发生率和严重程度很重要。