| 摘要: |
| ［摘要］ 目的 探讨64层螺旋CT在肺动脉CT血管成像中自动跟踪触扫描最佳应用阈值。方法 将80例临床怀疑肺动脉栓塞行肺动脉CT血管成像检查患者，随机分成4组（触发阈值分别为80 HU、100 HU、120 HU、140 HU），采用64层螺旋CT结合自动跟踪触发扫描行肺动脉CT血管成像检查，触发点感兴趣区（ROI）设在上腔静脉内。结果 阈值为100 HU组（参照组）肺动脉、段肺动脉和亚段以下肺动脉强化明显，肺动脉平均CT值为（442.5±91.7），而肺静脉强化不明显，动静脉密度差别大，经后处理显示的动脉图像清晰。阈值为80 HU组肺动脉主干CT值较低，平均CT值为（248.2±74.5），提示触发扫描过早；阈值为120 HU组肺静脉密度明显升高，CT值与肺动脉几乎相等；阈值为140 HU组肺动脉密度明显下降，肺静脉密度升高，CT值大于肺动脉，提示触发扫描过迟，与参照组比较差异有统计学意义（P<0.05）。结论 64层螺旋CT在肺动脉CT血管成像检查中，采用自动跟踪触发扫描，触发点设在上腔静脉内，造影剂35～40 ml，注射流速4.8 ml/s，触发阈值为100 HU时扫描图像质量较好。 |
| 关键词: 肺动脉 CT血管成像 自动触发 阈值 |
| DOI：10.3969/j.issn.1674-3806.2017.02.16 |
| 分类号:R 445 |
| 基金项目: |
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| The option of automatic tracking triggers scanning threshold value of 64- slice spiral CT in pulmonary angiography |
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ZENG Yu-ping, CHEN Guan-shang, LONG Shi-liang, et al.
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CT/MRI Room, the People′s Central Hospital of Zhanjiang City, Guangdong 524037, China
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| Abstract: |
| ［Abstract］ Objective To investigate the optimal threshold of 64-slice spiral CT in pulmonary angiography.Methods Eighty patients with suspected pulmonary embolisms and CT pulmonary angiography were randomly divided into four groups in which the triggering threshold values were 80 HU, 100 HU, 120 HU and 140 HU respectively. They were performed CT pulmonary angiography using 64-slice spiral CT combined with automatic tracking trigger scanning, and the ROIs of trigger points were located in the superior vena cava.Results The reference group of 100 HU threshold had marked enhancement in pulmonary artery, segmental pulmonary artery and sub-segmental pulmonary, with a high display rate of 6-level pulmonary artery. The mean pulmonary CT value was (442.5±91.7), while enhancement in pulmonary vein was unobvious, with great differences in arteriovenous density, and the display of treated arteries image was clear. The group of 80 HU threshold had lower value of CT pulmonary trunk, with the average CT value being(248.2±74.5), which prompted premature trigger scanning. The group of 120 HU threshold had a significantly increased density of the pulmonary vein, which was almost equal to the pulmonary artery in CT value. The group of 140 HU threshold had significantly decreased density of the pulmonary artery and increased density of the pulmonary vein, whose CT value was greater than the pulmonary artery, suggesting a late trigger scanning, with a significant difference compared with the reference group(P<0.05).Conclusion In CT pulmonary angiography, automatic tracking trigger scanning of 64-slice spiral CT, has a better quality of the scanned image in the condition that the trigger points are located in the superior vena cava, with the contrast agent being between 35 and 40 ml, the injection flow rate of 4.8 ml/s, and the trigger threshold of 100 HU. |
| Key words: Pulmonary artery CT angiography Autotrigger Threshold value |
