自动管电压选择技术在第3代双源CT大螺距主动脉CT血管成像扫描中的初步应用

发布时间：2018-07-10 19:12

本文选题：主动脉 + CT血管成像　；参考：《中国医学科学院学报》2017年01期

【摘要】：目的评价自动管电压选择技术在第3代双源CT大螺距心电门控主动脉CT血管成像(CTA)扫描中的应用情况。方法采用简单随机分组法将59例临床行全主动脉CTA扫描的患者随机分为2组:(1)组1(n=31):采用自动管电压选择技术进行扫描,参考管电压为100 kV,参考管电流为288 m A;(2)组2(n=28):采用自动管电流调节技术进行扫描,管电压固定100 kV,参考管电流为288 m A。两组患者均在第3代双源CT上进行扫描,探测器准直为2×192×0.6 mm,旋转时间为0.25 s;采用大螺距心电门控扫描方式进行扫描,螺距3.0。两组患者均为静脉团注370 mg I/L的对比剂,后续生理盐水:组1对比剂和生理盐水的剂量及注射速率根据实际管电压值来设定;组2均注射对比剂45 ml,注射速度4.5 ml/s,后续50 ml生理盐水,注射速度5.0 ml/s。两组患者扫描均采用自动团注跟踪触发技术,选取主动脉起始部放置感兴趣区(ROI),ROI内平均CT值达到100 HU时自动触发扫描,延迟时间6 s。分别计算两组患者主动脉扫描的有效剂量(ED)、图像信噪比(SNR)、对比噪声比(CNR),并对图像质量进行主观评价。结果组1扫描ED为(2.48±0.80)m Sv,较组2的(3.15±0.86)m Sv降低21.3%(t=-3.099,P=0.000)。两组患者在主动脉各部位(升主动脉、主动脉弓、腹主动脉起始部及腹主动脉分叉部位)的强化值、噪声、SNR和CNR差异均无统计学意义(P均0.05)。两组图像主观质量评价差异也无统计学意义[(1.41±0.50)分比(1.39±0.50)分;W=828.5,P=0.837]。结论与自动管电流调节技术相比,在第3代双源CT大螺距主动脉CTA扫描中采用自动管电压选择技术能够在保证图像质量的同时,显著降低辐射剂量。
[Abstract]:Objective to evaluate the application of automatic tube voltage selection technique in the third generation dual-source CT large pitch cardiac gated aortic angiography (CTA). Methods A total of 59 patients undergoing CTA were randomly divided into two groups: (1) Group 1 (n = 31): scanning by automatic tube voltage selection technique. The reference tube voltage is 100kV and the reference tube current is 288 m A; (_ 2) group 2 (n ~ (28): the automatic tube current regulation technique is used to scan, the tube voltage is fixed at 100kV, and the reference tube current is 288mA. The detector was collimated at 2 脳 192 脳 0.6 mm and rotated time was 0.25 s. The scan was performed with a large pitch ECG gated scan with a pitch of 3.0. The two groups were treated by intravenous infusion of 370 mg I / L contrast agent, followed by normal saline: the dose and injection rate of contrast agent and saline in group 1 were set according to the actual tube voltage. Group 2: 45 ml contrast agent, 4.5 ml / s, 50 ml saline, 5.0 ml / s. In both groups, automatic group injection tracking trigger technique was used, and the delay time was 6 s when the mean CT value of ROI in ROI was 100 Hu. The effective dose (Ed), image signal-to-noise ratio (SNR), contrast noise ratio (CNR) and image quality were calculated. Results the Ed in group 1 was (2.48 卤0.80) m Sv, which was lower than that in group 2 (3.15 卤0.86) mSv by 21.3% (t = 3.099m, P = 0.000). There was no significant difference in enhancement, noise, SNR and CNR between the two groups (ascending aorta, aortic arch, abdominal aorta origin and abdominal aorta bifurcation) (P 0.05). There was no significant difference in subjective quality evaluation between the two groups [(1.41 卤0.50) score ratio (1.39 卤0.50) score]. Conclusion compared with the automatic tube current regulation technique, the automatic tube voltage selection technique in the third generation dual-source CT large pitch aortic CTA scan can significantly reduce the radiation dose while ensuring the image quality.
【作者单位】：中国医学科学院北京协和医学院北京协和医院放射科;
【基金】：国家临床重点专科建设项目(2014) 卫生公益性行业科研专项项目(201402001、201402019)~~
【分类号】：R816.2

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