Study of Two-stage Injection of Contrast Agent in Combination with Bolus Tracking Technique in Computed Tomography Pulmonary Angiography
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摘要: 目的:探讨两段式对比剂注射结合团注跟踪技术在肺动脉CTA成像中的应用价值。方法:收集2022年7月至12月在首都医科大学附属北京同仁医院因怀疑肺栓塞行肺动脉CT增强检查的30例患者为试验组,使用两段式对比剂注射结合团注跟踪技术的方法。兴趣区(ROI)置于肺动脉主干,设定阈值为100 HU。对比剂和生理盐水注射顺序:①对比剂 10 mL;②生理盐水 30 mL;③对比剂 20 mL;④生理盐水 30 mL,注射流率均为5 mL/s。跟踪肺动脉主干CT值,达到设定阈值后延迟10 s开始扫描。收集2021年1月至2021年12月间30例患者为对照组,采用小剂量团注测试技术。先注射对比剂10 mL+生理盐水30 mL测量肺动脉主干达峰时间,再注射对比剂20 mL+生理盐水30 mL,以达峰时间+1 s作为延迟时间扫描。测量两组图像肺动脉、肺静脉、锁骨下静脉、升主动脉的CT值,并对两组图像肺动脉图像质量和上腔静脉硬化伪影进行评分。两组图像血管CT值的比较采用独立样本t检验;肺动脉图像质量评分、上腔静脉硬化伪影评分的比较采用非参数Mann-Whitney U检验。结果:试验组左肺动脉、右肺上叶动脉、右肺中叶动脉、右肺下叶动脉、左肺上叶动脉、升主动脉CT值大于对照组,差异有统计学意义;试验组和对照组肺动脉主干、右肺动脉、左肺下叶动脉、右上肺静脉、右下肺静脉、左上肺静脉、左下肺静脉、锁骨下静脉、右侧动静脉CT值差值、左侧动静脉CT值差值差异无统计学意义;试验组和对照组肺动脉影像质量评分差异无统计学意义;试验组和对照组上腔静脉硬化伪影评分差异无统计学意义。结论:肺动脉CTA检查使用两段式对比剂注射结合团注跟踪技术可获得稳定的图像质量,且操作步骤简单易行,过渡延迟时间适用于大多数CT设备,值得在临床推广。Abstract: Objective: To investigate the utility of a two-stage injection of contrast agent combined with a bolus tracking technique in computed tomography (CT) pulmonary angiography. Methods: We recruited 30 patients undergoing CT pulmonary angiography due to suspected pulmonary embolism at Beijing Tongren Hospital affiliated to Capital Medical University from February to April 2022 as the experimental group, using a two-stage injection of contrast agent combined with bolus tracking technique. The region of interest (ROI) was placed in the pulmonary trunk with a threshold of 100HU. Contrast agent and normal saline injection sequence: (1) contrast agent 10 mL; (2) normal saline 30 mL; (3) contrast agent 20 mL; (4) normal saline 30 mL; the injection rate for all was 5 mL/s. The CT value of the pulmonary trunk was tracked, and scanning was delayed for 10 s after reaching the set threshold. Using the test bolus technique, we recruited 30 patients from January to December 2021 as the control group. First, 10 mL of contrast plus 30 mL of normal saline was injected to measure the peak time of the main pulmonary artery. Then, 20 mL of contrast plus 30 mL of normal saline was injected, and the peak time +1 s was used as the delay time for the scan. CT values were measured for the pulmonary artery, pulmonary vein, subclavian vein, and ascending aorta in both groups. Both groups scored the quality of the pulmonary artery images and the sclerotic artifacts of the superior vena cava. We compared the CT values of the vessels in the two groups using independent sample t-tests. We compared the pulmonary artery image quality scores and the sclerotic artifact scores of the superior vena cava using a non-parametric Mann–Whitney U-test. Results: CT values of the left pulmonary artery, right upper lobe artery, right middle lobe artery, right lower lobe artery, left upper lobe artery, and ascending aorta of the experimental group were higher than those of the control group, and the difference was statistically significant. There was no significant difference in the main pulmonary artery, right pulmonary artery, left inferior pulmonary artery, right upper pulmonary vein, right lower pulmonary vein, left upper pulmonary vein, left lower pulmonary vein, subclavian vein, right arteriovenous difference, and left arteriovenous difference between both groups. Also, there was no significant difference in pulmonary artery image quality scores between both groups, likewise in the sclerosis artifact score of superior vena cava sclerosis. Conclusions: The two-stage contrast agent injection with the bolus tracking technique for CT pulmonary angiography provides stable image quality with a simple and easy procedure. The transition delay time suits most CT devices and deserves a clinical generalization.
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Key words:
- tomography /
- X-ray computed /
- pulmonary artery /
- contrast agent
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图 1 两段式对比剂注射方法,注射流率均为5 mL/s,两段对比剂开始注射时间间隔8 s,第1段对比剂达到设定阈值后10 s相当于第2段对比剂达到阈值后2 s
Figure 1. In the two-stage injection method, the injection flow rate was 5 mL/s, and the interval between the start of the two-stage contrast injection was 8 s; 10 s after the first stage of contrast reaches the set threshold is equivalent to 2 s after the second stage of contrast reaches the threshold
图 2 对照组患者使用小剂量团注测试技术,试验组患者使用两段式对比剂注射结合团注跟踪技术
(a)和(b)为对照组组患者,(a)横轴位厚层MIP图像,(b)冠状位厚层MIP图像,因扫描启动过晚导致肺静脉强化,肺动脉与肺静脉CT值差值小于150 HU,图像质量评分为3分;(c)和(d)为试验组患者,(c)横轴位厚层MIP图像,(d)冠状位厚层MIP图像,肺静脉略显影,肺动脉处于强化峰值,与肺静脉有良好的对比,CT值差值大于150 HU,图像质量评分为4分。
Figure 2. The control groups, using the test bolus technique, and the experimental groups, using a two-stage injection of contrast agent combined with bolus tracking technique
表 1 试验组和对照组测量血管的平均值、最小值和最大值的比较
Table 1. Comparison of mean, minimum, and maximum values of measured vessels between the experimental and control groups
测量血管 CT值/HU 统计检验 试验组$\bar{x}\pm s$(min~max) 对照组$\bar{x}\pm s$(min~max) t P 肺动脉主干 340±50(264~431) 312±65(183~483) 1.86 0.067 右肺动脉 339±51(251~435) 313±58(180~463) 1.86 0.068 左肺动脉 345±54(252~431) 314±57(188~466) 2.21 0.031 右肺上叶动脉 367±62(281~498) 329±61(185~497) 2.40 0.020 右肺中叶动脉 359±61(269~468) 322±58(202~472) 2.39 0.020 右肺下叶动脉 363±58(268~511) 329±61(206~469) 2.19 0.033 左肺上叶动脉 362±54(258~441) 330±59(197~467) 2.18 0.033 左肺下叶动脉 362±57(259~457) 332±63(195~474) 1.89 0.064 右上肺静脉 137±39(85~225) 128±57(40~263) 0.74 0.462 右下肺静脉 132±30(86~192) 122±53(45~225) 0.86 0.392 左上肺静脉 137±37(89~226) 134±56(42~265) 0.20 0.841 左下肺静脉 135±35(91~228) 124±52(40~244) 0.90 0.375 锁骨下静脉 935±250(469~1728) 840±303(317~1645) 1.32 0.193 升主动脉 120±21(84~165) 71±19(44~120) 9.50 0.000 右侧动静脉CT值差值 204±57(86~289) 188±89(-17~374) 0.87 0.389 左侧动静脉CT值差值 210±61(70~301) 184±86(6~376) 1.31 0.195 注:$\bar{x}\pm s$为平均值±标准差,min为最小值,max为最大值。 表 2 两名医师对试验组和对照组肺动脉影像质量、上腔静脉伪影评分分布和一致性分析结果
Table 2. Distribution and consistency of pulmonary artery image quality and superior vena sclerotic artifact scores analyzed by two physicians in the experimental and control groups
组别 医师1/例 医师2/例 评分
$({M}({Q}_{1}, t{Q}_{3} ))$一致性分析 4分 3分 2分 1分 4分 3分 2分 1分 Kappa值 P 肺动脉图像质量评分 试验组 22 8 0 0 23 7 0 0 4.0(3.5,4.0) 0.73 <0.001 对照组 15 13 2 0 19 11 0 0 3.75(3.0,4.0) 0.62 <0.001 上腔静脉硬化伪影评分 试验组 4 22 4 0 2 24 4 0 3.0(3.0,3.0) 0.66 <0.001 对照组 2 24 4 0 2 19 9 0 3.0(2.5,3.0) 0.63 <0.001 -
[1] 中华医学会呼吸病学分会肺栓塞与肺血管病学组, 中国医师协会呼吸医师分会肺栓塞与肺血管病工作委员会, 全国肺栓塞与肺血管病防治协作组. 肺血栓栓塞症诊治与预防指南[J]. 中华医学杂志, 2018,98(14): 1060−1087. doi: 10.3760/cma.j.issn.0376-2491.2018.14.007 [2] 刘建新, 孙红霞, 唐光健, 等. 多层螺旋CT低剂量对比剂肺动脉成像[J]. 中国医学影像技术, 2006,22(7): 1012−1014. DOI: 10.3321/j.issn:1003-3289.2006.07.013.LIU J X, SUN H X, TANG G J, et al. Multi slice spiral CT pulmonary artery angiography with low dose contrast medium[J]. Chinese Journal of Medical Imaging Technology, 2006, 22(7): 1012−1014. DOI: 10.3321/j.issn:1003-3289.2006.07.013. (in Chinese). [3] 张文明, 陈彬, 胡吉波, 等. 比较团注对比剂跟踪技术和小剂量团注测试技术在双能量CT肺灌注扫描中的应用[J]. 中华放射学杂志, 2013,47(10): 892−897. DOI: 10.3760/cma.j.issn.1005-1201.2013.10.006.ZHANG W M, CHEN B, HU J B, et al. Comparison of test bolus and bolus tracking techniques for dual-energy CT lung perfusion scan[J]. Chinese Journal of Radiology, 2013, 47(10): 892−897. DOI: 10.3760/cma.j.issn.1005-1201.2013.10.006. (in Chinese). [4] RODRIGUES J C L, MATHIAS H, NEGUS I S, et al. Intravenous contrast medium administration at 128 multidetector row CT pulmonary angiography: Bolus tracking versus test bolus and the implications for diagnostic quality and effective dose[J]. Clinical Radiology, 2012, 67(11): 1053−1060. DOI: 10.1016/j.crad.2012.02.010. [5] YU J, LIN S S, LU H, et al. Optimize scan timing in abdominal multiphase CT: Bolus tracking with an individualized post-trigger delay[J]. European Journal of Radiology, 2022, 148: 110139. DOI: 10.1016/j.ejrad.2021.110139. [6] CHIBA A, HARADA K, OHASHI Y, et al. Evaluation of computed tomography arterial portography scan timing using different bolus tracking methods[J]. Radiological Physics and Technology, 2020, 13(1): 92−97. DOI: 10.1007/s12194-020-00556-5. [7] HENZLER T, MEYER M, REICHERT M, et al. Dual-energy CT angiography of the lungs: Comparison of test bolus and bolus tracking techniques for the determination of scan delay[J]. European Journal of Radiology, 2012, 81(1): 132−138. DOI: 10.1016/j.ejrad.2010.06.023. [8] GOBLE E W, ABDULKARIM J A. CT pulmonary angiography using a reduced volume of high-concentration iodinated contrast medium and multiphasic injection to achieve dose reduction[J]. Clinical Radiology, 2014, 69(1): 36−40. DOI: 10.1016/j.crad.2013.07.023. [9] 中华医学会放射学分会心胸学组. 急性肺血栓栓塞放射学检查技术方案与诊断共识[J]. 中华放射学杂志, 2012,46(12): 1066−1070. doi: 10.3760/cma.j.issn.1005-1201.2012.12.002 [10] 周运锋, 史河水, 吴爱兰, 等. 选择MSCT肺动脉血管成像触发点位置及后处理技术[J]. 中国医学影像技术, 2010,26(8): 1561−1564. DOI: 10.13929/j.1003-3289.2010.08.030.ZHOU Y F, SHI H S, WU A L, et al. Choice of triggering position and post-processing technique in multi-slice CT pulmonary angiography[J]. Chinese Journal of Medical Imaging Technology, 2010, 26(8): 1561−1564. DOI: 10.13929/j.1003-3289.2010.08.030. (in Chinese). [11] 刘建新, 刘剑, 王霄英, 等. 对比剂智能跟踪与预试验肺动脉MSCT成像的对比研究[J]. 放射学实践, 2008,23(12): 1380−1382. DOI: 10.3969/j.issn.1000-0313.2008.12.025.LIU J X, LIU J, WANG X Y, et al. Multi-slice CT pulmonary arteriography: Comparison of bolus tracking with pretest time-density curve technique[J]. Radiologic Practice, 2008, 23(12): 1380−1382. DOI: 10.3969/j.issn.1000-0313.2008.12.025. (in Chinese). [12] 崔晨, 刘建新, 王霄英, 等. 三期团注法对比剂注射方案在肺动脉CTA检查中的应用研究[J]. 放射学实践, 2013,28(5): 493−495. DOI: 10.13609/j.cnki.1000-0313.2013.05.005.CUI C, LIU J X, WANG X Y, et al. Application of optimized contrast agent injection in CT pulmonary angiography[J]. Radiologic Practice, 2013, 28(5): 493−495. DOI: 10.13609/j.cnki.1000-0313.2013.05.005. (in Chinese). [13] 刘荣华, 徐宇崇, 万维佳. 64排CT多期双流混合注射跟踪法在肺动脉成像中的应用[J]. 放射学实践, 2014,29(12): 1478−1480. DOI: 10.13609/j.cnki.1000-0313.2014.12.034.LIU R H, XU Y C, WAN W J. Dual-flow multiphase injection technique with contrast medium-saline mixture for pulmonary angiography using 64-row multi-detector computed tomography[J]. Radiologic Practice, 2014, 29(12): 1478−1480. DOI: 10.13609/j.cnki.1000-0313.2014.12.034. (in Chinese). [14] DAS K, BISWAS S, ROUGHLEY S, et al. 3D CT cerebral angiography technique using a 320-detector machine with a time-density curve and low contrast medium volume: Comparison with fixed time delay technique[J]. Clinical Radiology, 2014, 69(3): e129−e135. DOI: 10.1016/j.crad.2013.10.021. [15] BISWAS S, CHANDRAN A, ROUGHLEY S, et al. Cerebral CT venography using a 320-MDCT scanner with a time-density curve technique and low volume of contrast agent: Comparison with fixed time-delay technique[J]. American Journal of Roentgenology, 2015, 205(6): 1269−1275. DOI: 10.2214/AJR.14.14200. [16] MORTIMER A M, SINGH R K, HUGHES J, et al. Use of expiratory CT pulmonary angiography to reduce inspiration and breath-hold associated artefact: Contrast dynamics and implications for scan protocol[J]. Clinical Radiology, 2011, 66(12): 1159−66. DOI: 10.1016/j.crad.2011.06.012. [17] RACZECK P, MINKO P, GRAEBER S, et al. Influence of respiratory position on contrast attenuation in pulmonary CT angiography: A prospective randomized clinical trial[J]. American Journal of Roentgenology, 2016, 206(3): 481−486. DOI: 10.2214/AJR.15.15176. [18] 黄书然, 姜鑫, 王洪杰, 等. 平静呼吸轻屏气在改善肺动脉CT强化效果中的应用研究[J]. 放射学实践, 2022,37(2): 186−190. DOI: 10.13609/j.cnki.1000-0313.2022.02.009.HUANG S R, JIANG X, WANG H J, et al. The application of “breath holding at ease” in improving the CT enhancement effect of pulmonary artery[J]. Radiologic Practice, 2022, 37(2): 186−190. DOI: 10.13609/j.cnki.1000-0313.2022.02.009. (in Chinese). -