双源CT低剂量前瞻性心电触发序列扫描在冠状动脉血管成像的应用

Objective To evaluate low-dose CT coronary angiography with prospective electrocardiogram (ECG)-triggering using dual-source CT scanner.Methods Sixty-eight patients who underwent coronary CT angiography using a dual-source CT scanner were divided into 2 groups: group A (38 cases) and group B (30 cases).Prospective ECG-triggering sequence scan mode was employed for group A.Inclusion criteria included: heart rate <70 bpm, sinus rhythm, and heart rate fluctuation less than 10 bpm.Data acquisition was set at 70% of the RR-interval.Retrospective ECG-gating helical scan was performed for group B.Inclusion criteria included heart rates < 70 bpm and sinus rhythm.The exclusion criteria included heart failure and serious arrhythmias.In both groups, patients with a BMI≥24 kg/m2 were examined with a tube voltage of 120 kV, whereas patients with a BMI <24 kg/m2 were examined with a tube voltage of 100 kV.All images were transferred to a workstation for further processing and analysis.The imaging quality was evaluated.The imaging quality of coronary artery segments were compared with rank sum test between the two groups, and the radiation dose were compared with t test.Results A total of 476 coronary artery segments were evaluated in group A and 372 segments were evaluated in group B.The mean score of imaging quality for coronary artery segments in group A was 3.48±0.59 and that in group B was 3.53±0.58.There was no statistical difference in imaging quality between the two groups (Z=-1.432, P=0.187).The effective dose was on average (2.51±0.54) mSv (range 1.3--3.3 mSv) in group A, whereas on average (14.55±3.54) rosy (range 7.1--20.2 mSv) in group B.There was a statistical difference between the two groups (t=18.484, P=0.000).Conclusions Low-dose prospective ECG-triggering sequence scan in dual-source CT coronary angiography is feasible in patients with low heart rate and regular cardiac rhythm.This scan mode can substantially reduce radiation doses while preserving good diagnostic image quality.     

双源CT低剂量前瞻性心电触发序列扫描在冠状动脉血管成像的应用

Objective To evaluate low-dose CT coronary angiography with prospective electrocardiogram (ECG)-triggering using dual-source CT scanner.Methods Sixty-eight patients who underwent coronary CT angiography using a dual-source CT scanner were divided into 2 groups: group A (38 cases) and group B (30 cases).Prospective ECG-triggering sequence scan mode was employed for group A.Inclusion criteria included: heart rate <70 bpm, sinus rhythm, and heart rate fluctuation less than 10 bpm.Data acquisition was set at 70% of the RR-interval.Retrospective ECG-gating helical scan was performed for group B.Inclusion criteria included heart rates < 70 bpm and sinus rhythm.The exclusion criteria included heart failure and serious arrhythmias.In both groups, patients with a BMI≥24 kg/m2 were examined with a tube voltage of 120 kV, whereas patients with a BMI <24 kg/m2 were examined with a tube voltage of 100 kV.All images were transferred to a workstation for further processing and analysis.The imaging quality was evaluated.The imaging quality of coronary artery segments were compared with rank sum test between the two groups, and the radiation dose were compared with t test.Results A total of 476 coronary artery segments were evaluated in group A and 372 segments were evaluated in group B.The mean score of imaging quality for coronary artery segments in group A was 3.48±0.59 and that in group B was 3.53±0.58.There was no statistical difference in imaging quality between the two groups (Z=-1.432, P=0.187).The effective dose was on average (2.51±0.54) mSv (range 1.3--3.3 mSv) in group A, whereas on average (14.55±3.54) rosy (range 7.1--20.2 mSv) in group B.There was a statistical difference between the two groups (t=18.484, P=0.000).Conclusions Low-dose prospective ECG-triggering sequence scan in dual-source CT coronary angiography is feasible in patients with low heart rate and regular cardiac rhythm.This scan mode can substantially reduce radiation doses while preserving good diagnostic image quality.     

320层CT心电门控双期心脏功能扫描一站式检查的初步研究

目的 初步探讨应用320层CT心电门控双期心功能扫描模式(DPCFA)一站式评价心脏、冠状动脉、肺动脉形态及左、右心室功能的能力.方法 回顾性分析40例经临床确诊患者的320层CT DPCFA扫描数据,分别以肺动脉期重建并观察肺动脉分支,以主动脉期重建并观察冠状动脉.分别以两期数据进行MPR重组并分析左、右心室功能,结果与超声心动图相对照.5例因图像质量欠佳排除组外,35例图像质量达到2级以上,可用作诊断,扫描平均心率(71.2±11.2)次/min,全部患者扫描期间未出现心律失常.应用Pearson检验进行相关性分析,应用配对t检验分析二者测量左心室射血分数(LVEF)的一致性.结果 (1)35例最终入组患者中,诊断单发肺动脉栓塞l1例,冠心病支架术后7例,单发冠心病5例,先天性心脏病房间隔缺损3例,特发性肺动脉高压3例,左房黏液瘤l例,肺动脉栓塞合并冠心病5例,全部符合临床诊断.(2)CT与超声心动图对照,35例患者的左、右心室舒张末期最大径分别为(36.7±3.3)、(43.3±3.4)mm,左、右心室收缩末期最大径分别为(31.6 ±5.1)、(41.3±5.1)mm,LVEF为47.1±15.1.超声心动图测得左、右心室舒张末期最大径分别为(40.3±3.1)、(47.3±4.2)mm,左、右心室收缩末期最大径分别为(37.3±5.6)、(45.3±3.3)mm,LVEF为46.0±14.8.CT与超声测量结果有显著的相关性(r=0.886～0.988,P值均＜0.01),LVEF的测量结果差异无统计学意义(t=0.692,P＞0.05).(3)应用DPCFA技术,平均射线剂量(5.4 ±0.5)mSv.结论 320层CT心电门控双期心功能扫描模式,可以用于心血管疾病一站式影像检查,可为临床心血管疾病的诊断、鉴别诊断、治疗方案的确定提供丰富的影像学信息,对左、右心功能不全相关临床问题的处理具有指导作用.

Abstract：

Objective To explore the feasibility of evaluating cardiac structure, coronary artery,pulmonary artery and cardiac function in one single scan by 320-row CT ECG-gated double phase cardiac function scan mode. MethodsForty patients underwent the 320-detector row CT double phase cardiovascular angiography. The pulmonary phase and aortic phase were reconstructed in order to evaluate the pulmonary and coronary artery. MPR reconstructions of both pulmonary and aortic phase were used to analyze the function of the two ventricles. And the results of the cardiac function were compared with those of transthoracic echocardiography. Thirty-five cases could be analyzed and diagnosed, while the other 5 cases had to be given up because of the poor imaging quality. The mean heart rate was (71.2 ± 11.2) beat per min (bpm). No arrhythmia case included. Results ( 1 ) Pulmonary embolism were diagnosed in 11 cases,coronary artery disease (CAD) were found in 5 cases, while post-stent implantation were observed in 7 cases. Six cases of congenital heart disease were diagnosed with 3 ASD and 3 primary pulmonary hypertension. Another one was diagnosed with left atrial myxoma, and 5 cases were pulmonary embolism associated with CAD. All of above cases were verified by final clinical diagnosis. (2) The heart function parameters including LVEDd , RVEDd, LVESd, RVESd and LVEF were (36.7 ±3.3), (43.3 ± 3.4) mm,(31.6±5.1), (41.3 ±5.1) mm and (47.1 ±15.1) for CT, while those were (40.3 ±3.1), (47.3 ±4.2) mm,(37.3 ±5.6), (45.3 ±3.3) mm,and (46.0 ± 14.8) for ultrasound, respectively. The CT results were correlated with the ultrasound ( n = 35, r = 0.886-0.988, P ＜ 0.01 ). (3) The average radiation exposure was ( 5.4 ± 0.5 ) mSv. Conclusions 320-row CT ECG-gated double phase cardiac function scan mode is feasible for the "one-stop-shop" examination of the cardiovascular disease. This noninvasive method is recommended for the diagnosis, differential diagnosis, treatment and prognosis of cardiovascular disease.     

双源CT对急性胸痛的诊断价值

目的 评价双源CT胸痛三联扫描计划对急诊胸痛诊断的准确性.方法 按照入选标准连续选取急性胸痛患者56例,采用西门子双源CT扫描仪胸痛三联扫描计划进行胸部CTA扫描,采集时间83 ms,按照体质指数调整对比剂注射的流速及流量.扫描范围自第1肋骨到心脏膈面的整个胸部,自气管隆突水平启动心电门控.对比剂采用三相注射法以便同时显示主动脉、冠状动脉、肺动脉三大血管床.评价三大血管床的图像质量,测量血管增强CT值.对15例同时有冠状动脉造影者进行对照分析,其他患者均随诊30 d以上.结果除1例患者因屏气不好影响图像评价被排除本研究外,余55例患者的三大血管床(主动脉、冠状动脉、肺动脉)均得到明显均匀强化和良好图像质量.冠状动脉图像质量评分平均3.8分.对比剂平均用量为(88±5)ml.平均辐射剂量为11.6 mSv (95% CI 6.9～13.1).本组病例中13例CTA为阴性,其余42例中14例冠状动脉粥样硬化,其中13例冠状动脉狭窄程度＞50%,12例行冠状动脉造影支架植入术.11例患者为Stanford A型主动脉夹层,肺栓塞11例.总的胸痛病因分布较为复杂.7例患者合并2种以上胸部疾病.CTA在本组病例"急性胸痛三联征"诊断中总的敏感性为98%,特异性96%.CTA阴性的随访人群2例随后诊断为反流性食管炎,其余患者30 d内均无严重不良事件发生.结论双源CT的胸痛三联扫描计划为急性胸痛患者的快速诊断及急诊分类提供了安全、有效的手段.     

螺距的选择对胸腹主动脉夹层320层CT成像质量的影响

目的：探讨螺距的选择对320层CT螺旋扫描模式胸腹主动脉夹层图像质量及辐射剂量的影响。方法：连续纳入可疑急性主动脉综合征患者100例,分为两组,A组（50例）采用螺距为53、B组（50例）采用螺距为95进行胸腹主动脉CTA扫描。使用Toshiba Aquilion one 320 CT机,120 kV,450 mA,0.35 s/r。选用体部前置滤线器和后置过滤器,重建层厚0.5 mm。应用SPSS 11.5软件分别对A组和B组的CT有效辐射剂量、图像噪声均值进行非配对t检验。结果：A组平均有效辐射剂量为18.19 mSv,B组为9.52 mSv,较A组有效辐射剂量平均减少50%。A组患者平均扫描时间为9.5 s,B组为4.53 s,较A组扫描时间平均减少5.07 s。A组患者的对比剂总量平均为83.6 ml,B组为71.8 ml,较A组对比剂总量平均减少12 ml。结论：在进行胸腹主动脉CTA检查中管电压和管电流恒定不变的情况下选择大螺距扫描,可以减少扫描时间、对比剂量并显著降低辐射剂量,在保证图像质量的同时,主动脉根部搏动伪影减小,可显示冠状动脉开口及近段,从而达到优化图像的同时降低辐射剂量的目的。     

第三代双源CT血管成像在急性胸痛患者扫描参数优化研究

目的:探讨第三代双源CT在急诊胸痛患者CTA临床应用和图像质量分析。方法:选取2018年1月至2018年7月,急诊胸痛患者210例,均行全主动脉CTA检查。按扫描时监测心率分为低心率组109例A组(80次/min)和高心率组101例B组(≥80次/min)。每一组再分为两个亚组即自由呼吸组(A1、B1)和屏气检查组(A2、B2)。评价比较各组间CTA的图像质量和图像可诊断率。结果:主动脉CTA平均曝光时间(0.9±0.16)s,平均辐射剂量(2.32±0.48)mSv。主动脉图像质量评分A组(1. 06±0.11),B组(1.08±0.15),差异无统计学意义(P0.05)。自由呼吸亚组(1.04±0.07)与屏气检查亚组(1.10±0.05)比较差异无统计学意义(P0.05)。肺动脉图像质量评分A组(1.2±0.19),B组(1.25±0.28)差异无统计学意义(P0.05)。自由呼吸亚组(1.26±0.31)与屏气检查亚组(1.16±0.17)比较差异无统计学意义(P0.05)。冠状动脉图像质量评分A组(1.67±0.65)B组(2.48±0.69)差异有统计学意义(P0.05)。A1组(1.68±0.58)与A2组(1.65±0.72)比较差异无统计学意义(P0.05)。各组血管内平均CT值,信噪比之间差异无统计学意义(P0.05)。结论:第三代双源对于急诊胸痛患者提供一站式成像解决方案。由于时间分辨率提高,在自由呼吸状态下不降低扫描的图像质量。但对于高心率患者,图像质量较低心率组有一定下降。     

多排螺旋CT血管成像多种重建方法在腹主动脉瘤术前影像学评估中的应用

目的 探讨综合应用多排螺旋CT血管成像(MSCTA)多种重建方法对腹主动脉瘤(AAA)进行术前影像学评估的临床应用价值.方法 回顾分析2009年6月至2010年5月共75例AAA患者的MSCTA资料,并对比分析其中61例成功实施血管腔内修复(EVAR)术患者的MSCTA及术中DSA资料.应用容积再现(VRT)、多平面重...     

双源CT低剂量前瞻性心电触发序列扫描在冠状动脉血管成像的应用

目的 研究双源CT低剂量前瞻性心电触发序列扫描技术在冠状动脉CTA的应用,并评价其图像质量.方法 将68例行冠状动脉CTA检查的患者分为2组,A组38例行前瞻性心电触发序列扫描,入组标准为心率70次/min(bpm)以下,窦性心律,心率波动范围在10 bpm以内.排除标准为心率不能控制在70 bpm以内及心律不齐患者、屏气不佳者以及冠状动脉存在严重钙化及明显狭窄者.采集期相70%R-R间期.B组30例为常规回顾性心电门控螺旋扫描,人组标准为心率70 bpm以下,窦性心律且规整.排除标准为心律不齐患者、屏气不佳者以及冠状动脉存在严重钙化及明显狭窄者.2组中管电压均随体质量指数(BMI)调整,BMI≥24 ks/m2管电压采用120 kV,BMI<24 ks/m2管电压采用100 kV.对2组扫描的冠状动脉分别做图像处理,应用秩和检验比较2组患者冠状动脉段图像质量评分,应用两独立样本t检验比较2组患者辐射剂量.结果 A组评价476段冠状动脉,B组评价372段冠状动脉.A组冠状动脉段图像质量评分为(3.48±0.59)分,B组均值为(3.53±0.58)分,2组之间比较差异无统计学意义(Z=-1.432,P=0.187).A组平均有效剂量为(2.51±0.54)mSv;B组平均有效剂量为(14.55±3.54)mSv,2组之间平均有效剂量比较差异有统计学意义(t=18.484,P=0.000).结论 在严格掌握心率及心律的基础上,可成功实现前瞻性触发序列扫描,该技术能显著降低辐射剂量而保证诊断所需图像质量.     

比较小剂量多巴酚丁胺负荷MRI和延迟强化MRI预测陈旧心肌梗死心功能恢复的价值

目的 比较小剂量多巴酚丁胺负荷MRI和延迟强化MRI预测陈旧心肌梗死心功能恢复价值.方法 10例陈旧心肌梗死病人于10 d内行小剂量多巴酚丁胺负荷(5～10 μg·kg-1·min-1)心脏电影MRI和延迟强化心脏MRI,所有病人均行血运重建术, 3～6月后再次行静息MRI心脏电影检查评价心功能恢复情况.结果 10例患者中38个心肌节段室壁运动异常,其中24个节段血运重建后功能恢复,14个节段功能未恢复.小剂量多巴酚丁胺负荷MRI和延迟强化MRI预测心功能恢复的敏感性、特异性、准确性分别为95.7% vs 85.7%(P=0.094＞0.05)、85.7%vs 78.5% (P=0.50＞0.05)、 92.1% vs 78.9%.ROC曲线下面积小剂量多巴酚丁胺负荷MRI和延迟强化MRI分别为0.91和0.79.结论 小剂量多巴酚丁胺负荷MRI与延迟强化MRI预测陈旧心肌梗死心功能恢复诊断能力相当.     

双低剂量全主动脉CT血管成像临床应用研究

目的利用双低剂量(80k V,30ml碘对比剂)结合迭代重建全主动脉CT血管成像,评价图像质量及应用可行性。材料和方法前瞻性收集60例主动脉术后接受主动脉CTA检查的患者,并分为两组。第一组采用120kv、60ml对比剂扫描方案,第二组采用80kv、30ml对比剂扫描方案扫描。第一组采用滤波反投影法(FBP)重建,第二组组采用迭代算法(SAFIRE)重建。比较两组间的主观(主动脉图像质量评分)和客观图像质量(图像噪声、信噪比SNR、对比噪声比CNR)的差异。记录两组辐射剂量。结果与第一组相比,第二组总体主观图像质量无明显差异(p>0.05),部分主动脉节段的图像噪声和SNR略有降低;第二组辐射剂量比第一组降低约72%(2.12±0.15m Sv m Sv vs.7.47±0.54,p<0.0001),对比剂用量减少50%(30ml vs 60ml,p<0.0001)。结论80kv、30ml对比剂全主动脉CTA扫描方案结合迭代重建算法显著降低辐射剂量和对比剂用量,其图像质量可满足诊断。