双源CT前瞻性和回顾性心电门控冠状动脉成像对比研究

目的:通过对双源CT前瞻性与回顾性心电门控冠状动脉成像的图像质量和辐射剂量等比较,探讨双源CT前瞻性触发序列扫描技术在冠状动脉成像中的应用价值.方法:将110例行双源CT冠状动脉血管成像检查的患者随机分为2组,A组60例行前瞻性触发序列门控扫描,B组50例行回顾性心电门控螺旋扫描.入组标准为心率75次/min(bpm)以下,心率相对规整(波动≤10bpm).管电压根据体重质量指数(BMI)调整:BM1≥25kg/m2,120kV;BMI＜25kg/m2,100kV.记录扫描中患者所接受辐射剂量,并对其图像质量进行评分.分别采用Wilcoxon秩检验和两独立样本t检验对两组的图像质量和辐射剂量进行统计学分析.结果:A组图像质量平均评分为(3.74±0.51)分,平均有效剂量为(2.38±0.83) mSv;B组图像质量平均评分为(3.68±0.58)分,平均有效剂量为(9.49±3.38)mSv.A、B两组图像质量评分差异无统计学意义(Z =-1.891,P=0.059);有效剂量差异有统计学意义(t=-14.522,P＜0.001),降低约75％.结论:双源CT在心率低且稳定的患者中行前瞻性触发序列扫描能够显著降低辐射剂量,并且可以获得满足临床诊断的图像质量.     

前瞻性心电门控技术在双源CT冠状动脉成像中的应用价值

目的:比较双源CT冠状动脉成像(CTCA)前瞻性心电门控与回顾性心电门控扫描的辐射剂量及图像质量。方法:以相同纳入标准,选取50例行前瞻性心电门控扫描的患者作为前瞻门控组,另选取50例行回顾性心电门控的患者作为回顾门控组。由两名CT医师分别对两组CTCA图像进行评估。记录并比较两组患者一般临床资料、辐射剂量及图像质量评分。结果:两组患者性别、年龄、体重指数、平均心率、心率波动、扫描范围差异均无统计学意义(P>0.05)。前瞻门控组有效辐射剂量(3.80±0.46)mSv,回顾门控组有效辐射剂量(20.64±3.14)mSv,两组差异具有统计学意义(P<0.001)。两组图像质量的差异无统计学意义(2=1.166,P=0.761)。结论:前瞻性心电门控较回顾性心电门控技术能够在保证图像质量的同时明显降低辐射剂量。     

前瞻性心电门控MSCT冠状动脉成像研究进展

近年来CT硬件水平的提升使得冠状动脉CT血管成像得以广泛应用,而传统回顾性心电门控冠状动脉CTA的高辐射剂量一直是令人担忧的问题。前瞻性心电门控冠状动脉CTA在影像质量无差别的情况下可以大幅降低病人受线剂量,具有替代回顾性心电门控冠状动脉CTA的潜在价值。目前,前瞻性心电门控技术的研究主要针对影像质量及辐射剂量两方面进行。64层以上机型的投入使用将会对前瞻性心电门控技术产生深远的影响。     

双源CT自适应前瞻性心电门控冠状动脉成像技术的初步应用

目的：初步探讨双源CT前瞻性心电门控冠状动脉成像的图像质量和辐射剂量。方法：对50例临床怀疑冠心病的受检者进行双源CT自适应前瞻性门控冠状动脉成像,检查前均未服用琥珀酸美托洛尔。图像质量分4级,依照美国心脏病协会（AHA）冠状动脉分段标准分别评价各个冠状动脉节段的图像质量,分别计算每例的有效辐射剂量（ED）。结果：50例受检者平均体重指数（BM I）为（25.00±2.58）kg/m2,扫描时平均心率（71.13±9.63）次/min,平均有效辐射剂量（3.31±1.08）mSv,显示了94.76%能满足诊断要求的冠状动脉节段,图像质量优秀占79.49%。结论：双源CT自适应前瞻性心电门控冠状动脉成像对于无严重心律失常的受检者都可得到满足诊断要求的图像,辐射剂量低,具有广阔的应用前景。     

双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

目的 与常规冠状动脉造影(CCA)对照,研究双源CT(DSCT)前瞻性心电门控序列扫描冠状动脉成像(SAS-CTCA)对冠状动脉狭窄诊断的准确性.方法 前瞻性的多中心研究,46例可疑冠心病患者[平均年龄(58±9)岁,体质量指数(BMI)(25±3)kg/m2]均进行了SAS-CTCA检查,并于14 d以内完成CCA检查.患者纳入标准:(1)心率控制在65次/min(bpm)以下;(2)窦性心律,心律规整,心率波动范围在6 bpm以内;(3)呼吸配合良好,屏气时间可达到12～15s.排除标准:(1)碘对比剂过敏、肝肾功能不全(血肌酐120 μmol/L)、心功能不全及严重心律不齐患者;(2)冠状动脉支架置入或冠状动脉搭桥患者;(3)心率快,而不能服用美托洛尔控制心率者;(4)不能服用硝酸甘油者;(5)体质量指数(body mass index,BMI)30 ks/m2 ;(6)其他心脏疾患:如心肌病、瓣膜病等.2名评价者分析SAS-CTCA及CCA的结果,计算SAS-CTCA对于冠状动脉狭窄诊断的敏感性、特异性、阳性预测值、阴性预测值,计算2名评价者间、两种检查方法之间的Kappa值,并对辐射剂量进行统计.结果 检查过程中患者的平均心率为(61±6)bpm,99.19%(614/619)的冠状动脉节段达到可供诊断的图像质量.与CCA相比,以冠状动脉血管为单位,SAS-CTCA在显示冠状动脉病变方面的敏感性、特异性、阳性预测值、阴性预测值分别为96.2%(75/78)、88.2%(60/68)、90.4%(75/83)、95.2%(60/63).两种检查方法之间的Kappa值为0.848(P=0.000).SAS-CTCA的平均有效剂量为(2.95±0.96)mSv.结论 在严格控制入选标准的前提下,SAS-CTCA检查可以在降低辐射剂量的同时获得满意的图像质量,并对诊断冠状动脉狭窄具有较高的可信性.     

双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.     

双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.     

双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.     

双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.     

双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.     

Systolic prospectively ECG-triggered dual-source CT angiography for evaluation of the coronary arteries in heart transplant recipients

Objectives  

To assess feasibility, image quality, and radiation dose of prospectively ECG-triggered coronary CT angiography (CTA) in orthotopic heart transplant (OHT) recipients.     

第二代双源CT前门控FLASH扫描与序列扫描冠状动脉成像比较

目的:比较第二代双源CT前门控大螺距螺旋扫描(FLASH扫描)与序列扫描模式在冠状动脉CT成像中的图像质量及辐射剂量。方法:回顾性分析采用第二代双源CT行前门控FIASH扫描(A组)与序列扫描(B组)冠状动脉CTA连续各50例患者,入组标准为心率70次/min以下,窦性心律,心率波动范围在10次/min以内。评价这2种成像模式的图像质量及辐射剂量。扫描参数:2组均采用Z轴飞焦点技术采集,探测器准直宽度0.6 mm,重建层厚0.75 mm,扫描时间0.28 s/r,单扇区时间分辨率75 ms,根据患者体质量指数(BMI)值设定管电压:100kV(BMI<24 kg/m~2)、120 kV(BMI≥24 kg/m~2),参考管电流370 mAs,采用管电流调制方案;FLASH扫描前门控心电触发选在60%R-R间期,螺距3.4;序列扫描采集时相为35%～75%R-R间期,步进采集宽度34.5 mm。冠状动脉图像质量分为4级(1级为优异,1～3级为可评价血管,4级为不可评价血管),相应评为1～4分。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组患者所接受的辐射剂量。结果:A、B 2组患者的年龄及BMI差异无统计学意义。A、B 2组可评价的冠状动脉节段百分比分别为98.21%和98.56%,差异无统计学意义(χ~2=0.244,P=0.621),平均图像质量评分分别为1.30±0.60和1.28±0.56,差异无统计学意义(Z=-0.489,P=0.625)。A、B 2组扫描的平均有效辐射剂量分别为(0.99±0.34)mSv和(4.80±2.21)mSv,差异有统计学意义(t=-12.048,P=0.000),FLASH扫描剂量明显低于序列扫描。结论:在心率低于70次/min、心律稳定的情况下,第二代双源CT前门控FLASH扫描可获得与序列扫描相似的高质量图像,但辐射剂量明显降低。     

Lowering heart rate with an optimised breathing protocol for prospectively ECG-triggered CT coronary angiography

Objectives

The aim was to prospectively characterise the effect of the level of breath-hold on heart rate in CT coronary angiography (CTCA) with prospective electrocardiogram (ECG) triggering and its impact on coronary artery attenuation.

Methods

260 patients (86 women; mean age 59 ± 11 years) underwent 64-slice CTCA using prospective ECG triggering. Prior to CTCA, heart rates were recorded during 15 s of breath-hold at three different levels of inspiration (normal, intermediate and deep). The inspiration level with the lowest heart rate was chosen for actual CTCA scanning. Coronary artery attenuation was measured, and the presence of backflow of contrast material into the inferior vena cava (as an indicator of increased intrathoracic pressure) was recorded.

Results

The mean heart rate at breath-hold was significantly different for the three inspiration levels (normal, 60 ± 8 bpm; intermediate, 59 ± 8 bpm; deep, 57 ± 7 bpm; p<0.001). The maximum heart rate reduction in each patient at breath-hold averaged 5.3 ± 5.1 bpm, and was observed at a normal inspiration depth in 23 (9%) patients, at an intermediate inspiration depth in 102 (39%) patients and at deep inspiration in 135 (52%) patients. Overall, there was no association between the level of breath-hold and coronary vessel attenuation (p-value was not significant). However, the backflow of contrast material into the inferior vena cava (n = 26) was found predominantly at deep inspiration levels (p<0.001), and, when it occurred, it was associated with reduced coronary attenuation compared with patients with no backflow (p<0.05).

Conclusion

The breath-hold level to best reduce heart rate for CTCA should be individually assessed prior to scanning because a mean heart rate reduction of 5 bpm can be achieved.Low-dose CT coronary angiography (CTCA) with prospective electrocardiogram (ECG) triggering has recently been introduced [1] and shown to offer a tremendous reduction in radiation dose [2-8], which makes its widespread clinical use feasible. Scanning in CTCA with prospective ECG triggering is exclusively performed during a short phase in diastole, called “diastasis”. The new technique appears to be more prone to artefacts caused by coronary motion. This is especially true in higher heart rates because diastasis disproportionally shortens with increasing heart rates [9] and the length of diastasis becomes shorter than the time required for image acquisition when the heart rate exceeds a certain threshold. Furthermore, when low-dose CTCA with prospective ECG triggering is performed with the smallest possible acquisition window to achieve the lowest possible radiation dose, it does not permit image reconstruction in other phases of the cardiac cycle to compensate for a possible reduction in image quality. An aggressive reduction in heart rate with β-blockers below a target heart rate of 63 bpm appears to be a prerequisite for low-dose CTCA [2,10].CTCA is generally performed during the patient''s breath-hold to avoid motion artefacts caused by movement of the thorax during image acquisition. However, the breath-hold and, particularly, the level (or depth) of breath-hold can affect heart rate [11]. Generally, heart rate is lowest at full vital capacity (deep inspiration) and highest at residual volume (normal inspiration) [11]. However, other factors, such as intrapleural and intrathoracic pressure and neural reflexes also determine the heart rate during breath-hold [11]. The lowest heart rates are not always reached at deep inspiration level during breath-hold. Furthermore, during CTCA, very deep inspiration for breath-hold may lead to an increased intrathoracic pressure (Valsalva effect), which may itself impair contrast material flow from the arm veins to the coronary arteries, and thus cause reduced coronary artery attenuation and decreased image quality.Accordingly, the purpose of this study was to describe and characterise the effect of breath-hold on heart rate and on coronary artery attenuation in CTCA with prospective ECG triggering.     

低剂量前瞻性心电触发序列扫描在房颤患者冠状动脉CT成像的研究

目的 研究前瞻性心电触发序列扫描在房颤患者冠状动脉CT成像的可行性.方法 前瞻性连续入组94例持续房颤患者,47例患者采用前瞻性心电门控序列扫描,另外47例采用回顾性心电门控螺旋扫描.设备采用第二代双源CT.以冠状动脉段为基础评价图像质量,比较两组的图像质量和辐射剂量.结果 前瞻组可诊断的血管段为99.5％（604/607）,回顾组为97.7％（570/584）,前瞻组显著高于回顾组（P＜0.001）.以患者为基础,前瞻组43例（92％）为可诊断,回顾组29例（62％）为可诊断病例.有效辐射剂量在前瞻和回顾组分别为（4.15±1.78）mSv和（12.15±5.38）mSv,两组之间差异有显著性（P＜0.001）.序列扫描降低辐射剂量66 ％.结论 采用第二代双源CT,前瞻性心电触发序列扫描对于房颤患者冠状动脉CT成像具有可行性,该扫描方案可以显著降低辐射剂量,并保证诊断所需图像质量.     

Systolic reconstruction in patients with low heart rate using coronary dual-source CT angiography

Objectives

The purpose of our study was to determine the relationship between the predictive factors and systolic reconstruction (SR) as an optimal reconstruction window in patients with low heart rate (LHR; less than 65 bpm).

Methods

391 patients (262 male and 129 female, mean age; 67.1 ± 10.1 years of age) underwent coronary CTA without the additional administration of a beta-blocker. Affecting factors for SR were analyzed in age, gender, body weight (BW), diabetes mellitus (DM), coronary arterial disease (CAD), ejection fraction (EF), systolic and diastolic body pressure (BP) and heart rate variability (HRV) during coronary CTA.

Results

In 29 (7.4%) of the 391 patients, SR was needed, but there was no apparent characteristic difference between the systolic and diastolic reconstruction groups in terms of gender, age, BW, DM, CAD and EF. In a multivariate analysis, the co-existence of DM [P < 0.05; OR, 0.27; 95% CI, 0.092-0.80], diastolic BP [P < 0.01; OR, 0.95; 95% CI, 0.92-0.98] and HRV [P < 0.01; OR, 0.98; 95% CI, 0.96-0.99] were found to be the factors for SR. In gender-related analysis, HRV was an important factor regardless of sex, but co-existence of DM affected especially for female and BP for male.

Conclusion

Especially in the patients with LHR who had a medication of DM, high HRV or high BP, SR, in addition to DR, was needed to obtain high-quality coronary CTA images.     

Age-related differences in image quality of prospectively ECG-triggered axial and helical scans for coronary CT angiography

We investigated the underlying reasons for the occurrence of misalignment artifacts in prospectively ECG-triggered axial coronary CT angiography scans. In this study we analyzed 56 consecutive patients scanned in axial mode and 66 consecutive patients scanned in helical mode. Predictors for the occurrence of misalignment artifacts were evaluated by multivariable logistic regression analysis for those patients scanned in the axial mode; advanced age was identified as the sole independent predictor (odds ratio: 1.088; 95 % CI: 1.012–1.170; p = 0.0228). In a comparison with the patients scanned in the helical mode, the image quality score for patients aged 65 years or older was significantly higher in helical mode than in axial mode (2.6 ± 0.5 and 2.4 ± 0.7, respectively; p = 0.0313). Misalignment artifacts in the image are more common in the elderly than in younger. Helical mode should be preferred in this older patient population to allow for good diagnostic image quality.     

Dual-step prospective ECG-triggered 128-slice dual-source CT for evaluation of coronary arteries and cardiac function without heart rate control: a technical note

Purpose

To describe prospective ECG-triggered dual-source CT dual-step pulsing (pECG_{dual_step}) for evaluation of coronary arteries and cardiac function.

Methods

Fifty-one consecutive patients pre- or post-cardiovascular surgery were examined with adaptive sequential tube current modulated (pECG_dual-step) 128-slice dual-source CT without heart rate control (main padding window: 40% RR interval?>65 bpm/70% RR interval?<65 bpm). Image quality of coronary arteries was graded (4-point scale), and cardiac function was evaluated.

Results

Mean HR was 68 bpm. Thirty-seven patients were in stable sinus rhythm (SR); 14 had arrhythmia. Image quality of coronary arteries was diagnostic in 804/816 (98%) of segments. The number of non-diagnostic segments was higher in patients with arrhythmia as compared to those in SR (4% vs. 0.5%; p?=?0.01), and there were fewer segments with excellent image quality (79% vs. 94%; p?<?0.001) and more segments with impaired image quality (p?<?0.001 and p?=?0.002). Global and regional LV function could be evaluated in 41 (80%) and 47 (92%) patients, and valvular function in 48 (94%). In 11/14 of patients with arrhythmia, the second step switched to full mAs, increasing radiation exposure to 8.6 mAs (p?<?0.001). The average radiation dose was 3.8 mSv (range, 1.7–7.9) in patients in SR.

Conclusion

pECG_dual-step128-slice DSCT is feasible for the evaluation of coronary arteries and cardiac function without heart rate control in patients in stable sinus rhythm at a low radiation dose.     

双源CT在冠状动脉造影技术方法的探讨

目的：探讨双源CT（DSCT）对冠状动脉造影具有再次重新定义的价值。方法：对520例患者进行常规冠脉造影检查,分析双源CT冠状动脉造影的技术方法,步骤及特殊的射线剂量调控技术（适应ECG门控剂量调控技术）及其功能。结果：520例患者中心率小于100次／min的患者共有390例,占75％,其平均心率为75±5．6次／min（60—100次／min）。心率高于100的患者有130例,占25％,其平均心率为（110．6＋10．8）次／min（101～130次／min）。冠状动脉重建的最佳时相均为心脏收缩期。结论：双源CT比传统CT少50％的放射剂量,在不需要控制心率的情况下完成心脏成像,提供高质量的冠状动脉和心脏图像,提高诊断冠状动脉病变的准确性。     

Application of prospective ECG-triggered dual-source CT coronary angiography for infants and children with coronary artery aneurysms due to Kawasaki disease

Objectives

The aim of this study was to prospectively evaluate the initial application and value of prospective electrocardiogram (ECG)-triggered dual-source CT coronary angiography (DSCTCA) in the diagnosis of infants and children with coronary artery aneurysms due to Kawasaki disease.

Methods

19 children [12 males; mean age 13.47 months, range 3 months to 5 years; mean heart rate 112 beats per minute (bpm), range 83–141 bpm] underwent prospective ECG-triggered DSCTCA with free breathing. Subjective image quality was assessed on a five-point scale (1, excellent; 5, non-diagnostic) by two blinded observers. The location, number and size of each aneurysm were observed and compared with those of transthoracic echocardiography (TTE) performed within 1 week. Interobserver agreement concerning the subjective image quality was evaluated with Cohen''s κ-test. Bland–Altman analysis was used to evaluate the agreement on measurements (diameter and length of aneurysms) between DSCTCA and TTE. The average effective dose required for DSCTCA was calculated for all children.

Results

All interobserver agreement for subjective image quality assessment was excellent (κ=0.87). The mean±standard deviation (SD) aneurysm diameter with DSCTCA was 0.76±0.36 cm and with TTE was 0.76±0.39 cm. The mean±SD aneurysm length with DSCTCA was 2.06±1.35 cm and with TTE was 2.00±1.22 cm. The Bland–Altman plot for agreement between DSCTCA and TTE measurements showed good agreement. The mean effective dose was 0.36±0.06 mSv.

Conclusion

As an alternative diagnostic modality, prospective ECG-triggered DSCTCA with excellent image quality and low radiation exposure has been proved useful for diagnosing infants and children with coronary artery aneurysms due to Kawasaki disease.

Advances in knowledge

Prospective ECG–triggered DSCTCA for infants and children allows rapid, accurate assessment of coronary aneurysms due to Kawasaki diseases, compared with TTE.Kawasaki disease (KD), also known as mucocutaneous lymph node syndrome, is an autoimmune vasculitis in which the small and medium vessels throughout the body become inflamed [1,2]. It predominantly occurs in infants and children (younger than 5 years old). It affects many organ systems; injury, such as aneurysm, dilation, ectasia, stenosis and embolism, to the heart is rare but serious, and fatal myocardial infarction can be induced in untreated cases [3-6]. It is crucial to detect coronary artery lesions at an early stage [7]. Diagnosis of KD is based on clinical signs, symptoms and laboratory findings, but no specific laboratory test exists and it is hard to establish the diagnosis, especially in the early course [8].Recently, multidetector CT, especially the advent of dual-source CT, has provided improved spatial and temporal resolution; moreover, multiple techniques on dose reduction have been applied in children. Electrocardiogram (ECG)-gated scans, especially retrospective ECG-gated scans, have been used to evaluate coronary artery lesions in children with KD [2,9]. The high radiation dose required remains the main concern [10]; even though dose-saving methods including low tube potential, tube current modulation and body size-adapted CT protocols have been adopted, the effective radiation dose is still high at up to 2.17–3.14 mSv [11-13].Recently, prospective ECG-triggered scans were considered to be the most promising approach for dose reduction as they were used in the assessment of cardiovascular deformities in children with congenital heart disease [14-17]; however, no further studies have been reported on the application of prospective ECG-triggered CT angiography in children with KD.The aim of this study was to evaluate the initial application of prospective ECG-triggered dual-source CT coronary angiography (DSCTCA) in infants and children with coronary artery aneurysms due to KD.     

双源CT血管成像评估冠状动脉异常起源的价值

目的：探讨双源CT血管成像对冠状动脉异常起源的诊断价值。方法：对8375例成人冠状动脉双源CT血管成像中109例显示为冠状动脉异常起源的图像进行回顾性分析。结果：本组中冠状动脉起源异常检出率为1.3%（109/8375）,包括左侧冠状动脉起源异常37例（窦上开口4例,窦后开口4例,回旋支异位开口于右侧冠状窦8例,回旋支独立开口于左冠状窦15例,左冠开口于右冠状窦或右冠状动脉4例,左冠开口于肺动脉1例,回旋支缺如1例）,右侧冠状动脉起源异常61例（高位开口29例,异位开口于左冠状窦24例,圆锥支独立开口8例）,左、右冠状动脉均起源异常11例;109例起源异常中发现伴随冠状动脉肺动脉瘘2例,心肌桥4例。结论：双源CT可以准确诊断冠状动脉起源异常,并可发现其它伴随病变,是一种无创有效的检查方法。