双源CT前瞻性心电门控低剂量扫描在小儿川崎病冠状动脉损害诊断中的应用

目的 评价双源CT(DSCT)前瞻性心电门控低剂量扫描在小儿川崎病(KD)冠状动脉损害诊断中的临床应用价值.方法 回顾性分析19例临床诊断为KD冠状动脉损害,同时行经胸多普勒超声(TTE)和DSCT前瞻性心电门控低剂量扫描的患儿资料;由2名放射科医师采用盲法独立阅片,以5分法评价整体图像质量,Kappa检验评价诊断的一致性;记录所有患儿冠状动脉瘤样扩张及动脉瘤的位置、数量并测量其大小;Pearson相关分析比较DSCT成像和TTE两种检查方法诊断结果的一致性;计算所有患儿的平均有效辐射剂量(ED).结果 19例患儿均成功完成DSCT前瞻性心电门控低剂量冠状动脉成像,可评价冠状动脉节段比率为91.5％(226/247),其中,15例患儿被诊断为川崎病冠状动脉瘤样扩张或动脉瘤形成,DSCT成像上共发现28个动脉瘤、15支血管瘤样扩张.其中,9个动脉瘤(2个位于右冠状动脉远段、2个位于左心室后支、1个位于前降支中段、1个位于回旋支中段、2个位于回旋支远段、1个位于钝缘支)及2支瘤样扩张(1支对角支、1支钝缘支)TTE未显示.DSCT成像与TTE对比显示冠状动脉瘤及瘤样扩张最大直径的平均测量值分别为(0.63 ±0.20)和(0.58 ±0.20) cm,相关性较好(r=0.989,P＜0.05);对瘤体及瘤样扩张最大长径的平均测量值分别为(1.49±0.83)和(1.22±0.66)cm,相关性较好(r=0.965,P＜0.05).2名影像科医师对所有患儿的CTA图像质量评分一致性好(Kappa=0.87).19例患儿的ED为(0.24±0.08) mSv.结论 相比TTE,DSCT前瞻性心电门控低剂量冠状动脉成像对小儿川崎病患儿冠状动脉远段的动脉瘤及瘤样扩张的显示较好.     

中等心率下64层螺旋CT 前瞻性心电门控冠状动脉成像的可行性研究

目的 采用回顾性心电门控模拟前瞻性心电门控冠状动脉CT 成像(CCTA),探讨前瞻性心电门控CCTA 在中等心率病人中的可行性.方法 本研究共纳入63 例病人[心率(HR)为65～75 次/min,心率变异性(HRv)＜5次/min,钙化积分＜400 分]行回顾性心电门控CCTA,扫描结束后以R-R 间期60%的相位为中心,按400 ms 占据曝光平均心率R-R 间期的比例以5%的间隔重建期相,以冠状动脉节段为单位,对所有重建的图像进行评分(5 分制:5分为优,1 分为差),以统计描述可用于诊断的冠状动脉节段数目所占比例评价前瞻性心电门控CCTA 在中等心率病人中的应用价值.结果 共有822 个冠状动脉节段参与评分,平均得分4.15±0.72,可用于诊断的冠状动脉节段数目比例为97.76%.结论 中等心率下前瞻性心电门控技术可通过预设60%采集期相,重叠时间设置为200 ms 可以重建出满足诊断的图像,且理论上可以大幅降低辐射剂量.     

256层CT前瞻与回顾性心电门控冠状动脉成像的应用研究

目的 通过256层CT前瞻性心电门控与回顾性心电门控冠状动脉成像的辐射剂量和成像质量等比较,探讨前瞻性心电门控CT冠状动脉成像的可行性.资料与方法 拟诊冠状动脉粥样硬化性心脏病(CHD)两组患者分别进行前瞻性和回顾性心电门控扫描,并采用最大密度投影(MIP)、容积再现(VR)、多平面重组(MPR)及曲面重组(CPR)多种重组技术显示各节段冠状动脉,图像质量根据对诊断影响分为优、良、差,并计算各自有效辐射剂量,进行统计学分析.结果 前瞻性组平均辐射剂量为(2.11±0.48)mSv,明显低于回顾性组的(9.15±1.59)mSv(P<0.01);前瞻性组冠状动脉节段图像质量优良及差者分别占96.7%(1259/1302)和3.3%(43/1302),与回顾性组的96.3%(1339/1390)和3.7%(51/1390)比较,差异无统计学意义.结论 256层CT前瞻性心电门控冠状动脉成像能以较低的辐射剂量取得优质图像,更适合CHD患者的早期筛查.     

256层CT前瞻性及回顾性心电门控冠状动脉成像质量和辐射剂量的初探

目的运用前瞻性心电门控与回顾性心电门控两种方法行冠状动脉CT成像,比较两者的成像质量与辐射剂量。资料与方法 70例疑似冠状动脉疾病的患者随机分为两组,前瞻性心电门控组和回顾性心电门控组,每组35例,两组心率均<70次/min,记录两组的成像质量和辐射剂量。结果前瞻性心电门控和回顾性心电门控两组冠状动脉成像质量评价差异无统计学意义(P>0.05);两组的有效剂量分别为(2.5±0.7)mSv和(9.6±1.7)mSv,差异有统计学意义(P<0.001),平均ED前瞻性心电门控组较回顾性心电门控组低74.4%。结论心率在一定范围内(﹤70次/min),256层前瞻性心电门控技术能够获得满足临床诊断需要的冠状动脉CTA图像,并有效地降低了辐射剂量。     

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。     

中等心率下64层螺旋CT前瞻性心电门控冠状动脉成像的可行性研究

目的采用回顾性心电门控模拟前瞻性心电门控冠状动脉CT成像（CCTA）,探讨前瞻性心电门控CCTA在中等心率病人中的可行性。方法本研究共纳入63例病人[心率（HR）为65～75次/min,心率变异性（HRv）〈5次/min,钙化积分〈400分]行回顾性心电门控CCTA,扫描结束后以R-R间期60%的相位为中心,按400ms占据曝光平均心率R-R间期的比例以5%的间隔重建期相,以冠状动脉节段为单位,对所有重建的图像进行评分（5分制：5分为优,1分为差）,以统计描述可用于诊断的冠状动脉节段数目所占比例评价前瞻性心电门控CCTA在中等心率病人中的应用价值。结果共有822个冠状动脉节段参与评分,平均得分4.15±0.72,可用于诊断的冠状动脉节段数目比例为97.76%。结论中等心率下前瞻性心电门控技术可通过预设60%采集期相,重叠时间设置为200ms可以重建出满足诊断的图像,且理论上可以大幅降低辐射剂量。     

30mL碘对比剂、70kV管电压下前瞻性心电门控大螺距冠状动脉CT血管成像的初步可行性研究

正摘要目的评估 30 mL 碘对比剂 70 kV 管电压下前瞻性心电门控大螺距冠状动脉 CT 血管成像(CCTA)的可行性、影像质量及辐射剂量。方法本前瞻性研究共纳入 58 例体质     

64排螺旋CT冠状动脉成像的前瞻性与回顾性心电门控技术的图像质量及辐射剂量的比较研究

目的 研究前瞻性心电门控触发(prospective ECG-triggering)与回顾性心电门控(retrosp-ective ECG gating)两种技术方法行冠状动脉CTA检查时,对冠状动脉图像质量及辐射剂量的比较.方法 33名疑似冠状动脉疾病的患者分两组进行对比研究.前瞻组16例为前瞻性心电门控成像,心率小于65次/min;回顾组17例为回顾性心电门控成像,心率小于75次/min.记录两组的辐射剂量并统计分析,同时进行图像质量评价.结果 两组图像质量比较,差异无统计学意义(P0.05).前瞻性心电门控冠状动脉CTA的平均DLP 234.4 mGy·cm,占回顾性心电门控冠状动脉CTA的平均DLP 974.4 mGy·cm的24.1%.前瞻性心电门控冠状动脉CTA的患者的平均有效剂量为3.2 mSy,回顾心电门控冠状动脉CTA患者的为13.6 mSv,降低76.47%.结论 64排螺旋CT在前瞻性心电门控冠状动脉CTA与回顾性心电门控冠状动脉CTA比较可以获得相似的图像质量,可大幅降低患者的有效剂量对于不能接受高辐射剂量且心率较低的受检人群具有重要的临床价值.     

64排螺旋CT冠状动脉成像的前瞻性与回顾性心电门控技术的图像质量及辐射剂量的比较研究

目的 研究前瞻性心电门控触发(prospective ECG-triggering)与回顾性心电门控(retrosp-ective ECG gating)两种技术方法行冠状动脉CTA检查时,对冠状动脉图像质量及辐射剂量的比较.方法 33名疑似冠状动脉疾病的患者分两组进行对比研究.前瞻组16例为前瞻性心电门控成像,心率小于65次/min;回顾组17例为回顾性心电门控成像,心率小于75次/min.记录两组的辐射剂量并统计分析,同时进行图像质量评价.结果 两组图像质量比较,差异无统计学意义(P0.05).前瞻性心电门控冠状动脉CTA的平均DLP 234.4 mGy·cm,占回顾性心电门控冠状动脉CTA的平均DLP 974.4 mGy·cm的24.1%.前瞻性心电门控冠状动脉CTA的患者的平均有效剂量为3.2 mSy,回顾心电门控冠状动脉CTA患者的为13.6 mSv,降低76.47%.结论 64排螺旋CT在前瞻性心电门控冠状动脉CTA与回顾性心电门控冠状动脉CTA比较可以获得相似的图像质量,可大幅降低患者的有效剂量对于不能接受高辐射剂量且心率较低的受检人群具有重要的临床价值.     

64排螺旋CT冠状动脉成像的前瞻性与回顾性心电门控技术的图像质量及辐射剂量的比较研究

目的 研究前瞻性心电门控触发(prospective ECG-triggering)与回顾性心电门控(retrosp-ective ECG gating)两种技术方法行冠状动脉CTA检查时,对冠状动脉图像质量及辐射剂量的比较.方法 33名疑似冠状动脉疾病的患者分两组进行对比研究.前瞻组16例为前瞻性心电门控成像,心率小于65次/min;回顾组17例为回顾性心电门控成像,心率小于75次/min.记录两组的辐射剂量并统计分析,同时进行图像质量评价.结果 两组图像质量比较,差异无统计学意义(P0.05).前瞻性心电门控冠状动脉CTA的平均DLP 234.4 mGy·cm,占回顾性心电门控冠状动脉CTA的平均DLP 974.4 mGy·cm的24.1%.前瞻性心电门控冠状动脉CTA的患者的平均有效剂量为3.2 mSy,回顾心电门控冠状动脉CTA患者的为13.6 mSv,降低76.47%.结论 64排螺旋CT在前瞻性心电门控冠状动脉CTA与回顾性心电门控冠状动脉CTA比较可以获得相似的图像质量,可大幅降低患者的有效剂量对于不能接受高辐射剂量且心率较低的受检人群具有重要的临床价值.     

第二代双源CT前门控冠状动脉成像与冠状动脉造影比较的初步研究

目的:探讨第二代双源CT前门控冠状动脉成像(CTCA)对冠状动脉狭窄病变的诊断价值。方法:连续44例同期行第二代双源CT前门控CTCA(其中前门控序列扫描35例,前门控大螺距螺旋扫描9例)及选择性冠状动脉造影(SCA)检查的患者,按冠脉病变狭窄程度分为:无狭窄;轻度狭窄(狭窄≤50%);中度狭窄(狭窄50%～75%);重度狭窄(狭窄≥75%);闭塞(狭窄100%),将中度及中度以上狭窄定义为有意义狭窄。以SCA为金标准,分析第二代双源CT前门控CTCA诊断冠状动脉狭窄的敏感性、特异性、阳性和阴性预测值及准确度,同时计算第二代双源CT前门控CTCA的辐射剂量。结果:44例患者冠脉直径2mm以上的节段共570个,其中12段图像质量较差,无法评估,可评估节段占97.89%。第二代双源CT前门控CTCA按冠脉节段计算,诊断冠状动脉狭窄的敏感度、特异度、阳性和阴性预测值、准确度分别为90.18%、93.05%、76.52%、97.42%、92.47%,诊断冠状动脉有意义狭窄的敏感度、特异度、阳性和阴性预测值、准确度分别为90.14%、95.69%、75.29%、98.52%、94.98%。第二代双源CT前门控CTCA与SCA比较对冠状动脉狭窄评价的差异无统计学意义(χ2=2.10,P>0.05),对冠状动脉有意义狭窄评价的差异无统计学意义(χ2=1.46,P>0.05)。第二代双源CT前门控CT-CA的平均辐射剂量为(3.36±1.59)mSv,其中前门控序列扫描的平均辐射剂量为(3.99±1.18)mSv,前门控大螺距螺旋扫描的平均辐射剂量为(1.11±0.44)mSv。结论:第二代双源CT前门控成像对诊断冠状动脉狭窄的准确度稍低于SCA,但其阴性预测值较高,同时其辐射剂量较低,可作为临床冠心病筛查的无创性检查手段。     

基于冠状动脉CT血管成像定量钙化负荷的可行性研究

目的 探讨冠状动脉CT血管成像（CCTA）一站式计算冠状动脉钙化积分（CCTA-CS）和体积积分（CCTA-VS）的可行性,并分析其与心电门控CT平扫测得标准积分（CACS、VS）的相关性。 方法 本研究回顾性连续纳入1 075例受试者,男447例,女628例,平均年龄（56.79±9.49）岁。全部受试者均行包括门控CT平扫和CCTA的常规冠状动脉CT检查,测量CACS、VS、CCTA-CS和CCTA-VS。选择CACS与CCTA-CS均不为0的影像数据进行分析。采用组内相关系数（ICC）评估2名观察者间及观察者内测量CCTA-CS和CCTA-VS的一致性。采用线性相关分析与Bland-Altman检验分析CCTA与门控CT平扫所测评分的相关性与一致性。根据CACS对受试者进行心血管病危险度分层,并采用Kruskal-Wallis H检验比较多组间的CCTA-CS与CCTA-VS。采用二元Logistic回归分析影响钙化积分的危险因素。采用独立样本t检验比较CCTA和常规冠状动脉CT检查的有效辐射剂量（ED）。 结果 CACS和CCTA-CS不为0的受试者共437例。2名观察者间和观察者内测量的CCTA-CS和CCTA-VS的一致性均较好（均ICC>0.960）。CCTA-CS与CACS、CCTA-VS与VS均呈较好的正相关（r²=0.98、0.96,均P<0.05）。Bland-Altman检验结果显示CCTA与门控CT平扫所测评分间的一致性较高。不同危险分层病人的CCTA-CS和CCTA-VS差异均有统计学意义（均P<0.05）。Logistic回归分析显示高血压、糖尿病、高脂血症、吸烟史、脑血管病均为CACS、CCTA-CS的危险因素。CCTA检查的ED低于常规冠状动脉CT检查,Flash扫描可减少21.2%,Sequence扫描可减少18.6%。 结论 CCTA一站式测量可以精确定量钙化,测得的CCTA-CS、CCTA-VS与标准积分有较好的相关性,且能有效降低辐射剂量。     

Coronary artery noninvasive imaging in adult Kawasaki disease

Coronary artery aneurysms, stenoses, and thromboses are significant complications of Kawasaki disease (KD). While appearing in childhood, coronary complications are often left unrecognized until early and mid-adulthood. Along with the increasing capacity of noninvasive coronary artery imaging modalities, especially computed tomography and magnetic resonance, radiologists are more likely to face the diagnosis of KD in adults. This article will review the clinical aspects of KD for radiologists and will compare coronary imaging modalities in the diagnosis of KD.     

Cardiac imaging to detect coronary artery disease in athletes aged 35 years and older. A scoping review

Sudden cardiac death (SCD ) is a devastating event in athletes. Screening efforts that were first directed at athletes younger than 35 years are now focusing on the rapidly growing group of older sportspersons. Athletes aged ≥35 years have a 10‐fold increased risk of exercise‐related cardiac arrest, mostly due to coronary artery disease (CAD ). Although cardiac imaging is pivotal in identifying CAD , the role of imaging modalities in screening asymptomatic older sportspersons remains unclear. We performed a scoping review to identify the role of cardiac imaging to detect CAD in older sportspersons and to identify gaps in the existing literature. We searched MEDLINE , EMBASE and the Cochrane library for studies reporting data on cardiac imaging of CAD in sportspersons ≥35 years. The systematic search yielded 1737 articles, and 14 were included in this scoping review. Imaging modalities included two echocardiography, one unenhanced computed tomography (CT ) for coronary artery calcium scoring (CACS ), three CACS and contrast‐enhanced CT angiography (CCTA ), two CACS and cardiac magnetic resonance (CMR ), one CCTA with CMR and echocardiography, two CCTA , two CMR , and one myocardial perfusion imaging article. The low number of relevant articles and the selection bias introduced by studying specific groups, like veteran marathon runners, indicate the need for future research. Cardiac CT (CACS and CCTA ) probably has the highest potential for pre‐participation screening, with high diagnostic value to detect CAD and low radiation dose. However, currently there is insufficient evidence for incorporating routine cardiac imaging in the pre‐participation screening of asymptomatic sportspersons over 35 years.     

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.     

第3代双源CT低剂量Turbo Flash成像图像质量与诊断效能的临床研究

目的探讨第3代双源CT大螺距前瞻性心电门控扫描模式(Turbo Flash)冠状动脉CT成像(CCTA)评价冠状动脉狭窄的准确性、图像质量及有效辐射剂量。方法前瞻性收集2016年4月至2017年4月接受第3代双源CCTA检查的患者1003例,其中有70例患者在CCTA检查后30 d内行冠状动脉造影(CAG)。对冠状动脉各节段图像质量进行评分,计算有效辐射剂量。以CAG结果为“金标准”,计算CCTA显示冠状动脉病变的灵敏度、特异度、阳性预测值和阴性预测值;CCTA与CAG评价冠状动脉狭窄分级的一致性采用Kappa值并进行U检验。结果(1) 图像质量:右冠状动脉不可诊断血管节段为0,左冠状动脉主干及前降支不可诊断血管节段为0,左冠状动脉回旋支不可诊断血管节段为0.04% (3/835)。(2)准确性评价:基于节段水平分析,Force CT诊断冠状动脉狭窄的灵敏度为97.0% (289/298)、特异度为98.3% (706/718)、阳性预测值为96.0% (289/301)、阴性预测值为98.7% (706/715);基于血管分析,灵敏度为97.5% (159/163)、特异度为85.1% (40/47)、阳性预测值为95.8% (159/166)、阴性预测值为90.9% (40/44);基于患者分析,灵敏度、特异度、阳性预测值、阴性预测值均为100%。CCTA与CAG显示的冠状动脉狭窄部位高度一致(U=2.4,P=0.008)。(3)辐射剂量:有效辐射剂量为(1.17±0.29)mSv。结论第3代双源CT Turbo Flash模式可以在自然呼吸、无心率干预下进行冠状动脉成像,扫描成功率高,图像质量佳,评价冠状动脉狭窄的准确性高,有效辐射剂量低。     

The evaluation of coronary artery-to-pulmonary artery fistula in adulthood on 256-slice CT coronary angiography: Comparison with coronary catheter angiography and transthoracic echocardiography

ObjectiveTo review the imaging features of coronary artery-to-pulmonary artery fistula (CPAF) on CT coronary angiography (CTCA) and evaluate its diagnostic performance compared with coronary catheter angiography (CCA) and transthoracic echocardiography (TTE).Materials and methodsWe retrospectively reviewed with a diagnosis of CPAF from among 19855 consecutive CCTA performed with 256-slice MDCT scanner for suspected coronary artery disease. CT images were evaluated for – origin, number, size and course (tubular/worm-like dilation/significant aneurysm formation/wall attachment sign) of fistula vessels, drainage site, drainage site imaging features (pierced sign, isodensity sign, smoke sign, jet sign), and main pulmonary artery (MPA) enlargement. 25 patients of CPAF also underwent CCA and 47 patients underwent TTE.ResultsThere were 72 patients with CPAF (0.36%) in our study, of which 44 were men and 28 were women, with mean age of 55.8 ± 13.2 years (range 22–85 years). CPAF originated from conus artery, left anterior descending artery (LAD), combined conus artery and LAD in 55, 67, 50 cases, respectively. Tubular dilation, worm-like dilation and aneurysm was seen in 14, 58 and 35 cases, respectively. Wall attachment sign was noted in 69 cases. All the cases demonstrated only a single drainage site, with left lateral wall, left anterolateral, anterior, right lateral and right anterolateral walls of MPA in 44, 21, 5, 1 and 1 cases, respectively. The mean diameter of the fistula drainage site was 2.6 ± 1.3 mm. Pierced sign, jet sign, smoke sign, isodensity sign was seen in 72, 46, 41 and 24 cases, respectively. MPA enlargement was seen in 20 patients. CCA showed CPAF in only 20 cases among 25 patients; while TTE showed CPAF in only 9 patients among 47 patients.ConclusionCTCA is competent in detecting and characterizing CPAF with an excellent diagnostic performance as the first imaging modality of choice, which is valuable for giving a distinct and intuitive explanation to patients and physicians and making an objective and exact assessment for further management.     

320层螺旋CT冠状动脉成像低剂量扫描方法初步探讨

目的：探讨320层螺旋CT冠状动脉成像低剂量扫描方法的临床应用价值。方法：采用320层螺旋CT,选取100例临床拟诊为冠心病的患者,随机分为2组：研究组50例,采用改良法（低剂量）回顾性心电门控扫描;对照组50例,采用传统回顾性心电门控扫描。对比分析2组中冠状动脉可评估率及辐射剂量。结果：研究组血管可评估率为95.0%,对照组为95.8%。两组冠状动脉段图像质量比较差异无统计学意义（P〉0.05）。实验组平均有效辐射剂量为（2.90±0.37）mSv,对照组为（10.33±1.65）mSv,两组辐射剂量比较差异有统计学意义（P〈0.05）。结论：320层螺旋CT冠状动脉成像中,应用改良法回顾性心电门控技术在保证血管可评估率及图像质量的前提下可降低72%的辐射剂量。     

Cardiac-CT with the newest CT scanners: An incoming screening tool for competitive athletes?

Competitive athletes of all skill levels are at risk of sudden cardiac death (SCD) due to certain heart conditions. Prior to engagement in high-intensity athletics, it is necessary to screen for these conditions in order to prevent sudden cardiac death. Cardiac-CT angiography (CCTA) is a reliable tool to rule out the leading causes of SCD by providing an exceptional overview of vascular and cardiac morphology. This allows CCTA to be a powerful resource in identifying cardiac anomalies in selected patients (i.e. unclear symptoms or findings at ECG or echocardiography) as well as to exclude significant coronary artery disease (CAD). With the advancement of technology over the last few years, the latest generations of computed tomography (CT) scanners provide better image quality at lower radiation exposures. With the amount of radiation exposure per scan now reaching the sub-millisievert range, the number of CT examinations it is supposed to increase greatly, also in the athlete's population. It is thus necessary for radiologists to have a clear understanding of how to make and interpret a CCTA examination so that these studies may be performed in a responsible and radiation conscious manner especially when used in the younger populations. Our work aims to illustrate the main radiological findings of CCTAs and highlight their clinical impact with some case studies. We also briefly describe critical features of state-of-the-art CT scanners that optimize different acquisitions to obtain the best quality at the lowest possible dose.     

Prospectively ECG-triggered sequential dual-source coronary CT angiography in patients with atrial fibrillation: comparison with retrospectively ECG-gated helical CT

Objective

To investigate the feasibility of applying prospectively ECG-triggered sequential coronary CT angiography (CCTA) to patients with atrial fibrillation (AF) and evaluate the image quality and radiation dose compared with a retrospectively ECG-gated helical protocol.

Methods

100 patients with persistent AF were enrolled. Fifty patients were randomly assigned to a prospective protocol and the other patients to a retrospective protocol using a second-generation dual-source CT (DS-CT). Image quality was evaluated using a four-point grading scale (1 = excellent, 2 = good, 3 = moderate, 4 = poor) by two reviewers on a per-segment basis. The coronary artery segments were considered non-diagnostic with a quality score of 4. The radiation dose was evaluated.

Results

Diagnostic segment rate in the prospective group was 99.4 % (642/646 segments), while that in the retrospective group was 96.5 % (604/626 segments) (P?<?0.001). Effective dose was 4.29?±?1.86 and 11.95?±?5.34 mSv for each of the two protocols (P?<?0.001), which was a 64 % reduction in the radiation dose for prospective sequential imaging compared with retrospective helical imaging.

Conclusion

In AF patients, prospectively ECG-triggered sequential CCTA is feasible using second-generation DS-CT and can decrease >60 % radiation exposure compared with retrospectively ECG-gated helical imaging while improving diagnostic image quality.

Key Points

? Coronary computed tomographic angiography (CCTA) can be difficult in patients with arrhythmias. ? Prospectively ECG-triggered sequential CCTA is feasible in patients with atrial fibrillation. ? Prospective sequential imaging can improve quality compared with retrospective analysis. ? Prospective sequential imaging decreases radiation exposure by 64 % compared with retrospective mode.