Coronary computed tomography(CT)angiography has been increasingly used in the diagnosis of coronary artery disease due to improved spatial and temporal resolution with high diagnostic value being reported when compare...Coronary computed tomography(CT)angiography has been increasingly used in the diagnosis of coronary artery disease due to improved spatial and temporal resolution with high diagnostic value being reported when compared to invasive coronary angiography.Diagnostic performance of coronary CT angiography has been significantly improved with the technological developments in multislice CT scanners from the early generation of 4-slice CT to the latest 320-slice CT scanners.Despite the promising diagnostic value,coronary CT angiography is still limited in some areas,such as inferior temporal resolution,motion-related artifacts and high false positive results due to severe calcification.The aim of this review is to present an overview of the technical developments of multislice CT and diagnostic value of coronary CT angiography in coronary artery disease based on different generations of multislice CT scanners.Prognostic value of coronary CT angiography in coronary artery disease is also discussed,while limitations and challenges of coronary CT angiography are highlighted.展开更多
目的探讨不同剂量多层螺旋计算机断层扫描（MSCT）胸部扫描对尘肺病的筛查效果。方法采用随机抽样方法,抽取40名粉尘作业工人,分别采用常规剂量（管电压130 k V,管电流25.0~75.0 m As）与方案1（管电压110 k V,管电流50 m As）、方案2...目的探讨不同剂量多层螺旋计算机断层扫描（MSCT）胸部扫描对尘肺病的筛查效果。方法采用随机抽样方法,抽取40名粉尘作业工人,分别采用常规剂量（管电压130 k V,管电流25.0~75.0 m As）与方案1（管电压110 k V,管电流50 m As）、方案2（管电压110 k V,管电流16.0 m As）、方案3（管电压80 k V,管电流16.0 m As）的低剂量扫描,分别对轴位1.5 mm薄层高分辨率重建、5.0 mm普通层厚高分辨率重建和5.0 mm厚层冠状位最大密度投影的重建图像进行对比分析。结果方案1和方案2的图像质量得分和低剂量MSCT图像评价得分均优于方案3（P〈0.01）。方案1和方案2的图像对40名研究对象的p、q、s和t小阴影均能显示;除方案2对t小阴影显示的得分外,方案1和方案2的图像对4种小阴影显示的得分分别与常规剂量组比较,差异均无统计学意义（P〉0.02）。方案3的图像对4种小阴影的显示明显减少,伪影较多;该方案的图像对p、q和t小阴影显示的得分均低于常规剂量组（P〈0.01）。评价MSCT辐射剂量的指标容积CT剂量指数、加权CT剂量指数、剂量长度乘积和平均有效剂量,在4种MSCT方案中从高到低均呈常规剂量组〉方案1组〉方案2组〉方案3组的趋势（P〈0.05）。结论低剂量MSCT方案可满足对尘肺病筛查的需要;采用管电压110 KV及管电流16 m As的方案在获得较好质量图像的同时,有利于降低筛查者接受的辐射量。展开更多
Background There are few reports of quantitative and qualitative measuring of left main coronary artery （LMCA） plaques by multislice computed tomography coronary angiography （MSCTA）, especially when compared with ...Background There are few reports of quantitative and qualitative measuring of left main coronary artery （LMCA） plaques by multislice computed tomography coronary angiography （MSCTA）, especially when compared with intravascular ultrasound （IVUS） as reference standard. The aim of this study was to evaluate the use of 64-MSCTA in the diagnosis of LMCA disease, and the accuracy of MSCTA in the quantitative and qualitative assessment of the LMCA lesion as compared with IVUS.Methods A total of 91 patients （53 men, 38 women, mean age （64.78±9.19） years） were examined by 64-MSCTA and IVUS. Compared with the IVUS, the sensitivity, specificity, positive and negative predictive values （PPV and NPV） of the MSCTA on the diagnosis of LMCA diseases were calculated. Also, kappa index （K） for the agreement between MSCTA and IVUS was calculated. Minimal lumen area （MLA）, external elastic membrane cross-sectional area （EEM-CSA） and plaque burden were measured by two blinded and independent operators on MSCTA cross-sectional reconstruction and compared with the parameters measured from IVUS by manually tracing. The CT value of soft, fibrous and calcific plaques was measured using IVUS classification of the plaques.Results The sensitivity, specificity, PPV and NPV of MSCTA for detecting LMCA plaques were 93.1%, 84.2%, 95.7%, 76.2%, respectively. Kappa index （K=0.744, P〈0.001） indicated excellent agreement between MSCTA and IVUS. The Pearson index between MLA on IVUS and MLA on MSCTA was 0.815 （P 〈0.01）. The Pearson index of plaque burden and EEM-CSA between IVUS and MSCTA was 0.736 and 0.740 respectively （both P 〈0.01）. The CT value of soft plaque, fibrous plaque and calcific plaque compared with IVUS were （52.52±15.71） HU, （108.32±43.44） HU and （604.16±377.67） HU （P〈0.001）. Receiver operating characteristic curve analysis of CT value of non-calcific plaques for predicting soft plaques showed the cutpoint was 54.35 HU, with a sensitivity of 83.3% and specific展开更多
AIM: To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature.METHODS: A search of articl...AIM: To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature.METHODS: A search of articles on coronary CT angiography in the diagnosis of CAD was performed during a 6-year-period between 2005 and 2010 from f ive main radiology journals namely, Radiology, American Journal of Roentgenology, European Radiology, European Journal of Radiology and British Journal of Radiology. Analysis of the references was focused on the research directions of coronary CT angiography with regard to the type of studies in terms of diagnostic value, application of dose-reduction strategies and resultant effective radiation doses with use of these techniques.RESULTS: One hundred and forty two studies were identified which met the selection criteria and were included in the analysis. 64-slice CT (single source anddual-source CT) dominated 78% of the coronary CT angiography studies. Prior to 2007, research was focused on the diagnostic value of coronary CT angiography, but since 2008 more attention has been paid to radiation dose reduction. Radiation dose was reported in 64 studies, representing 45% of total studies published in the f ive radiology journals. Various dose-saving strategies have been implemented and prospective electrocardiography-triggering and high pitch techniques were found to be the most effective approaches for radiation dose reduction, with the corresponding mean effective dose being 3.5 ± 1.9 mSv and 1.7 ± 0.6 mSv, respectively.CONCLUSION: This review shows that the current research in coronary CT angiography has shifted from the previous focus on diagnostic accuracy in CAD to more emphasis on radiation dose reduction.展开更多
Atrial fibrillation is the most common arrhythmia and in symptomatic patients with a drug-refractory form,catheter ablation aimed at electrically disconnecting the pulmonary veins(PVs) has proved more effective than u...Atrial fibrillation is the most common arrhythmia and in symptomatic patients with a drug-refractory form,catheter ablation aimed at electrically disconnecting the pulmonary veins(PVs) has proved more effective than use of antiarrhythmic drugs in maintaining sinus rhythm during follow-up.On the other hand,this ablation procedure is complex,requires specific training and adequate clinical experience.A main challenge is represented by the need for accurate sequential positioning of the ablation catheter around each veno-atrial junction to deliver point-by-point radiofrequency energy applications in order to achieve complete and persistent electrical disconnection of the PVs.Imaging integration is a new technology that enables guidance during this procedure by showing a three-dimensional,pre-acquired computed tomography or magnetic resonance image and the relative real-time position of the ablation catheter on the screen of the electroanatomic system.Reports in the literature suggest that imaging integration provides accurate visual information with improvement in the procedure parameters and/or clinical outcomes of the procedure.展开更多
文摘Coronary computed tomography(CT)angiography has been increasingly used in the diagnosis of coronary artery disease due to improved spatial and temporal resolution with high diagnostic value being reported when compared to invasive coronary angiography.Diagnostic performance of coronary CT angiography has been significantly improved with the technological developments in multislice CT scanners from the early generation of 4-slice CT to the latest 320-slice CT scanners.Despite the promising diagnostic value,coronary CT angiography is still limited in some areas,such as inferior temporal resolution,motion-related artifacts and high false positive results due to severe calcification.The aim of this review is to present an overview of the technical developments of multislice CT and diagnostic value of coronary CT angiography in coronary artery disease based on different generations of multislice CT scanners.Prognostic value of coronary CT angiography in coronary artery disease is also discussed,while limitations and challenges of coronary CT angiography are highlighted.
文摘目的探讨不同剂量多层螺旋计算机断层扫描（MSCT）胸部扫描对尘肺病的筛查效果。方法采用随机抽样方法,抽取40名粉尘作业工人,分别采用常规剂量（管电压130 k V,管电流25.0~75.0 m As）与方案1（管电压110 k V,管电流50 m As）、方案2（管电压110 k V,管电流16.0 m As）、方案3（管电压80 k V,管电流16.0 m As）的低剂量扫描,分别对轴位1.5 mm薄层高分辨率重建、5.0 mm普通层厚高分辨率重建和5.0 mm厚层冠状位最大密度投影的重建图像进行对比分析。结果方案1和方案2的图像质量得分和低剂量MSCT图像评价得分均优于方案3（P〈0.01）。方案1和方案2的图像对40名研究对象的p、q、s和t小阴影均能显示;除方案2对t小阴影显示的得分外,方案1和方案2的图像对4种小阴影显示的得分分别与常规剂量组比较,差异均无统计学意义（P〉0.02）。方案3的图像对4种小阴影的显示明显减少,伪影较多;该方案的图像对p、q和t小阴影显示的得分均低于常规剂量组（P〈0.01）。评价MSCT辐射剂量的指标容积CT剂量指数、加权CT剂量指数、剂量长度乘积和平均有效剂量,在4种MSCT方案中从高到低均呈常规剂量组〉方案1组〉方案2组〉方案3组的趋势（P〈0.05）。结论低剂量MSCT方案可满足对尘肺病筛查的需要;采用管电压110 KV及管电流16 m As的方案在获得较好质量图像的同时,有利于降低筛查者接受的辐射量。
文摘Background There are few reports of quantitative and qualitative measuring of left main coronary artery （LMCA） plaques by multislice computed tomography coronary angiography （MSCTA）, especially when compared with intravascular ultrasound （IVUS） as reference standard. The aim of this study was to evaluate the use of 64-MSCTA in the diagnosis of LMCA disease, and the accuracy of MSCTA in the quantitative and qualitative assessment of the LMCA lesion as compared with IVUS.Methods A total of 91 patients （53 men, 38 women, mean age （64.78±9.19） years） were examined by 64-MSCTA and IVUS. Compared with the IVUS, the sensitivity, specificity, positive and negative predictive values （PPV and NPV） of the MSCTA on the diagnosis of LMCA diseases were calculated. Also, kappa index （K） for the agreement between MSCTA and IVUS was calculated. Minimal lumen area （MLA）, external elastic membrane cross-sectional area （EEM-CSA） and plaque burden were measured by two blinded and independent operators on MSCTA cross-sectional reconstruction and compared with the parameters measured from IVUS by manually tracing. The CT value of soft, fibrous and calcific plaques was measured using IVUS classification of the plaques.Results The sensitivity, specificity, PPV and NPV of MSCTA for detecting LMCA plaques were 93.1%, 84.2%, 95.7%, 76.2%, respectively. Kappa index （K=0.744, P〈0.001） indicated excellent agreement between MSCTA and IVUS. The Pearson index between MLA on IVUS and MLA on MSCTA was 0.815 （P 〈0.01）. The Pearson index of plaque burden and EEM-CSA between IVUS and MSCTA was 0.736 and 0.740 respectively （both P 〈0.01）. The CT value of soft plaque, fibrous plaque and calcific plaque compared with IVUS were （52.52±15.71） HU, （108.32±43.44） HU and （604.16±377.67） HU （P〈0.001）. Receiver operating characteristic curve analysis of CT value of non-calcific plaques for predicting soft plaques showed the cutpoint was 54.35 HU, with a sensitivity of 83.3% and specific
文摘AIM: To investigate the research directions of coronary computed tomography (CT) angiography in the diagnosis of coronary artery disease (CAD) based on a systematic review of the literature.METHODS: A search of articles on coronary CT angiography in the diagnosis of CAD was performed during a 6-year-period between 2005 and 2010 from f ive main radiology journals namely, Radiology, American Journal of Roentgenology, European Radiology, European Journal of Radiology and British Journal of Radiology. Analysis of the references was focused on the research directions of coronary CT angiography with regard to the type of studies in terms of diagnostic value, application of dose-reduction strategies and resultant effective radiation doses with use of these techniques.RESULTS: One hundred and forty two studies were identified which met the selection criteria and were included in the analysis. 64-slice CT (single source anddual-source CT) dominated 78% of the coronary CT angiography studies. Prior to 2007, research was focused on the diagnostic value of coronary CT angiography, but since 2008 more attention has been paid to radiation dose reduction. Radiation dose was reported in 64 studies, representing 45% of total studies published in the f ive radiology journals. Various dose-saving strategies have been implemented and prospective electrocardiography-triggering and high pitch techniques were found to be the most effective approaches for radiation dose reduction, with the corresponding mean effective dose being 3.5 ± 1.9 mSv and 1.7 ± 0.6 mSv, respectively.CONCLUSION: This review shows that the current research in coronary CT angiography has shifted from the previous focus on diagnostic accuracy in CAD to more emphasis on radiation dose reduction.
文摘Atrial fibrillation is the most common arrhythmia and in symptomatic patients with a drug-refractory form,catheter ablation aimed at electrically disconnecting the pulmonary veins(PVs) has proved more effective than use of antiarrhythmic drugs in maintaining sinus rhythm during follow-up.On the other hand,this ablation procedure is complex,requires specific training and adequate clinical experience.A main challenge is represented by the need for accurate sequential positioning of the ablation catheter around each veno-atrial junction to deliver point-by-point radiofrequency energy applications in order to achieve complete and persistent electrical disconnection of the PVs.Imaging integration is a new technology that enables guidance during this procedure by showing a three-dimensional,pre-acquired computed tomography or magnetic resonance image and the relative real-time position of the ablation catheter on the screen of the electroanatomic system.Reports in the literature suggest that imaging integration provides accurate visual information with improvement in the procedure parameters and/or clinical outcomes of the procedure.
