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.     

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冠状动脉成像辐射剂量的优化

目的：探讨使用更窄的曝光时间窗对双源CT冠状动脉成像图像质量和辐射剂量的影响。方法：选择心律稳定、配合屏气在本院行冠状动脉CTA检查者共360例,按心率及扫描方案随机分为5组：当心率＜65次/分时,行回顾性心电门控扫描,用70％-80％曝光时间窗成像冠状动脉（A组）;窄窗方案根据前瞻性心电门控平扫所获得的最佳时相,选择此时相为中心总长1％作为曝光时间窗,行前瞻心电性门控冠状动脉成像（B组）。当心率≥65次/时,行回顾性心电门控扫描,常规使用30％-80％曝光时间窗成像冠状动脉（C组）;窄窗方案根据前瞻性心电门控平扫所获得的最佳时相,以此时相为中心选择总长10％的曝光时间窗,分别用前瞻性心电门控（D 组）和低剂量回顾性心电门控行冠状动脉成像（E组）;分别计算各组平均有效辐射剂量以及冠状动脉图像质量（4分制评分）,并作统计学分析。结果：A 组[（8．11±1．54）mSv]和B组[（3．63±0．82）mSv],C 组[（10．56±2．51）mSv]和 D 组[（4．42±1．16）mSv],D 组[（4．42±1．16）mSv]和E组[（5．43±1．14）mSv]的辐射剂量相比较均有统计学差异（P＜0．05）,采用窄窗方案前瞻性心电门控技术的辐射剂量最少;而各组间图像质量,均无统计学差异（P＞0．05）。结论：前瞻性心电门控通过平扫获得最佳时相,当心率＜65次/分时,选择曝光总长1％的时间窗,而当心率≥65次/分时,选择曝光总长10％的时间窗,能获得高质量的、满足诊断要求的图像,并可有效地降低辐射量。     

双源CT冠状动脉成像最佳心电脉冲窗范围与心率的关系及对放射剂量的影响

目的：研究双源CT冠状动脉成像（CTCA）最佳心电脉冲窗范围与心率的关系,以降低双源CTCA检查的放射剂量。方法：250例患者行双源CTCA检查,并根据心率分成慢心率组（〈70bpm）、中等心率组（70～80bpm）和快心率组（〉80bpm）,在25%～80%R-R间期内每隔3%R-R间隔依次进行重建并对冠状动脉图像质量进行分析,确定最佳收缩期（OS）和最佳舒张期（OD）的时相范围。同时比较在OS时相范围内重建、OD时相范围内重建及联合OS和OD时相范围内重建冠状动脉的图像质量,以确定不同心率组最佳心电脉冲窗的范围,并探讨运用最佳心电脉冲窗技术时的放射剂量。结果：慢心率组、中等心率组和快心率组最佳心电脉冲窗范围分别为61%～77%R-R间期、30%～78%R-R间期和32%～49%R-R间期。运用最佳心电脉冲窗技术时,如果将脉冲窗外管电流降低至标准管电流的20%时,慢心率组、中等心率组和快心率组的放射剂量将分别下降48.8%、8.0%和41.5%;如果将脉冲窗外管电流降低至标准管电流的4%时,放射剂量相应地将分别下降68.5%、21.0%和62.2%。结论：双源CTCA的最佳心电脉冲窗范围与患者心率密切相关,运用最佳心电脉冲窗技术能明显降低患者行双源CTCA检查的放射剂量,而图像质量不受影响。     

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。     

腹腔动脉CT血管成像固定毫安秒低剂量技术探讨

目的 探讨16层CT进行低剂量CTA的可行性,以及与平扫噪声和增强值的关系.方法 选取连续上腹部增强检查中,动脉期主动脉增强CT值300.0 HU以上的43例患者,采用16层CT扫描,回顾性动脉期重建和标准算法.在平扫图像上选择右侧后膈脚水平图像测定腹主动脉腔的CT值,CT值的标准差(SD)定义为图像噪声;增强图像上测定腹腔动脉根部水平的主动脉CT值.动脉期数据进行VR后处理,其图像评价分优、良、差,并以此为标准进行图像质量与主动脉增强值和平扫SD值之间关系的受试者操作特性曲线(ROC)分析.结果 增强主动脉CT值在300.0～400.0 HU之间共25例,SD=12.00时,图像为优的敏感性75%,特异性62%.主动脉CT值在400.0 HU以上共18例,SD=12.25时,图像为优的敏感性和特异性均为100%;SD=13.35时,图像为优的敏感性100%,特异性75%.按主动脉强化值与CTA VR图像质量相关性分析,ROC曲线下面积0.907,图像为优的敏感性100%、特异性60%时的强化值阈值为356.7 HU;敏感性78%、特异性80%时的强化值阈值为389.8 HU;特异性100%时的最低强化值为442.4 HU,此时敏感性56%.结论 低剂量CTA切实可行,保证良好成像效果的前提下,平扫SD值越小,使用的mAs就越小;而成像效果越好,则可以使用的mAs值也可以减小.     

双源CT低剂量适应性序列扫描对高心率冠状动脉成像的初步研究

目的 研究双源CT低剂量适应性序列扫描技术在高心率患者冠状动脉CTA的应用,并评价其图像质量.方法 将72例心率70次/min(bpm)以上行冠状动脉CTA检查的患者按扫描方式分为2组.A组40例行适应性序列扫描.B组32例行常规回顾性心电门控螺旋扫描.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总体评分,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501段冠状动脉,B组评价400段冠状动脉.可评价的冠状动脉段图像质量评分平均秩次,A组为475.42,B组为420.41,2组间比较差异有统计学意义(Z=-3.509,P=0.000).平均有效剂量A组为(6.2±0.9)mSv,B组为(14.7 ±1.9)mSv,2组间差异有统计学意义(t=-27.011,P=0.000).结论 适应性序列扫描对高心率患者冠状动脉CTA检查具有可行性,该技术能显著降低辐射剂量而保证诊断所需图像质量.     

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.     

70kVp管电压和30mL对比剂的前瞻性心电门控触发大螺距CT冠状动脉成像

目的：联合前瞻性心电门控及大螺距技术,探讨70 kVp管电压、30 mL对比剂CT冠状动脉成像（CTCA）的可行性。方法：将80例体质指数≤25 kg/m^2、心率≤70次/分行 CTCA 的患者随机分为两组,其中40例患者采用100 kVp,60 mL对比剂的扫描方案行CTCA检查,另40例患者采用70 kVp,30 mL对比剂的扫描方案行CTCA检查。所有CTCA检查都在前瞻性心电门控及大螺距（3．4）模式下进行。100 kVp 组数据采用滤波反投影重建算法进行重建,而70 kVp组数据采用迭代重建算法进行重建。测量每例患者主动脉根部、各冠状动脉起始处部及纵膈脂肪CT值和标准差并计算各段血管的信噪比（SNR）和对比噪声比（CNR）。两名放射科医师对所有图像以4分法进行评分。比较两组图像质量及辐射剂量。结果：70 kVp组的平均冠状动脉CT值[（603±86）HU]及图像噪声[（42±5）HU]均明显高于100 kVp组的平均冠状动脉CT值[（503±68）HU,P＜0．001]及图像噪声[（25±4）HU,P＜0．01],而70 kVp 组的SNR 及CNR （14．6±3．0,17．8±3．4）均明显低于100 kVp组（20．7±3．8,24．4±4．1,P＜0．001）。两组间各冠状动脉主观图像质量评分无统计学差异（P＞0．05）。70 kVp 组患者所接受的辐射剂量比100 kVp 组降低了76％,对比剂用量降低了50％。结论：联合前瞻性心电门控、大螺距及迭代重建技术,70 kVp管电压、30 mL对比剂CTCA在体质量指数≤25 kg/m^2、心率≤70次/分的患者中是可行的,可在大幅度降低辐射剂量及对比剂用量的条件下获得满足诊断的图像质量。     

双源CT低管电压技术在超重患者冠状动脉成像中的应用

目的 探讨在超重患者双源CT冠状动脉成像中低管电压技术的应用价值,评价其图像质量和辐射剂量.方法 将66例接受双源CT冠状动脉检查,体质量<85 kg、且体质量指数(BMI)为25.0～30.0 ks/m2的患者完全随机化分为A、B 2组.A组30例,管电压为120 kVp;B组36例,管电压为100 kVp.所有患者均采用回顾性心电门控螺旋扫描和四维智能在线剂量调控(CARE Dose 4D)技术,严格控制扫描范围.对2组的扫描数据分别进行多种图像后处理,由影像科副主任医师和副主任技师各1名采用双盲法评估图像质量.测量并计算信噪比(SNR)、对比信噪比(CNR).记录CT容积剂量指数(CTDIvol)和剂量长度乘积(DLP),计算有效辐射剂量(ED).应用两独立样本t检验比较2组患者图像ROI的CT值、噪声、SNR、CNR、辐射剂量及对比剂用量、图像质量评分等.应用X2检验比较两组患者冠状动脉图像质量分级显示段数.应用Kappa检验判断2名评价者评分的一致性.以P<0.05为差异有统计学意义.结果 图像ROI内CT值、噪声(以标准差SD计算)、SNR测量值:A组右冠状动脉(RCA)起始部分别为(429.3±77.4)HU,24.0±8.2、21.8±9.9,左冠状动脉主干(LMA)起始部分别为(436.7±79.0)HU、19.4±7.3、22.3±9.8;B组RCA分别为(503.5±95.4)HU、34.0±12.6、21.0±10.7,LMA分别为(491.7±96.2)HU、33.4±15.5、20.6±11.4;CNR测量值:A组为24.4±10.3,B组为21.9±8.2.2组患者冠状动脉血管腔内强化平均CT值、噪声比较,B组大于A组,差异有统汁学意义(P值均<0.05);2组间SNR、CNR筹异无统计学意义(P值均>0.05);2组CTDIvol比较,A组为(42.2±13.8)mGy,B组为(20.2±6.5)mGy,差异有统计学意义(P<0.05);A组ED为(9.5±3.6)roSy,B组为(4.8±1.7)mSv,差异有统汁学意义(P<0.05);A组图像质量评分为(4.5±1.0)分,B组为(4.7±0.5)分,筹异无统计学意义(P>0.05);A绀评价383段冠状动脉,图像优良者377段(98.4%)B组评价490段冠状动脉,图像优良者483段(98.6%).结论 对于BMI在25.0～30.0 kg/m2的患者,使用100 kVp管电压配合CARE Dose 4D技术进行双源CT冠状动脉检查,可以获得较好的图像质量,并且可以显著降低辐射剂量.

Abstract：

Objective To investigate the image quality and the radiation dose of dual-source computed tomography coronary angiography by using low kilovohage combination with low tube current in overweight patients.Methods Sixty-six patients with body mass inde,(BMI)25.(0-30.0 kg/m2 and a body weight<85 kg were randomized two groups(group A and group B).Thirty patients in group A were examined with 120 kVp,and 36 patients in group B with 100 kVp.ECG-pulsing and care dose 4D for radiation dose reduction were used in all patients.All images were transferred to Siemens workstation for post processing and analysis.Two observers blimted to clinical data independently assessed the image quality of each coronary segment by using a 5-point scoring scale(5:excellent,1:no diagnostic).and measured the different image parameters including image noise,signal-to-noise ratio(SNR)and contrast-to-noise ratio (CNR).The effective dose(ED)was calculated by using CT dose volume index(CTDIvol)and the doselength product (DLP). The mean intraluminal attenuation, image noise, SNR, CNR, radiation dose,volume of contrast medium, and mean image quality scores were compared between the two groups with t test. The grading quantity of coronary artery segment was compared with Chi-square test. The interobserver agreement was determined by Kappa statistics. Results The mean intraluminal attenuation, image noise,SNR in group A were (429. 3±77.4 ) HU, 24.0±8.2, 21.8±9. 9 in right coronary artery ( RCA), and (436. 7±79. 0) HU, 19.4±7.3, 22. 3±9. 8 in left main coronary artery (LMA ), and that in group B were (503.5±95.4) HU, 34.0±12.6, 21.0±10.7 in RCA, and (491.7±96.2) HU, 33.4±15.5,20.6±11.4 in LMA. The CNR were 24.4±10.3 in group A and 21.9±8.2 in group B. The mean intraluminal attenuation and image noise were significantly higher for group B compared with group A ( P <0. 05 ). There were no difference in SNR and CNR between the two groups ( P > 0. 05 ). Estimated ED in group B was significantly lower than that in group A [CTDIvol = (42. 2±13. 8) mGy, ED = (9. 5±3.6)mSv in group A vs. CTDIvol = ( 20. 2±6.5 ) mGy, ED = (4. 8±1.7 ) mSv in group B ; each P < 0. 05 ].Mean image quality scores were not significantly different between two groups ( 4. 5±1.0 in group A vs.4. 7±0. 5 in group B, P > 0. 05 ). A total of 383 coronary artery segments were evaluated in group A and 490 segments in group B. The difference of grading quantity of coronary artery segment was no statistical significant between two groups. Conclusions 100 kVp combination with ECC-pulsing and CARE Dose 4D of dual-source CTCA was valuable for patients with BMI ranging from 25 to 30 kg/m2 which have a better image quality and low radiatiun dose.     

70kV低剂量CT血管成像在儿童胡桃夹综合征中的应用

目的：评价70 kV管电压CT血管成像在诊断儿童胡桃夹综合征中的应用价值。方法：27例临床疑似胡桃夹综合征的患者进行了新双源CT 70 kV CT动静脉混合期血管成像（70 kV组）,另37例患者行120 kV腹部增强双期扫描（120 kV组）。测量患者左肾静脉、肠系膜上动脉、腹主动脉、腰大肌的CT值及皮下脂肪的标准差并计算图像的信噪比（SNR）和对比噪声比（CNR）。两名放射科医师对所有病例以四分法进行评分。计算有效剂量（ED）。比较两组间的图像质量及辐射剂量。结果：70 kV组左肾静脉的CT 值、SNR 及 CNR 明显高于120 kV 组,差别有统计学意义（P＜0．01）,70 kV组肠系膜上动脉、腹主动脉的CT值、SNR及CNR与120 kV动脉期组比较差别无统计学意义（P＞0．05）,与120 kV静脉期组比较明显提高,差别有统计学意义（P＜0．001）。70 kV组图像质量主观评分高于120 kV组,与120 kV动脉期组比较差别无统计学意义（P＝0．137）,与120 kV 静脉期组比较差别有统计学意义（P＜0．001）。70 kV 组辐射剂量与120 kV组比较明显降低,有效辐射剂量降低了93．7％,差异有统计学意义（P＜0．001）。结论：临床疑似胡桃夹综合征的儿童70 kV动静脉混合期CT血管成像在保证图像质量满足诊断的同时大幅降低了辐射剂量。