Computerized left ventricular regional ejection fraction analysis for detection of ischemic coronary artery disease with multidetector CT angiography

Regional ejection fraction (REF) provides important functional information of the left ventricular regional myocardium. We aimed to test the diagnostic accuracy of computerized REF analysis for detecting the ischemia and significant stenosis with multidetector CT angiography (MDCT). This is a retrospective study including 155 patients who underwent MDCT scans for evaluation of coronary artery disease. Among them, 83 patients also underwent SPECT imaging and invasive coronary angiography (ICA). Two groups of patients were defined: Control group with 0 coronary artery calcium and normal global and regional ventricular function, and comparison group. REF measurement was performed on all patients using computerized software. Control group REF measurements will be used as reference standard (mean-2SD REF/mean global ejection fraction) to define abnormal REF. The sensitivity, specificity, positive and negative predictive value of REF in detecting perfusion defects (fixed and reversible) was 73, 80, 75 and 79 % respectively, in a patient based analysis of comparison group. The diagnostic accuracy of REF in predicting significant stenosis (>50 %) on ICA compared with SPECT was 72 versus 61 % and 85 versus 79 % in patient and vessel based analysis of comparison group, respectively. ROC curve analysis showed REF to be a better predictor of perfusion defects on SPECT compared with significant stenosis (>50 %) alone or stenosis combined with REF (P < 0.05). The computerized assessment of REF analysis is comparable to SPECT in predicting ischemia and a better predictor of significant stenosis than SPECT. This study also provides reference standard to define abnormal values.     

腺苷超声与核素心肌显像推测心绞痛相关狭窄血管的比较

目的 比较腺苷超声心动图与腺苷核素心肌灌注显像诊断冠心病及推测稳定型心绞痛患者相关狭窄血管的价值。方法 51例临床诊断为稳定型心绞痛的住院患者同期进行腺苷超声心动图与腺苷核素心肌灌注显像检查,超声心动图示室壁运动障碍,心肌显像检测核素分布稀疏或缺损,并在2周内行冠状动脉造影对照。结果 51例患者接受冠状动脉造影,诊断冠心病42例,9例排除冠心病,诊断狭窄血管74支。超声心动图阳性者33例,心肌显像阳性者39例。超声心动图诊断狭窄血管敏感性62%,特异性86%,准确性75%。核素心肌显像诊断狭窄血管敏感性80%,特异性89%,准确性84%。二者诊断符合率84%。结论 研究结果显示,与腺苷超声心动图诊断稳定型心绞痛患者狭窄血管相比较,腺苷心肌灌注显像具有更高的敏感性,尤其识别多支病变及中重度狭窄血管更敏感。     

Computer-Aided CT coronary artery stenosis detection: comparison with human reading and quantitative coronary angiography

To evaluate computer-aided stenosis detection for computed tomography coronary angiography (CTA) in comparison with human reading and conventional coronary angiography (CCA) as the reference standard. 50 patients underwent CTA and CCA and out of these 44 were evaluable for computer-aided stenosis detection. The diagnostic performance of the software and of human reading were compared and quantitative coronary angiography (QCA) served as the reference standard for the detection of significant stenosis (>50 %). Overall, three readers with high (reader 1), intermediate (reader 2) and low (reader 3) experience in cardiac CT imaging performed the manual CTA evaluation on a commercially available workstation, whereas the automated software processed the datasets without any human interaction. The prevalence of coronary artery disease was 41 % (18/44) and QCA indicated significant stenosis (>50 %) in 33 coronary vessels. The automated software accurately diagnosed 18 individuals with significant coronary artery disease (CAD), and correctly ruled out CAD in 10 patients. In summary the sensitivity of computer-aided detection was 100 %/94 % (per-patient/per-vessel) and the specificity was 38 %/70 %, the positive predictive value (PPV) was 53 %/42 % and the negative predictive value (NPV) was 100 %/98 %. In comparison, reader 1–3 showed per-patient sensitivities of 100/94/89 %, specificities of 73/69/50 %, PPVs of 72/68/55 % and NPVs of 100/95/87 %. Computer-aided detection yields a high NPV that is comparable to more experienced human readers. However, PPV is rather low and in the range of an unexperienced reader.     

Diagnostic accuracy of quantitative cardiac MRI evaluation compared to stress single-photon-emission computed tomography

Background: Cardiac MRI (cMRI) perfusion is a promising non-invasive tool to assess myocardial ischemia. The accuracy of quantitative cMRI perfusion has been recently demonstrated, but to date no previous study has compared this technique with stress single-photon-emission computed tomography (SPECT). The aim of this study was to evaluate the diagnostic accuracy of myocardial perfusion reserve (MPR) based on cMRI compared with SPECT. Methods: We examined 24 patients who underwent coronary angiography, stress SPECT and cMRI perfusion. Qualitative assessment of both SPECT and cMRI images, quantification of cMRI perfusion, and quantitative coronary angiography (QCA) were independently performed. MPR was calculated using Fermi deconvolution technique. Accuracy of quantitative and qualitative data was examined to detect > 50% diameter stenosis (DS) by QCA. Results: Qualitative analysis was obtained in 198 segments and quantitative analysis was performed in 171 segments. Significant coronary artery disease (CAD) was present in 81.8% of patients. Visual cMRI assessment yielded sensitivity of 74.4% and specificity of 79.4% to predict > 50%DS, while SPECT showed sensitivity of 67.4% and specificity of 81.3%. The sensitivity for SPECT in the right coronary artery territory and apex was low compared to cMRI. Sensitivity and specificity for detection of significant CAD were 89.5% and 46.6% for MPR (cutoff 1.92). Area under the curve was 0.75 for MPR (P < 0.01). Conclusions: The diagnostic accuracy of qualitative examination of perfusion cardiac MRI and stress SPECT were comparable. The high sensitivity and low operator dependency of quantitative cMRI makes it an attractive tool to evaluate myocardial perfusion.     

Accuracy of dual-source CT to identify significant coronary artery disease in patients with uncontrolled hypertension presenting with chest pain: comparison with coronary angiography

It has been previously reported that the sensitivity and specificity of multislice CT for detecting significant CAD (coronary artery disease) is high. Chest pain is a common presentation in patients with uncontrolled hypertension. We investigated the sensitivity and specificity of Dual-Source CT to detect and rule out significant CAD in patients presenting with uncontrolled hypertension accompanied by chest pain. 260 consecutive patients presenting with acute chest pain in the context of stage 2 hypertension (systolic pressure ≥160 and/or diastolic pressure ≥100) were enrolled in the study. After admission, control of blood pressure and risk stratification, 82 patients were excluded due to renal insufficiency, prior coronary revascularisation or refused participation in the study. 90 further patients with low pre-test probability of CAD were also excluded. 88 remaining patients were subjected to CT coronary angiography using Dual-Source CT (Definition, Siemens Medical Solutions, Forchheim, Germany) within 24 h before invasive coronary angiography. A contrast-enhanced volume dataset was acquired (120 kV, 400 mAs/rot, collimation 2 × 64 × 0.6 mm, retrospective ECG gating). Data sets were evaluated concerning the presence or absence of significant coronary stenoses and validated against invasive coronary angiography. A significant stenosis was assumed if the diameter reduction was ≥50%. 88 patients (mean age 66 ± 11 years, mean heart rate 61 ± 9 bpm) were evaluated regarding the presence or absence of significant CAD (at least one stenosis ≥50% diameter reduction). Mean systolic blood pressure on presentation was 203 ± 20 mmHg and mean diastolic blood pressure was 103 ± 13 mmHg. On a per patient basis, the sensitivity and specificity for Dual-Source CT to detect significant CAD in vessels >1.5 mm diameter was 100% (36/36, 95% CI 90-100) and 90% (47/52, 95% CI 79-97), respectively with a negative predictive value (NPV) of 100% (47/47, 95% CI 92-100) and a positive predictive value (PPV) of 88% (36/41, 95% CI 74-96). On a per artery basis, 352 vessels were evaluated (left main, left anterior descending, left circumflex and right coronary artery in 88 patients, 12 vessels could not be assessed due to either motion artefacts or heavy calcification and were considered positive for stenoses) with a sensitivity of 84% (54/64, 95% CI 72-95) and specificity of 94% (272/288, 95% CI 88-100); NPV was 96% (272/282, 95% CI 90-100) and PPV was 77% (54/70, 95% CI 62-91). Our study demonstrates high sensitivity, specificity and negative predictive value of Dual-Source CT to detect significant CAD in patients presenting with uncontrolled hypertension accompanied by chest pain. Dual-Source CT angiography may be useful to safely rule out coronary artery stenoses and avoid invasive angiograms in these patients.     

双源CT冠状动脉造影评价冠状动脉狭窄

目的 评价双源CT(DSCT)冠状动脉造影诊断冠状动脉狭窄的准确性.方法 收集104例临床疑诊或确诊冠心病并于30日内先后接受DSCT冠状动脉造影检查和导管法冠状动脉造影(CAG)患者,以CAG诊断结果作为金标准,分别评估DSCT诊断冠状动脉狭窄性病变(＜50％、≥500％和≥75％)的价值.结果 CAG显示1296段冠状动脉.DSCT可评估的冠状动脉为1217段,可评估率为93.90％(1217/1296);诊断＜500％、≥50％和≥75％狭窄的敏感度分别为79.12％ (144/182) 、84.73％ (172/203)和89.83％(106/118),特异度分别为97.33％(802/824) 、99.21％(1006/1014)和99.82％(1097/1099),阳性预测值为86.75％(144/166)、95.56％(172/180)和98.15％(106/108),阴性预测值为95.48％(802/840) 、97.01％(1006/1037)和98.92％(1097/1 109),准确率为94.04％(946/1006) 、96.80％ (1178/1217)和98.85％(1203/1217).钙化斑块是导致血管不可评估及误诊的主要原因.结论 DSCT冠状动脉造影判断冠状动脉狭窄程度的准确性较高,可作为临床筛查冠心病的较为可靠的方法.     

Patterns of coronary arterial lesion calcification by a novel, cross-sectional CT angiographic assessment

To investigate the patterns and diagnostic implications of coronary arterial lesion calcification by CT angiography (CTA) using a novel, cross-sectional grading method, we studied 371 patients enrolled in the CorE-64 study who underwent CTA and invasive angiography for detecting coronary artery stenoses by quantitative coronary angiography (QCA). The number of quadrants involving calcium on a cross-sectional view for ≥30 and ≥50 % lesions in 4,511 arterial segments was assessed by CTA according to: noncalcified, mild (one-quadrant), moderate (two-quadrant), severe (three-quadrant) and very severe (four-quadrant calcium). Area under the receiver operating characteristic curve (AUC) were used to evaluate CTA diagnostic accuracy and agreement versus. QCA for plaque types. Only 4 % of ≥50 % stenoses by QCA were very severely calcified while 43 % were noncalcified. AUC for CTA to detect ≥50 % stenoses by QCA for non-calcified, mildly, moderately, severely, and very severely calcified plaques were 0.90, 0.88, 0.83, 0.76 and 0.89, respectively (P < 0.05). In 198 lesions with severe calcification, the presence or absence of a visible residual lumen by CTA was associated with ≥50 % stenosis by QCA in 20.3 and 76.9 %, respectively. Kappa was 0.93 for interobserver variability in evaluating plaque calcification. We conclude that calcification of individual coronary artery lesions can be reliably graded using CTA. Most ≥50 % coronary artery stenoses are not or only mildly calcified. If no residual lumen is seen on CTA, calcified lesions are predictive of ≥50 % stenoses and vice versa. CTA diagnostic accuracy for detecting ≥50 % stenoses is reduced in lesions with more than mild calcification due to lower specificity.     

Comparison of non-invasive electron-beam and multislice CT angiography efficacy for detection of coronary artery stenosis

AIM: To compare diagnostic value of electron-beam CT (EBT) and multislice CT (MSCT) angiography in detection of coronary artery stenosis in patients with coronary artery disease (CAD). MATERIAL AND METHODS: 140 CAD patients who had undergone EBT (n = 97) or 4-slice CT (n = 43) coronary angiography and conventional coronary angiography as a gold standard were included in the study. RESULTS: Sensitivity and specificity of EBT angiography in coronary stenosis detection (proximal and mid segments) were 86 and 97%, respectively. Sensitivity and specificity of MSCT angiography were 87 and 98%, respectively. 6 and 7% of coronary segments were excluded from the study because of bad image quality in EBT and MSCT groups, respectively. CONCLUSION: No significant difference was registered in diagnostic value of EBT and 4-slice MSCT angiography in coronary artery stenosis detection.     

心肌灌注显像在女性冠心病诊断中价值

目的评价心肌灌注显像对女性冠心病患者的诊断价值。方法 344例有胸痛、胸闷症状女性患者,行静息+药物负荷心肌灌注显像检测,并与冠状动脉造影结果进行对比分析。结果冠状动脉狭窄178例患者中心肌灌注显示异常者130例;冠状动脉造影无异常或不规则166例中心肌灌注显像异常50例,无异常116例;以冠状动脉造影结果为标准,心肌灌注显像对女性冠心病诊断的敏感度、特异度、阳性预测值、阴性预测值分别为73.0%,69.9%,72.2%,70.7%。结论心肌灌注显像对女性冠心病患者的诊断及是否进一步行冠状动脉造影的筛选有一定价值。     

16层CT冠状动脉成像与选择性冠状动脉造影的对比研究

目的:探讨16层CT对冠状动脉粥样硬化病变的显示情况及临床价值。方法:39例患者进行16层CT冠状动脉造影检查(疑似冠心病者31例,PTCA术后8例)及选择性冠状动脉造影。分析16层CT对冠状动脉各节段的显示情况。以管腔直径减小>50%为标准,判定冠状动脉狭窄。分析16层CT诊断冠状动脉狭窄的敏感性、特异性及符合率,及对病变性质的显示情况。结果:16层CT对冠状动脉的总体显示率为94.8%(333/351)。评价冠状动脉病变的总体敏感性为82.2%,特异性为94.7%,符合率为86.0%。16层CT显示钙化及非钙化斑块混合存在致血管狭窄21处,高估3处;中间密度斑块致狭窄8处,高估3处;软斑块3处,无显著狭窄。16层CT能清晰显示支架位置、形态及远端血流,1例再狭窄,1例闭塞,余通畅,其结果与选择性冠状动脉造影一致。另外,16层CT显示冠状动脉起源变异2例,前降支冠状动脉瘤1例,室壁瘤1例,房间隔缺损1例。结论:16层CT冠状动脉成像是一种颇具潜力的无创性检查方法,能够较为准确、全面的评价冠状动脉病变。     

64排螺旋CT心肌灌注显像评价冠状动脉狭窄对心肌缺血的诊断效能

目的 利用99mTc-MIBI心肌灌注显像(MPI)探讨64排螺旋CT冠状动脉造影(CTCA)发现的冠状动脉狭窄对心肌缺血的诊断效能.方法 30例患者接受MPI和CTCA检查.将CTCA三支冠状动脉分为12段,以MPI为诊断标准,分别以CTCA血管狭窄≥50%和≥75%为截断值,统计对应节段MPI是否出现异常,分析CTCA诊断的冠状动脉狭窄对心肌缺血的效能评价.结果 MPI发现灌注异常9例(6例可逆性,3例固定性血流灌注减低).CTCA共分析327个冠状动脉节段,其中狭窄≥50%者占25段(7.65%);狭窄≥75%者12段(3.67%).以MPI异常为标准观察病变血管,以狭窄≥50%为界值时,CTCA的敏感性、特异性、阴性预测值(NPV)、阳性预测值(PPV)和准确性分别是68.42%、96.14%、99.01%、52.00%和95.41%;以狭窄≥75%为界值,则分别为66.67%、99.04%、98.73%、66.67%、97.55%.以MPI异常为标准观察患者,当血管狭窄≥50%为界值时,CTCA 的敏感性、特异性、NPV、PPV和准确性分别是66.67%、57.14%、80.00%、40.00%和60.00%;当≥75%为界值时,上述指标分别是55.56%、85.71%、81.82%、62.50%和76.67%.结论 正常CTCA对心肌缺血患者的排查是可靠的,CTCA异常是否存在心肌缺血需要进一步检查.     

320排CT冠状动脉成像与冠状动脉造影的影像对比研究

目的以选择性冠状动脉造影（SCA）为＂金标准＂评价320排CT冠状动脉成像技术对诊断冠状动脉狭窄的准确性。方法选择冠心病诊断明确或可疑冠心病患者共86例（男49例,女37例）。所有患者的心律均为窦性心律,心率≥75次/min的患者口服倍他乐克控制心率;均同期行320排器官动态容积CT（DVCT）与SCA,将320排DVCT与SCA的结果进行对照研究,直径≥1.5mm的冠状动脉节段纳入结果分析,冠状动脉狭窄定义为≥50%的狭窄,分析320排DVCT对冠状动脉不同节段、不同分支狭窄判断的准确性;并根据有无伪影和是否符合进一步狭窄评价的要求将冠状动脉图像质量分为四个等级（Ⅰ～Ⅳ级）。结果 320排DVCT显示的1032个冠状动脉节段均符合影像学评价要求（Ⅰ～Ⅲ级）;计算320排DVCT评价冠状动脉有无狭窄的总体敏感度、特异度、阳性预测值和阴性预测值分别为92.7%、96.1%、86.4%和98.0%,准确度为94.7%。结论 320排DVCT能清楚显示冠状动脉各分支节段,较为准确的诊断冠状动脉狭窄程度,亦可作为无创性诊断冠状动脉疾病的有力工具。     

MRI检测活性心肌及其与冠状动脉造影、SPECT和PET对比研究

目的：分析MRI对冠心病患者心肌活性的诊断价值并与冠状动脉造影、SPECT和PET结果对比。方法：应用MRI对21例临床符合冠心病的患者进行检查，并将结果与冠状动脉造影、SPECT和PET检查结果对照。结果：MRI静息心肌灌注扫描检出的缺血节段比狭窄冠状动脉的供血节段少但无统计学差异（Z=-1.732，P=0．083）；比SPECT心肌灌注扫描检出的缺血节段多且有统计学差异（Z=-3．691，P=0．000）。SPECT心肌灌注扫描检出的缺血节段比狭窄冠状动脉的供血节段少且有统计学差异（Z=-3．029，P=0．002）。以正电子发射断层显像（PET）结果为标准，MR延迟扫描检测活性心肌的灵敏度为97．6％，特异度为98．4％，总符合率为98．2%，Kappa值为0．953。MR延迟扫描检出的活性心肌比PET检出的少但无统计学差异（Z=-0．209，P=0．835）。结论：MR心脏检查清晰显示心肌梗死的位置、程度和附壁血栓情况，并可对左室室壁运动进行直观显示。常规SPECT心肌灌注显像由于空间分辨率低明显低估心肌缺血范围。心肌PET显像空间分辨率低，无法显示心肌梗死的透壁程度，且不能直观显示室壁运动情况。     

多巴酚丁胺负荷超声造影诊断冠心病的初步研究

目的探讨多巴酚丁胺负荷超声造影（DESC）在冠心病（CAD）诊断中的应用价值。 方法选取2015年11月至2019年6月于东莞康华医院心血管中心行DSEC,并完成了冠状动脉造影（CAG）或冠状动脉CT血管造影（CTA）的患者375例。分别以冠状动脉狭窄≥50%、≥75%为CAD诊断标准,以CAG或CTA结果为对照标准,应用四格表计算DSEC诊断CAD的敏感度、特异度和准确性。 结果冠状动脉狭窄≥50%为CAD诊断标准时,以CAG或CTA结果为对照标准,DSEC诊断CAD的敏感度为43%,特异度为95%,准确性为67%。冠状动脉狭窄≥75%为CAD诊断标准时,以CAG或CTA结果为对照标准,DSEC诊断CAD的敏感度为71%,特异度为96%,准确性为88%,较≥50%时的敏感度、特异度和准确性均有提高。2015年11月至2019年6月行DSEC检查的1300例患者中,因发生不良反应导致检查失败16例,心律失常发生率为25%,其中室性早搏最常见。 结论DSEC对CAD有较好的诊断和指导治疗价值,药物和运动协同负荷是对传统负荷超声造影的改良,方法简易可行,多巴酚丁胺不良反应可防可治。     

冠状动脉钙化多层螺旋 CT检查及与冠状动脉造影的对比研究

目的研究多层螺旋CT所见冠状动脉钙化与冠状动脉狭窄之间关系,并与冠状动脉造影进行对比.方法 23例临床怀疑或确诊冠心病患者(男17例,女6例,年龄31～74岁)均行 MSCT检查及冠状动脉造影.MSCT扫描采用心电门控触发成像,单次扫描时间为 0.32 s,层厚为2 mm×4 mm.将MSCT所见钙化与常规冠状动脉造影对比.结果 58支发现钙化的血管中,78%有冠状动脉狭窄 (>50% ), 47支造影证实冠状动脉狭窄 (>50% )的血管中,96%发现冠状动脉钙化.青年组与老年组相比,冠状动脉钙化预测冠心病的敏感性较低而特异性较高.结论多层螺旋CT检出冠状动脉钙化简便易行,可广泛用于临床预测及早期诊断冠心病.     

CT和MRI在冠状动脉疾病诊断中的应用比较

目的比较心脏计算机断层扫描(CT)和心脏磁共振成像(MRI)在冠状动脉疾病的诊断的应用方法。方法 2008年2月到2010年2月我们前瞻性的连续选择了94例已知或者疑似CAD的患者,进行MRI心肌灌注、传统的冠状动脉造影、前瞻性ECG-门控的冠脉CTA分析,并比较了MRI心肌灌注和CA、前瞻性ECG-门控冠脉CTA加MRI心肌灌注和CA;评估了血流动力学相关狭窄。结果 MRI心肌灌注揭示了60/94(63.8%)的人具有心肌缺损(灌注缺损或梗阻)。CA揭示了94例病人中有66例冠状动脉中有150例大于50%直径的狭窄。平均每名患者的有效辐射剂量为2.5±1.1mSv。检测冠状动脉狭窄大于50%,在CA的敏感性,特异性,NPV,PPV和准确率低于MRI心肌灌注以及冠脉CTA加MRI心肌灌注。其中1例病人在CD伴随着MRI心肌灌注的LAD灌注缺损,在冠脉CTA被判定为没有明显狭窄。结论在诊断血流动力学相关的CAD,冠状动脉CTA可能取代CA。     

Detection of single‐vessel coronary artery disease by dipyridamole stress echocardiography: no longer a problem?

We aimed to evaluate whether addition of myocardial contrast echocardiography (MCE) perfusion data improves the sensitivity of stress echocardiography for detection of single‐vessel coronary artery disease (svCAD) and to compare the diagnostic value of MCE and single‐photon emission computed tomography (SPECT) for detection of svCAD. Methods One hundred and three patients with suspected or known stable CAD underwent dipyridamole (0·84 mg kg^?1 intravenously over 4 min)‐atropine (up to 1 mg intravenously) stress echocardiography combined with MCE. Wall motion abnormalities (WMA) and perfusion defects were assessed visually. Presence of CAD was detected by coronary angiography. Results Single‐vessel coronary artery disease defined as ≥70% stenosis was detected in 30% of patients, whereas 26% of patients had svCAD defined as ≥50% stenosis. Presence of inducible WMA had 35% and 26% sensitivity for detection of svCAD defined as ≥70% and ≥50% stenosis, respectively. Concomitant evaluation of MCE increased the sensitivity to 74% (P = 0·005) and 56% (P = 0·053), respectively, using any inducible abnormality (WMA or perfusion defects) as a criterion. Presence of any (inducible or fixed) WMA had 77% and 59% sensitivity for detection of svCAD defined as ≥70% and ≥50% stenosis, respectively. In case of such criterion for stress test positivity, the improvement in sensitivity provided by addition of MCE (to 94% and 78%, respectively) did not reach statistical significance. Conclusions Addition of MCE perfusion analysis during stress echocardiographical examination based on evaluation of inducible abnormalities improves the test sensitivity for detection of svCAD. This benefit is less apparent when fixed WMA and perfusion defects are incorporated into the stress test positivity criterion.     

CT angiography for evaluation of coronary artery disease in inner-city outpatients: an initial prospective comparison with stress myocardial perfusion imaging

To evaluate the utility of CT coronary angiography (CTA) for demonstrating coronary artery disease in inner-city outpatients, we prospectively compared CTA with stress SPECT myocardial perfusion imaging in an ethnically diverse, gender balanced population. All patients gave written informed consent for this IRB approved, HIPAA compliant study. Sixty-one patients completed both CTA and SPECT. About 67% were ethnic minorities, 51% were women. A stenosis of ≥70% on CTA was considered positive. Results were compared with perfusion defects on SPECT and correlated with clinical endpoints (hospital admissions, cardiovascular events, coronary interventions and deaths). CTA and SPECT data were compared with results of coronary angiography, when performed. There was moderate global agreement of 79% (48/61) between CTA and SPECT, κ = 0.483 (SE ± 0.13, P = 0.0001). With SPECT as the reference standard, CTA had sensitivity of 73% (11/15), specificity of 80% (37/46), negative predictive value of 90% (37/41) and positive predictive value of 55% (11/20). Positive SPECT was associated with positive CTA, (P < 0.0001, OR = 22). Eleven (18%) underwent subsequent cardiac catheterization, which was positive in 91% (10/11). CTA and SPECT had positive predictive values of 90 and 83% compared with catheterization. This study lends preliminary evidence to support to the utility of CTA as an alternative modality for the evaluation of CAD in an ethnically diverse, gender balanced inner-city outpatient population. Similar to more homogenous groups, CTA had a high negative predictive value and demonstrated disease occult to SPECT. Further study is necessary to evaluate the impact of CTA on patient outcomes.     

双源CT 冠状动脉血管成像对冠状动脉狭窄的诊断价值分析

目的:探讨应用双源CT冠状动脉血管成像(DSCT-CA)的检查方式对诊断冠状动脉狭窄的价值。方法:选取2019年1月—2020年5月期间我院65例疑似冠状动脉狭窄的患者,均接受冠脉造影(CAG)与DSCT-CA检查,以CAG检查为金标准,评价DSCT-CA对狭窄情况的诊断价值,并且以冠状动脉狭窄50%为界限,分析DSCT-CA诊断的准确度、敏感度及特异度。结果:检出595个冠状动脉节段,经CAG检出狭窄节段158个(26.55%),经DSCT-CA检出狭窄节段142个(23.87%);经DSCT-CA对冠状动脉狭窄50%的诊断准确度为96.92%(63/65)、敏感度为100.00%(47/47)、特异度为88.89%(16/18)。结论:应用DSCT-CA可对不同程度的冠状动脉狭窄的诊断价值显著,值得推广。     

Improved evaluation of calcified segments on coronary CT angiography: a feasibility study of coronary calcium subtraction

We explore the feasibility of coronary calcium subtraction computed tomography angiography (CCTA) in patients with high calcium scores using invasive coronary angiography as the gold standard. Eleven patients with calcium scores of >400 underwent CCTA using a subtraction protocol followed by invasive coronary angiography. In addition to standard reconstructions, subtracted images were obtained using a dedicated subtraction algorithm. A total of 55 calcified segments were evaluated for image quality [using a 4-point scale ranging from 1 (uninterpretable) to 4 (good)] and the presence of significant (≥50 %) luminal stenosis. Conventional and subtracted CCTA were compared using quantitative coronary angiography (QCA) as the gold standard. The average image quality of conventional CCTA was 2.5 ± 0.6 versus 3.1 ± 0.6 on subtraction CCTA (P < 0.001). The percentage of segments with a score 1 or 2 was reduced from 41.8 to 12.7 % after coronary calcium subtraction (P = 0.002). On QCA, significant stenosis was observed in 16 segments. The area under the receiver operating characteristics curve to detect ≥50 % stenosis on QCA increased from 0.741 [95 % confidence interval (CI) 0.598–0.885] for conventional CCTA to 0.905 (95 % CI 0.791–1.000) for subtraction CCTA (P = 0.003). In patients with extensive calcifications undergoing CCTA, coronary calcium subtraction may improve the evaluation of calcified segments.