64-multislice detector computed tomography coronary angiography as potential alternative to conventional coronary angiography: a systematic review and meta-analysis.

AIMS: To evaluate the diagnostic accuracy of 64-slice multi-detector computed tomography coronary angiography (64-SCTA) compared with the standard reference conventional coronary angiography (CCA). METHODS AND RESULTS: Based on a systematic search, 27 studies including 1740 patients were eligible for meta-analyses. Nineteen studies examined native coronary arteries (n = 1,251), four studies examined coronary artery by-pass grafts (CABG) (n = 271), and five studies examined coronary stents (n = 270). Overall 18 920 segments were assessable and 810 (4%) were unassessable. The prevalence of native coronary artery stenosis in per-segment (19 studies) and per-patients (13 studies) populations were 19 and 57.5% respectively. Accuracy tests with 95% confidence intervals comparing 64-SCTA vs. CCA showed that sensitivity, specificity, positive predictive and negative predictive values for native coronary arteries were 86(85-87), 96(95.5-96.5), 83, and 96.5% by per-segment analysis; 97.5(96-99), 91(87.5-94), 93, and 96.5% by per-patient analysis; 98.5(96-99.5), 96(93.5-97.5), 92 and 99% for CABGs; 80(70-88.5), 95(92-97), 80, and 95% for stent restenosis; and 87(86.5-88), 96(95.5-96.5), 83.5, and 97% by overall per-segment analysis. CONCLUSION: The high diagnostic accuracy of 64-SCTA validates this non-invasive technique as a potential alternative to CCA in carefully selected populations suspected for coronary stenosis.     

Minimizing radiation dose for coronary CT angiography

Coronary CT angiography is a rapidly growing technique that offers distinct advantages over traditional imaging techniques. However, because of rapid growth of this technique, radiation dose safety has been placed under the spotlight. There are several main determinants of total radiation dose, and these are outlined in this review. Integration of these dose-saving techniques will go a long way in maintaining diagnostic image quality and improving patient safety.     

Prognostic value of coronary CT angiography

Coronary computed tomography angiography (CTA) is a highly accurate noninvasive test that is increasingly used in symptomatic patients primarily for the diagnosis of coronary artery disease (CAD). Beyond its proven accuracy, data have now clearly demonstrated the incremental prognostic information available from coronary CTA related to the presence, extent, and severity of obstructive and nonobstructive CAD across a variety of clinical settings and patient populations. Current evidence supports the use of coronary CTA not only for the diagnosis of CAD in appropriately selected symptomatic patients but also to further refine their cardiovascular risk assessment following testing.     

Identifying and redefining stenosis by CT angiography

Coronary computed tomographic angiography (CCTA) has emerged as a novel noninvasive method for the evaluation of not only coronary artery stenosis but also arterial wall and plaque features. Recent developments in CCTA technology enable the simultaneous assessment of coronary stenosis, atherosclerotic plaque characteristics, physiologic significance of lesion-specific ischemia, and cardiac function. Through these studies, the prognostic significance of individual coronary lesions and ventricular function can be determined and used to direct therapy. Future studies are needed to establish the totality of coronary artery plaque measures that improve clinical utility.     

心律不齐、心率过快患者冠状动脉CT检查的研究进展

随着人们生活水平的提高和人口的老龄化,冠状动脉粥样硬化性心脏病（简称冠心病）发病率有不断升高趋势,成为严重威胁人类健康的常见病、多发病。常规冠状动脉造影术虽然是诊断冠状动脉疾病的金标准,但其费用较高,具有一定的创伤和风险,因此临床上应用受到一定程度的限制。     

64-slice CT for diagnosis of coronary artery disease: a systematic review

Purpose

The purpose of this systematic review was to assess the accuracy of 64-slice CT coronary angiography for the diagnosis of coronary artery disease.

Methods

We attempted to identify all published trials in all languages that used 64-slice CT to diagnose coronary artery disease. Results of 64-slice CT coronary angiography were compared with invasive coronary angiography or intravascular ultrasound.

Results

Sensitivity of 64-slice CT for significant (≥50%) stenosis, based on pooled data from all studies, was ≥90% in patient-based evaluations, named vessels, segments, and coronary artery bypass grafts, except the left circumflex (sensitivity 88%), distal segments (80%), and stents (88%). Specificity was 88% in patient-based evaluations, and ≥90% at individual sites. Positive predictive values for patient-based evaluations, left main coronary artery, and coronary artery bypass grafts ranged from 91% to 93%, but elsewhere ranged from 69% to 84%. Negative predictive values were 96% to 100%. Positive likelihood ratios for patient-based evaluations were 8.0 and, at specific sites, were ≥9.7. Negative likelihood ratios, except for distal segments, were <0.1.

Conclusion

Negative 64-slice CT reliably excluded significant coronary disease. However, the data suggest that stenoses shown on 64-slice CT require confirmation. Combining the results of 64-slice CT with a pre-CT clinical probability assessment would strengthen the diagnosis. Due to the risk of radiation-induced cancer, patients should be selected carefully for this test, and scan protocols should be optimized to minimize risk.     

Adjunctive value of CT coronary angiography in the diagnostic work-up of patients with typical angina pectoris.

AIMS: To determine the adjunctive value of CT coronary angiography (CTCA) in the diagnostic work-up of patients with typical angina pectoris. METHODS AND RESULTS: CTCA was performed in 62 consecutive patients (45 male, mean age 58.8 +/- 7.7 years) with typical angina undergoing diagnostic work-up including exercise-ECG and conventional coronary angiography. Only patients with sinus heart rhythm and ability to breath hold for 20 s were included. Patients with initial heart rates >/=70 beats/min received beta-blockers. We determined the post-test likelihood ratios, to detect or exclude patients with significant (>/=50% lumen diameter reduction) stenoses, of exercise-ECG and CTCA separately, and of CT performed after exercise-ECG testing. The prevalence of patients with significant coronary artery disease (CAD) was 74%. Positive and negative likelihood ratios for exercise-ECG were 2.3 [95% confidence interval (CI): 1.0-5.3] and 0.3 (95% CI: 0.2-0.7) and for CTCA 7.5 (95% CI: 2.1-27.1) and 0.0 (95% CI: 0.0-8), respectively. CTCA increased the post-test probability of significant CAD after a negative exercise-ECG from 58 to 91%, and after a positive exercise-ECG from 89 to 99%, while CT correctly identified patients without CAD (probability 0%). CONCLUSION: Non-invasive CTCA is a potentially useful tool, in the diagnostic work-up of patients with typical angina pectoris, both to detect and to exclude significant CAD.     

Relationship of coronary artery plaque composition to coronary artery stenosis severity: results from the prospective multicenter ACCURACY trial

Objectives

The purpose of this study was to determine the relationship of coronary artery plaque composition as detected by coronary computed tomographic angiography (CCTA) to luminal diameter stenosis severity quantified by quantitative coronary angiography (QCA) in individuals without known coronary artery disease (CAD) presenting with stable chest pain syndrome.

Background

While CCTA has been previously evaluated for its ability to detect and exclude coronary artery stenosis, CCTA also permits assessment of other important plaque characteristics, including plaque composition. Identification of the relationship between plaque composition by CCTA and plaque severity by invasive angiography may provide valuable insight into the pathophysiology of coronary artery plaque.

Methods

Patients enrolled in the ACCURACY trial, a 16-site multicenter study of patients with stable chest pain syndrome but without known CAD undergoing both CCTA and invasive coronary angiography (ICA), comprised the study population. CCTAs were scored on a per-segment basis for plaque composition and graded as non-calcified (>70% non-calcified), calcified (>70% calcified) or “mixed” (30–70% non-calcified or calcified) by concordance of ≥2 of 3 readers. CCTAs were also scored on a per-patient basis, and individuals were categorized as possessing primarily non-calcified plaques, primarily calcified plaques or primarily mixed plaques. Quantitative coronary angiography (QCA) was performed in all patients, used as the reference standard for stenosis severity, and interpreted blinded to patient characteristics and CCTA results.

Results

230 subjects comprised the study population (59.1% male, 57 ± 10 years). QCA was performed in all subjects following CCTA (mean inter-test interval 5.9 ± 4.3 days), and demonstrated obstructive CAD in 24.8% and 13.9% at the 50% and 70% stenosis severity threshold, respectively. On a per-segment based analysis, obstruction by QCA at both the 50% and 70% stenoses thresholds was more often for mixed composition plaques by CCTA (69.1% and 67.9%, respectively), as compared to non-calcified plaques (24.7% and 28.6%, respectively) and calcified plaques (6.1% and 3.6%, respectively) [p < 0.01 for comparisons]. On a per-patient basis, patients with mixed plaque or mixtures of plaque types more often exhibited obstructive coronary stenosis by QCA at the 50% level (39/96; 40.6%) compared to those with primarily non-calcified (12/43; 27.9%) or primarily calcified (4/29; 13.8%) plaques [p = 0.02].

Conclusions

In this multicenter trial of chest pain patients without known CAD, QCA-confirmed obstructive coronary stenosis was associated with mixed plaque composition by CCTA at both the per-segment and the per-patient levels. Coronary artery segments exhibiting calcified plaque were rarely associated with obstructive coronary stenosis.     

双源CT 冠状动脉成像在冠状动脉搭桥术后的应用

目的探讨双源cT冠状动脉造影（CTA）在冠状动脉搭桥术后的应用价值。方法24例冠状动脉搭桥术后患者,采用双源CT行冠状动脉造影扫描,将所得原始数据进行容积再现、最大密度投影、曲面重建和多平面重建等图像后处理,全面观察桥血管及冠脉狭窄情况。结果30例冠状动脉搭桥术患者共有81条桥血管,其CTA图像均能清晰显示,其中5支桥血管轻度狭窄,6支桥血管严重狭窄。结论双源CTA作为一种无创性的检查,在冠状动脉搭桥术后随访中具有很高的临床应用价值。     

Detection of coronary artery stenoses using multi-detector CT with 16x0.75 collimation and 375 ms rotation

Aims Insufficient spatial and temporal resolutions have limitedimage quality and accuracy of multi-detector CT (MDCT) for coronaryartery visualization and detection of stenoses. We assessedthe accuracy of a new 16-slice scanner with 370 ms rotationand 0.75 mm collimation for detection of coronary stenosesusing an analysis approach based on coronary artery segments. Methods and results Fifty consecutive patients scheduled fordiagnostic coronary angiography in stable clinical conditionand sinus rhythm were enrolled. All patients with a heart rate>60 b.p.m. received 100 mg atenolol p.o. and upto four doses of 5 mg metoprolol i.v. before the scan.MDCT was performed using 16x0.75 mm collimation, 120 kV,and ECG-gated tube current modulation. Ninety millilitres ofcontrast agent was injected intravenously. MDCT images werevisually analysed using the 16-segment coronary artery modelof the American Heart Association and compared with invasive,quantitative coronary angiography in a blinded fashion. A significantstenosis was assumed if the diameter reduction was 50%. Meanheart rate was 58 b.p.m. during MDCT. After exclusion oftwo patients with not fully evaluable data sets, MDCT correctlyidentified at least one coronary stenosis in all 25 patientswith significant coronary lesions in angiography and correctlydemonstrated the absence of stenoses in 19/23 patients (sensitivity100%, specificity 83%). Sensitivity and specificity for all50 patients were 93 and 83%, respectively. On a per-segmentbasis, nine coronary segments distal of total occlusions and128 coronary segments with a reference diameter <1.5 mmwere excluded from the analysis. Twenty-eight of the included663 segments (4%) were unevaluable due to calcification or motionartefact. In the remaining 635 segments, 50/53 stenoses weredetected by MDCT (sensitivity 94%, specificity 96%, negativepredictive value 99%, positive predictive value 69%). Conclusion Increasing temporal and spatial resolutions of MDCTlead to improved evaluation and diagnostic accuracy for detectionof coronary stenoses.     

心房颤动对双源CT冠状动脉血管成像的影响

目的探讨心房颤动（房颤）平均心室率、心率波动和心率变异性对冠状动脉CT血管成像（CTA）图像质量的影响。方法87例房颤患者和107例心律正常者进行了双源CT冠状动脉血管成像。平均心室率、心率波动和心率变异性与图像质量之间的关系采用相关分析和线性回归分析判断,各分段图像质量之间的差别采用卡方检验和非参数检验。结果房颤组共1218段血管纳入分析,达到诊断标准的血管共1038段（85．2％）。房颤组的平均心室率为（90．1±22．0）次／min,心率波动为（55．8±34．3）次／min,心率变异性为0．55±0．29,均高于对照组（P〈0．01）。部分动脉图像质量与平均心率无关（P〉0．05）。除左主干外,心率波动与其他分段图像质量呈负相关（P〈0．01）。心率变异性与所有分段图像质量呈负相关（0．01〈P〈0．05和P〈0．01）。左主干和回旋支近段高质量图像百分率较高,而后降支和钝缘支图像质量较差。结论双源CT能对大多数房颤患者冠状动脉进行评价,其获得的各近段动脉图像质量高于远段动脉。心率波动对房颤冠状动脉CTA图像质量起主导影响作用。     

冠状动脉CT血管成像狭窄评分定量评估缺血相关病变的临床价值

目的:分析冠状动脉CT血管成像狭窄评分(CCTA-SS)在定量评估缺血相关病变中的临床价值.方法:回顾性分析经冠状动脉CT血管成像(CCTA)诊断为左前降支单支病变的冠状动脉粥样硬化性心脏病(冠心病)疑似患者的临床资料.患者入院1周内接受有创冠状动脉造影(ICA)及血流储备分数(FFR)检查,分析影像特征并计算CCTA...     

Incidental coronary calcifications on routine chest CT: Clinical implications

Coronary artery calcification (CAC) is a marker of atherosclerosis and an independent risk factor for cardiac-related mortality, with much of the 50% decline in mortality over the past 30 years being attributed to early detection of coronary disease and intervention of modifiable risk factors. With over 10 million computed tomography (CT) examinations of the chest performed in the United States yearly, CAC can be identified in a very large number of patients. In this review, we discuss the clinical evidence underlying the relationship between radiologic identification of CAC, atherosclerosis, and cardiac outcomes and the implications of its assessment on standard chest CT. We conclude that reporting of incidental coronary calcification found on non-gated chest CT would have a great impact on both management and mortality and thus, in the appropriate setting, should be noted in the impression of the radiologic report when identified.     

Appropriateness of angiography for suspected coronary artery disease

The aim of this study was to assess the appropriate use of diagnostic catheterizations (DC) for the patients with suspected coronary artery disease performed in Iran. The Electronic Health Record System database and manual review of files were utilised to collect data between 2012 and 2014. Patients were categorized in three groups as appropriate, uncertain, and inappropriate usage of DC and the logistic regression was used to investigate the relationships between variables. One-quarter of the 2458 angiographies were rated as inappropriate, out of which 99% had no previous stress test. The rate of inappropriate DC between various hospitals were approximately the same. The regression showed that some risk factors (Sex, high cholesterol, smoking, chronic heart failure, renal failure, diabetes) were significantly associated with inappropriate rate.     

冠状动脉CTA双低技术的临床应用

目的探讨应用双低技术——低千伏(100 kV)技术联合低对比剂浓度在冠状动脉CT血管造影(CCTA)中的可行性。方法选取拟行冠状动脉CTA检查患者80例患者(体重指数≤26.0 kg/m2),随机分为A、B两组,A组(n=40)采用100kV,270 mg/ml威视派克对比剂及自适应迭代算法重建(ASiR),B组(n=40)采用120 kV,350 mg/ml欧乃派克对比剂及滤波反投影算法重建(FBP)。测量主动脉、皮下脂肪和竖脊肌的CT值和SD值,平均SD值计算为图像噪声。测量左冠状动脉前降支(LAD),左冠状动脉回旋支(LCX)和右冠状动脉(RCA)的CT值和SD值,并计算对比噪声比(CNR)。采用5分法对所有图像进行主观质量评分。记录CT剂量指数,并进行有效辐射剂量计算。结果A组患者平均碘用量比B组患者下降22.8%。两组患者LAD、LCX和RCA血管CT值、CNR值、图像噪声及图像质量主观评分,均无统计学差异(P均0.05)。A组患者的有效辐射剂量明显低于B组患者,差异有统计学意义(P0.05)。结论对于体重指数≤26的患者,低对比剂浓度和低千伏(100 kV)相对于常规扫面能够提供相似的图像质量,并减少对比剂的碘用量及有效辐射剂量。     

双源CT血管造影检测颅内动脉瘤:与数字减影血管造影的比较

目的 探讨双源CT血管造影(dual-source CT angiography,DSCTA)对颅内动脉瘤的诊断价值.方法 收集95例蛛网膜下腔出血(subarachnoid hemorrhage,SAH)患者的DSCTA和数字减影血管造影(digital subtraction angiogaphy,DSA)资料,回顾性分析二者检出颅内动脉瘤并描述相关形态特征的效能.结果 DSCTA在88例SAH患者中检出动脉瘤117个.2例疑有动脉瘤,5例未检出动脉瘤,对这些病例行DSA复查,4例确诊动脉瘤,3例未检出动脉瘤.以DSA结果为金标准,DSCTA检诊颅内动脉瘤的特异性为100％,敏感性为96.7％,准确性为96.8％.颅内动脉瘤体积越大,DSCTA诊断的敏感性越高.即便对于微小动脉瘤,DSCTA诊断的敏感性亦可达90％以上.此外,DSCTA对动脉瘤最大径和瘤颈宽度的测量结果与DSA基本一致.结论 DSCTA是一种无创、快速、可靠、有效的方法,能准确提供手术所需的影像学资料.DSCTA诊断动脉瘤的特异性和敏感性与DSA基本相同,在颅内动脉瘤的急诊手术时较DSA更具优越性.     

Multislice CT angiography in coronary artery disease: Technical developments, radiation dose and diagnostic value

Multislice computed tomography (CT) angiography has been increasingly used in the detection and diagnosis of coronary artery disease because of its rapid technical evolution from the early generation of 4-slice CT scanners to the latest models such as 64-slice, 256-slice and 320-slice CT scanners. Technical developments of multislice CT imaging enable improved diagnostic value in the detection of coronary artery disease, and this indicates that multislice CT can be used as a reliable less-invasive alternative to invasive coronary angiography in selected patients. In addition, multislice CT angiography has played a significant role in the prediction of disease progression and cardiac events. Despite promising results reported in the literature, multislice CT has the disadvantage of having a high radiation dose which could contribute to the radiation-induced malignancy. A variety of strategies have been currently undertaken to reduce the radiation dose associated with multislice CT coronary angiography while in the meantime acquiring diagnostic images. In this article, the author will review the technical developments, radiation dose associated with multislice CT coronary angiography, and strategies to reduce radiation dose. The diagnostic and prognostic value of multislice CT angiography in coronary artery disease is briefly discussed, and future directions of multislice CT angiography in the diagnosis of coronary artery disease will also be highlighted.     

Use of 64-slice CT in symptomatic patients after coronary bypass surgery: evaluation of grafts and coronary arteries.

AIMS: Although previous generations of multislice computed tomography (CT) have demonstrated accurate detection of obstructive bypass graft disease, progression of coronary disease is a more frequent cause for ischaemic symptoms late after bypass graft surgery. We explored the diagnostic performance of 64-slice CT in symptomatic patients after bypass surgery, for the assessment of both grafts and native coronary arteries. METHODS AND RESULTS: The 64-slice CT angiography (Siemens Sensation 64, Germany) was performed in 52 symptomatic patients, 10 +/- 5 years after bypass surgery. Two independent, blinded observers assessed all grafts and coronary arteries for stenosis, using conventional quantitative angiography as a reference. A total of 109 grafts (182 graft segments), 123 distal coronary run-offs, and 116 non-bypassed coronary branches (288 segments) were analysed. Per-segment detection of graft disease yielded a sensitivity of 99% (71/72) and specificity of 96% (106/110). Sensitivity and specificity to detect run-off disease were 89% (8/9) and 93% (106/114), positive predictive value was 50% (8/16). In non-grafted coronary segments, CT detected significant stenosis with a sensitivity and specificity of 97% (62/64) and 86% (192/224). Overestimation occurred more frequently in calcified segments (P = 0.002). CONCLUSION: The 64-slice CT allows angiographic evaluation of grafts and coronary arteries, although overestimation of coronary obstruction occurs, particularly in the presence of calcified disease.     

Advances in CT angiography for peripheral arterial disease

Multidetector CT scan (MDCT) has revolutionized the diagnosis of peripheral arterial disease. The most recent generation of CT scan systems increases the number of detector arrays, which allows further increases in volume coverage and acquisition of large volumes rapidly. These have provided advantages in vascular imaging. The introduction of dual-source scanners has allowed the possibility of tissue characterization in CT scans. This article briefly discusses the basic principles of MDCT and provides an overview of its application in vascular diseases.     

肥厚型心肌病冠状动脉造影特征

目的　了解肥厚型心肌病患者冠状动脉造影有何特征性改变。方法　对我院自 1987年 8月至 1999年 8月 5 0例肥厚型心肌病患者冠状动脉造影资料进行分析。结果　 5 0例中 6例冠状动脉为左优势型 ,占 12 %。本组冠状动脉近端平均血管内径测量值 :LM :(5 1± 1 0 )mm ,LADp :(4 2±1 0 )mm ,LCXp :(3 8± 0 9)mm ,RAp :(3 8± 0 9)mm ,与正常左冠状动脉近端平均血管内径 (LM :(4 6±0 6 )mm ,LADp :(3 7± 0 6 )mm ,LCXp :(3 4± 0 6 )mm比较 ,明显增粗 ,P≤ 0 0 5 ,而本组病例右冠状动脉与之比较差异无显著性。冠状动脉肌桥 14例 ,发生率为 2 8% (14 5 0 ) ,其中 12例位于前降支 ,且大多位于其中段。 13例冠状动脉有单支或多支≥ 5 0 %的狭窄病变 ,占 2 6 %。结论　本组冠状动脉造影特点 :冠状动脉左优势型的比例明显增高 ;冠状动脉血管粗大 ,以左冠状动脉增粗为主 ;冠状动脉肌桥发生率高 ,大多出现于前降支中段 ;约 1 4的患者合并冠状动脉狭窄 (≥ 5 0 % )。