Diagnostic performance of 64-slice computed tomography coronary angiography to detect significant coronary artery stenosis

OBJECTIVE: We aimed to determine the diagnostic accuracy of 64-slice multi-slice computed tomography (MSCT) to detect significant coronary artery stenosis with comparison to conventional coronary angiography (CCA). METHODS: In 100 patients (70 men, average age 58 +/- 10 years and age range 31-75 years) scheduled to have conventional coronary angiography, MSCT was performed before catheterization (within 2 months). All patients were in sinus rhythm, able to hold breath for 15 seconds, and had serum creatinine levels < 1.5 mg/dl. MSCT scans were analysed by a radiologist and a cardiologist. Sensitivity, specificity, positive and negative predictive values for the detection of significant stenoses by MSCT in comparison with CCA were calculated on patient, vessel, and segmental bases. RESULTS: 64-slice computed tomography is able to detect significant coronary artery stenosis on a segmental basis with a sensitivity of 88% and specificity of 99% when compared with CCA. All patients with significantly stenotic coronary artery disease are correctly diagnosed. The presence of significant stenosis was correctly diagnosed by MSCT in 126 of 144 segments. Twelve non-significant lesions on CCA were overestimated by MSCT. On vessel-based analysis, the sensitivity and specificity of MSCT for detecting significant stenosis were 91% and 97%, respectively. CONCLUSION: Our results indicate that 64-slice computed coronary angiography is a reliable diagnostic modality for the detection of significant coronary artery stenosis in patients with sinus rhythm and scheduled to have CCA, but still has limitations of diagnostic performance on a per-segment and per-vessel basis.     

Diagnostic accuracy of coronary in-stent restenosis using 64-slice computed tomography: comparison with invasive coronary angiography.

OBJECTIVES: This study sought to evaluate the diagnostic accuracy of coronary binary in-stent restenosis (ISR) with angiography using 64-slice multislice computed tomography coronary angiography (CTCA) compared with invasive coronary angiography (ICA). BACKGROUND: A noninvasive detection of ISR would result in an easier and safer way to conduct patient follow-up. METHODS: We performed CTCA in 81 patients after stent implantation, and 125 stented lesions were scanned. Two sets of images were reconstructed with different types of convolution kernels. On CTCA, neointimal proliferation was visually evaluated according to luminal contrast attenuation inside the stent. Lesions were graded as follows: grade 1, none or slight neointimal proliferation; grade 2, neointimal proliferation with no significant stenosis (<50%); grade 3, neointimal proliferation with moderate stenosis (> or =50%); and grade 4, neointimal proliferation with severe stenosis (> or =75%). Grades 3 and 4 were considered binary ISR. The diagnostic accuracy of CTCA compared with ICA was evaluated. RESULTS: By ICA, 24 ISRs were diagnosed. Sensitivity, specificity, positive predictive value, and negative predictive value were 92%, 81%, 54%, and 98% for the overall population, whereas values were 91%, 93%, 77%, and 98% when excluding unassessable segments (15 segments, 12%). For assessable segments, CTCA correctly diagnosed 20 of the 22 ISRs detected by ICA. Six lesions without ISR were overestimated as ISR by CTCA. As the grade of neointimal proliferation by CTCA increases, the median value of percent diameter stenosis increased linearly. CONCLUSIONS: Binary ISR can be excluded with high probability by CTCA, with a moderate rate of false-positive results.     

64层CT冠状动脉成像技术和冠状动脉造影对冠状动脉疾病诊断的对照研究

目的比较64层计算机断层摄影扫描冠状动脉成像技术(64-slice computed tomography coronaryangiography,64-SCTCA)和冠状动脉造影(coronary artery angiography,CAG)在冠状动脉粥样硬化性心脏病(冠心病)诊断中的价值。方法回顾性分析126例疑似冠心病的患者64-SCTCA和CAG检查资料,并对两组资料进行对比分析。结果 64-SCTCA和CAG检查结果中可用于评价的病变血管段支数比较,差异无统计学意义(P0.05)。CAG共发现≥50%狭窄节段242个,64-SCTCA共发现≥50%狭窄节段199个,两种检查方法对病变狭窄的显示情况比较,差异无统计学意义(P0.05)。全部126例冠心病患者中有91%通过64-SCTCA发现(110/121)。64-SCTCA诊断冠状动脉病变血管的敏感性、特异性、阳性预测值、阴性预测值分别为81.6%、98.8%、79.5%、99%。结论 64-SCTCA可作为冠心病无创、便捷、可靠的检查方法。     

Improved noninvasive assessment of coronary artery bypass grafts with 64-slice computed tomographic angiography in an unselected patient population.

OBJECTIVES: In this prospective evaluation we investigated the accuracy of 64-slice computed tomography angiography (CTA) in an unselected but symptomatic patient population for detection of stenoses in bypass grafts when compared with invasive angiography. BACKGROUND: The assessment of significant stenosis in bypass grafts is important for patients with recurrent angina symptoms after bypass surgery. METHODS: High-resolution 64-slice computed tomography (0.6 mm collimation, 330 ms gantry rotation time) and invasive angiography were performed in 138 consecutive patients with a total of 418 bypass grafts. Relevant stenosis was defined as diameter reduction > or =50%. During CTA, arrhythmias were present in 42 (30%) patients who were not excluded from the analysis. RESULTS: The assessment of stenosis or occlusion of bypass grafts resulted in a sensitivity of 97%, specificity of 97%, and positive and negative predictive values of 93% and of 99%, respectively. The diagnostic accuracy for the detection of graft occlusion or stenosis did not differ between arterial and venous grafts. The evaluability of bypass grafts was significantly lower in patients with arrhythmias or with heart rates > or =65 beats/min during scanning. However, in the assessment of evaluable bypass grafts, no significant differences were detected in the diagnostic accuracy in these subgroups. CONCLUSIONS: This large prospective study demonstrates that 64-slice CTA is a reliable method for the assessment of bypass graft patency and stenoses even in an unselected "real-world" patient population.     

Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography

OBJECTIVES: The aim of our study was to evaluate the diagnostic accuracy of multislice computed tomography (MSCT) coronary angiography using a new 64-slice scanner. BACKGROUND: The new 64-slice MSCT scanner has improved spatial resolution of 0.4 mm and a faster rotation time (330 ms) compared to prior MSCT scanners. METHODS: We studied 70 consecutive patients undergoing elective invasive coronary angiography. Patients were excluded for atrial fibrillation, but not for high heart rate, coronary calcification, or obesity. All vessels were analyzed, including those <1.5 mm in diameter; MSCT lesions were analyzed quantitatively as well as by a qualitative scale and compared to quantitative coronary angiography (QCA). Results were also analyzed for significant coronary stenoses (over 50% luminal narrowing) by segment, by artery, and by patient. RESULTS: All scans showed diagnostic image quality. Of 1,065 segments, 935 (88%) could be evaluated, and 773 of 935 (83%) could be assessed quantitatively by both MSCT and QCA. The Spearman correlation coefficient between MSCT and QCA was 0.76 (p < 0.0001). Bland-Altman analysis demonstrated a mean difference in percent stenosis of 1.3 +/- 14.2%. A total of 26% of patients had calcium scores above 400 Agatston U, 25% had heart rates >70 beats/min, and 50% were obese. Specificity, sensitivity, and positive and negative predictive values for the presence of significant stenoses were: by segment (n = 935), 86%, 95%, 66%, and 98%, respectively; by artery (n = 279), 91%, 92%, 80%, and 97%, respectively; by patient (n = 70), 95%, 90%, 93%, and 93%, respectively. CONCLUSIONS: Our results indicate high quantitative and qualitative diagnostic accuracy of 64-slice MSCT in comparison to QCA in a broad spectrum of patients.     

64层螺旋CT冠状动脉成像对冠心病诊断的应用价值

目的 通过探讨64层螺旋CT冠状动脉成像(64-SCTCA)对冠心病诊断的应用价值以明确临床上适于该项检查的人群.方法 回顾性分析285例接受64-SCTCA检查、并于4周内接受冠状动脉造影(CAG)检查的冠心病疑诊患者的临床资料.依照冠心病概率Duke模型,将受检者分为冠心病低危(n=80)、中危(n=92)和高危(n=113)3组,以CAG为"金标准",判断64-SCTCA诊断冠心病的准确性以及冠状动脉钙化、不同部位血管节段等因素对诊断准确性的影响.结果 64-SCTCA诊断冠心病的敏感性、特异性、阳性预测值、阴性预测值和诊断准确指\数分别为81.2%、93.3%、68.0%、96.6%和74.5%.冠心病概率Duke模型的低危组、中危组和高危组,其冠心病检出率分别为46.3%、72.8%和82.3%;64-SCTCA在低危组诊断冠心病的敏感性及阳性预测值明显低于中危组和高危组.对于冠状动脉Agatston钙化积分＞400分组,64-SCTCA诊断冠心病的敏感性(95.0%)明显高于0～100分组和101～400分组(77.4%和77.3%,P均＜0.05),特异性(82.2%)明显低于上述两组(94.0%和95.3%,P均＜0.05).其诊断远端血管病变的敏感性、阳性预测值均明显低于近、中段血管(P均＜0.05).结论 64-SCTCA主要适用于冠心病概率Duke模型临床分层的中危人群.其诊断准确性受冠状动脉钙化、病变部位、管腔直径等因素影响.     

Diagnostic accuracy of 64-slice multidetector computed tomography in evaluation of post-coronary artery bypass grafts in correlation with invasive coronary angiography

64-slice multidetector computed tomography (MDCT) allows more reliable and non-invasive evaluation of the coronary artery bypass grafts for occlusion or stenosis both in symptomatic and asymptomatic patients and also progression of disease in native coronary vessels.     

Diagnostic accuracy of 64-slice multislice computed tomography in the noninvasive evaluation of significant coronary artery disease

The purpose of the present study was to determine the diagnostic accuracy of current 64-slice multislice computed tomography (MSCT) in the detection of significant coronary artery disease, using conventional coronary angiography as the gold standard. In 61 patients scheduled for conventional coronary angiography, 64-slice MSCT was performed and evaluated for the presence of significant (>or=50% luminal narrowing) stenoses. One patient had to be excluded because of a heart rate>90 beats/min during data acquisition. In the remaining 60 patients (46 men, 14 women; average age 60+/-11 years), 854 segments were available for evaluation. Of these segments 842 (99%) were of sufficient image quality. Conventional coronary angiography identified 73 lesions, of which 62 were detected by MSCT. The corresponding sensitivity and specificity were 85% and 97%, respectively. On a patient-per-patient analysis, sensitivity, specificity, and positive and negative predictive values were 94%, 97%, 97%, and 93%, respectively. In conclusion, the present study confirms that 64-slice MSCT enables the accurate and noninvasive evaluation of significant coronary artery stenoses.     

Diagnostic accuracy of multidetector computed tomography coronary angiography in patients with angiographically proven coronary artery disease

OBJECTIVES: The aim of the present study was to evaluate the diagnostic accuracy in detecting high-grade coronary stenoses in patients with known coronary artery disease (CAD) using multidetector computed tomography (MDCT). BACKGROUND: The MDCT systems with electrocardiographic (ECG)-gating permit visualization of the coronary arteries. However, severe calcifications and higher heart rates are known to degrade image quality and limit correct diagnosis. METHODS: Sixty-six patients with proven CAD as assessed by conventional coronary angiography (CCA) were studied by MDCT (mean time 24 months postangiography). Total calcium score and all coronary arteries, including distal segments and side branches, were assessed with respect to evaluability, presence of high-grade coronary artery stenoses (>70%), and correct diagnosis. Results were compared to CCA. RESULTS: A total of 105 lesions were detected by CCA. The MDCT correctly detected 39 lesions (sensitivity 37%, specificity 99%). The correct clinical diagnosis could be obtained in 24 patients (36%). Artifacts due to elevated heart rates or severe coronary artery calcification were the main cause of degraded image quality inhibiting correct diagnosis. In 21/66 patients (32%) all four major coronary vessel segments could be visualized. A threshold for maximum heart rate and a maximum calcification level were established (65 beats/min and an Agatston Score Equivalent of 335, respectively). A second analysis was made using these thresholds. Of all patients studied, 10/11 (91%) were correctly diagnosed when adhering to these thresholds. CONCLUSIONS: When using MDCT as a noninvasive diagnostic modality to assess advanced CAD, it appears to be mandatory to preselect patients in order to achieve reliable results.     

64层螺旋CT与冠状动脉造影诊断冠状动脉狭窄的对比研究

目的评价64层螺旋CT冠状动脉成像(64-slice spiral computed tomographic coronary angiography,64-SCTCA)对冠状动脉各节段狭窄病变的诊断价值。方法85例疑诊为冠状动脉性心脏病(冠心病)患者,先后行64-SCTCA和冠状动脉造影(coronary angiography,CAG)检查,评价64-SCTCA诊断冠状动脉各节段狭窄病变的敏感性、特异性、阳性预测值、阴性预测值和准确性。结果①在CAG可清晰显影的744个节段中,64-SCTCA造影可清晰显示和评价的占639段(85.89%),另外105段(14.11%)显影不清。左主干和前降支可评价节段的比例显著高于左回旋支和右冠状动脉(P0.001),同一支血管中近段可评价的比例显著高于远段(P0.001);②64-SCTCA诊断冠心病的敏感度、特异度、准确度、阳性和阴性预测值分别为96.23%、90.63%、94.44%、93.55%、94.12%。按可评价节段计算,64-SCTCA诊断冠状动脉各节段有意义狭窄病变总的敏感性、特异性、准确性、阳性和阴性预测值分别为89.06%、95.89%、84.44%、95.33%、94.32%;③按可评价节段计算,64-SCTCA对诊断左主干、左前降支、左回旋支和右冠状动脉各节段病变的价值相似,但检测冠状动脉近中段病变的价值高于远段(χ2=4.66,P=0.03)。结论64-SCTCA对冠状动脉狭窄病变有较好的诊断价值,其检测左主干和左前降支病变的价值高于左回旋支和右冠状动脉,对冠状动脉近段病变的诊断价值高于远段,适合于冠心病的筛查。     

Non-invasive coronary angiography with 64-slice computed tomography

Multislice computed tomography is a rapidly emerging technique for the non-invasive visualization of coronary arteries. Over the past 5 years several scanner generation were introduced with a progressive improvement in the diagnostic accuracy in the detection of coronary artery stenosis in selected patients populations. The introduction of 64-slice technology has further improved the diagnostic performance. This technique is at the edge of clinical implementation and, even though large clinical trials are still missing, an increased demand for these type of studies is observed all over the world. We describe our experience of more than 1 year with 64-slice CT coronary angiography providing clues on reasonable clinical applications.     

Comparison of accuracy of 64-slice cardiovascular computed tomography with coronary angiography in patients with suspected coronary artery disease

Cardiovascular computed tomography (CVCT) with the recently released 64-slice technology increases spatial resolution and decreases acquisition times and slice thickness. We investigated the accuracy of 64-slice CVCT in relation to catheter angiography. We studied 66 sequential subjects who underwent 64-slice CVCT and catheter angiography within 30 days. Accuracy results were 94% for interpretable images, 95% for sensitivity, 96% for specificity, 97% for positive predictive value, and 92% for negative predictive value for lesions with >50% stenosis. We found 100% agreement between 64-slice CVCT and catheterization among vein graft evaluations (9 of 9). These metrics are vastly improved from the 16-slice generation and support 64-slice CVCT as a reliable diagnostic tool.     

64层CT冠状动脉成像的前瞻性与回顾性心电门控比较

目的 比较前瞻性心电门控和回顾性心电门控64层CT冠状动脉成像的辐射剂量和成像质量,探讨低剂量前瞻性心电门控CT冠状动脉成像的可行性.方法 两组心率≤65次/min各100例患者分别进行前瞻性和回顾性心电门控扫描,并采用多平面重组(MPR)、最大密度投影(MIP)、曲面重组(CPR)及容积再现(VR)多种重组技术显示冠状动脉,图像质量根据运动伪影影响分为优、良、差,使用剂量长度计算各自的有效辐射剂量,并进行统计学分析.结果 前瞻性组平均辐射剂量为(2.81±0.48)mSv明显低于回顾性组的(10.16±1.09)mSv(P＜0.01);前瞻性组诊断性冠状动脉节段和非诊断性冠状动脉节段为95.2%(1165/1224)和4.8%(59/1224),与回顾性组的94.1%(1186/1261)和5.9%(75/1261)比较,差异无统计学意义.结论 对于心率稳定在65次/min以下的患者,前瞻性心电门控64层CT冠状动脉成像,能以较低的辐射剂量达到回顾性心电门控诊断质量的影像,是切实町行的方法.     

16层螺旋CT对冠状动脉疾病的诊断价值

目的：评价16层螺旋CT诊断冠状动脉疾病的准确性及局限性。方法：20例患者做16层螺旋CT冠状动脉成像(回顾性心电门控、0．42s螺旋扫描)，并与常规冠状动脉造影对照。结果：在20例患者的136个节段(血管直径≥2mm)中，CT图像能满足诊断要求的有122个节段(占89．7％)。对于CT图像能满足诊断要求的冠状动脉节段，显示中度或中度以上狭窄的敏感度和特异度分别为87．5％和96．6％。若将不能满足诊断要求的14个节段包括在内，则显示中度或中度以上狭窄的敏感度为77．7％。结论：在冠状动脉中高度狭窄的诊断上，16层螺旋CT冠状动脉成像是一种有效的无创性诊断方法。局限性是时间分辨率较低，伪影的影响不可避免。     

16层螺旋CT对冠状动脉疾病的诊断价值

目的评价16层螺旋CT诊断冠状动脉疾病的准确性及局限性. 方法20例患者做16层螺旋CT冠状动脉成像(回顾性心电门控、0.42s螺旋扫描),并与常规冠状动脉造影对照. 结果在20例患者的136个节段(血管直径≥2mm)中,CT图像能满足诊断要求的有122个节段(占89.7%).对于CT图像能满足诊断要求的冠状动脉节段,显示中度或中度以上狭窄的敏感度和特异度分别为87.5%和96.6%.若将不能满足诊断要求的14个节段包括在内,则显示中度或中度以上狭窄的敏感度为77.7%. 结论在冠状动脉中高度狭窄的诊断上,16层螺旋CT冠状动脉成像是一种有效的无创性诊断方法.局限性是时间分辨率较低,伪影的影响不可避免.