64层螺旋CT冠状动脉成像在冠状动脉搭桥术后的应用

目的：探讨64层螺旋CT冠状动脉造影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在心电门控技术下采用64层螺旋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：24例冠状动脉搭桥术的患者共有38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：64层螺旋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。     

64层螺旋CT在冠状动脉搭桥术后随访中的初步应用

目的:评价64层螺旋CT在冠状动脉搭桥术后随访中的应用价值.方法:14例搭桥术后患者行64层螺旋CT冠状动脉造影检查,分别评价CT图像桥血管近远端吻合口、桥血管本身和吻合口远端引流血管的图像质量及冠状动脉图像质量.有选择性冠状动脉造影作对照的病例,评价CT诊断桥血管通畅性和冠状动脉是否存在狭窄的可靠性,以管腔狭窄大于50%作为诊断血管狭窄的指标.结果:14例患者共发现桥血管33根,桥血管近远端吻合口可评价率分别为93.9%(31/33)和90.9%(30/33);桥血管本身近、中、远三段的可评价率分别为97.0%(32/33)、100%(33/33)和97.0%(32/33);远端引流血管的可评价率为93.9%(31/33).CTA共显示冠状动脉139段,冠状动脉节段可评价率为69.1%(96/139).CTA对评价桥血管的通畅性和冠状动脉是否存在狭窄未出现假阳性及假阴性结果.结论:64层螺旋CT在冠状动脉搭桥术后随访中具有重要的临床应用价值.     

双源CT冠状动脉成像评价冠状动脉搭桥术后桥血管通畅情况

目的探讨双源 CT 冠状动脉成像对冠状动脉搭桥术后桥血管通畅状况的诊断价值.资料与方法38例患者于冠状动脉搭桥术后行双源 CT 冠状动脉成像与冠状动脉造影检查,以冠状动脉造影作为“金标准”,对双源 CT 冠状动脉成像结果进行分析.结果38例患者共检出桥血管92支,其中内乳动脉桥31支,大隐静脉桥61支;31支内乳动脉桥中,26支(83.9%)桥血管通畅,5支(16.1%)管腔狭窄、闭塞;61支大隐静脉桥血管中35支(57.4%)桥血管通畅;26支(42.6%)管腔狭窄、闭塞.大隐静脉桥血管狭窄、闭塞的发生率明显高于内乳动脉桥血管(P<0.05).双源 CT 冠状动脉成像评价桥血管狭窄、闭塞的敏感性为93.9%,特异性为100.0%.结论双源 CT 冠状动脉成像对冠状动脉搭桥术后桥血管通畅状况的评价有较高的诊断价值,是一种快速、无创、准确、安全的检查方法.     

64层螺旋CT对冠状动脉粥样硬化血管狭窄的评价

目的:探讨64层螺旋CT对冠状动脉粥样硬化各种程度血管狭窄的评估价值.方法:120例患者行64层螺旋CT血管造影(CTA)检查评价冠状动脉各段的狭窄程度,并与冠状动脉血管造影(CAG)比较,统计64层螺旋CTA诊断冠状动脉各种程度狭窄的敏感性、特异性、阳性预测值(PPV)和阴性预测值(NPV).结果:64层螺旋CTA评...     

64层螺旋CT冠状动脉造影对冠状动脉狭窄的诊断价值

目的：评价64层螺旋CT冠状动脉造影（64-slice CTCA）诊断冠状动脉狭窄的临床应用价值。方法：对120例临床怀疑冠状动脉疾病及支架置入术、冠脉搭桥术后的患者进行64层螺旋CT冠状动脉成像。采用回顾性心电门控扫描,并采用曲面重建、多平面重组,容积再现及最大密度投影技术显示冠状动脉主干及分支,其中30例患者近期行传统冠状动脉造影（CCA）。结果：120例患者可评价冠脉节段1377个,可满足诊断的冠脉节段1341个,占97．39％。30例患者近期行CCA检查,MSCTCA诊断冠脉狭窄节段103个与CCA相符,占88．03％,显示轻、中、重度狭窄及血管闭塞与CCA符合率分别为77．8％、93．3％、91．6％、77．8％,得出64SCTCA诊断冠脉狭窄敏感性97．52％,特异性96．02％,阳性预测值95．16％,阴性预测值96．01％。结论：64层螺旋CT冠状动脉造影在诊断冠状动脉疾病方面有很高的诊断价值,可以成为筛查、排除冠状动脉病变及支架、搭桥术后随访的常规检查方法。     

256层 CT 冠状动脉成像对冠状动脉桥血管的诊断价值

目的：探讨256层CT冠状动脉成像对冠状动脉搭桥术后桥血管的诊断价值。方法收集冠状动脉搭桥术后行256层CT 冠状动脉成像检查29例,回顾性分析256层 CT 冠状动脉成像桥血管的情况。结果29例搭桥血管共77支,搭桥血管1支6例,2支6例,3支10例,4支6例,5支1例,平均2.75支。59支(76.62%)桥血管通畅,17支(22.08%)桥血管管腔狭窄,1支(1.30%)桥血管闭塞。内乳动脉桥6支,大隐静脉桥71支;6支内乳动脉桥中,5支(83.33%)桥血管通畅,1支(16.67%)桥血管管腔狭窄;71支大隐静脉桥中,54支(76.06%)桥血管通畅,16支(22.54%)管腔狭窄,1支(1.40%)管腔闭塞。大隐静脉与内乳动脉桥血管狭窄、闭塞的发生率差异没有显著意义(P >0.05)。结论256层 CT 冠状动脉成像对冠状动脉搭桥术后桥血管的评价有较高的诊断价值,是一种简便、快速、无创、准确、安全的检查方法。     

64层螺旋CT冠状动脉造影评价冠状动脉支架再狭窄

目的 探讨64层螺旋CT冠状动脉造影对冠状动脉支架再狭窄评价的准确性.方法 采用西门子SOMATOM SENSATION CARDIAC 64层螺旋CT对59例冠脉支架植入后患者(共计112枚支架)行CT冠状动脉造影,以冠状动脉造影结果为金标准,分析检测的灵敏度、特异度等指标.结果 64层螺旋CT显示植入的112枚支架中109枚支架内腔得到清晰显示,总显示率97.3%(109/112).12处中、重度狭窄,多层螺旋CT冠状动脉造影诊断正确10处;15处轻度狭窄,多层螺旋CT冠状动脉造影正确5处,误诊10处,无漏诊.再狭窄诊断的灵敏度83.3%(10/12),特异度99%(99/100),阳性预测值90.9%(16/24),阴性预测值98%(99/101),准确率97.3%(109/112).结论 64层螺旋CT对冠状动脉支架再狭窄诊断有较高的准确性,可作为一种无创性检查用于支架术后的随访.     

64层螺旋CT冠状动脉成像与冠状动脉造影的对比研究

目的 评价64层螺旋CT冠状动脉造影对冠状动脉疾病的临床诊断价值.方法 59例临床诊断或可疑冠心病患者行64层螺旋CT冠状动脉成像检查,并以冠状动脉造影结果作为对照,分段评价结果,冠状动脉狭窄≥50%为阳性病变.分析64层螺旋CT冠状动脉血管成像(CTA)诊断冠状动脉狭窄的敏感性、特异性、阳性预测值及阴性预测值.结果 共评价741段冠状动脉,64层螺旋CT冠状动脉血管成像用于诊断冠心病的敏感性、特异性、阳性预测值、阴性预测值分别为58.8%、97.7%、76.9%、94.8%.结论 64层螺旋CT冠状动脉血管成像有较高的诊断准确性,可以作为评价冠状动脉狭窄的一种无创检查方法.     

双源CT在冠状动脉搭桥术后随访中的临床应用

目的 评价双源CT冠状动脉造影对冠状动脉搭桥术后桥血管病变随访的应用价值.方法 50例冠状动脉搭桥患者,术后6～20个月行双源CT冠状动脉造影检查;对原始数据行VR、CPR、MIP多种图像后处理技术进行重建.由2位有经验的放射科医生对重建图像进行观察,对桥血管通畅性进行分级诊断.结果 50例患者总计140支桥血管,134支桥血管显示良好,其中通畅或狭窄＜50％的桥血管共127支（91％）,狭窄≥50％的桥血管7支（5％）,闭塞未显示的桥血管共6支（4％）.结论 DSCT冠状动脉造影能够清晰显示并评价冠状动脉桥血管病变,尤其是重度狭窄和闭塞的桥血管,可作为冠状动脉搭桥术后随访的有效评价手段.     

64层螺旋CT冠状动脉成像与冠状动脉造影的对比研究

目的评价64层螺旋CT冠状动脉成像诊断冠状动脉狭窄的准确性。方法 50例患者先后进行64层螺旋CT冠状动脉成像和冠状动脉造影检查,以冠状动脉造影为诊断冠状动脉疾病的"金标准",比较CT冠状动脉成像的符合率,评价64层螺旋CT冠状动脉成像诊断冠心病的准确性。结果 64层螺旋CT冠状动脉成像评价冠状动脉狭窄程度大于或等于50%的敏感性为98.6%,诊断狭窄程度小于50%的敏感性为87.0%,诊断冠状动脉狭窄的特异性为92.5%,阴性预测值为97.7%。结论 64层螺旋CT冠脉成像诊断冠状动脉狭窄有很高的准确率。     

Coronary artery bypass graft (CABG) patency: assessment with high-resolution submillimeter 16-slice multidetector-row computed tomography (MDCT) versus coronary angiography

PURPOSE: To investigate the ability of 16-slice multidetector-row computed tomography (MDCT) to visualize coronary artery bypass graft (CABG) patency and to detect bypass stenoses. MATERIALS AND METHODS: Thirty-two patients with 94 grafts (20 mammary artery grafts, 74 venous grafts) were investigated by 16-slice MDCT using a scan protocol with 12 x 0.75 mm slice collimation (pitch 0.3), 420 ms rotation time and simultaneous electrocardiogram (ECG)-registration. One hundred milliliters iodinated contrast agent were injected with a delay according to the individually determined contrast agent transit time. Patients with heart rates above 60 bpm received oral beta-blockade. Cross-sectional images with a slice width of 1.0 mm (0.5 mm increment) were reconstructed using an ECG-gated half-scan reconstruction or a multisegment reconstruction algorithm depending on the heart rate. Bypass grafts were evaluated concerning patency and presence of stenoses > or = 50% diameter reduction on cross-sectional images, multiplanar reformations and maximum intensity projections by two independent observers. Results were compared to coronary bypass angiography. RESULTS: Sixteen-slice MDCT results were compared to those of invasive coronary angiography concerning absence or presence of bypass graft occlusion or relevant stenosis > or = 50% lumen reduction. Coronary CT angiography (CTA) permitted detection of bypass occlusion with 100% sensitivity (28/28) and 98% specificity (64/65). Seventy-eight percent (observer 1) and 84% (observer 2) of all patent grafts were found to be evaluable concerning presence or absence of stenosis. In 34 of 40 (observer 1) and 38 of 43 (observer 2) bypass grafts, high-grade stenoses were correctly ruled out (specificity 85% versus 88%, sensitivity 80% and 82%). Yet, if all patients with either unevaluable grafts/graft anastomosis or relevant graft stenosis were excluded, only 8/32 patients (25%) had fully diagnostic "negative" graft-CTA. According to Kappa statistics, agreement between the observers was 1.0 and 0.93 concerning occlusion and relevant stenosis, respectively. CONCLUSION: Sixteen-slice coronary CTA with sub-millimeter spatial resolution and premedication with oral beta-blockade permits non-invasive assessment of coronary artery bypass grafts with decreasing numbers of unevaluable graft segments. However, patient-based analysis reveals that only a relatively small number of patients ("negative" and completely evaluable graft-CTA) truly profits from noninvasive work-up and could be spared invasive angiography.     

Non-invasive assessment of coronary artery bypass graft with retrospectively ECG-gated four-row multi-detector spiral computed tomography

The purpose of this study was to assess the accuracy of four-row multi-detector CT (MDCT) in the evaluation of coronary artery bypass graft (CABG) in patients with at least a left internal mammary artery (LIMA) grafted to the left anterior descending artery (LAD), because of the conduit of choice in bypass surgery and the greater difficulty of evaluation with non-invasive diagnostic tools. Included in the study were 57 patients with a total of 122 grafts (95 arterial and 27 venous) who underwent MDCT (4×2.5-mm detector-collimation, 3-mm slice width, 1.5-mm reconstruction increment) with retrospective ECG gating. Twelve patients (21%) with high heart rates were given beta-blockers in order to obtain a heart rate 70 bpm in all patients. The ECG-synchronized axial images, reconstructed in the mid-diastole, MPR, MIP and 3D-VR images were independently and blindly assessed by two radiologists for graft patency and presence of high grade stenosis. Conventional angiography was the standard of reference. MDCT correctly classified 92/94 patent grafts and 26/28 occluded grafts (sensitivity/specificity 93%/97.8%); sensitivity and specificity of MDCT for assessment of arterial grafts were 100 and 98.7% (77/78 patent grafts and 17/17 occluded grafts). Image quality was considered adequate for assessment of significant stenoses in 62/92 (67%) patent grafts, with a significant differences between LIMA and non-LIMA conduits (44/57 vs. 18/65; P=0.002), according to the coronary vessel area supplied (anterior>lateral>posterior-inferior wall; P=0.002). In the remaining 30 patent grafts (33%), the assessment of stenoses was hampered by surgical clips, calcifications and motion artifacts. Sensitivity and specificity of MDCT for detection of significant graft stenoses were 80 and 96%, respectively. Inter-observer agreement was good (K=0.73). MDCT seems to be a valuable diagnostic tool for non-invasive assessment of patency of both venous and arterial grafts. An accurate evaluation of distal anastomoses and native coronary arteries may still represent a limitation of four-row MDCT, which will improve with the newest MDCT scanner.     

Noninvasive evaluation of coronary artery bypass graft patency using three-dimensional angiography obtained with contrast-enhanced electron beam CT

OBJECTIVE: The purpose of this study was to determine the accuracy of three-dimensional coronary angiography obtained with electron beam CT in the assessment of the patency of coronary artery bypass grafts. SUBJECTS AND METHODS: Twenty-five patients who had undergone coronary artery bypass graft surgery were included. All patients underwent electron beam CT and conventional coronary angiography for the evaluation of the status of their bypass grafts. Three-dimensional reconstructions of the heart and bypass grafts were compared with selective angiographic images of the bypass grafts. RESULTS: Fifty-seven saphenous vein grafts and 22 left internal mammary artery grafts were evaluated for occlusion or patency. Sensitivity and specificity of electron beam CT in revealing left internal mammary artery patency were 80% and 82.4%, respectively. Sensitivity and specificity of electron beam CT in revealing saphenous vein graft patency were 91.7% and 91.1%, respectively. Sensitivity and specificity of electron beam CT for evaluating saphenous vein grafts according to coronary area were as follows: saphenous vein grafts to left anterior descending artery, 100% and 100%, respectively; to diagonal branch, 100% and 100%; to left circumflex artery, 100% and 88.9%; and to right coronary artery, 75% and 85.7%. CONCLUSION: Three-dimensional coronary angiography obtained with electron beam CT is a promising, useful, and relatively accurate diagnostic imaging technique for the evaluation of graft patency in patients who have undergone coronary artery bypass graft surgery.     

Sixty four multi-detectors CT coronary angiography: An easy and accurate method to detect graft patency post CABG

Objective

To assess the accuracy of coronary CTA in detection of coronary artery bypass graft patency, occlusion and stenosis.

Patients and methods

Twenty-four patients with past history of coronary bypass surgery were included in this study and underwent MDCT coronary angiography. Invasive coronary angiography was done within 2 weeks of MDCT coronary angiography. All grafts considered patent were then evaluated for the presence of significant stenosis. Significant stenosis was defined as reduction in diameter of more than 50%.

Results

All the MDCT scans were interpretable and a total number of 78 CABG conduits were analyzed. At MDCT angiography 4 (5.2%) grafts were classified as occluded and 74 (94.8%) grafts were patent. Significant stenosis was detected in 7 (9.4%) out of the 74 patent grafts. At invasive coronary angiography; when occlusion and significant stenosis pooled together they were 9 grafts; 4 arterial and 5 venous. All these 9 grafts were detected at MSCT (sensitivity is 100%). In 67 out of 69 grafts occlusion or significant stenosis was correctly ruled out (specificity 97.1%). The diagnostic accuracy of MDCT angiography when compared with invasive angiography was 97.4%. The negative predictive value was 100% and positive predictive value was 81.8%.

Conclusion

MDCT coronary angiography is an accurate imaging technique for the evaluation of CABG patency and in detection of graft stenosis and confirms of previous studies using 64 MDCT.     

Coronary artery bypass graft imaging using ECG-gated multislice computed tomography: comparison with catheter angiography

AIM: To compare the value of multislice computerized tomography (MSCT) in imaging coronary artery bypass grafts (CABGs) by direct quantitative comparison with standard invasive angiography. METHODS: Using MSCT, 50 consecutive patients who had previously undergone CABG surgery and had recently undergone invasive angiography for recurrent angina pectoris, were studied further using MSCT after intravenous injection of non-ionic contrast agent; cardiac imaging was performed during a single breath-hold. Graft anatomy was quantified, using both quantitative coronary angiography (QCA) and MSCT, by different investigators blinded to each other. Reproducibility was quantified using the standard error of the measurement expressed as a percentage in log-transformed values (CV%) and intraclass correlation (ICC). RESULTS: All 150 grafts were imaged using MSCT; only 4 patent grafts were not imaged using selective angiography. Good agreement was achieved between MSCT and QCA on assessment of proximal anastomoses (CV% 25.2, ICC 0.84), mid-vessel luminal diameter (CV% 15.5, ICC 0.91) and aneurysmal dilations (CV% 14.3). Reasonable agreement was reached on assessment of distal anastomoses (CV% 26.7, ICC 0.66) and categorization of distal run-off (ICC 0.73). Good agreement was observed for stenoses of over 50% luminal loss (CV% 8.7, ICC 0.97) but agreement on assessment of less severe lesions was poor (CV% 208.7, ICC 0.51). CONCLUSION: This study demonstrates that CABGs can be quantitatively evaluated using MSCT, and that significant lesions present in all CABG segments can be reliably identified. Agreement between MSCT and QCA for lesions of less than 50% luminal loss was poor.     

Interpretability of coronary CT angiography performed with a novel whole-heart coverage high-definition CT scanner in 300 consecutive patients with coronary artery bypass grafts

AimsCoronary CT angiography (CCTA) is an accurate non-invasive tool for the evaluation of coronary artery bypass graft (CABG). However, inability to sustain a long breath-hold, high heart rate (HR) and atrial fibrillation may affect image quality. Moreover, radiation exposure is still a matter of some concern. A scanner combining 0.23-mm spatial resolution, new iterative reconstruction and fast gantry rotation time has been recently introduced in the clinical field. The aims of our study were to evaluate interpretability, radiation exposure and diagnostic accuracy of CCTA performed with the latest generation of cardiac-CT scanners compared to invasive coronary angiography (ICA) in the assessment of bypass grafts, and non-grafted and post-anastomotic native coronary arteries.Methods and resultsWe prospectively enrolled 300 patients undergoing clinically indicated CCTA with a 16-cm z-axis coverage, 256-detector rows, and 0.28-sec gantry rotation time scanner. Coronary artery and graft interpretability, image quality and effective dose (ED) were assessed in all patients and diagnostic accuracy was evaluated in a subgroup of 100 patients who underwent ICA.Mean HR during the scan was 69.6 ± 10.8. Sinus rhythm was present in 118 patients with HR < 75 bpm and in 112 patients with HR ≥ 75 bpm, while 70 patients had atrial fibrillation. CABG interpretability was 100%. Compared to ICA, CCTA was able to correctly detecting occlusions or significant stenoses of all CABG segments. Overall interpretability of native coronary segments was 95.6%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of coronary arteries were 98.3%, 97.4%, 93.1%, 99.3% and 96.5%, respectively. The diagnostic accuracy in a patient based analysis was 95.2%. Mean ED was 3.14 ± 1.7 mSv.ConclusionsThe novel whole-heart coverage CT scanner allows to evaluating CABG and native coronary arteries with excellent interpretability and low radiation exposure even in the presence of unfavorable heart rhythm.     

双源CT“双低”成像在冠状动脉桥血管的初步研究

目的：评价双源C T“双低”成像在冠状动脉桥血管检查的可行性和有效性。方法连续入组38例冠状动脉搭桥术后患者。冠状动脉CT血管造影（CCTA）采用前瞻性心电触发序列扫描、低管电压结合迭代算法,采用等渗低浓度碘对比剂碘克沙醇（270mgI／ml）。其中20例患者进行了有创冠状动脉造影（CAG ）检查。两位评价者评价桥血管的CTA图像质量和是否存在显著狭窄（≥50％）和闭塞,以CAG为参照标准,评价CCTA诊断桥血管显著狭窄和闭塞的敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）。结果38例患者共评价76支桥血管,按照分段,评价387段桥血管,可诊断的血管段达到99．5％（385／387）。20例造影患者中以CAG为参照标准,CCTA诊断桥血管显著狭窄的敏感性、特异性、PPV和NPV分别为100％（4／4）、97．6％（40／41）、80．0％（4／5）和100％（40／40）。CCTA准确诊断了9支闭塞的桥血管。结论双源CT“双低”扫描方案对于桥血管检查具有可行性,该扫描方案可以显著降低辐射剂量和对比剂的碘负荷而保证诊断所需图像质量。对桥血管显著狭窄和闭塞的诊断准确性较高。     

Diagnostic value of MDCT angiography in assessment of coronary artery bypass graft

Purpose

To evaluate the diagnostic value of MDCT angiography in assessment of coronary bypass grafts. We studied 51 patients from April 2008 to October 2011. All patients gave written informed consent, and the study protocol was approved by the Institutional Review Board. 96 grafts including 35 left internal mammary artery (LIMA) grafts, 5 radial artery grafts, and 56 saphenous vein grafts (SVG) were assessed by 64-MDCT and the results were compared with conventional coronary angiography as reference standard.

Results

The diagnostic value of multi-detector computed tomography for graft occlusion was: 100% sensitivity, 100% specificity, 100% positive predictive value, and 100% negative predictive value. The diagnostic power of multi-detector computed tomography for stenosis of the graft anastomosis was: 100% sensitivity, 96% specificity, 87.5% positive predictive value, and 100% negative predictive value, and 96.4% accuracy.

Conclusion

Multi-detector computed tomography has become an alternative to coronary angiography to diagnose graft occlusion and stenosis after coronary artery bypass. In addition, multidetector CT has the added advantage over traditional angiographic evaluation of simultaneously allowing evaluation for alternate postoperative complications that may also manifest with chest pain and dyspnea, thereby mimicking recurrent angina.