Visualization of coronary tree and detection of coronary artery stenosis using 16-slice, sub-millimeter computed tomography: preliminary experience

PURPOSE: multislice CT has been shown as a promising tool for coronary artery imaging. Our goal was to investigate the value of the new sixteen-slice, CT technology for non-invasive visualization of coronary arteries and assessment of coronary stenosis. MATERIALS AND METHODS: we assessed coronary artery visualization in 30 consecutive patients using 16-slice CT and compared the findings with conventional coronary angiography. The whole heart was scanned using 0.75 millimeter slices after injection of contrast medium. Retrospective ECG-gated reconstructions were performed and images were analyzed using axial CT, maximum intensity projection and 3D images, blind to the conventional angiography findings. Seventeen main coronary segments of more than 1.5 mm were analyzed and stenosis was graded on a four-point scale. RESULTS: CT angiography attained diagnostic quality for the whole coronary artery tree in 90% (27/30) of patients. Sixteen of 493 segments (4%) were not interpreted because of substantial motion artifacts (n=12) or heavy calcifications or stenting (n=4). Thirty seven of the 43 cases of significant stenosis (>50%) identified on coronary angiograms were correctly identified with multislice CT. All 6 false negatives involved stenosis of the circumflex artery or branches. Five false positive stenoses were found in 432 non stenotic segments. The sensitivity was thus 86%, specificity 99% for stenosis of more than 50%. CONCLUSION: 16-slice CT provides an excellent visualization of the coronary tree in most patients, allowing accurate non-invasive detection of significant coronary stenosis. Stenoses of the left circumflex artery remain more difficult to detect.     

Comparison of 16 slice multi-detector computed tomography and breath hold 3D magnetic resonance angiography in the detection of coronary stenosis

Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant (> 50%) coronary stenoses in patients with suspected coronary artery disease. Methods Forty patients were examined by 16-slice CT (GE, Lightspeed 16) and MR (GE,Twinspeed) within 3 days; 31 of them underwent conventional coronary angiography (CAG) within 2 weeks after CT and MR scan. CT was performed with 16×1.25 mm detector collimation, 0.5 s rotation time and images were reconstructed at 60%-75% of the cardiac cycle. MR was performed with breath hold 3D FIESTA (TR4.0 ms, TE1 .7 ms, flip angle 65, slice thickness 3 mm, FOV 280 mm, matrix 256×192). Mean heart rate was 63±5.8 bpm andβ-blocker was used in 24 patients. MR and CT image quality was evaluated in 9 coronary segments (RCA1, RCA2, RCA3, LM, LAD1, LAD2, LAD3, LCX1, LCX2) using a four-point grading scale. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for detection of significant stenosis using CAG as the gold standard. Results 16-slice CT showed higher image quality in most coronary segments except RCA2. Forty-three segments were diagnosed as significant stenosis by CAG, 36 and 27 of these were correctly detected by CT and MR respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of 16-slice CT and MR for detecting significant stenosis were 83%, 84%. 49%, 97%. and 63%, 90%, 55%, 93%, respectively. Conclusion Sixteen-slice CT showed higher image quality in most coronary segments excepted for middle RCA. 16-slice CT had higher sensitivity than MR for detection of coronary significant stenosis, whereas MR had higher specificity than CT. Both CT and MR showed high negative predictive value, which is useful for excluding coronary stenosis in symptomatic patients. (J Geriatr Cordial 2006; 3(1): 24-28)     

Accuracy of MSCT coronary angiography with 64-slice technology: first experience.

AIMS: The aim of our study was to investigate the accuracy of 64-slice computed tomography (CT) for assessing haemodynamically significant stenoses of coronary arteries. METHODS AND RESULTS: CT angiography was performed in 67 patients (50 male, 17 female; mean age 60.1+/-10.5 years) with suspected coronary artery disease and compared with invasive coronary angiography. All vessels > or =1.5 mm were considered for the assessment of significant coronary artery stenosis (diameter reduction >50%). Forty-seven patients were identified as having significant coronary stenoses on invasive angiography with 18% (176/1005) affected segments. None of the coronary segments needed to be excluded from analysis. CT correctly identified all 20 patients having no significant stenosis on invasive angiography. Overall sensitivity for classifying stenoses was 94%, specificity was 97%, positive predictive value was 87%, and negative predictive value was 99%. CONCLUSION: Sixty-four-slice CT provides a high diagnostic accuracy in assessing coronary artery stenoses.     

Accuracy of multislice computed tomography in the preoperative assessment of coronary disease in patients with aortic valve stenosis.

OBJECTIVES: To evaluate multislice computed tomography (MSCT) as an alternative to coronary angiography, we prospectively studied its diagnostic accuracy for the detection of significant coronary artery lesions in patients with significant aortic valve stenosis undergoing valve surgery. BACKGROUND: In patients with aortic valve stenosis, coronary angiography is still recommended before surgery. Multislice computed tomography is a promising noninvasive technique for the detection of significant coronary artery lesions. METHODS: Fifty-five consecutive patients scheduled for coronary angiography in the preoperative assessment of aortic valve stenosis underwent 16-slice MSCT 24 h before coronary angiography. We analyzed coronary lesions, image quality, and arterial calcium score. RESULTS: The sensitivity of the MSCT-based strategy in detecting significant stenosis was 100%, and its specificity 80%. The positive and negative predictive values were respectively 55% and 100%. For calcium scores <1,000 (77% of patients), MSCT detected all patients without coronary artery disease, enabling conventional coronary angiography to be avoided in 35 of 55 cases (80%). For calcium scores >1,000, MSCT enabled conventional coronary angiography to be avoided in only 6% of cases, either because significant stenosis was found with a possible indication of revascularization, or because the examination was not interpretable. CONCLUSIONS: The results of this initial experience in relatively few patients suggest that MSCT-based coronary angiography may serve as an alternative to invasive coronary angiography to rule out significant coronary artery disease in patients scheduled for elective aortic valve replacement. Larger studies are necessary to fully explore the potential of coronary MSCT to improve preoperative risk stratification.     

Aortic valve replacement in patients with mild or moderate aortic stenosis and coronary bypass surgery

PURPOSE: To assess whether there is survival benefit for patients with mild or moderate aortic stenosis if they undergo aortic valve replacement at the time of coronary artery bypass surgery. METHODS: From 1985 to 1995 we evaluated all patients at our institution who underwent coronary artery bypass surgery and who had the echocardiographic diagnosis of mild (mean gradient <0 mm Hg and/or valve area >1.5 cm(2)) or moderate (mean gradient > or =30 and < or =40 mm Hg and/or valve area >1.0 < or =1.5 cm(2)) aortic stenosis. Using propensity analysis, survival was compared between 129 patients who underwent coronary artery bypass surgery alone and 78 patients who underwent concomitant coronary artery bypass surgery and aortic valve replacement. RESULTS: Perioperative mortality was similar among patients who underwent coronary artery bypass surgery alone compared with patients who underwent concomitant coronary artery bypass surgery and aortic valve replacement. By Kaplan-Meier analysis, 1-year and 8-year survival were better at 90% and 55% for patients who underwent concomitant coronary artery bypass surgery and aortic valve replacement compared with 85% and 39% for patients who underwent coronary artery bypass surgery alone (P <0.001). This benefit was limited to patients with moderate aortic stenosis (propensity-adjusted relative risk = 0.43; 95% confidence interval: 0.20 to 0.96; P = 0.04). CONCLUSION: Concomitant aortic valve replacement at the time of coronary artery bypass surgery for mild or moderate aortic stenosis appears to convey a survival advantage for patients with moderate aortic stenosis but not for those with mild aortic stenosis.     

Prevalence of atherosclerosis of the coronary and extracranial cerebral arteries in patients undergoing aortic valve replacement for calcified stenosis

BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate the coexistence of various atherosclerotic changes in patients with non-rheumatic calcific aortic valve stenosis (AS), since calcific AS shares various clinical risk factors with atherosclerosis. METHODS: In 282 consecutive patients with severe calcific stenosis of a tricuspid aortic valve scheduled for aortic valve replacement, the prevalence of atherosclerotic changes of the coronary and extracranial cerebral arteries were assessed using coronary angiography and Doppler sonography, respectively. RESULTS: The severities of coronary and extracranial cerebral artery atherosclerosis were significantly associated (p = 0.005). The prevalence and severity of both coronary and extracranial cerebral artery atherosclerosis were age-dependent. Coronary or extracranial cerebral artery stenosis was present in 59% and 16% of patients, respectively, while 91% of the study population and all patients aged > 80 years showed atherosclerosis of the coronary and/or extracranial cerebral arteries. CONCLUSION: The data obtained indicated a very high prevalence of atherosclerotic changes in patients with calcific AS, suggesting pathogenetic similarities of both disorders. Routine screening of the extracranial cerebral arteries is warranted in all patients with calcific AS and scheduled for valve replacement.     

64层CT与冠状动脉造影在老年冠心病诊断中的对比研究

目的评价64层CT与冠状动脉造影在老年冠心病诊断中的价值。方法70例疑似和确诊的冠心病患者进行64层CT检查,男性45例,女性25例,平均年龄(69.97±9.75)岁,其中50例与冠状动脉造影比较,冠状动脉狭窄>50%。包括曾行冠状动脉旁路移植术5例、冠状动脉内支架置入术10例。平均心率(68.31±6.26)次/min,37例服用美托洛尔12.5~25 mg。64层CT检查与冠状动脉造影检查间隔1~15天。结果50例患者共分析了739个血管节段,200支血管,单支血管病变11例,双支血管病变26例,3支血管病变21例,40例有钙沉积。其中,轻中度钙化(<400分)21例,重度钙化(≥400分)19例。冠状动脉轻度狭窄(≥50%或不规则狭窄)38个节段,中度狭窄(70%~90%)44个节段,重度狭窄(≥90%)44个节段,完全闭塞7个节段。冠状动脉造影7例阴性者,64层CT完全符合。影响诊断因素的3例4个节段因心率>80次/min、呼吸配合不佳出现伪影,4例7个节段严重钙化影响狭窄的判断。敏感性91.7%,特异性97.5%,阳性相关率96.1%,阴性相关率98.6%。结论64层CT可以作为老年冠心病无创检查和治疗初筛的可靠方法。     

Comparison of 64-slice computed tomography planimetry and Doppler echocardiography in the assessment of aortic valve stenosis

BACKGROUND AND AIM of the study: The study aim was to compare, prospectively, the planimetry of aortic stenosis on 64-slice computed tomography (CT), with the area calculated by Doppler transthoracic echocardiography (TTE) in symptomatic patients evaluated before potential aortic valve replacement. METHODS: Fifty-two consecutive patients (27 males, 25 females; mean age 74 +/- 10 years) admitted to the authors' institution during 2005 were evaluated with 64-slice CT and Doppler TTE. The time interval between the two evaluations was 2 +/- 1 weeks. Planimetry of the anatomic orifice area (AOA) drawn on 64-slice CT was compared to the effective area determined by Doppler TTE by Bland and Altman analysis, and the anatomic area threshold value corresponding to a significant effective aortic stenosis (50.75 cm2) was determined by receiver operating characteristic (ROC) analysis. RESULTS: The aortic orifice area measured by 64-slice CT correlated well with the effective area (r = 0.76; p <0.0001), but was significantly greater, with a systematic overestimation (0.132 cm(2)) and a variability of 0.239 cm(2). There was good agreement between planimetry determined by two independent radiologists (difference = 0.002, variability = 0.115 cm(2)). ROC analysis showed that a threshold value of 0.95 cm(2) as measured by 64-slice CT planimetry identifies significant aortic stenosis with sensitivity, specificity, accuracy, positive and negative predictive values of 82%, 77%, 81%, 91% and 59%, respectively. CONCLUSION: 64-slice CT is a reproducible and reliable non-invasive method to evaluate aortic valve stenosis compared to the reference method of Doppler TTE. Indeed, the CT approach could replace the latter evaluation when measurements used in the continuity equation are inadequate.     

Noninvasive imaging of the coronary arteries

A reliable noninvasive imaging method for significant coronary artery stenosis would have enormous implications related to cost of diagnosis and enhanced patient safety. Cardiac motion and calcified plaques, in the past, rendered a substantial number of computed tomographic (CT) images of the coronary arteries uninterpretation. The accuracy of multidetector CT for the detection of coronary stenosis appears to have progressively improved as the imaging equipment increased from 4-slice and 16-slice to 64-slice CT. With 64-slice CT, scanning of the entire coronary artery tree is possible in 10 to 13 s. Pooled data of results of a few investigations with 64-slice CT showed that the proportion of unevaluable segments is only 4%. The sensitivity of 64-slice CT for the detection of significant (>50% or = or >50%) coronary stenosis in a patient, based on pooled data, was 97% and specificity was 91%. Regarding detection of significant stenosis in any segment, the sensitivity, based on pooled data, was 91% with 64-slice CT and specificity was 96%. In a limited number of patients, sensitivity for detection of significant stenoses in proximal segments was 100%, in mid segments it was 94%, and in distal segments sensitivity it was 80%. Multi-detector CT provides the opportunity to quantify non-calcified coronary artery plaques, which may potentially be a strong predictor of cardiac events. It was also shown to be useful for the detection of stenosis in coronary artery bypass grafts.     

40层螺旋CT冠状动脉成像在冠心病诊断和随访中的价值

目的:分析897例临床确诊或疑似冠心病患者的40层螺旋CT冠状动脉成像结果,以探讨40层螺旋CT冠状动脉成像在冠心病诊断和随访中的价值.方法:262例临床确诊和579例疑似冠心病患者予以40层螺旋CT冠状动脉成像检查,经最大密度投影、容积重建和曲面多平面重建等后处理,其中207 例患者曾行选择性冠状动脉造影检查,将40层螺旋CT冠脉成像检查结果对照冠状动脉造影检查结果计算其敏感性、特异性、准确性、阳性预测值和阴性预测值.有135例患者1年后再次做40层螺旋CT冠状动脉成像检查.结果:94%患者冠状动脉成像图像可用于分析.有斑块伴中重度狭窄病例512例,包括单支病变 216例,2支病变169例,3支病变127例.男女性可疑冠心病患者40层螺旋CT 冠状动脉成像结果显示:无斑块或有斑块伴轻度狭窄的比例女性患者为56.98%(200/351),男性患者为45.18%(103/228),χ~2 =7.72,P<0.01,随着年龄的增长,冠状动脉多支病变逐渐增多.207例多层螺旋CT 冠状动脉成像与冠状动脉造影结果对比显示,冠状动脉分支血管有意义狭窄( ≥50%)的敏感性为84.5%(223/264);特异性为97.3%(1117/1148);阳性预测值为87.8%(223/254);阴性预测值为96.5%(1117/1158);准确性为94.9%(1340/1412).135例患者1年后重复40层螺旋CT冠状动脉成像显示有斑块消失6处、有斑块缩小5处、有新斑块出现9处、有斑块扩大10处.结论:40 层螺旋C T 作为无创性冠状动脉病变诊断技术可作为冠心病筛查,随访的良好方法,尤其适合临床症状较多的女性患者的鉴别诊断以及合并有高血压、糖尿病、血脂异常的高龄患者的随访.     

Evaluation of coronary artery lumen diameter with 16-slice multidetector-row computed tomography.

BACKGROUND: When using 16-slice multidetector-row computed tomography (MDCT) to detect coronary artery stenosis, coronary arteries measuring 1.5 mm or larger in lumen diameter are usually evaluated. The purpose of this study was to investigate the frequency of the visualized lumen in each coronary artery segment measuring more than 1.5 mm in diameter. METHODS AND RESULTS: Electrocardiographic-gated 16-slice MDCT was used to scan 20 patients after administration of nitroglycerin. The luminal diameter of each coronary artery segment was measured on cross-sectional images using a caliper method. The frequency of the visualized lumen of each coronary artery segment measuring larger than 1.5 mm in diameter was as follows: #1: 100%, #2: 100%, #3: 100%, #4PD: 85%, #4AV: 80%, #5: 100%, #6: 100%, #7: 100%, #8: 90%, #9: 85%, #10: 40%, #11: 100%, #12: 65%, #13: 100%, #14: 80%. Averaged lumen diameter+/-standard deviation (mm) larger than 1.5 mm in all patients was calculated as follows: #1: 3.8+/-0.70, #2: 3.5+/-0.69, #3: 3.2+/-0.82, #5: 4.2+/-1.04, #6: 3.4 +/-0.79, #7: 2.9+/-0.62, #11: 2.9+/-0.69, #13: 2.6+/-0.57. CONCLUSION: Luminal diameter larger than 1.5 mm of each coronary artery segment can be assessed in most cases by 16-slice MDCT.     

Klinischer Stellenwert der Cardio-CT-Koronarangiographie

As compared to conventional CT scanners, multi-slice spiral CT (MSCT) has improved temporal and spatial resolution. Dedicated image reconstruction algorithms permit to create cross-sectional images with a temporal resolution of approximately 150-250 ms, and a slice thickness of 0.75-1.3 mm (see Figure 1). In addition, image reconstruction can be synchronized to the ECG. This permits to use MSCT for visualization of the coronary artery lumen and detection of stenosis (see Figures 2 and 3). Various post-processing techniques can be used to display the coronary arteries. A low heart rate has been identified as an important prerequisite to obtain a sufficiently high image quality, and most authors recommend routine use of beta blocker premedication. Comparisons of 4-slice MSCT to invasive angiography concerning the detection of hemodynamically relevant coronary artery stenoses have resulted in sensitivities ranging from 72-93% and specificities ranging from 84-98%. However, up to 32% of all coronary segments had to be excluded from evaluation due to impaired image quality, in most cases due to severe calcification or insufficient suppression of motion artifacts. Initial results obtained with 16-slice MSCT scanners, which provide somewhat higher temporal and--through decreased slice thickness--improved spatial resolution, show promise that diagnostic accuracy may be increased while the number of coronary artery segments with nondiagnostic image quality may be reduced as compared to the prior generation of 4-slice scanners. Further studies are necessary to identify patient subgroups which might benefit from MSCT "noninvasive coronary angiography" in a clinical setting.     

Diagnosis of aortic valvular stenosis by multislice cardiac computed tomography.

AIMS: Current improvements in spatial, temporal, and contrast resolution of multislice computed tomography (CT) could be useful in the assessment of valvular diseases. We evaluated the diagnostic accuracy of multislice CT for the identification and quantification of aortic valvular stenosis (AS), compared with echography. METHODS AND RESULTS: Consecutive patients, referred for coronary CT, were evaluated for AS, by the use of standard electrocardiography-gated 16-slice CT protocol. Multiplanar reformat was applied to systolic phases of the cardiac cycle, with projection on thick slices for measuring the aortic valvular area (AVA). CT results were compared with echocardiographic-based measurement of the AVA. Among 107 enrolled patients, CT analysis of the AVA was feasible in 103. Among the 30 patients with AS, Bland-Altman analysis showed good agreement between the two methods [mean difference -7 mm(2) (-40-25 mm(2))]. CONCLUSION: CT analysis of aortic valve is feasible in most cases and allows for reliable diagnosis and quantification of AS.     

Clinical utility of coronary CT angiography: coronary stenosis detection and prognosis in ambulatory patients.

INTRODUCTION: Multislice CT coronary angiography (MSCTA) accurately detects stenosis in patients undergoing coronary arteriography, but its accuracy in clinical outpatients is less certain. This study retrospectively analyzed MSCTA performance in a large outpatient cohort and examined 6-month clinical follow-up in those without invasive CA. METHODS: Patients underwent MSCTA for clinical indications including symptoms or noninvasive results being either equivocal or suspected as incorrect by referring clinicians. Standard 16-slice CT scanner techniques were used, and results were analyzed on the basis of both patient and vessel. Patients were treated medically or sent to invasive angiography on the basis of MSCTA results and judgment of referring clinicians. All invasive angiograms were analyzed using quantitative coronary angiography. Six-month clinical follow-up was determined in patients without CA. RESULTS: One thousand fifty-three consecutive patients were referred for MSCTA, resulting in 994 interpretable scans. Mean age was 58+/-13 years, 55% were male, 50% had prior noninvasive testing, and 90% had symptoms. Invasive angiography was performed in 160 patients, with significant stenoses present in 69%. MSCTA demonstrated 87% and 89% accuracy by patient- and vessel-based analysis, respectively, and was most accurate in the left main and right coronary arteries. Only two patients not referred for angiography had significant stenosis in those undergoing 6-month follow-up. CONCLUSIONS: MSCTA accurately detects obstructive coronary stenosis in clinical patients with possible cardiac symptoms, and effectively triages them for invasive angiography. Negative results are highly accurate in ruling out obstructive disease. Six-month prognosis is excellent in patients without significant disease determined by MSCT.     

Accuracy of 64-slice computed tomography for the preoperative detection of coronary artery disease in patients with chronic aortic regurgitation

We studied the diagnostic accuracy of 64-slice computed tomography for the diagnosis of significant coronary artery disease (CAD) compared with conventional coronary angiography (CA) in patients with chronic aortic regurgitation (AR) referred for elective aortic valve surgery. Fifty consecutive patients with chronic AR (38 men, mean age 54 +/- 14 years) scheduled for valve surgery underwent 64-slice computed tomographic (CT) coronary angiography and CA. Significant stenosis was defined as a luminal diameter decrease >50%. Mean heart rate during CT scanning was 65.5 +/- 7.4 beats/min. Mean Agatston score was 136 +/- 278 (range 0 to 1207); prevalence of significant CAD in the study population was 26% (13 of 50 patients). Thirteen of 742 segments (1.8%) in 3 patients were considered nondiagnostic with computed tomography because of motion artifacts (n = 9) or calcium (n = 4). In a patient-based analysis taking nonevaluative segments as falsely positive, sensitivity, specificity, and positive and negative predictive values of computed tomography were 100%, 95%, 87%, and 100%, respectively. Preoperative CA could have been avoided in 70% of patients (35 of 50), CA would have been performed to confirm the CT diagnosis in 26% (13 of 50), and unnecessary CA would have been performed in 4% (2 of 50) on the basis of false-positive CT ratings. In conclusion, 64-slice CT coronary angiography provides high diagnostic accuracy for diagnosing significant CAD in patients with chronic AR and may be used as a filter test before valve surgery to decide whether CA should be performed.     

Significance of angina pectoris in aortic valve stenosis.

Of 60 patients aged 45 to 66 years with aortic valve stenosis, 28 (47 per cent) had angina pectoris. Significant coronary arterial obstruction was shown by selective coronary cineangiography in 14 of them. Systolic pressure gradients across the aortic valve were lower in patients with angina than in those without. In those with angina, systolic gradients were higher in those with normal coronary arteriograms than in those with demonstrable coronary arterial disease. Aortic valve replacement relieved the angina in all patients who had normal coronary arteriograms. When valve replacement was combined with coronary bypass grafting in those with coronary arterial disease, surgical mortality was higher and symptomatic relief less predictable. Incapacitating angina in patients with aortic stenosis was nearly always associated with significant coronary disease. In those with less severe angina it was impossible to predict the state of the coronary arteries. Two patients, who did not have angina and who did not undergo coronary arteriography, died after aortic valve replacement and were found at necropsy to have unsuspected severe coronary disease. We, therefore, suggest that coronary arteriography should be carried out in all patients over the age of 40 years in whom surgery is being considered for aortic stenosis.     

Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography: a comparative study with quantitative coronary angiography and intravascular ultrasound

OBJECTIVES: The aim of the present study was to determine the diagnostic accuracy of 64-slice computed tomography (CT) to identify and quantify atherosclerotic coronary lesions in comparison with catheter-based angiography and intravascular ultrasound (IVUS). BACKGROUND: Currently, the ability of multislice CT to quantify the degree of coronary artery stenosis and dimensions of coronary plaques has not been evaluated. METHODS: We included 59 patients scheduled for coronary angiography due to stable angina pectoris. A contrast-enhanced 64-slice CT (Senation 64, Siemens Medical Solutions, Forchheim, Germany) was performed before the invasive angiogram. In a subset of 18 patients, IVUS of 32 vessels was part of the catheterization procedure. RESULTS: In 55 of 59 patients, 64-slice CT enabled the visualization of the entire coronary tree with diagnostic image quality (American Heart Association 15-segment model). The overall correlation between the degree of stenosis detected by quantitative coronary angiography compared with 64-slice CT was r = 0.54. Sensitivity for the detection of stenosis <50%, stenosis >50%, and stenosis >75% was 79%, 73%, and 80%, respectively, and specificity was 97%. In comparison with IVUS, 46 of 55 (84%) lesions were identified correctly. The mean plaque areas and the percentage of vessel obstruction measured by IVUS and 64-slice CT were 8.1 mm2 versus 7.3 mm2 (p < 0.03, r = 0.73) and 50.4% versus 41.1% (p < 0.001, r = 0.61), respectively. CONCLUSIONS: Contrast-enhanced 64-slice CT is a clinically robust modality that allows the identification of proximal coronary lesions with excellent accuracy. Measurements of plaque and lumen areas derived by CT correlated well with IVUS. A major limitation is the insufficient ability of CT to exactly quantify the degree of stenosis.     

64层螺旋CT血管成像与冠状动脉造影对冠心病诊断价值的对比研究

目的评价64层螺旋CT在冠状动脉造影方面的诊断价值。方法58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,分别对左主干、左前降支、回旋支和右冠状动脉及其分支的重建图像行影像学评价,所有患者均行常规选择性冠状动脉造影检查作为对照。结果58例患者共757(87.0%)节段的冠状动脉(血管直径≥1.5 mm)成像,638节段(84.3%)可用于多层螺旋CT和冠状动脉造影定量分析。冠状动脉造影共发现狭窄101节段,多层螺旋CT发现狭窄104节段,多层螺旋CT对冠状动脉狭窄诊断的敏感性为86.1%,特异性为96.8%。结论64层螺旋CT冠状动脉造影可作为诊断冠状动脉病变的一种无创筛选方法。     

The simultaneous assessment of aortic valve area and coronary artery stenosis using 16-slice multidetector-row computed tomography in patients with aortic stenosis comparison with echocardiography.

BACKGROUND: Recent advancements in 16-slice multidetector-row computed tomography (16-slice MDCT) provide for non-invasive assessment of not only coronary artery disease (CAD), but also myocardial properties and the anatomy of the whole heart. The purpose of the present study was to investigate whether the aortic valve area (AVA) in patients with aortic stenosis (AS) assessed by 16-slice MDCT corresponds to echocardiographic assessment and to evaluate simultaneously the clinical accuracy in detecting CAD with 16-slice MDCT. METHODS AND RESULTS: The AVA of 29 consecutive AS patients with transthoracic echocardiography (TTE) and 16-slice MDCT were analyzed. The AVA was estimated by means of the continuity equation method in 2-dimensional echocardiography (DE) and the quantitative planimetric method after multi-planar reformation in 16-slice MDCT. Concomitantly, the severity of the coronary artery stenosis was assessed by 16-slice MDCT. In the present study, the AVA assessed by TTE and 16-slice MDCT was 1.34+/-0.32 cm(2) and 1.38+/-0.32 cm(2), respectively. Regression analysis showed that the AVA in patients with AS determined by 16-slice MDCT correlated well with those determined by 2-DE (r=0.96, p<0.001). Significant coronary artery stenosis of more than 50% diameter reduction was present in 48% of the study population. CONCLUSIONS: In patients with AS, the analysis of the severity of the AVA by 16-slice MDCT provides a feasible and accurate estimation with the concomitant evaluation of CAD.     

Significance of angina pectoris in aortic valve stenosis.

Of 60 patients aged 45 to 66 years with aortic valve stenosis, 28 (47 per cent) had angina pectoris. Significant coronary arterial obstruction was shown by selective coronary cineangiography in 14 of them. Systolic pressure gradients across the aortic valve were lower in patients with angina than in those without. In those with angina, systolic gradients were higher in those with normal coronary arteriograms than in those with demonstrable coronary arterial disease. Aortic valve replacement relieved the angina in all patients who had normal coronary arteriograms. When valve replacement was combined with coronary bypass grafting in those with coronary arterial disease, surgical mortality was higher and symptomatic relief less predictable. Incapacitating angina in patients with aortic stenosis was nearly always associated with significant coronary disease. In those with less severe angina it was impossible to predict the state of the coronary arteries. Two patients, who did not have angina and who did not undergo coronary arteriography, died after aortic valve replacement and were found at necropsy to have unsuspected severe coronary disease. We, therefore, suggest that coronary arteriography should be carried out in all patients over the age of 40 years in whom surgery is being considered for aortic stenosis.