Diagnostic value of 16-slice multidetector computed tomography in symptomatic patients with suspected significant obstructive coronary artery disease

We investigated the diagnostic value and limitations of 16-slice multidetector computed tomography (MDCT) to detect significant obstructive coronary artery disease in symptomatic patients. A total of 43 symptomatic patients underwent conventional coronary angiography and 16-slice multidetector computed tomography for the detection of significant obstructive coronary artery disease. The diagnostic value and limitations of 16-slice multidetector computed tomography to detect significant coronary stenoses were determined by analyzing all coronary arteries and proximal segments, both including and excluding unevaluable segments. Analysis of all 592 coronary artery segments demonstrated moderate sensitivity (67%) and positive predictive value (69%), with a high specificity (95%) and negative predictive value (94%) for the detection of significant coronary artery stenoses. When the unevaluable segments had been excluded, with the analysis of all evaluable segments, proximal segments, and evaluable proximal segments, sensitivity increased (71%, 77%, and 83%, respectively), and high specificity (95%, 96%, and 96%, respectively) and negative predictive value (95%) were maintained. When we repeated the analysis taking only the patients into account, 16-slice MDCT correctly diagnosed 88% of all patients but a moderate negative predictive value (63%) was obtained. Artifacts caused by cardiac motion were the most frequent reason for unevaluable segments. Calcification was the leading cause of degraded image quality and incorrect diagnosis. Our results demonstrated that 16-slice MDCT has a moderate diagnostic value for the correct diagnosis of symptomatic patients with significant coronary artery disease. This result suggests that 16-slice MDCT may not be able to exclude significant coronary artery disease reliably in patients at high risk.     

Feasibility and accuracy of coronary imaging in elderly patients using the 64-row multi-detector computed tomography: a correlation study with conventional coronary angiography

Background Elderly patients generally have higher occurrence of coronary calcification, increased heart rate and difficulty with prolonged breath-holding. The aim of our study was to investigate the feasibility and accuracy of using 64-row multi-detector computed tomography (MDCT) in the assessment of coronary artery stenoses in elderly patients. Methods One hundred and fifty two patients with suspected or known coronary artery disease were divided into 4 groups according to their age (Group A: 40-49 years, n=34; Group B: 50-59 years, n=57; Group C: 60-69 years, n=48; Group D: 70 years and above; n=13). Coronary CT angiography (CTA) using a 64-row MDCT was performed and the findings were compared with that of conventional coronary angiography (CCA). Using axial images, multi-planar reconstructions (MPR) and maximum intensity projections (MIP), coronary segments of lumen diameter = 1.5mm were analyzed for the presence of significant stenosis (= 50% ). Results Percentages of poor image quality from coronary CTA preventing reliable correlations with CCA were 21%, 14%, 19% and 62% in Groups A to D respectively. Patients in Group D had significantly higher calcium scores compared with the other groups (P<0.001). In patients where CTA images were of acceptable quality, percentages of accurate correlations with CCA were 89.8%, 93.4%, 86.6% and 78.0% for Groups A to D respectively. There were no significant difference in serum creatinine, heart rate and contrast volume between the 4 groups. Conclusions The 64-row MDCT coronary angiography was less accurate and feasible for patients aged 70 years or above due to heavy coronary calcification and inability to perform a satisfactory breath-hold. However, a high diagnostic accuracy with the MDCT is possible in patients aged less than 70 years.(J Geriatric Cardiol 2006;3(1):9-14)     

Diagnostic accuracy of noninvasive coronary imaging using 16-detector slice spiral computed tomography with 188 ms temporal resolution

OBJECTIVES: The aim of our study was to evaluate the diagnostic accuracy of 16-multi-detector spiral computed tomography (MDCT) with 188 ms temporal resolution. BACKGROUND: Because of rapid technical innovations, MDCT coronary imaging has significantly improved in the last five years. Recent results indicate a high diagnostic accuracy, especially in patients with clinical suspicion of coronary artery disease (CAD). METHODS: A total of 72 consecutive patients (30 women, 42 men, age 64 +/- 10 years) scheduled for invasive coronary angiography (ICA) because of suspected CAD were additionally studied by MDCT (Sensation 16 Speed 4D, Siemens, Forchheim, Germany). Thirty-seven of 72 patients (51%) received an additional beta-blockade before MDCT because of heart rates >65 beats/min. The MDCT scans were analyzed regarding the presence of coronary artery lesions. Results were compared with ICA. RESULTS: All 72 scans showed diagnostic image quality (heart rate: 64.1 +/- 9.2 beats/min, calcium mass: 86 +/- 156 mg). Thirteen coronary segments were evaluated in each patient. Sixty-two of 936 (6.6%) segments showed a nondiagnostic image quality. All segments were included in the analysis. A total of 117 relevant lesions (diameter stenosis >50%) were detected using ICA, and 96 of 117 (82%) were detected by MDCT. Sensitivity, specificity, and positive and negative predictive values for the whole study group were as follows: 82%, 98%, 87%, and 97%, respectively. The correct clinical diagnosis of presence or absence of significant CAD was obtained in 65 of 72 (90%) patients. All stenoses were detected by MDCT in 52 of 72 (72%) patients. CONCLUSIONS: Our results indicate a high diagnostic accuracy of 16-slice MDCT with improved temporal resolution.     

Role of 16-multidetector computed tomography in the assessment of coronary artery stenoses: A prospective study of consecutive patients

BACKGROUND: Recent studies have demonstrated a high sensitivity (S) of 16-multidetector computed tomography (16-MDCT) for the detection of significant coronary artery stenoses. Whether these results are applicable to clinical practice is unclear. Therefore, the aim of the present study was to compare 16-MDCT angiography with conventional coronary angiography (CCA) for the detection of significant coronary artery stenoses in a consecutive series of patients. METHOD: A total of 93 consecutive patients (mean [+/- SD] age 59+/-9 years), in whom CCA was performed for stable angina pectoris, underwent 16-MDCT angiography (16x0.75 mm, table feed 6.5 mm/s, rotation time 0.42 s; Sensation 16, Siemens Medical Solutions, Germany) the day before performing CCA. Patients with diabetes mellitus, serum creatinine level higher than 132.6 mumol/L and/or acute coronary syndromes were excluded. Two observers blinded to CCA results evaluated MDCT angiograms according to standard criteria. Segment-based (13 segments per patient) and patient-based (at least one stenosis greater than 50% lumen diameter reduction) analyses were performed. RESULTS: A total of 1209 segments were analyzed. Of these segments, 173 (14%) were excluded due to poor image quality or massive calcification. In 86 segments, CCA revealed significant coronary artery stenosis (greater than 50% diameter reduction). However, 16-MDCT detected only 47 of these, resulting in a S of 55% and a specificity (SP) of 97% (positive predictive value 64%; negative predictive value 96%). On a patient-based analysis, the S increased to 89%, whereas the SP still remained high (87%). CONCLUSION: In this relatively large consecutive cohort, S for the detection of significant coronary artery stenoses was moderate on a segment-based analysis but increased on a patient-based analysis using 16-MDCT. In contrast, SP was high in both analyses, supporting the use of 16-MDCT for the exclusion of significant coronary artery stenoses. Further improvement of spatial and temporal resolution in MDCT technology may lead to a lower exclusion rate and higher S.     

Detection of vein graft disease using 4-row computed tomography. Evaluation of coronary bypass graft patency and correlation with the Ca-score

BACKGROUND: Multi-row computed tomography (MDCT) is a promising non-invasive technique and capable of rapid imaging of cardiac structures, including coronary arteries and bypass grafts during a single held breath. In this study, we evaluated coronary artery bypass graft (CABG) patency by comparing 4-slice computed tomography with conventional contrast angiography. One disadvantage of MDCT is the limited diagnostic accuracy with + increased calcification of the grafts. Therefore, the correlation between Ca-grading and diagnostic accuracy was examined. METHODS: We examined 30 patients with 104 bypass grafts with a 4-row MDCT scanner. On the basis of the Ca-score, patients were divided into 3 groups. RESULTS: It was possible to assess the exact degree of stenosis in 25 of 32 > 50% stenoses with 4-row MDCT, 7 stenoses were underestimated. All occlusions in 21 patients were identified correctly, 33 graft segments were underestimated in MDCT, of which 28 were in the group with a Ca-score of > 800. CONCLUSIONS: MDCT allows non-invasive angiographic evaluation of coronary bypass grafts with a high diagnostic accuracy. However, the method strongly depends on the degree of vascular calcification and underrates the degree of stenosis subject to the Ca-score. This is a distinct limitation in distal vascular segments of small calibre which cannot be validly displayed. In patients with low or moderate Ca-score values, MDCT coronary angiography is promising new technique with a high diagnostic accuracy for the detection of graft stenosis or occlusions.     

Non-invasive coronary angiography with high resolution multidetector-row computed tomography. Results in 102 patients.

AIMS: A new generation of multidetector-row CT (MDCT) scanners allows complete coronary coverage using retrospective ECG gating and 1mm slices. The purpose of this study was to investigate the potential of high resolution MDCT angiography with retrospective gating for detection of coronary artery stenoses. METHODS AND RESULTS: A total of 102 patients underwent both conventional and MDCT coronary angiography. After intravenous injection of a non-ionic contrast medium the entire heart was scanned within a single breath hold using 1mm slices. All MDCT data sets were reconstructed with retrospective gating at 20% to 80% in increments of 10% relative to the cardiac cycle. Two blinded independent reviewers analysed image quality for segments 1-4 (right coronary artery), 5-8 (left main, left anterior descending), and 11, 12 (left circumflex). These segments were evaluated for the presence or absence of significant (>or=50%) stenoses. The results were compared with those of invasive coronary angiography in a blinded fashion. Overall sensitivity for the detection of significant stenoses (>or=50%) were 0.86 (reader 1) and 0.93 (reader 2), specificity 0.96 (reader 1) and 0.97 (reader 2), negative predictive value 0.98 (reader 1) and 0.99 (reader 2). CONCLUSIONS: High resolution MDCT angiography with retrospective gating permits the non-invasive detection of coronary artery stenoses with high accuracy if image quality is optimized for each of the three major coronary arteries.     

Differential coronary artery calcification detected by electron beam computed tomography as an indicator of coronary stenosis among patients with stable angina pectoris.

BACKGROUND: The detection of coronary artery calcification by electron beam computed tomography (EBCT) has been suggested as an indicator of atherosclerosis and coronary artery disease (CAD). There is no consensus on the correlation between coronary calcification and angiographically significant stenosis on an artery-by-artery basis. OBJECTIVE: To examine the relationship between coronary calcification score (CCS) and the presence of significant CAD on an artery-by-artery basis in patients with stable angina pectoris. METHODS AND RESULTS: EBCT and coronary angiogram (CAG) were evaluated in 71 patients with stable angina and in nine control subjects. The CCSs of each of the four major coronary arteries were highest in patients with significant CAD (n=43), followed by patients with insignificant CAD (n=5), patients with syndrome X (n=23) and control subjects, respectively. Calcification scores of the four major coronary arteries appeared to have different predictive power for significant stenosis on the same vessel. For left main (LM) and left anterior descending (LAD) coronary arteries, CCSs of vessels with significant stenoses were not different from those without significant stenoses (values expressed as medians: LM 0 versus 1; LAD 98.5 versus 70; not significant). Calcification scores of left circumflex (LCX) and right coronary arteries (RCA) were significantly higher in vessels with significant stenosis (LCX 49.5 versus 0; RCA 53 versus 1; P<0.05). CCSs appeared to be moderately useful to predict significant stenoses in these two vessels (areas under receiver operating characteristic curves: LCX 0.68+/-0.08, 95% CI 0.52 to 0.81; RCA 0.71+/-0.08, 95% CI 0.55 to 0.84). CONCLUSIONS: The CCSs of RCA and LCX arteries, but not those of LM and LAD arteries, may predict significant angiographic stenosis on an artery-by-artery basis among patients with stable angina pectoris.     

Noninvasive detection of coronary artery stenosis using contrast-enhanced three-dimensional breath-hold magnetic resonance coronary angiography

OBJECTIVES: The purpose of this study was to evaluate a contrast-enhanced three-dimensional (3D) breath-hold magnetic resonance (MR) technique for detection of coronary artery stenoses. BACKGROUND: The accuracy of previously published MR coronary angiography protocols varies widely. Recently, coronary artery imaging using T1-shortening contrast agent has become possible, but so far there are no data concerning its clinical application. METHODS: Magnetic resonance coronary angiography was performed in 50 patients with suspected coronary artery disease. Magnetic resonance data acquisition using an ultrafast 3D gradient-echo sequence lasted over 32 heartbeats within one single breath-hold. Twenty milliliters of gadopentetate dimeglumine was injected at a flow rate of 1 ml/s for two successive studies covering the main coronary arteries in single-oblique planes. Stenosis assessment by MR was compared with significant (diameter stenosis > 50%) stenoses on X-ray angiography. Evaluation was limited to the proximal and mid-coronary artery segments. RESULTS: Two hundred sixty-eight of 350 artery segments (76.6%) could be evaluated. Left circumflex coronary artery was only evaluable in 50% of cases by MR. In the evaluable segments, 48 of 56 stenoses and 193 of 212 nonstenotic segments were correctly classified by MR. On a patient basis, MR correctly identified 34 of 36 patients with and 8 of 14 patients without significant coronary stenoses as demonstrated by X-ray angiography (sensitivity 94.4%, specificity 57.1%). CONCLUSIONS: Oblique projection contrast-enhanced MR coronary angiograms obtained within one single breath-hold permit identification of patients with coronary stenoses in the proximal and mid segments of the major coronary arteries with satisfactory accuracy.     

Assessment of coronary artery by four-detector multislice computed tomography: diagnostic accuracy and limitations for coronary artery lesions

OBJECTIVES: The applicability of four-detector multislice computed tomography (MSCT) was investigated for evaluating coronary arteries. METHODS: MSCT (Somatom Volume Zoom, Siemens) was used to evaluate the coronary arteries in 94 patients. The reconstructed images were analyzed using retrospective electrocardiographic gating to determine the image quality of the coronary arteries. In addition, the ability of MSCT to detect coronary artery lesions of > or = 70% (> or = 50% in the left main trunk) diameter stenoses documented by standard coronary angiography was assessed in 67 patients who underwent coronary angiography within the same period. RESULTS: Good image quality was displayed in 488 (58%) and fair in 184 (22%) of a total of 846 coronary segments, but non-assessable in 174 (21%) due to degraded image quality. MDCT detected 33 stenotic lesions correctly in 494 assessable segments, comparable to coronary angiography. The sensitivity and specificity of MSCT were 0.79 and 0.95, respectively. However, an additional 15 lesions were detected by coronary angiography among the non-assessable segments. In total, 24 lesions were missed by MSCT. Accordingly, coronary segments were completely assessable and correctly detected by MSCT in only 20 patients (30%), or 35 (52%) if the distal coronary segments were excluded from analysis. CONCLUSIONS: Four-detector MSCT for detection of coronary artery lesions was applicable to assessable segments. However, clinical use may presently be limited because of the insufficient overall accuracy. Further technical improvement is expected in the near future.     

Diagnostic value of CT angiography in coronary arteries stenosis detection

BACKGROUND: Noninvasive imaging of coronary arteries is very important. CT angiography (multislice computed tomography and electron beam computed tomography -- MSCT and EBT) is most reliable method for noninvasive coronary visualization. PURPOSE: The aim of our study was to evaluate the diagnostic value of CT angiography in coronary arteries stenoses detection in patients with coronary arteries disease (CAD). MATERIALS AND METHODS: 140 patients with CAD who underwent 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 CT angiography in coronary stenoses detection (proximal and mid segments) were 86% and 97%, respectively. Positive and negative predictive values were 90% and 96%, respectively. Overall accuracy was 95%. 6.2% of coronary segments were excluded from the study because of unsatisfactory image quality. CONCLUSIONS: CT angiography is noninvasive method for coronary stenoses detection with high sensitivity and specificity. Nevertheless EBT and 4-slice CT angiography can not replace conventional coronary angiography because of lower temporal and spatial resolution, artifacts in patients with arrhythmias and huge coronary calcification.     

Non-invasive detection of coronary artery disease in patients with left bundle branch block using 64-slice computed tomography.

OBJECTIVES: The goal of this study was to evaluate the diagnostic accuracy of 64-slice computed tomography (CT) to identify coronary artery disease (CAD) in patients with complete left bundle branch block (LBBB). BACKGROUND: Left bundle branch block increases risk of cardiac mortality, and prognosis is primarily determined by the underlying coronary disease. Non-invasive stress tests have limited performance, and conventional coronary angiography (CCA) is usually required. METHODS: Sixty-six consecutive patients with complete LBBB and sinus rhythm admitted for CCA were enrolled. Computed tomography was performed 3 +/- 3.9 days before CCA. The accuracy of 64-slice CT to detect significant stenosis (>50% lumen narrowing) was compared with quantitative coronary angiography. All segments were analyzed regardless of image quality from coronary calcification or motion artifacts. Results were analyzed by patient and by coronary segment (990) using the American Heart Association 15-segment model. RESULTS: Lower heart rates were associated with improved image quality. Computed tomography correctly identified 35 of 37 (95%) patients without significant stenosis and 28 of 29 (97%) patients with significant stenosis on CCA. Computed tomography correctly assessed 68 of 94 (72%) significant stenosis. Overall, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CT for identifying CAD by patient was 95%, 97%, 95%, 93%, and 97%, respectively, and by segment was 97%, 72%, 99%, 91%, and 97%, respectively. CONCLUSIONS: In a routine clinical practice, 64-slice CT detects with excellent accuracy a significant CAD in patients with complete LBBB. A normal CT in this clinical setting is a robust tool to act as a filter and avoid invasive diagnostic procedures.     

Quantitative parameters of image quality in multidetector spiral computed tomographic coronary imaging with submillimeter collimation

Multidetector computed tomography (MDCT) permits visualization of the coronary arteries, but limited spatial and temporal resolution can lead to artifacts. We quantitatively evaluated the image quality that can be obtained with the latest generation of MDCT scanners with submillimeter collimation and increased gantry rotation speed. Thirty patients with angiographically proved absence of significant coronary artery stenoses (mean age 56 +/- 13 years, mean heart rate 62 +/- 13 beats/min) were studied by MDCT (12 x 0.75 mm collimation, 420-ms tube rotation, 210-ms temporal resolution, 500 mA, 120 kVp, retrospective electrocardiographic gating). In multiplanar reconstructions of the 4 major coronary arteries (left main, left anterior descending, left circumflex, and right coronary artery), the overall visualized vessel length and the length of segments without motion artifacts were measured. Vessel diameters at 8 predefined locations were measured in MDCT maximum intensity projections and in corresponding invasive angiograms. The mean lengths of visualized coronary arteries were left main 13 +/- 6 mm, left anterior descending 138 +/- 39 mm, left circumflex 84 +/- 34 mm, and right coronary artery 155 +/- 41 mm. On average, 93 +/- 13% of the total visualized vessel length was depicted without motion artifacts (left main 100 +/- 0%, left anterior descending 93 +/- 12%, left circumflex 91 +/- 17%, and right coronary artery 87 +/- 14%). The percentage of vessel length visualized free of motion artifacts was significantly higher in patients with a heart rate 60 beats/min (96 +/- 8% vs 89 +/- 17%, p <0.05). Vessel diameters in MDCT correlated closely to quantitative coronary angiography (R(2) 0.83 to 0.87). In conclusion, MDCT with submillimeter collimation and improved temporal resolution permits reliable visualization of the vessel lumen and accurate measurements of vessel dimensions.     

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.     

多层螺旋CT诊断冠状动脉狭窄的价值和限度

目的 评价多层螺旋CT(MSCT)在冠状动脉狭窄诊断中的价值和限度.方法 临床诊断或可疑冠心病的65例患者接受冠状动脉MSCT检查,采用回顾性心电门控、0.5 s/转的螺旋扫描、单扇区重建算法和静脉注射对比剂,其检查结果与导管法,冠状动脉造影进行对照.结果 在65例患者的冠状动脉889节段(直径≥1.5 mm)中,CT图像满足管腔评价为795节段(占89.4%).对于CT图像满足管腔评价的冠状动脉节段,MSCT对冠状动脉中度和中度以上狭窄(≥50%)诊断的敏感度和特异度分别为88.6%和95.1%,阳性预测值和阴性预测值分别为82.7%和96.9%;MSCT显示冠状动脉高度狭窄(≥75%)的敏感度和特异度分别为90.7%和97.6%,阳性预测值和阴性预测值分别为82.1%和98.9%.结论 如果冠状动脉CT图像满足管腔评价,MSCT对冠状动脉狭窄的诊断准确性很高.MSCT可用于冠状动脉狭窄的初步诊断和介入治疗的筛选.     

Predictive value of noninvasive coronary angiography with multidetector computed tomography to detect significant coronary stenosis before valve surgery

Quantitative coronary angiography (QCA) is routinely performed before valve surgery for severe acquired valvular disease. This technique is relatively invasive, especially in a population with an average risk for significant coronary stenosis. Multidetector computed tomography (MDCT) coronary angiography allows the noninvasive evaluation of the coronary anatomy. The aim of this prospective study was to evaluate the predictive values of 16-slice MDCT in the detection of significant coronary stenosis (> or = 50%) before valve surgery in patients with severe valvular disease without known coronary artery disease and average risk, in comparison with conventional QCA. Forty patients with severe acquired valvular disease (mean age 70 +/- 8.6 years; 20 women; 27 with severe aortic stenosis) underwent coronary MDCT 2 days before cardiac catheterization with QCA. The mean heart rate was 64.7 +/- 8.8 beats/min (range 41 to 78). Four hundred fifty-eight of 600 coronary artery segments (77.3%) were considered assessable by MDCT. In a per-segment analysis, the sensitivity of MDCT for the detection of significant coronary lesions > or = 50% was 77.7%, the specificity was 98%, the positive predictive value was 42.4%, and the negative predictive value was 99%. The main cause of false-positive or false-negative results or nonassessable evaluations was severe coronary calcification. In a per-patient analysis, in comparison with QCA, MDCT correctly classified 33 of 40 patients (82.5%). In conclusion, in patients with an average risk for coronary stenosis before valve surgery, MDCT coronary angiography detected significant obstructive coronary artery disease, with a 99% NPV.     

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.     

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.     

Effect of age and plaque morphology on diagnostic accuracy of dual source multidetector computed tomography coronary angiography

Background Multidetector computed tomography （MDCT） coronary angiography represents one of the most exciting technological revolutions in cardiac imaging and it has been increasingly used in the diagnosis of coronary artery disease. The purpose of this study is to investigate the effect of age and coronary plaque calcification on diagnostic accuracy of MDCT. Methods The patients were examined by using dual-source MDCT and conventional coronary angiography. MDCT results were analyzed with regard to the severity （＆gt;50%stenosis） and morphology （non-calcified, mixed, or calcified） of coronary atherosclerotic plaques evaluated in a 16-segment model. Results In total, 181 patients （94 men and 87 women） with 2,687 coronary artery segments were examined with MDCT. Ninety three patients were older than 65 years of age （group A, 42 men） and 88 were younger （group B, 52 men）. Two-hundred nine coronary artery segments （7.2%） were ex-cluded because of small distal coronary vessel segments and/or motion artifacts. The overall number of segments with non-diagnostic image quality was similar in both groups of patients. Of the 2,687 evaluated segments, 157 （5.8%） were significantly diseased, and 144 of them were correctly detected by MDCT. Diagnostic evaluation showed that the sensitivity, positive predictive value, specificity, and negative pre-dictive value were 89.5%, 62.5%, 96.0%, and 99.2%, respectively in group A, and 95.2%, 64.8%, 97.5%, and 99.8%in group B, respectively. In addition, detailed segment-based analyses in coronary segments with non-calcified, mixed and calcified plaques in both groups were simi-lar diagnostic accuracy. Conclusions Very high diagnostic accuracy observed in this study suggests that MDCT coronary angiography could be a suitable diagnostic tool for not only younger patients but also for older patients.     

Noninvasive detection of coronary lesions using 16-detector multislice spiral computed tomography technology: initial clinical results

OBJECTIVES: The aim of our study was to evaluate the feasibility of detecting coronary artery lesions using a new computed tomography (CT) scanner with 16 detectors and faster gantry rotation. BACKGROUND: Computed tomography angiography of the coronaries permits assessment of the coronaries; however, image quality is still impaired by motion artifacts and calcifications. METHODS: Sixty patients scheduled for conventional coronary angiography (CCA) were additionally studied by multislice spiral computed tomography (MSCT).Calcium scores and a contrast-enhanced visualization of the coronaries were performed and analyzed regarding evaluability, presence of coronary artery lesions, and correct clinical diagnosis. RESULTS: Calcium scoring was successful in all patients; 58 of 60 patients had a diagnostic contrast-enhanced scan. Mean calcium score was 506 +/- 743 Agatston score equivalent (ASE); 13 of 58 (22%) patients had an ASE >or=1,000, 46 of 58 (78%) patients <1,000. In 763 coronary segments, CCA detected a total of 75 lesions >or=50%. The MSCT correctly assessed 54 of these. Twenty-one lesions were missed or incorrectly underestimated. Sensitivity was 72%, specificity 97%. When restricting analysis to patients with an ASE <1,000, 40 significant lesions >or=50% were seen on CCA, and MSCT correctly detected 39 lesions (sensitivity 98%, specificity 98%). Regardless of any threshold, the correct clinical diagnosis could be obtained in 58 of 60 (97%) of all patients. CONCLUSIONS: In individuals with low-to-moderate amounts of coronary artery calcium, 16-detector CT coronary angiography has high sensitivity and specificity for the diagnosis of significant coronary artery stenosis.     

Non-invasive evaluation of coronary artery bypass grafts using 16-row multi-slice computed tomography with 188 ms temporal resolution

BACKGROUND: Cardiac multi-slice computed tomography (MSCT) scanners permit visualization of the coronary arteries and coronary artery bypass grafts. The latest MSCT generation with true 16-detector slices (Sensation 16 Speed 4 D, Siemens, Forchheim, Germany) provides improved temporal and spatial resolution, as well as significantly reduced scan time. To assess, whether this technical improvement has also an impact on image quality and accuracy of MSCT diagnosis in patients with previous coronary artery bypass graft (CABG) surgery the following study was conducted. METHODS AND MATERIAL: Thirteen consecutive patients (pts) (10 male, 3 female, mean age 62 +/- 6.4 [55-73] years, heart rate 68 +/- 11 [52-88] bpm) and a total number of 43 coronary bypass grafts (11 arterial, 32 venous grafts) were examined by MSCT (gantry rotation time 375 ms). In addition to the analysis of coronary bypass grafts, 13 coronary segments (sgts) were evaluated in each patient (n = 169 sgts). MSCT results were compared with coronary angiography. RESULTS: Forty-one of 43 bypass grafts (95%) were analyzable by MSCT. In conventional angiography 16 of 43 (37%) grafts were occluded. Sixteen of them were correctly diagnosed by MSCT (sensitivity 100%). One graft showed a 50% anastomosis stenosis which was also detected. Twenty-five of 27 grafts without severe lesion showed no significant stenosis in MSCT (specificity 93%, positive predictive value (PPV) 89%, negative predictive value (NPV) 100%). Ninety of 108 (83%) high-grade stenosis (>70%) of the native coronary vessels were correctly detected (sensitivity 83%, PPV 78%). From the 61 sgts without high grade stenosis 36 were correctly classified (specificity 59%, NPV 67%). If sgts number 8, 9 and 10, which are normally not target for revascularization, are excluded sensitivity rises to 89%, specificity to 71%, PPV to 87% and NPV to 75%. The correct clinical diagnosis (absence or presence of a high grade stenosis of at least one bypass graft) was achieved in all patients. CONCLUSIONS: True 16-slice MSCT with faster gantry rotation time allows detection of lesions in coronary artery bypass grafts with high sensitivity and specificity. The evaluation of native vessels in pts with known CAD remains a diagnostic challenge. However, the correct clinical diagnosis was achieved in all pts. MSCT is a non-invasive tool to assess coronary artery bypass grafts.