Per-segment Analysis Research Articles

Diagnostic accuracy of 64-slice computed tomography coronary angiography in a large population of patients without revascularisation: registry data in NSTEMI acute coronary syndrome and influence of gender and risk factors

This study sought to evaluate the diagnostic accuracy of computed tomography coronary angiography (CTCA) for detecting significant coronary artery stenosis (≥50% lumen reduction) compared with conventional coronary angiography (CAG) in non-ST-elevation myocardial infarction-acute coronary syndrome (NSTEMI-ACS) and in subgroups selected by gender and number of risk factors (RF). We selected from a population of 1,500 patients in a multicentre registry with NSTEMI-ACS who had undergone CTCA and CAG, (n=237; 187 men, mean age 63±10 years). Diagnostic accuracy and likelihood ratios (LR) of CTCA were assessed against CAG in the total population and subgroups (men, women: 0 RF = absence of RF, 1-2 RF = presence of one or two RF, >2 RF = presence of more than two RF). The prevalence of obstructive disease was 53%. In the per-patient analysis, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CTCA were 100% (men 100%; women 100%; 0 RF 100%; 1-2 RF 100%; >2 RF 100%), 95% (men 98%; women 50%; 0 RF NA% (NA, not assessable); 1-2 RF 96%; >2 RF 96%), 95% (men 98%; women 91%; 0 RF 91%; 1-2 RF 96%; >2 RF 96%), 100% (men 100%; women 100%; 0 RF NV%; 1-2 RF 100%; >2 RF 100%), respectively. The per-segment analysis showed a reduction in PPV (ranging between 56% and 67%). The per-patient LR+ ranged between 18 and 27, whereas LR-were always 0. We observed no significant differences in diagnostic accuracy between subgroups. CTCA is a reliable diagnostic modality with high sensitivity and NPV in NSTEMI-ACS patients who are not candidates for early revascularisation, regardless of gender and number of risk factors.

Diagnostic performance of 320-detector CT coronary angiography in patients with atrial fibrillation: preliminary results

To evaluate the feasibility, diagnostic accuracy, and radiation dose of CT coronary angiography (CTCA) in patients with atrial fibrillation (AF) using 320-detector CT. Thirty-seven patients with persistent AF and suspected coronary artery disease (CAD) were enrolled. All patients underwent both 320-detector CTCA and conventional coronary angiography (CCA). CT image quality and the presence of significant (≥ 50%) stenosis were evaluated by two radiologists blinded to the results of CCA. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated using CCA as the reference standard. Differences in detection of coronary artery stenosis between 320-detector CTCA and CCA were evaluated with McNemar's test. Patient radiation dose was calculated by multiplying dose length product by conversion coefficient of 0.017. In total 474 evaluated coronary segments, 459 (96.8%) segments were diagnostically evaluable. On per-segment analysis, sensitivity, specificity, PPV and NPV were 90.0% (18 of 20), 99.3% (436 of 439), 85.7% (18 of 21) and 99.5% (436 of 438). No significant difference was found between 320-detector CTCA and CCA on the detection of significant stenosis (P = 1.000). Effective doses of 320-detector CTCA was 13.0 ± 4.7 mSv. 320-detector CTCA is feasible and accurate in excluding CAD in patients with AF.

Diagnostic accuracy of dual-source CT coronary angiography: The effect of average heart rate, heart rate variability, and calcium score in a clinical perspective

Dual-source CT coronary angiography (CTCA) has been used to detect coronary artery disease; however, the factors with potential to affect its diagnostic accuracy remain to be defined. To prospectively evaluate the accuracy of dual-source CTCA in diagnosing coronary artery stenosis according to conventional coronary angiography (CAG), and the effect of average heart rate, heart rate variability, and calcium score on the accuracy of CTCA. A total of 113 patients underwent both dual-source CTCA and CAG. The results were used to evaluate the findings in dual-source CTCA to assess the accuracy in the diagnosis of > or =50% (significant stenosis) and >75% (severe stenosis) of coronary artery according to those by CAG. Patients were divided into subgroups according to their heart rate (HR), HR variability (HRV), and calcium score, and the accuracy of CTCA was further evaluated. The chi-square test was used to analyze the difference in sensitivity and specificity for the detection of > or =50% and >75% coronary stenosis among subgroups. The generalized estimation equation method was used in per-vessel analysis to adjust for within-patient correlation. In all, 113 patients had 338 vessels and 1661 segments evaluated by CAG. Dual-source CTCA displayed 1527 segments (91.9%). Among them, 1468 segments (calcium score by CAG score 1, n=1018; score 2, n=270; score 3, n=180) were assessable in CTCA. On a per-patient analysis, the sensitivity and specificity of CTCA were 93.9% and 93.5% for significant stenosis and 86.9% and 98.1% for severe stenosis. On a per-vessel basis, the sensitivity and specificity were 90.2% and 97.1% for significant and 83.3% and 98.1% for severe stenosis. On a per-segment analysis, the sensitivity and specificity were 90.2% and 97.1% for significant and 83.3% and 98.1% for severe stenosis. Average HR had no effect on the sensitivity and specificity of CTCA (P>0.05); whereas HRV and calcium score had some effect on the sensitivity and specificity of CTCA (P<0.05). On a per-patient, per-vessel, and per-segment basis, dual-source CTCA has a high sensitivity and specificity for the diagnosis of coronary artery stenosis. Average HR has no effect on the diagnostic accuracy of CTCA, while HRV and calcium score have a statistically significant effect on the sensitivity and specificity of CTCA.

Assessment of liver metastases from colorectal adenocarcinoma following chemotherapy: SPIO-MRI versus FDG-PET/CT

This study compared superparamagnetic iron-oxide-enhanced magnetic resonance imaging (SPIO-MRI) and combined fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) in evaluating liver metastases from colorectal adenocarcinoma following chemotherapy. Nineteen patients were included in this retrospective study. SPIO-MRI and PET/CT results were compared with surgery, intraoperative ultrasound and pathology results in 11 patients and with the follow-up in eight patients. SPIO-MRI and PET/CT identified 125 and 71 metastases, respectively. False negative lesions were 11 for SPIO-MRI and 65 for PET/CT. In the whole study population, the per-lesion analysis of SPIO-MRI and PET/CT showed a sensitivity of 92% and 52% (p<0.001) and the per-segment analysis a sensitivity of 99% and 79% (p<0.001), respectively. In patients who underwent surgery, the per-lesion analysis of SPIO-MRI and PET/CT showed a sensitivity of 85% and 58% (p<0.05) and the per-segment analysis a sensitivity of 97% and 63% (p<0.05), respectively. In patients who underwent follow-up, the per-lesion analysis of SPIO-MRI and PET/CT showed a sensitivity of 97% and 47% (p<0.001) and the per-segment analysis a sensitivity of 100% and 63% (p<0.007), respectively. For lesions ≥15 and <30 mm and for lesions <15 mm, SPIO-MRI demonstrated a higher sensitivity than PET/CT (p<0.001). SPIO-MRI appears superior to PET/CT in evaluating liver metastases from colorectal adenocarcinoma following chemotherapy.

Evaluation of coronary in-stent restenosis by 64-slice computed tomography in patients with optimal heart rate control by systematic administration of beta-blocker drugs

Imaging artifacts due to metallic stent struts can reduce the diagnostic accuracy of multislice computed tomography (MSCT) in the evaluation of in-stent restenosis (ISR). Our aim was to determine the accuracy of binary ISR exclusion using a 64-slice MSCT scanner and a systematic administration of beta-blockers having an aggressive heart rate (HR) control. We performed 64-slice MSCT in 218 consecutive patients revascularized by stenting. All patients were treated with oral/intravenous beta-blocker drugs in order to obtain a HR less than 65 beats/min in the prescan phase. Coronary stents were evaluated by two experienced observers in order to rule out the presence of significant (>50%) ISR. Quantitative conventional coronary angiography (CCA) served as a standard for reference. Five patients (2.3%) were excluded from the analysis; mean HR was 59 +/- 3 beats/min in the prescan phase and 62 +/- 5 beats/min during acquisition. In the 321 stented coronary segments, CCA found 27 significant ISRs. MSCT correctly diagnosed 26 significant ISRs, with two false-positive and one false-negative case. In a per-segment analysis, the sensitivity was 96%, specificity 99%, positive predictive value (PPV) 92.8%, and negative predictive value (NPV) 99%. In a per-patient analysis, the sensitivity was 100%, specificity 98.9%, PPV 92.8%, and NPV 100%. In our study, the evaluation of significant ISR by MSCT showed an excellent diagnostic accuracy with a PPV of 92.8% and a NPV of 99%. Selection criteria and radiation exposure can be considered a limitation of the method.

Feasibility of 64-slice gadolinium-enhanced cardiac CT for the evaluation of obstructive coronary artery disease

ObjectiveTo assess the feasibility of gadolinium-enhanced 64-slice cardiac CT (CCT) for the diagnosis of obstructive coronary artery disease.DesignComparative prospective study.SettingOutpatient Imaging Diagnostic Centre, Diagnóstico Maipú, Buenos Aires, Argentina.PatientsTwenty patients with...

Relationship Between Regional Myocardial Oxygenation and Perfusion in Patients With Coronary Artery Disease

Background— It is recognized that the interplay between myocardial ischemia, perfusion, and oxygenation in the setting of coronary artery disease (CAD) is complex and that myocardial oxygenation and perfusion may become dissociated. Blood oxygen level–dependent (BOLD) cardiovascular magnetic resonance (CMR) has the potential to noninvasively measure myocardial oxygenation, whereas positron emission tomography (PET) with oxygen-15 labeled water is the gold standard technique for myocardial blood flow quantification. Thus, we sought to apply BOLD CMR at 3 T and oxygen-15–labeled water PET in patients with CAD and normal volunteers to better understand the relationship between regional myocardial oxygenation and blood flow during vasodilator stress. Methods and Results— Twenty-two patients (age, 62�8 years; 16 men) with CAD (at least 1 stenosis ≥50% on quantitative coronary angiography) and 10 normal volunteers (age, 58�6 years; 6 men) underwent 3-T BOLD CMR and PET. For BOLD CMR, 4 to 6 midventricular short-axis images were acquired at rest and during adenosine stress (140 μg/kg/min). Using PET with oxygen-15–labeled water, myocardial blood flow was measured at baseline and during adenosine in the same slices. BOLD images were divided into 6 segments, and mean signal intensities calculated. Taking ≥50% stenosis on quantitative coronary angiography as the gold standard, cutoff values for stress myocardial blood flow (&lt;2.45 mL/min/g; AUC, 0.83) and BOLD signal intensity change (&lt;3.74%; AUC, 0.78) were determined to define ischemic segments. BOLD CMR and PET agreed on the presence or absence of ischemia in 18 of the 22 patients (82%) and in all normal subjects. On a per-segment analysis, 40% of myocardial segments with stress myocardial blood flow below the cutoff of 2.45 mL/min/g did not show deoxygenation, whereas 88% of segments with normal perfusion also had normal oxygenation measurements. Conclusions— Regional myocardial perfusion and oxygenation may be dissociated, indicating that in patients with CAD, reduced perfusion does not always lead to deoxygenation.

Initial experience of evaluation of coronary artery with 320-slice row CT system in high pre-test probability population without heart rate (rhythm) control

Objective To investigate the accuracy of 320-slice row CT system for the detection of coronary artery disease(CAD)in high pre-test probability population without heart rate/rhythm control.Methods Thirty patients with a high pre-test probability of CAD underwent 320-slice row CT without preceding heart rate/rhythm control.Invasive coronary angigraphy(ICA)served as the standard reference.Data sets were evaluated by 2 observers in consensus with respect to stenoses≥50%decreased diameter.The sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV)and Youden index were analyzed;the impact of heart rate and calcification on image quality as well as diagnostic accuracy were also analyzed by Chi-square test Results Mean heart rate during scanning was 73.7±15.4 beats per min(bpm),and median(QR)of Agatston score of segment was 45.6(181).On a per-segment analysis,overall sensitivity was 96.1%(74/77,95%CI:89.03%-99.19%),specificity was 98.3%(337/343,95%CI:96.23%-99.36%),PPV was 92.5%(74/80,95%CI:84.39%-97.20%),NPV of 99.1%(337/340,95%CI:97.44%-99.82%)and the Youden index was 0.94.In both heart-rate subgroups(242 in heart rate＜70 bpm group,169 in heart ratet≥70 bpm group),diagnostic accuracy for the assessment of coronary artery stenosis was similar(P＜0.05).The accuracy and the quality score of the subgroup Agatston score≥100 were lower than that of the subgroup Agatston score＜100;however,the difiercnce of results between 320-slice row CT and ICA was not significant(P＜0.05).Conclusion 320-detector row CT can reliably detect coronary artery stenoses in a high pre-test probability population without heart rate/rhythm control. Key words: Coronary disease; Tomography,X-ray computed; Coronary angiography

Evaluation of 64-slice MDCT in the real world of cardiology: A comparison with conventional coronary angiography

Multi-detector row computed tomography (MDCT) offers an alternative to diagnostic coronary angiography for visualizing coronary arteries. The major limitation of recently published studies, aside from being monocentric in nature and the low number of patients included, is the selection of patients. These studies do not provide any answers for patients who are seen daily in cardiology consultation. The purpose of our study was to determine the diagnostic accuracy of MDCT as compared with coronary angiography on a population of average patients who were not selected. Forty-eight patients with suspected coronary artery disease successively underwent 64-slice MDCT followed by coronary angiography with 24 to 48hours. The diagnostic accuracy detection of significant coronary stenoses (greater than 50% stenoses in arteries greater than 1.5mm in diameter) was determined and the two techniques were compared. Nearly half of the patients included had known histories of coronary artery disease (N=24; 50%). The sensitivity, specificity, positive and negative predictive value, and the diagnostic accuracy of MDCT in detecting significant coronary stenoses were 81.2, 98.2, 87.5, 97 and 93.9% in per-segment evaluation. During the per-patient evaluation, the efficacy of MDCT dropped with the values being 77.4, 92.3, 87.8, 79.2 and 81.6% respectively. The use of 64-slice MDCT results in excellent diagnostic accuracy and in an increased negative predictive value for detecting significant coronary stenoses in per-segment analysis. Per-patient analysis significantly reduced the value of the scan, demonstrating that patients with a high probability of coronary artery disease do not benefit from this type of non-invasive approach.

Coronary calcium score as gatekeeper for 64-slice computed tomography coronary angiography in patients with chest pain: per-segment and per-patient analysis

We sought to investigate the performance of 64-slice CT in symptomatic patients with different coronary calcium scores. Two hundred patients undergoing 64-slice CT coronary angiography for suspected coronary artery disease were enrolled into five groups based on Agatston calcium score using the Mayo Clinic risk stratification: group 1: score 0, group 2: score 1-10, group 3: score 11-100, group 4: score 101-400, and group 5: score > 401. Diagnostic accuracy for the detection of significant (>/=50% lumen reduction) coronary artery stenosis was assessed on a per-segment and per-patient base using quantitative coronary angiography as the gold standard. For groups 1 through 5, sensitivity was 97, 96, 91, 90, 92%, and specificity was 99, 98, 96, 88, 90%, respectively, on a per-segment basis. On a per-patient basis, the best diagnostic performance was obtained in group 1 (sensitivity 100% and specificity 100%) and group 5 (sensitivity 95% and specificity 100%). Progressively higher coronary calcium levels affect diagnostic accuracy of CT coronary angiography, decreasing sensitivity and specificity on a per-segment base. On a per-patient base, the best results in terms of diagnostic accuracy were obtained in the populations with very low and very high cardiovascular risk.

Early detection of coronary artery disease by 64-slice multidetector computed tomography in asymptomatic hypertensive high-risk patients

Background The 64-slice multidetector-row computed tomography (MDCT) is an accurate noninvasive technique for assessing the degree of luminal narrowing in coronary arteries of patients with chronic ischemic disease. Aim of this study was to determine the value of MDCT in comparison to invasive coronary angiography (ICA) for detecting the presence and extent of coronary atherosclerotic plaques in a population of asymptomatic, hypertensive patients considered to be at high risk for cardiovascular events. Methods We studied 67 asymptomatic, hypertensive patients at high-risk (Euro Score > 5%). All patients had negative or nondiagnostic findings at exercise stress testing and therefore underwent both MDCT and ICA. Results In the per-patient analysis, MDCT correctly identified 16/17 (94%) patients with significant coronary artery disease involving at least 1 vessel and 48/50 (96%) normal subjects. In the per-segment analysis, MDCT correctly detected 21/22 (95%) coronary segments with a stenosis ≥ 50% and 856/868 (98%) normal segments, with a high negative predictivity of normal scans (100%). There was a good concordance between MDCT and ICA, with a high Pearson correlation coefficient between the coronary narrowings with the two techniques ( r = 0.84, p < 0.01). Mean coronary calcium score was higher for the 17 patients with significant coronary artery disease on ICA than in the 50 patients without (422 ± 223 HU vs 72 ± 21 HU p < 0.001). The ROC curves identified 160 as the best calcium volumetric score cut-off value able to identify ≥ 1 significant coronary stenosis with sensitivity 88% and specificity 85%. Conclusions MDCT is an excellent noninvasive technique for early identification of significant coronary stenoses in high risk asymptomatic hypertensive patients and might provide unique information for the screening of this broad population.

Accuracy of quantitative coronary angiography with computed tomography and its dependency on plaque composition

To determine the impact of plaque composition on accuracy of quantitative 64-slice computed tomography coronary angiography (CTCA). The institutional review board approved this study; written informed consent was obtained from all patients. One hundred consecutive patients (42 women, mean age 64.6 +/- 9.4 years, age range 39-87 years) underwent CTCA and invasive quantitative coronary angiography (QCA) to determine (a) the diagnostic accuracy of CTCA for the detection of significant stenosis (diameter reduction of > or =50%), and (b) the accuracy of stenosis grading. In CTCA stenosis severity was graded in 10% steps and evaluated separately for calcified and non-calcified coronary lesions using Pearson-linear-regression analysis, Bland/Altman-analysis (BA), and Mann-Whitney-U-test. In 60/100 patients 139 significant coronary artery stenoses were identified with QCA. On a per-segment analysis, sensitivity of CTCA was 75.5%, and specificity was 96.6% (positive predictive value: 72.9%, negative predictive value: 97.0%). Quantification of stenosis grading correlated moderately between methods (r = 0.60; P < 0.001), with an overestimation by CTCA of 5.5% (BA limits-of-agreement -29 to 39%). BA limits-of-agreement were greater in calcified lesions (-29.2 to 45.6%; mean error 8.2%) than in non-calcified lesions (-25.9 to 30.2%; mean error 2.2%) and differed significantly (P < 0.05). Diagnostic accuracy of CTCA is high, however agreement for quantitative lesion severity assessment between CTCA and QCA is moderate for calcified but superior for non-calcified lesions.

Comparison of Diagnostic Accuracy of 64-Slice Computed Tomography Coronary Angiography in Women Versus Men With Angina Pectoris

We compared the diagnostic accuracy of 64-slice computed tomographic (CT) coronary angiography to detect significant coronary artery disease (CAD) in women and men. The 64-slice CT coronary angiography was performed in 402 symptomatic patients, 123 women and 279 men, with CAD prevalence of 51% and 68%, respectively. Significant CAD, defined as > or =50% coronary stenosis on quantitative coronary angiography, was evaluated on a patient, vessel, and segment level. The sensitivity and negative predictive value to detect significant CAD was very good, both for women and men (100% vs 99%, p = NS; 100% vs 98%, p = NS), whereas diagnostic accuracy (88% vs 96%; p <0.01), specificity (75% vs 90%, p <0.05), and positive predictive value (81% vs 95%, p <0.001) were lower in women. The per-segment analysis demonstrated lower sensitivity in women compared with men (82% vs 93%, p <0.001). The sensitivity in women did not show a difference in proximal and midsegments, but was significantly lower in distal segments (56% vs 85%, p <0.05) and side branches (54% vs 89%, p <0.001). In conclusion, CT coronary angiography reliably rules out the presence of obstructive CAD in both men and women. Specificity and positive predictive value of CT coronary angiography were lower in women. The sensitivity to detect stenosis in small coronary branches was lower in women compared with men.

Diagnostic Accuracy of Dual-Source Computed Tomography in the Diagnosis of Coronary Artery Disease

The aim of this study was to evaluate the diagnostic accuracy of dual-source computed tomography (DSCT) with reference to invasive coronary angiography in the diagnosis of coronary artery disease (CAD) on a per-patient as well as on a per-segment basis. Thirty-five patients with known or suspected CAD underwent both DSCT (Somatom Definition, Siemens Medical Solutions) and quantitative x-ray coronary angiography (QCA). Parameters of CT acquisition were gantry rotation time 0.330 seconds (ie, temporal resolution 83 milliseconds), tube voltage 120 kV, tube current 560 mA with ECG-triggered tube current modulation and full current at 70% of the cardiac cycle for heart rates below 70 beats per minute or full current between 30% and 80% for higher and arrhythmic heart rates. The pitch was also adapted to the heart rate, ranging from 0.2 to 0.43. Volume and flow rate of contrast material (Ultravist 370, Schering AG) were adapted to the patient's body weight. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DSCT in the detection or exclusion of significant CAD (ie, stenoses >50%) were evaluated on a per-patient and per-segment basis. All 35 CT angiograms were of diagnostic image quality. QCA demonstrated significant CAD in 48% (n = 17) and nonsignificant disease or normal coronary angiograms in 52% (n = 18) of the patients. Sensitivity, specificity, PPV, and NPV of DSCT on a per-patient basis were 100%, 89%, 89%, and 100%, respectively. On a per-segment basis, 473 of 481 coronary artery segments were assessable (98%). QCA demonstrated stenoses >50% in 32 segments (7%), and no disease or nonsignificant disease in 433 segments (93%). For the detection of stenoses >50% on a per-segment basis, DSCT showed a sensitivity, specificity, PPV, and NPV of 88%, 98%, 78%, and 99%, respectively. The comparison of coronary DSCT with QCA shows a very robust image quality and a high diagnostic accuracy in a patient-based as well as a per-segment analysis. Maximal sensitivity and NPV in the per-patient analysis show the strength of the technique in ruling out significant CAD.

Assessment of Aortoiliac and Renal Arteries: MR Angiography with Parallel Acquisition versus Conventional MR Angiography and Digital Subtraction Angiography

To prospectively compare the image quality, sensitivity, and specificity of three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography accelerated by parallel acquisition (ie, fast MR angiography) with MR angiography not accelerated by parallel acquisition (ie, conventional MR angiography) for assessment of aortoiliac and renal arteries, with digital subtraction angiography (DSA) as the reference standard. The study was approved by the institutional review board; informed consent was obtained from all patients. Forty consecutive patients (33 men, seven women; mean age, 63 years) suspected of having aortoiliac and renal arterial stenoses and thus examined with DSA underwent both fast (mean imaging time, 17 seconds) and conventional (mean imaging time, 29 seconds) MR angiography. The arterial tree was divided into segments for image analysis. Two readers independently evaluated all MR angiograms for image quality, presence of arterial stenosis, and renal arterial variants. Image quality, sensitivity, and specificity were analyzed on per-patient and per-segment bases for multiple comparisons (with Bonferroni correction) and for dependencies between segments (with patient as the primary sample unit). Interobserver agreement was evaluated by using kappa statistics. Overall, the image quality with fast MR angiography was significantly better (P=.001) than that with conventional MR angiography. At per-segment analysis, the image quality of fast MR angiograms of the distal renal artery tended to be better than that of conventional MR angiograms of these vessels. Differences in sensitivity for the detection of arterial stenosis between the two MR angiography techniques were not significant for either reader. Interobserver agreement in the detection of variant renal artery anatomy was excellent with both conventional and fast MR angiography (kappa=1.00). Fast MR angiography and conventional MR angiography do not differ significantly in terms of arterial stenosis grading or renal arterial variant detection.

Diagnostic Performance of 64-Channel Multislice Computed Tomography in Assessment of Significant Coronary Artery Disease in Symptomatic Subjects

The recent development of 64-channel multislice computed tomography (MSCT) has resulted in noninvasive coronary artery imaging improvement. This study was conducted to determine the accuracy of 64-slice MSCT in a relatively unselected group of 143 patients with presentations suggestive of coronary artery disease, including those with unstable angina pectoris, who underwent both coronary computed tomographic angiography and invasive coronary angiography. No arrhythmia was considered an exclusion criterion except for atrial fibrillation or frequent extrasystoles. In patients with fast heart rates, a beta blocker was administered orally. Data were obtained using electrocardiography gated 64-slice MSCT. Computed tomographic angiography and invasive coronary angiography findings of each coronary segment were compared to determine the sensitivity, specificity, positive predictive value, and negative predictive value of MSCT in the detection of their normalcy or insignificant (<50% diameter decrease) stenosis versus significant (>or=50% diameter decrease) stenosis or total occlusion. In per-patient assessment, the calculated sensitivity, specificity, positive predictive value, and negative predictive value of MSCT were 96%, 67%, 91%, and 83%, respectively. These values in per-artery evaluation were 94%, 94%, 87%, and 97%, and corresponding values in per-segment analysis were 92%, 97%, 77%, and 99%, respectively. In conclusion, computed tomographic angiography has high diagnostic performance in the assessment of significant coronary artery disease in most patients in a daily routine practice, including those presenting with unstable angina pectoris symptoms.

Usefulness of 64-Slice Multidetector Computed Tomography in Diagnostic Triage of Patients With Chest Pain and Negative or Nondiagnostic Exercise Treadmill Test Result

The usefulness of 64-slice multidetector coronary computed tomography (MDCT) in a diagnostic triage of 100 consecutive patients (age 55.8+/-11.6 years; 57% men) with chest pain suspected to be ischemic in origin and a negative or nondiagnostic exercise treadmill test (ETT) result was examined. None of the patients had previously known coronary artery disease (CAD). MDCT showed obstructive (>or=50%) CAD in 29 patients; 13 of 59 patients (22%) with a negative and 16 of 41 patients (39%) with a nondiagnostic ETT result. High-risk (left main and/or 3-vessel) CAD was present in 3.3% of patients with a negative and 4.9% with a nondiagnostic ETT result. The 29 patients with obstructive CAD on MDCT had a higher mean Agatston calcium score (221+/-402 vs 40+/-77 U, p<0.001). Invasive coronary angiography confirmed MDCT findings in 26 of 29 patients (positive predictive value 90%) and 45 of 54 stenotic segments (83%) in a per-segment analysis. For the 71 patients without obstructive CAD on MDCT, clinically driven invasive angiography detected CAD in 1 of 15 patients (1 false-negative MDCT result) and 2 of another 5 patients who were referred for invasive angiography later during a 12-month follow-up period. In the remaining 51 patients, MDCT findings effectively allowed exclusion of obstructive CAD, and there were no major adverse clinical events during follow-up. In conclusion, in patients with chest pain possibly ischemic in origin, no previously known CAD, and a negative or nondiagnostic ETT result, contrast-enhanced 64-slice MDCT scanning was a useful tool to provide direct noninvasive coronary angiography and rapidly advance diagnostic triage.

Diagnostic Performance of Multislice Spiral Computed Tomography of Coronary Arteries as Compared With Conventional Invasive Coronary Angiography: A Meta-Analysis

This study was designed to define the current role of multislice spiral computed tomography (MSCT) for the diagnosis of coronary artery disease (CAD) using a meta-analytic process. Multislice spiral computed tomography has recently been proposed as an alternative to conventional coronary angiography (CA) for the diagnosis of CAD. Using Medline, we identified 29 studies (2,024 patients) evaluating CAD by means of both MSCT (> or =16 slices) and conventional CA before July 2006. After data extraction the analysis was performed according to a random-effects model. The per-segment analysis pooled the results from 27 studies corresponding to a cumulative number of 22,798 segments. Among unassessable segments, 4.2% were excluded from the analysis and 6.4% were classified at the discretion of the investigators, underscoring the shortcomings of MSCT. With this major limitation, the per-segment sensitivity and specificity were 81% (95% confidence interval [CI] 72% to 89%) and 93% (95% CI 90% to 97%), respectively, with positive and negative likelihood ratios of 21.5 (95% CI 13.1 to 35.5) and 0.11 (95% CI 0.06 to 0.21), respectively, and positive and negative predictive values of 67.8% (95% CI 57.6% to 78.0%) and 96.5% (95% CI 94.7% to 98.3%), respectively. As expected, the per-patient analysis has shown an increased sensitivity of 96% (95% CI 94% to 98%) but a decreased specificity of 74% (95% CI 65% to 84%). Multislice spiral computed tomography has shortcomings difficult to overcome in daily practice and, at the more clinically relevant per-patient analysis, continues to have moderate specificity in patients with high prevalence of CAD. Studies evaluating the diagnostic performance of the newest generation of MSCT, including patients with low to moderate CAD prevalence, will be critical in establishing the clinical role of this emerging technology as an alternative to CA.

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.

Usefulness of Multidetector Row Spiral Computed Tomography With 64- × 0.6-mm Collimation and 330-ms Rotation for the Noninvasive Detection of Significant Coronary Artery Stenoses

Eighty-four patients with suspected coronary artery disease were studied to determine the accuracy of noninvasive coronary angiography using a multidetector computed tomographic scanner with 64- x 0.6-mm collimation and 330-ms gantry rotation. All coronary artery segments with a diameter >1.5 mm were assessed with respect to stenoses >50% decreased diameter. Results were compared with quantitative coronary angiographic findings. After exclusion of unevaluable coronary segments (4%), multidetector computed tomography demonstrated a sensitivity of 93%, a specificity of 97%, and a negative predictive value of 100% in a per-segment analysis. In a per-artery analysis, 15 of 336 arteries (4%) were unevaluable. Sensitivity and specificity in evaluable arteries were 95% and 93%, respectively. In a per-patient analysis (81 of 84 patients included), sensitivity and specificity were 96% and 91%, respectively.