Maffei, E.

Predictive Value of Cardiac Computed Tomography and the Impact of Renal Function on All Cause Mortality (from Coronary Computed Tomography Angiography Evaluation for Clinical Outcomes) (Article)

2013-03-18T00:00:00Z

Patients with chronic kidney disease have a worse cardiovascular prognosis than those without. The aim of this study was to determine the incremental prognostic value of coronary computed tomographic angiography in predicting mortality across the entire spectrum of renal function in patients with known or suspected coronary artery disease (CAD). A large international multicenter registry was queried, and patients with left ventricular ejection fraction (LVEF) and creatinine data were screened. National Cholesterol Education Program Adult Treatment Panel III risk was calculated. Coronary computed tomographic angiographic results were evaluated for CAD severity (normal, nonobstructive, or obstructive) and an LVEF <50%. Patients were followed for the end point of all-cause mortality. Among 5,655 patients meeting the study criteria, follow-up was available for 5,572 (98.9%; median follow-up duration 18.6 months). All-cause mortality (66 deaths) significantly increased with every 10-unit decrease in renal function (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.07 to 1.41). All-cause mortality occurred in 0.33% of patients without coronary atherosclerosis, 1.82% of patients with nonobstructive CAD, and 2.43% of patients with obstructive CAD. Multivariate Cox proportional-hazards models revealed that impaired renal function (HR 2.29, 95% CI 1.65 to 3.18), CAD severity (HR 1.81, 95% CI 1.31 to 2.51), and an abnormal LVEF (HR 4.16, 95% CI 2.45 to 7.08) were independent predictors of all-cause mortality. In conclusion, coronary computed tomographic angiographic measures of CAD severity and the LVEF provide effective risk stratification across a wide spectrum of renal function. Furthermore, renal dysfunction, CAD severity, and the LVEF have additive value for predicting all-cause death in patients with suspected obstructive CAD.

CT coronary angiography at an ultra-low radiation dose (<0.1 mSv): feasible and viable in times of constraint on healthcare costs (Article)

2013-01-24T00:00:00Z

Computed tomography coronary angiography (CTCA) has reached very high standards both in terms of diagnostic performance and radiation dose reduction. This commentary follows a report on CTCA using less than 0.1 mSv in selected patients. This is an extraordinary accomplishment, both for technology and for medicine. The difficult task is now to implement this tool in clinical practice so it can play the best possible role. CTCA can improve diagnostic pathways, can save money for healthcare systems and could even improve pharmacological therapy. All of this may happen, but it will require the combined effort of all the experienced operators in this field, including the referring clinicians. In times of financial constraint, CTCA may also help to restrict ineffective medical expenses. Key Points • CT coronary angiography provides high diagnostic standards in non-invasive cardiovascular medicine. • It should therefore replace other less effective diagnostic tools. • Inappropriate catheter angiography is costly to healthcare systems. • CTCA could help reduce costs of cardiac investigations by around 33 %. • Low radiation doses in CTCA lead to risk-free individualised pharmacological treatment.

Major adverse cardiac events and the severity of coronary atherosclerosis assessed by computed tomography coronary angiography in an outpatient population with suspected or known coronary artery disease (Article)

2012-01-01T00:00:00Z

PURPOSE: To investigate the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major adverse cardiac events (MACEs) in patients with suspected or known coronary artery disease (CAD). MATERIALS AND METHODS: Seven hundred and sixty-seven consecutive patients (496 men, age 62±11 y) with suspected or known heart disease referred to an outpatient clinic underwent 64-slice CTCA. The patients were followed for the occurrence of MACE (ie, cardiac death, nonfatal myocardial infarction, unstable angina). RESULTS: Eleven thousand five hundred and sixty-four coronary segments were assessed. Of these, 178 (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed the absence of CAD in 219 (28.5%) patients, nonobstructive CAD (coronary plaque ≤50%) in 282 (36.8%) patients, and obstructive CAD in 266 (34.7%) patients. A total of 21 major cardiac events (4 cardiac deaths, 12 myocardial infarctions, and 5 unstable angina) occurred during a mean follow-up of 20 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD, and 4 events occurred in the group with nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. In multivariate analysis, the presence of obstructive CAD and diabetes were the only independent predictors of MACE. CONCLUSIONS: Coronary plaque evaluation by CTCA provides an independent prognostic value for the prediction of MACE. Patients with normal CTCA findings have an excellent prognosis at follow-up. Copyright

Prevalence and severity of coronary artery disease and adverse events among symptomatic patients with coronary artery calcification scores of zero undergoing coronary computed tomography angiography: Results from the CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) registry (Article)

2011-12-06T00:00:00Z

Objectives: The purpose of this study was to describe the prevalence and severity of coronary artery disease (CAD) in relation to prognosis in symptomatic patients without coronary artery calcification (CAC) undergoing coronary computed tomography angiography (CCTA). Background: The frequency and clinical relevance of CAD in patients without CAC are unclear. Methods: We identified 10,037 symptomatic patients without CAD who underwent concomitant CCTA and CAC scoring. CAD was assessed as <50%, ≥50%, and ≥70% stenosis. All-cause mortality and the composite endpoint of mortality, myocardial infarction, or late coronary revascularization (≥90 days after CCTA) were assessed. Results: Mean age was 57 years, 56% were men, and 51% had a CAC score of 0. Among patients with a CAC score of 0, 84% had no CAD, 13% had nonobstructive stenosis, and 3.5% had ≥50% stenosis (1.4% had ≥70% stenosis) on CCTA. A CAC score >0 had a sensitivity, specificity, and negative and positive predictive values for stenosis ≥50% of 89%, 59%, 96%, and 29%, respectively. During a median of 2.1 years, there was no difference in mortality among patients with a CAC score of 0 irrespective of obstructive CAD. Among 8,907 patients with follow-up for the composite endpoint, 3.9% with a CAC score of 0 and ≥50% stenosis experienced an event (hazard ratio: 5.7; 95% confidence interval: 2.5 to 13.1; p < 0.001) compared with 0.8% of patients with a CAC score of 0 and no obstructive CAD. Receiver-operator characteristic curve analysis demonstrated that the CAC score did not add incremental prognostic information compared with CAD extent on CCTA for the composite endpoint (CCTA area under the curve = 0.825; CAC + CCTA area under the curve = 0.826; p = 0.84). Conclusions: In symptomatic patients with a CAC score of 0, obstructive CAD is possible and is associated with increased cardiovascular events. CAC scoring did not add incremental prognostic information to CCTA.

Coronary plaque burden in patients with stable and unstable coronary artery disease using multislice CT coronary angiography (Article)

2011-12-01T00:00:00Z

Purpose: We evaluated the multislice computed tomography (MSCT) coronary plaque burden in patients with stable and unstable angina pectoris. Materials and methods: Twenty-one patients with stable and 20 with unstable angina pectoris scheduled for conventional coronary angiography (CCA) underwent MSCT-CA using a 64-slice scanner offering a fast rotation time (330 ms) and higher X-ray tube output (900 mAs). To determine the MSCT coronary plaque burden, we assessed the extent (number of diseased segments), size (small or large), type (calcific, noncalcific, mixed) of plaque, its anatomic distribution and angiographic appearance in all available ≥2-mm segments. In a subset of 15 (seven stable, eight unstable) patients, the detection and classification of coronary plaques by MSCT was verified by intracoronary ultrasound (ICUS). Results: Sensitivity and specificity of MSCT compared with ICUS to detect significant plaques (defined as ≥1-mm plaque thickness on ICUS) was 83% and 87%. Overall, 473 segments were examined, resulting in 11.6±1.5 segments per patient. Plaques were present in 62% of segments and classified as large in 47% of diseased segments. Thirty-two percent were noncalcific, 25% calcific and 43% mixed. Plaques were most frequently located in the proximal and mid segments. Plaque was found in 33% of segments classified as normal on CCA. Unstable patients had significantly more noncalcific plaques when compared with stable patients (45% vs. 21%, p<0.05). Conclusions: MSCT-CA provides important information regarding the coronary plaque burden in patients with stable and unstable angina.

Computed tomography coronary angiography in asymptomatic patients (Article)

2011-12-01T00:00:00Z

Purpose: This study assessed the accuracy of computed tomography coronary angiography (CT-CA) for detecting significant coronary artery disease (CAD; ≥50% lumen reduction) in intermediate/high-risk asymptomatic patients. Materials and methods: A total of 183 consecutive asymptomatic individuals (92 men; mean age 54±11 years) with more than one major risk factor (obesity, hypertension, diabetes, hypercholesterolaemia, family history, smoking) and an inconclusive or nonfeasible noninvasive stress test result (stress electrocardiography, stress echocardiography, nuclear stress scintigraphy) underwent CT-CA in an outpatient setting. All patients underwent conventional coronary angiography (CAG) within 4 weeks. Data from CT-CA were compared with CAG regarding the presence of significant CAD (≥50% lumen reduction). Results: Mean calcium score was 177±432, mean heart rate during the CT-CA scan was 58±8 bpm and the prevalence (per-patient) of obstructive CAD was 19%. CT-CA showed single-vessel CAD in 9% of patients, two-vessel CAD in 9% and three-vessel CAD in 0%. Per-patient sensitivity, specificity, positive predictive value and negative predictive value of CT-CA were 100% (90-100), 98% (96-99), 97% (85-99), 100% (97-100), respectively. Positive and negative likelihood ratios were 151 and 0, respectively. Conclusions: CT-CA is an excellent noninvasive imaging modality for excluding significant CAD in intermediate/ high-risk asymptomatic patients with inconclusive or nonfeasible noninvasive stress test.

Prognostic value of Morise clinical score, calcium score and computed tomography coronary angiography in patients with suspected or known coronary artery disease (Article)

2011-12-01T00:00:00Z

Purpose: Our aim was to determine the prognostic value of computed tomography coronary angiography (CTCA), coronary artery calcium scoring (CACS) and Morise clinical score in patients with known or suspected coronary artery disease (CAD). Materials and methods: A total of 722 patients (480 men; 62.7±10.9 years) who were referred for further cardiac evaluation underwent CACS and contrast-enhanced CTCA to evaluate the presence and severity of CAD. Of these, 511 (71%) patients were without previous history of CAD. Patients were stratified according to the Morise clinical score (low, intermediate, high), to CACS (0-10, 11-100, 101-400, 401-1,000, >1,000) and to CTCA (absence of CAD, nonsignificant CAD, obstructive CAD). Patients were followed up for the occurrence of major events: cardiac death, nonfatal myocardial infarction, unstable angina and revascularisation. Results: Significant CAD (>50% luminal narrowing) was detected in 260 (36%) patients; nonsignificant CAD (<50% luminal narrowing) in 250 (35%) and absence of CAD in 212 (29%). During a mean follow-up of 20±4 months, 116 events (21 hard) occurred. In patients with normal coronary arteries on CTCA, the major event rate was 0% vs. 1.7% in patients with nonsignificant CAD and 7.3% in patients with significant CAD (p<0.0001). Three hard events (14%) occurred in patients with CACS≤100 and two (9.5%) in patients with intermediate Morise score; one revascularisation was observed in a patient with low Morise score. At multivariate analysis, diabetes, obstructive CAD and CACS >1,000 were significant predictors of events (p<0.05). Conclusions: An excellent prognosis was noted in patients with a normal CTCA (0% event rate). CACS ≤100 and low-intermediate Morise score did not exclude the possibility of events at follow-up.

Performance of the traditional age, sex, and angina typicality-based approach for estimating pretest probability of angiographically significant coronary artery disease in patients undergoing coronary computed tomographic angiography: Results from the multinational coronary CT angiography evaluation for clinical outcomes: An international multicenter registry (CONFIRM) (Article)

2011-11-29T00:00:00Z

Background-Guidelines for the management of patients with suspected coronary artery disease (CAD) rely on the age, sex, and angina typicality-based pretest probabilities of angiographically significant CAD derived from invasive coronary angiography (guideline probabilities). Reliability of guideline probabilities has not been investigated in patients referred to noninvasive CAD testing. Methods and Results-We identified 14048 consecutive patients with suspected CAD who underwent coronary computed tomographic angiography. Angina typicality was recorded with the use of accepted criteria. Pretest likelihoods of CAD with 50 diameter stenosis (CAD50) and 70 diameter stenosis (CAD70) were calculated from guideline probabilities. Computed tomographic angiography images were evaluated by 1 expert reader to determine the presence of CAD50 and CAD70. Typical angina was associated with the highest prevalence of CAD50 (40 in men, 19 in women) and CAD70 (27 men, 11 women) compared with other symptom categories (P<0.001 for all). Observed CAD50 and CAD70 prevalences were substantially lower than those predicted by guideline probabilities in the overall population (18 versus 51 for CAD50, 10 versus 42 for CAD70; P<0.001), driven by pronounced differences in patients with atypical angina (15 versus 47 for CAD50, 7 versus 37 for CAD70) and typical angina (29 versus 86 for CAD50, 19 versus 71 for CAD70). Marked overestimation of disease prevalence by guideline probabilities was found at all participating centers and across all sex and age subgroups. Conclusion-In this multinational study of patients referred for coronary computed tomographic angiography, determination of pretest likelihood of angiographically significant CAD by the invasive angiography-based guideline probabilities greatly overestimates the actual prevalence of disease.

Prognostic assessment of coronary artery bypass patients with 64-slice computed tomography angiography (Article)

2011-11-29T00:00:00Z

Objectives: We sought to determine the incremental prognostic value of 64 multi-slice coronary computed tomography angiography (CCTA) in coronary artery bypass graft (CABG) patients. Background: Prognostication in CABG patients can be difficult. Anatomical assessment of native coronary artery disease and graft patency might provide useful information, but the utility of CCTA in the assessment of CABG patients is unknown. Methods: Six hundred fifty-seven CABG patients with all-cause mortality follow-up were identified from a multicenter CCTA registry, of 10,628 patients from 5 CCTA centers. Clinical risk was profiled with modified logistic and additive EuroSCOREs (European Systems for Cardiac Operative Risk Evaluations). The CCTA defined coronary anatomy. Patients were classified by unprotected coronary territory (UCT) or a summary of native vessel disease and graft patency: the coronary artery protection score (CAPS). Results: Forty-four deaths occurred during a mean follow-up of 20 months. Left ventricular ejection fraction, creatinine, age, severity of native vessel disease, UCT, CAPS, and EuroSCOREs were univariate predictors of mortality (p < 0.001). In multivariate analysis with additive EuroSCORE, UCT (p = 0.004) and CAPS were predictive of events (p < 0.001). In comparison with additive EuroSCORE, CAPS score was associated with a 27% net reclassification index. Conclusions: Coronary computed tomography angiography provides incremental anatomical data to clinical risk assessment to help determine the prognosis of patients after CABG. The CAPS evaluation with CCTA might help identify those patients at highest risk.

Diagnostic accuracy of second-generation dual-source computed tomography coronary angiography with iterative reconstructions: a real-world experience (Article)

2011-11-24T00:00:00Z

Purpose: The authors evaluated the diagnostic accuracy of second-generation dual-source (DSCT) computed tomography coronary angiography (CTCA) with iterative reconstructions for detecting obstructive coronary artery disease (CAD). Materials and methods: Between June 2010 and February 2011, we enrolled 160 patients (85 men; mean age 61.2±11.6 years) with suspected CAD. All patients underwent CTCA and conventional coronary angiography (CCA). For the CTCA scan (Definition Flash, Siemens), we use prospective tube current modulation and 70-100 ml of iodinated contrast material (Iomeprol 400 mgI/ ml, Bracco). Data sets were reconstructed with iterative reconstruction algorithm (IRIS, Siemens). CTCA and CCA reports were used to evaluate accuracy using the threshold for significant stenosis at ≥50% and ≥70%, respectively. Results: No patient was excluded from the analysis. Heart rate was 64.3±11.9 bpm and radiation dose was 7.2±2.1 mSv. Disease prevalence was 30% (48/160). Sensitivity, specificity and positive and negative predictive values of CTCA in detecting significant stenosis were 90.1%, 93.3%, 53.2% and 99.1% (per segment), 97.5%, 91.2%, 61.4% and 99.6% (per vessel) and 100%, 83%, 71.6% and 100% (per patient), respectively. Positive and negative likelihood ratios at the per-patient level were 5.89 and 0.0, respectively. Conclusions: CTCA with second-generation DSCT in the real clinical world shows a diagnostic performance comparable with previously reported validation studies. The excellent negative predictive value and likelihood ratio make CTCA a first-line noninvasive method for diagnosing obstructive CAD.

Diagnostic accuracy of 64-slice computed tomography coronary angiography in a large population of patients without revascularisation: Registry data on the impact of calcium score (Article)

2011-10-01T00:00:00Z

Purpose: This study evaluated the diagnostic accuracy of computed tomography coronary angiography (CTCA) for detecting significant coronary artery stenosis (≥50% lumen reduction) at different coronary calcium score (CACS) values with conventional coronary angiography (CAG) as the reference standard. Material and methods: A total of 1,500 patients (928 men, mean age 58.2±12.5 years) in sinus rhythm who underwent CTCA (64-slice technology) and CAG were enrolled. Diagnostic accuracy and likelihood ratios (LR) of CTCA were evaluated against CAG for the total population and in different CACS classes (0; 1-10; 11-100; 101-400; 401-1,000; >1,000). Results: The prevalence of obstructive disease was 51% (23.5% single vessel; 27.5% multivessel; progressive increase from 17.9% to 94% through the CACS classes). In the per-patient analysis, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CTCA were 99%, 92%, 94% and 99%, respectively. Per-patient analysis showed a worse PPV of CTCA (76-77%) in classes with low CACS (1-10/11-100). Per-patient LR were higher in classes with extreme CACS values (0 = LR+ 18.3 and LR- = 0.0; c1,000 = LR+ 17.0 and LR- = 0.0) with values always >7 for LR+ and <0.033 for LR- for all CACS classes. Conclusions: CTCA is a reliable diagnostic modality, with high sensitivity and NPV regardless of CACS.

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 (Article)

2011-10-01T00:00:00Z

Purpose: 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). Materials and methods: 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). Results: 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. Conclusions: 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.

Prognostic value of computed tomography coronary angiography in patients with chest pain of suspected cardiac origin (Article)

2011-08-01T00:00:00Z

Purpose: The authors sought to determine the prognostic value of computed tomography coronary angiography (CTCA) in patients with acute chest pain (ACP). Materials and methods: A total of 145 consecutive patients (75 men; 64±12 years) with ACP were referred from the Emergency Department for CTCA, which was performed with a standard protocol using a 64-slice scanner. Patients were stratified according to the Morise clinical score (low, intermediate, high) and to the CTCA findings [absence of coronary artery disease (CAD), nonobstructive CAD, obstructive CAD]. Patients were followed up for the occurrence of major events: cardiac death, nonfatal myocardial infarction, unstable angina and revascularisation. Results: One hundred and twenty-seven (87.6%) patients were without a history of CAD, and 18 (12.4%) patients had a history of CAD. Obstructive CAD (>50% luminal narrowing) was detected in 35 (24%) patients; nonobstructive CAD (≤50% luminal narrowing) in 62 (43%) and absence of CAD in 48 (33%) patients. During a mean follow-up of 20±3 months, 20 events occurred (four hard events). Sixteen events (three hard events) occurred in patients without a history of CAD, and four events (one hard event) occurred in patients with a history of CAD. In patients with absence of CAD as detected by CTCA, the rate of events was 0%. At multivariate analysis, hypercholesterolaemia and obstructive CAD were significant predictors of events (p<0.05). Conclusions: An excellent prognosis was observed in patients with ACP and normal CTCA. CTCA shows the potential for optimal stratification of patients with ACP.

A clinical prediction rule for the diagnosis of coronary artery disease: Validation, updating, and extension (Article)

2011-06-01T00:00:00Z

AimsThe aim was to validate, update, and extend the DiamondForrester model for estimating the probability of obstructive coronary artery disease (CAD) in a contemporary cohort. Methods and resultsProspectively collected data from 14 hospitals on patients with chest pain without a history of CAD and referred for conventional coronary angiography (CCA) were used. Primary outcome was obstructive CAD, defined as <50 stenosis in one or more vessels on CCA. The validity of the DiamondForrester model was assessed using calibration plots, calibration-in-the-large, and recalibration in logistic regression. The model was subsequently updated and extended by revising the predictive value of age, sex, and type of chest pain. Diagnostic performance was assessed by calculating the area under the receiver operating characteristic curve (c-statistic) and reclassification was determined. We included 2260 patients, of whom 1319 had obstructive CAD on CCA. Validation demonstrated an overestimation of the CAD probability, especially in women. The updated and extended models demonstrated a c-statistic of 0.79 (95 CI 0.770.81) and 0.82 (95 CI 0.800.84), respectively. Sixteen per cent of men and 64 of women were correctly reclassified. The predicted probability of obstructive CAD ranged from 10 for 50-year-old females with non-specific chest pain to 91 for 80-year-old males with typical chest pain. Predictions varied across hospitals due to differences in disease prevalence. Conclusion Our results suggest that the DiamondForrester model overestimates the probability of CAD especially in women. We updated the predictive effects of age, sex, type of chest pain, and hospital setting which improved model performance and we extended it to include patients of 70 years and older.

The clue of ST-elevation myocardial infarction by means of integrated non-invasive imaging (Article)

2011-03-01T00:00:00Z

We describe the case of a 24-year-old man who presented at our emergency department with ST-elevation myocardial infarction (STEMI). The patient showed no coronary artery disease on conventional coronary angiography (CAG). Computed tomography coronary angiography (CTCA) and cardiac magnetic resonance (MR) performed thereafter allowed the highly probable diagnosis of the culprit lesion (i.e. vulnerable plaque) and of the infarcted area. We demonstrated the impact of integrated non-invasive imaging in defining the diagnosis of STEMI with normal coronary arteries on CAG.

Atherosclerotic pattern of coronary myocardial bridging assessed with CT coronary angiography (Article)

2011-02-25T00:00:00Z

The aim of our study was to evaluate the atherosclerotic pattern of patients with coronary myocardial bridging (MB) by means of CT Coronary Angiography (CT-CA). 254 consecutive patients (166 male, mean age 58.6 ± 10.3) who underwent 64-slice CT-CA according to current clinical indications were reviewed for the presence of MB and concomitant segmental atherosclerotic pattern. Coronary plaques were assessed in all patients enrolled. 73 patients (29%) presented single (90%) or multiple (10%) MB, frequently (93%) localized in the mid-distal left anterior descending artery. The MB segment was always free of atherosclerosis. Segments proximal to the MB presented: no atherosclerotic disease (n = 37), positive remodeling (n = 23), <50% (n = 14), or >50% stenoses (n = 7). Distal segments presented a different atherosclerosis pattern (P < 0.0001): absence of disease (n = 73), no significant lesions (n = 8). No significant differences were found between segments proximal to MB and proximal coronary segments apart from left main trunk. Pattern of atherosclerotic lesions located in segments 6 and 7 significantly differs between patients with MB and patients without MB (P < 0.05). CT-CA is a reliable method to non-invasively demonstrate MB and related atherosclerotic pattern. CT-CA provides new insight regarding atherosclerosis distribution in segments close to MB.

Prognostic value of CT coronary angiography: Focus on obstructive vs. nonobstructive disease and on the presence of left main disease (Article)

2011-02-01T00:00:00Z

Purpose: The authors investigated the prognostic value of computed tomography coronary angiography (CTCA) for major adverse cardiac events (MACE) in patients with suspected or known coronary artery disease (CAD), with particular focus on left main (LM) disease and obstructive vs. nonobstructive disease. Materials and methods: A total of 727 consecutive patients (485 men, age 62±11years) with suspected (514; 70.1%) or known (213; 29.9%) CAD underwent CTCA. Patients were followed up for the occurrence of MACE (i.e. cardiac death, nonfatal myocardial infarction, unstable angina, percutaneous/surgical revascularisation). Results: A total of 117 MACE [five cardiac deaths, 11 acute myocardial infarctions (AMI), five unstable angina, 86 percutaneous coronary interventions, ten coronary artery bypass grafts] occurred during a mean follow-up of 20 months. Severity and extension of CAD was associated with a progressively worse prognosis. The event rate was 0% among patients with normal coronary arteries at CTCA. The presence of LM disease was not associated with a worse prognosis either in patients with no history of CAD or in those with a history of CAD. At multivariate analysis, presence of obstructive CAD and diabetes were the only independent predictors of MACE. Conclusions: Evaluation of atherosclerotic burden by CTCA provides an independent prognostic value for prediction of MACE. Patients with normal CTCA findings have an excellent prognosis at follow-up.

Impact of Clinical Presentation and Pretest Likelihood on the Relation Between Calcium Score and Computed Tomographic Coronary Angiography (Article)

2010-12-15T00:00:00Z

The purpose of the present study was to assess the impact of clinical presentation and pretest likelihood on the relation between coronary calcium score (CCS) and computed tomographic coronary angiography (CTA) to determine the role of CCS as a gatekeeper to CTA in patients presenting with chest pain. In 576 patients with suspected coronary artery disease (CAD), CCS and CTA were performed. CCS was categorized as 0, 1 to 400, and >400. On CT angiogram the presence of significant CAD (≥50% luminal narrowing) was determined. Significant CAD was observed in 14 of 242 patients (5.8%) with CCS 0, in 94 of 260 patients (36.2%) with CCS 1 to 400, and in 60 of 74 patients (81.1%) with CCS >400. In patients with CCS 0, prevalence of significant CAD increased from 3.9% to 4.1% and 14.3% in nonanginal, atypical, and typical chest pain, respectively, and from 3.4% to 3.9% and 27.3% with a low, intermediate, and high pretest likelihood, respectively. In patients with CCS 1 to 400, prevalence of significant CAD increased from 27.4% to 34.7% and 51.7% in nonanginal, atypical, and typical chest pain, respectively, and from 15.4% to 35.6% and 50% in low, intermediate, and high pretest likelihood, respectively. In patients with CCS >400, prevalence of significant CAD on CT angiogram remained high (>72%) regardless of clinical presentation and pretest likelihood. In conclusion, the relation between CCS and CTA is influenced by clinical presentation and pretest likelihood. These factors should be taken into account when using CCS as a gatekeeper for CTA.

Low dose CT of the heart: a quantum leap into a new era of cardiovascular imaging (Article)

2010-12-01T00:00:00Z

In 10 years, computed tomography coronary angiography (CTCA) has shifted from an investigational tool to clinical reality. Even though CT technologies are very advanced and widely available, a large body of evidence supporting the clinical role of CTCA is missing. The reason is that the speed of technological development has outpaced the ability of the scientific community to demonstrate the clinical utility of the technique. In addition, with each new CT generation, there is a further broadening of actual and potential applications. In this review we examine the state of the art on CTCA. In particular, we focus on issues concerning technological development, radiation dose, implementation, training and organisation.

CT coronary angiography and exercise ECG in a population with chest pain and low-to-intermediate pre-test likelihood of coronary artery disease (Article)

2010-12-01T00:00:00Z

Objective: To evaluate diagnostic accuracy of exercise ECG (ex-ECG) versus 64-slice CT coronary angiography (CT-CA) for the detection of significant coronary artery stenosis in a population with low-to-intermediate pre-test likelihood of coronary artery disease (CAD). Design: Retrospective single centre. Setting: Tertiary academic hospital. Patients: 177 consecutive patients (88 men, 89 women, mean age 53.5±7.6 years) with chest pain and low-to-intermediate pre-test likelihood of CAD were retrospectively enrolled. Interventions: All patients underwent ex-ECG, CT-CA and invasive coronary angiography (ICA). Main outcome measure: A lumen diameter reduction of ≥50% was considered as significant stenosis for CT-CA. Ex-ECG was classified as positive, negative or non-diagnostic. Results were compared with ICA. Diagnostic accuracy of CT-CA and ex-ECG was calculated using ICA as the reference standard. A parallel comparative analysis using a cut-off value of 70% for significant lumen reduction was also performed too. Results: ICA disclosed an absence of significant stenosis (≥50% luminal narrowing) in 85.3% (151/177) patients, single-vessel disease in 9.0% (16/177) patients and multivessel disease in 5.6% (10/177) patients. Prevalence of obstructive disease at ICA was 14.7% (26/177). Sensitivity, specificity, positive and negative predictive values at the patient level were 100.0%, 98.7%, 92.9%, 100%, respectively, for CT-CA and 46.2%, 16.6%, 8.7%, 64.1%, respectively, for ex-ECG. Agreement between CT-CA and ex-ECG was 20.9%. CT-CA performed equally well in men and women, while ex-ECG had a better performance in men. After considering the cut-off value of 70% for significant stenosis, the difference between CT-CA and ex-ECG remained significant (p<0.01), with a low agreement (21.5%). Conclusions: CT-CA provides optimal diagnostic performance in patients with atypical chest pain and low-to-intermediate risk of CAD. Ex-ECG has poor diagnostic accuracy in this population. Concerns are related to risk of radiation dose versus the benefits of correct disease stratification.

Left ventricular ejection fraction: Real-world comparison between cardiac computed tomography and echocardiography in a large population [La frazione di eiezione del ventricolo sinistro: confronto nel mondo reale tra cardio-TC ed ecocardiografia in un'ampia popolazione] (Article)

2010-10-01T00:00:00Z

Purpose: This study compared cardiac computed tomography (CT) and two-dimensional transthoracic echocardiography (ECC) for assessing left ventricular ejection fraction (LVEF) using real-world data from a large patient population. Materials and methods: We studied 450 patients (284 males; mean age 64±12 years; range 12-88) who underwent CT and ECC due to suspected coronary artery disease. For CT, we used multiphase short-axis reconstructions and evaluated them with a dedicated software tool that uses Simpson's rule to compute LV volumes. For ECC, computation was based on the biplane Simpson's method. Results in terms of EF were compared with the paired Student's t test, Pearson's correlation coefficient (r), and Bland-Altman analysis. Results: EF was 52%±15% for CT and 55%±13% for ECC. Statistically significant differences, albeit with good correlation, were observed between the measurements (r=0.71; p<0.05). ECC showed a slight tendency to overestimate EF. When the population was divided into subgroups according to EF, this was underestimated by ECC in the subgroup with EF >50% and overestimated in those with EF 35%-50% and <35%, with consistently significant differences between ECC and CT (p<0.05) and progressively lower levels of agreement. Conclusions: In the real-world assessment of EF, ECC provides significantly different data from CT, with a bias that increases proportionally to LV systolic dysfunction.

Impact of tube current in the quantitative assessment of acute reperfused myocardial infarction with 64-slice delayed-enhancement CT: A porcine model [Impatto della corrente del tubo sulla valutazione quantitativa dell'infarto miocardico acuto riperfuso mediante TC 64 strati e tecnica di delayed enhancement: esperienza in modello animale porcino] (Article)

2010-10-01T00:00:00Z

Purpose: This study evaluated the impact of tube current (mAs) in delayed-enhancement computed tomography (CT) imaging for assessing acute reperfused myocardial infarction in a porcine model. Materials and methods: In five domestic pigs (mean weight 24 kg), the circumflex coronary artery was balloon-occluded for 2 h and then reperfused. After 5 days, CT imaging was performed following administration of iodinated contrast material. A 64-slice CT system was used to perform first-pass coronary angiography with a tube current of 15 mAs/kg [Arterial Phase (ART)] followed by two delayed-enhancement (DE) scans 15 min after contrast material administration, with a tube current of 15 mAs/kg and 37.5 mAs/kg, respectively (DE1 and DE2). The mean heart rate decreased to 51±9 beats/min after administration of zatebradine (10 mg/kg IV). The data set was reconstructed during the end-diastolic phase of the cardiac cycle. Areas with DE, no reflow and remote myocardium [remote left ventricular (LV)] were calculated. CT values expressed in Hounsfield units (HU) were measured using five regions of interest (ROI): DE, no reflow, remote LV, LV cavity (LV lumen) and in air, respectively. Differences, correlations, image quality [signal-to-noise ratio (SNR)] and contrast resolution [contrast-to-noise ratio (CNR)] were calculated. Results: Significant differences were found between attenuation of areas of DE, no reflow and remote LV (p<0.001) within the different scans. There was a fair correlation between DE and no-reflow attenuation (r=0.6; p<0.001). In DE 1 vs. DE2, areas of DE and no reflow were not significantly different (p>0.05). The SNR and CNR were not significantly different in DE1 vs. DE2 (p>0.05). Conclusions: Tube current does not significantly affect infarction area, image quality or contrast resolution of DE imaging with CT.

Functional parameters of the left ventricle: comparison of cardiac MRI and cardiac CT in a large population (Article)

2010-08-01T00:00:00Z

Purpose: The authors sought to compare magnetic resonance imaging (MRI) and computed tomography (CT) for assessing left ventricular (LV) function parameters in a large patient population. Materials and methods: The study was conducted on 181 patients who underwent cardiac MRI and cardiac CT for various indications. For MRI, we used two-dimensional cine balanced steady-state free precession (b-SSFP) sequences, and for CT we used multiphase short-axis reconstructions. Volume data sets were evaluated with dedicated software. Results were compared with a paired, two-tailed Student's t test, Pearson's correlation (r), and Bland-Altman analysis. Results: A high level of concordance was observed between cardiac MRI and CT. Ejection fraction (EF) was 53±14% for MRI vs. 53%±15% for CT. There was good correlation for EF (r=0.71; p>0.05) and end-systolic volume (r=0.74; p>0.05). End-diastolic volume (74±23 ml at MRI vs. 71±19 ml at CT; r=0.58; p<0.05) and myocardial mass (63±20 g at MRI and 56±18 g at CT; r=0.89; p<0.01) showed statistically significant differences, although the discrepancy had no clinical impact. Conclusions: MRI and CT show a good level of agreement in assessing LV function parameters, and both can be used interchangeably in clinical practice.

Diabetes: Prognostic value of CT coronary angiography - Comparison with a nondiabetic population (Article)

2010-07-01T00:00:00Z

Purpose: To evaluate the prognostic value of multidetector computed tomographic (CT) coronary angiography in a diabetic population known to have or suspected of having coronary artery disease (CAD) compared with that in nondiabetic individuals. Materials and Methods: Institutional review board approval and patient informed consent were obtained. Three hundred thirteen patients with type 2 diabetes mellitus (DM) and 303 patients without DM underwent unenhanced 64-detector row CT, at which a calcium score was obtained, followed by CT angiography. Multidetector CT coronary angiograms were retrospectively classified as normal, showing nonobstructive CAD (≤50% luminal narrowing), or showing obstructive CAD (> 50% luminal narrowing). During follow-up after CT angiography, major events (cardiac death, nonfatal myocardial infarction, and unstable angina requiring hospitalization) and total events (major events plus coronary revascularizations) were recorded for each patient. Cox proportional hazards analysis and Kaplan-Meier analysis were used to compare survival rates. Results: In the group of 313 patients with DM, there were 213 men, and the mean age was 62 years ± 11 (standard deviation). In the group of 303 patients without DM, there were 203 men, and the mean age was 63 years ± 11. The mean number of diseased segments (5.6 vs 4.4, P =.001) and the rate of obstructive CAD (51% vs 37%, P < .001) were higher in patients with DM. Patients were followed up for a mean of 20 months ± 5.4 (range, 6-44 months). At multivariate analysis, DM (P < .001) and evidence of obstructive CAD (P < .001) were independent predictors of outcome. Obstructive CAD remained a significant multivariate predictor for both patients with DM and patients without DM. In both patients with DM and patients without DM with absence of disease, the event rate was 0%. The event rate increased to 36% in patients without DM but with obstructive CAD and was highest (47%) in patients with DM and obstructive CAD. Conclusion: In both patients with DM and patients without DM, multidetector CT coronary angiography provides incremental prognostic information over baseline clinical variables, and the absence of atherosclerosis at CT coronary angiography is associated with an excellent prognosis. Multidetector CT coronary angiography might be a clinically useful tool for improving risk stratification in both patients with DM and patients without DM.

Giant aneurysm of Valsalva's sinus: Diagnosis and preoperative planning using 64-slice computed tomography (Article)

2010-07-01T00:00:00Z

We describe a giant unruptured acquired aneurysm of the noncoronary sinus of Valsalva, which was detected incidentally in a 30-year-old rugby player with clinical suspicion of dermatomyositis. Sixty-four-slice cardiac computed tomography showed a giant aneurysm (diameters: 91 × 78 × 100 mm) of noncoronary sinus of Valsalva compressing both atrial chambers. The patient underwent cardiac surgery according to the Tirone David technique based on the information provided by cardiac computed tomography.

Diagnostic accuracy of 64-slice computed tomography coronary angiography for the detection of in-stent restenosis: A meta-analysis (Article)

2010-06-01T00:00:00Z

Background: We sought to evaluate the diagnostic accuracy of 64-slice multi-detector row computed tomography (MDCT) compared with invasive coronary angiography for in-stent restenosis (ISR) detection. Methods: MEDLINE, Cochrane library, and BioMed Central database searches were performed until April 2009 for original articles. Inclusion criteria were (1) 64-MDCT was used as a diagnostic test for ISR, with >50% diameter stenosis selected as the cut-off criterion for significant ISR, using invasive coronary angiography and quantitative coronary angiography as the standard of reference; (2) absolute numbers of true positive, false positive, true negative, and false negative results could be derived. Standard meta-analytic methods were applied. Results: Nine studies with a total of 598 patients with 978 stents included were considered eligible. On average, 9% of stents were unassessable (range 0-42%). Accuracy tests with 95% confidence intervals (CIs) comparing 64-MDCT vs invasive coronary angiography showed that pooled sensitivity, specificity, positive and negative likelihood ratio (random effect model) values were: 86% (95% CI 80-91%), 93% (95% CI 91-95%), 12.32 (95% CI 7.26-20.92), 0.18 (95% CI 0.12-0.28) for binary ISR detection. The symmetric area under the curve value was 0.94, indicating good agreement between 64-MDCT and invasive coronary angiography. Conclusions: 64-MDCT has a good diagnostic accuracy for ISR detection with a particularly high negative predictive value. However, still a relatively large proportion of stents remains uninterpretable. Accordingly, only in selected patients, 64-MDCT may serve as a potential alternative noninvasive method to rule out ISR.

Lumen enhancement influences absolute noncalcific plaque density on multislice computed tomography coronary angiography: Ex-vivo validation and in-vivo demonstration (Article)

2010-05-01T00:00:00Z

Aim: The purpose of this study was to define the in-vitro and in-vivo effects of intracoronary enhancement on the absolute density values of coronary plaques during multislice computed tomography. Methods: We studied seven ex-vivo left coronary artery specimens surrounded by olive oil and filled with isotonic saline and four solutions with decreasing dilutions of contrast material: control (isotonic saline), 1/200, 1/80, 1/50, and 1/20. The multislice computed tomography protocol was: slice/collimation 32 × 2 × 0.6 mm and rotation time 330 ms. The attenuation (Hounsfield units) value of atherosclerotic plaques was measured for each dilution in lumen, plaque (noncalcified coronary wall thickening), calcium, and surrounding oil. In-vivo assessment was performed in 12 patients (nine men; mean age 58.7 ± 9.9 years) who underwent two subsequent multislice computed tomography scans (arterial and delayed) after intravenous administration of a single bolus of contrast material. The attenuation values of lumen and plaques during arterial and delayed computed tomography were compared. The results were compared with one-way analysis of variance and correlated with Pearson's test. Results: Mean lumen (45 ± 38-669 ± 151 HU) and plaque (11 ± 35-101 ± 72 HU) attenuation differed significantly (P < 0.001) among the different dilutions. The attenuation of lumen and plaque of coronary plaques showed moderate correlation (r = 0.54, P < 0.001). The mean attenuation value in vivo for the arterial and delayed phase scans differed significantly (P < 0.001) for lumen (325 ± 70 and 174 ± 46 HU, respectively) and plaque (138 ± 71 and 100 ± 52 HU, respectively). Conclusion: Coronary plaque attenuation values are significantly modified by differences in lumen contrast densities both ex vivo and in vivo. This should be taken into account when considering the distinction between lipid and fibrous plaques.

Diagnostic accuracy of 64-slice computed tomography coronary angiography in a large population of patients without revascularisation: Registry data and review of multicentre trials (Article)

2010-04-01T00:00:00Z

Purpose. This study was undertaken to evaluate the diagnostic accuracy of computed tomography coronary angiography (CT-CA) for the detection of significant coronary artery stenosis (≥50% lumen reduction) compared with conventional coronary angiography (CCA) in a registry and to review major multicentre trials. Materials and methods. A total of 1,372 patients (882 men, 490 women; mean age 59.3±11.9 years) in sinus rhythm were studied with CT-CA (64-slice technology) and CCA. The diagnostic accuracy of CT-CA was evaluated against quantitative CCA as a reference standard for coronary artery stenosis. Positive and negative likelihood ratios and inter-and intraobserver agreement were calculated. Results. The prevalence of disease was 53%. CCA demonstrated the absence of significant coronary artery disease in 46.6% (639/1372), single-vessel disease in 24.7% (337/1372) and multivessel disease in 28.9% (396/1372) of patients. In per-patient analysis sensitivity, specificity and positive and negative predictive value of CT-CA were 99% [confidence interval (CI) 97-99], 92% (CI 89-94), 94% (CI 91-95) and 99% (CI 97-99), respectively. Per-patient and per-segment likelihood ratios (LR+=12.4 and LR-=0.011; LR+=18.3 and LR-=0.064, respectively), were good. Inter-and intraobserver variability was 0.78 and 0.85, respectively. Conclusions. CT-CA is a reliable diagnostic modality both in terms of sensitivity and negative predictive value. Differences in trial results are also due to the different parameters used for patient inclusion.

Stress-ECG vs. CT coronary angiography for the diagnosis of coronary artery disease: A "real-world" experience (Article)

2010-04-01T00:00:00Z

Purpose. This study aimed to evaluate the diagnostic accuracy of stress electrocardiogram (ECG) and computed tomography coronary angiography (CTCA) for the detection of significant coronary artery stenosis (≥50%) in the real world using conventional CA as the reference standard. Materials and methods. A total of 236 consecutive patients (159 men, 77 women; mean age 62.8±10.2 years) at moderate risk and with suspected coronary artery disease (CAD) were enrolled in the study and underwent stress ECG, CTCA and CA. The CTCA scan was performed after i.v. administration of a 100-ml bolus of iodinated contrast material. The stress ECG and CTCA reports were used to evaluate diagnostic accuracy compared with CA in the detection of significant stenosis ≥50%. Results. We excluded 16 patients from the analysis because of the nondiagnostic quality of stress ECG and/or CTCA. The prevalence of disease demonstrated at CA was 62% (n=220), 51% in the population with comparable stress ECG and CTCA (n=147) and 84% in the population with equivocal stress ECG (n=73). Stress ECG was classified as equivocal in 73 cases (33.2%), positive in 69 (31.4%) and negative in 78 (35.5%). In the per-patient analysis, the diagnostic accuracy of stress ECG was sensitivity 47%, specificity 53%, positive predictive value (PPV) 5(31.4%) and negative in 78 (35.5%). In the per-patient analysis, the diagnostic accuracy of stress ECG was sensitivity 47%, specificity 53%, positive predictive value (PPV) 5)51% and negative predictive value (NPV) 49%. On stress ECG, 40 (27.2%) patients were misclassified as negative, and 34 (23.1%) patients with nonsignificant stenosis were overestimated as positive. The diagnostic accuracy of CTCA was sensitivity 96%, specificity 65%, PPV 74% and NPV 94%. CTCA incorrectly classified three (2%) as negative and 25 (17%) as positive. The difference in diagnostic accuracy between stress ECG and CTCA was significant (p <0.01). Conclusions. CTCA in the real world has significantly higher diagnostic accuracy compared with stress ECG and could be used as a first-line study in patients at moderate risk.

A bullet wandering through the heart (Article)

2010-03-01T00:00:00Z

We report a case of young male with a penetrating chest trauma due to a gunshot. The bullet was detected by conventional X-ray and localized within the lateral wall of the left ventricle by CT. During surgery the bullet was not found. Thereafter conventional X-ray showed migration of the bullet within the lung parenchyma.

Impact of contrast material volume on quantitative assessment of reperfused acute myocardial infarction using delayed-enhancement 64-slice CT: Experience in a porcine model (Article)

2010-02-01T00:00:00Z

Purpose: Our purpose in this study was to compare the impact of contrast material volume in delayed-enhancement computer tomography (CT) imaging for assessing acute reperfused myocardial infarction. Materials and methods: In five domestic pigs (20-30 kg), the circumflex coronary artery (CX) was balloon-occluded for 2 h followed by reperfusion. After 5 days, CT imaging was performed after intravenous administration of iodinated contrast material (Iomeprol 400mgI/ml; Bracco, Italy). A 64-slice multidetector CT (MDCT) (Sensation 64, Siemens) scanner was used for imaging, with standard angiography characteristics. Three scans were performed: first, coronary angiography at first pass with 1.25 gI/kg of contrast material (ART); and remaining delayed-enhancement (DE1-DE2) 15 min after administration of 1.25 (DE1) and 15 min after additional administration of 2.50 gI/kg (=total 3.75 gI/kg-DE2). Mean heart rate decreased to 51±9 bpm after intravenous administration of Zatebradine (10 mg/kg). Data sets were reconstructed during the end-diastolic phase of the cardiac cycle. Areas of infarction-enhanced (DE), no-reflow (no-reflow) and remote myocardial [remote left ventricle (LV)] were manually contoured. CT attenuation values (Hounsfield units) were measured using five regions of interest: DE, no-reflow, remote LV, left ventricular cavity (lumen LV) and in air. Differences, correlations, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Results: We found significant differences between the attenuation of DE, no-reflow and remote LV (p<0.001). DE and no-reflow size were assessed accurately with DEMDCT. In particular, SNR and CNR showed higher values in DE2(∼6.0 and 3.5, respectively; r2=0.90) vs. DE1(∼4.0 and 2.2, respectively; r2=0.85). Conclusions: The increase of contrast material volume determines a significant improvement in myocardial infarction image quality with DE-MDCT.

Dose reduction in spiral CT coronary angiography with dual source equipment. Part II. Dose surplus due to slope-up and slope-down of prospective tube current modulation in a phantom model (Article)

2010-02-01T00:00:00Z

Purpose: This study was undertaken to estimate surplus radiation dose in retrospectively electrocardiography (ECG)-gated dual-source computed tomography coronary angiography (DSCT-CA) due to the slope-up and slope-down of the tube current using prospectively ECG-triggered tube modulation. Materials and methods: We used an anthropomorphic phantom with an ECG-gated retrospective protocol and a DSCT scanner (Definition, Siemens). We used four tube current modulation algorithms: narrow pulsing window, with tube current reduction to 20% (A) and 4% (B) of peak current; and wide pulsing window, with tube current reduction to 20% (C) and 4% (D). Each algorithm was applied at five heart rates (HR=45, 60, 75, 90 and120 bpm) with adaptive pitch values (0.2-0.5). Data sets were reconstructed in 5% increments from 0-95% of the R-R interval. Noise was measured at each R-R step in order to identify low noise (100% dose), medium noise (slope-up/down) and high noise (4/20% dose). Width of the transition window (slope-up/slope-down from 4/20% to 100% dose) was calculated. The surplus dose due to slope-up/slope-down was calculated. Results: Surplus dose was 19% (A), 34% (B), 14% (C) and 21% (D). The transition window lasted 10%+10% (slope-up + down) for HR ≤75 bpm and all HR in C (except for 120 bpm; 25%+15%), 15%+15% for HR ≤90 bpm (A). For C and D, instead, the slope-up increased with progressively higher HR (10%-25% of the R-R interval, except for 90 bpm, 10%), whereas the slope-down remained constant at 5% (except for 120 bpm; 10%). Conclusions: The adaptive ECG-pulsing windows produced an increment of the surplus dose with increasing HR. The transition window was a constant source of surplus radiation dose in the range of 14%-34%.

Diagnostic accuracy of computed tomography coronary angiography in patients with a zero calcium score (Article)

2010-01-01T00:00:00Z

To evaluate the diagnostic accuracy of 64-slice CT coronary angiography (CT-CA) for the detection of significant coronary artery stenosis in patients with zero on the Agatston Calcium Score (CACS). We enrolled 279 consecutive patients (96 male, mean age 48±12 years) with suspected coronary artery disease. Patients were symptomatic (n=208) or asymptomatic (n=71), and underwent conventional coronary angiography (CAG). For CT-CA we administered an IV bolus of 100 ml of iodinated contrast material. CT-CA was compared to CAG using a threshold for significant stenosis of ≤50%. The prevalence of disease demonstrated at CAG was 15% (1.4% in asymptomatic). The population at CAG showed no or non-significant disease in 85% (238/279), single vessel disease in 9% (25/279), and multi-vessel disease in 6% (16/279). Sensitivity, specificity, and positive and negative predictive values of CT-CA vs. CAG on the patient level were 100%, 95%, 76%, and 100% in the overall population and 100%, 100%, 100%, and 100% in asymptomatic patients, respectively. CT-CA proves high diagnostic performance in patients with or without symptoms and with zero CACS. The prevalence of significant disease detected by CT-CA was not negligible in asymptomatic patients. The role of CT-CA in asymptomatic patients remains uncertain.

Assessment of coronary artery disease and calcified coronary plaque burden by computed tomography in patients with and without diabetes mellitus (Article)

2010-01-01T00:00:00Z

Purpose: To compare the coronary atherosclerotic burden in patients with and without type-2 diabetes using CT Coronary Angiography (CTCA). Methods and Materials: 147 diabetic (mean age: 65 ± 10 years; male: 89) and 979 nondiabetic patients (mean age: 61 ± 13 years; male: 567) without a history of coronary artery disease (CAD) underwent CTCA. The per-patient number of diseased coronary segments was determined and each diseased segment was classified as showing obstructive lesion (luminal narrowing >50%) or not. Coronary calcium scoring (CCS) was assessed too. Results: Diabetics showed a higher number of diseased segments (4.1 ± 4.2 vs. 2.1 ± 3.0; p < 0.0001); a higher rate of CCS > 400 (p < 0.001), obstructive CAD (37% vs. 18% of patients; p < 0.0001), and fewer normal coronary arteries (20% vs. 42%; p < 0.0001), as compared to nondiabetics. The percentage of patients with obstructive CAD paralleled increasing CCS in both groups. Diabetics with CCS ≤ 10 had a higher prevalence of coronary plaque (39.6% vs. 24.5%, p = 0.003) and obstructive CAD (12.5% vs. 3.8%, p = 0.01). Among patients with CCS ≤ 10 all diabetics with obstructive CAD had a zero CCS and one patient was asymptomatic. Conclusions: Diabetes was associated with higher coronary plaque burden. The present study demonstrates that the absence of coronary calcification does not exclude obstructive CAD especially in diabetics.

Coronary calcium score and computed tomography coronary angiography in high-risk asymptomatic subjects: Assessment of diagnostic accuracy and prevalence of non-obstructive coronary artery disease (Article)

2010-01-01T00:00:00Z

Objectives: The aim of the study was to compare the coronary artery calcium score (CACS) and computed tomography coronary angiography (CTCA) for the assessment of non-obstructive/obstructive coronary artery disease (CAD) in high-risk asymptomatic subjects. Methods: Two hundred and thirteen consecutive asymptomatic subjects (113 male; mean age 53.6 ± 12.4 years) with more than one risk factor and an inconclusive or unfeasible non-invasive stress test result underwent CACS and CTCA in an outpatient setting. All patients underwent conventional coronary angiography (CAG). Data from CACS (threshold for positive image: Agatston score 1/100/1,000) and CTCA were compared with CAG regarding the degree of CAD (non-obstructive/obstructive;

"in-house" pharmacological management for computed tomography coronary angiography: Heart rate reduction, timing and safety of different drugs used during patient preparation (Article)

2009-12-01T00:00:00Z

We retrospectively evaluated the effect, timing and safety of different pharmacological strategies during 64-slice CT coronary angiography (CT-CA). From the institutional database of CT-CA we enrolled 560 consecutive patients with suspected coronary artery disease. The type of drug preparation (group 1 = no treatment; group 2 = oral metoprolol; group 3 = other; group 4=intravenous (IV) atenolol; group 5=IV atenolol + nitrates; NR = non-responders), timing, and adverse effects were recorded. Heart rate (HR) during different preparation phases was recorded. Four adverse effects were recorded, none of which was attributable to pharmacological treatment. In all groups, except group 1, the HR on arrival was significantly reduced by the pharmacological treatment (p<0.01). Group 4 showed the best (-16±8 bpm) HR reduction. There was no significant effect on HR due to nitrates (p=0.49), while a slight increase due to contrast material was noted (p<0.05). Average time required for preparation was 44±25 min. Groups 4 and 5 showed the most effective timing (8±9 min and 8±8 min, respectively; p<0.01). Pharmacological preparation in patients undergoing CT-CA is safe and effective. Best results in terms of HR reduction and fast preparation are obtained with IV administration of beta-blockers.

Computed tomography coronary angiography plaque burden in patients with suspected coronary artery disease (Article)

2009-12-01T00:00:00Z

Purpose: To determine the relationship between established cardiovascular risk factors, clinical presentation and the extent of coronary artery disease (CAD), as described with computed tomography coronary angiography. MATERIAL AND Methods: In this cross-sectional study, we included 567 symptomatic individuals without a history of CAD who consecutively underwent 64-slice computed tomography coronary angiography for evaluation of suspected CAD. We analyzed the prevalence of CAD depending on sex, age, symptoms and risk factors. Results: A total of 8542 segments were analyzed. No evidence of CAD was observed in 225 patients (40%), nonsignificant CAD in 221 patients (39%) and significant CAD (luminal narrowing >50%) in the remaining 121 patients (21%). CAD increased with advancing age, significantly above 50 years (P < 0.05). Female patients had a higher prevalence of normal coronary arteries and males of significant CAD (P < 0.01). With the increase of risk factors, there was a significant increase of the significant disease (P < 0.01). Typical pain with respect to atypical pain had the strongest association with significant CAD (16 vs. 38%; P < 0.05). In multivariate analysis, the number of risk factors, age, male sex and typical pain remained strong predictors of significant CAD (P < 0.0001). Conclusion: Computed tomography coronary angiography may play an important role in risk stratification of patients with suspected CAD.

Dose reduction in spiral CT coronary angiography with dual-source equipment. Part I. A phantom study applying different prospective tube current modulation algorithms (Article)

2009-10-01T00:00:00Z

Purpose: The authors sought to compare different algorithms for dose reduction in retrospectively echocardiographically (ECG)-gated dual-source computed tomography (CT) coronary angiography (DSCT-CA) in a phantom model. Materials and methods: Weighted CT dose index (CTDI) was measured by using an anthropomorphic phantom in spiral cardiac mode (retrospective ECG gating) at five pitch values adapted with two heart-rate-adaptive ECG pulsing windows using four algorithms: narrow pulsing window, with tube current reduction to 20% (A) and 4% (B) of peak current outside the pulsing window; wide pulsing window, with tube current reduction to 20% (C) and 4% (D). Each algorithm was applied at different heart rates (45, 60, 75, 90, 120 bpm). Results: Mean CTDI volume (CTDIvol) was 36.9±9.7 mGy, 23.9±5.6 mGy, 49.7±16.2 mGy and 38.5±12.3 mGy for A, B, C and D, respectively. Consistent dose reduction was observed with protocols applying the 4% tube current reduction (B and D). Using the conversion coefficient for the chest, the mean effective dose was the highest for C (9.6 mSv) and the lowest for B (4.6 mSv). Heart-ratedependent pitch values (pitch=0.2, 0.26, 0.34, 0.43, 0.5) and the use of heart-rate-adaptive ECG pulsing windows provided a significant decrease in the CTDIvol with progressively higher heart rates (45, 60, 75, 90, 120 bpm), despite using wider pulsing windows. Conclusions: Radiation exposure with DSCT-CA using a narrow pulsing window significantly decreases when compared with a wider pulsing window. When using a protocol with reduced tube current to 4%, the radiation dose is significantly lower.

Assessment of left ventricular volumes with cardiac MRI: Comparison between two semiautomated quantitative software packages (Article)

2009-08-01T00:00:00Z

Purpose: This study compared two quantitative semiautomated software packages for volumetric analysis of the left ventricle (LV) by magnetic resonance (MR) imaging using two-dimensional (2D) cine balanced steady-state free precession (b-SSFP) sequences. Materials and methods: We included 46 consecutive patients who underwent cardiac MR imaging for various indications. Two-dimensional cine b-SSFP sequences were used to assess the LV. Data sets were evaluated with two dedicated software packages: ViewForum, version 4.2, and Argus, version Va60C. Results were compared with Student's t test for paired samples, Pearson's r correlation coefficient and R2 coefficient of determination; ejection fraction differences were assessed with Bland-Altman analysis. The time required for analysis was also recorded. Results: We observed very high levels of concordance and reproducibility. High correlation was observed for ejection fraction (p>0.05; r=0.9; R2=0.82). The time required for analysis was 7.6±2.78 min vs. 7.52±2.4 min (p>0.05; r=0.85; R2=0.73). Intraobserver and interobserver variability did not show significant differences. Conclusions: LV volume evaluation is an integral part of cardiac MR imaging. In our experience, there is no significant difference between the commonly used software packages in either quantitative output or time required for analysis.

Computed tomography coronary angiography vs. stress ECG in patients with stable angina (Article)

2009-06-01T00:00:00Z

This study compared the role of multislice computed tomography coronary angiography (MSCT-CA) and stress electrocardiography (ECG) in the diagnostic workup of patients with chronic chest pain. MSCT-CA was performed in 43 patients (31 men, 12 women, mean age 58.8±7.7 years) with stable angina after a routine diagnostic workup involving stress ECG and conventional CA. The following inclusion criteria were adopted: sinus rhythm and ability to hold breath for 12 s. Beta-blockers were administered in patients with heart rate ≥70 beats/minute. In order to identify or exclude patients with significant stenoses (≥50% lumen), we determined posttest likelihood ratios of stress test and MSCT-CA separately and of MSCT-CA performed after the stress test. The pretest probability of significant coronary artery disease (CAD) was 74%. Positive and negative likelihood ratios were 2.3 [95% confidence interval (CI) 1.0-5.3] and 0.3 (95% CI: 0.2-0.7) for the stress test and 10.0 (95% CI: 1.8-78.4) and 0.0 (95% CI: 0.0-∞) for MSCT-CA, respectively. MSCT-CA increased the posttest probability of significant CAD after a negative stress test from 50% to 86% and after a positive stress test from 88% to 100%. MSCT-CA correctly detected all patients without CAD. Noninvasive MSCT-CA is a potentially useful tool in the diagnostic workup of patients with stable angina owing to its capability to detect or exclude significant CAD.

Breast cancer in the heart (Article)

2009-05-01T00:00:00Z

We present a case of a 46-year-old woman who presented to our institution with a history of quadrantectomy and a current progressive dyspnea. Multislice computed tomography of the heart and coronary arteries was performed with standard protocol. The investigation demonstrated a hypodense mass infiltrating the interventricular septum, the cardiac apex and the right ventricular chamber. The mass also surrounded the left anterior descending coronary artery without any sign of occlusion. Cardiac computed tomography is performed in the follow-up of almost all cancer patients. Therefore, we expect that the increased survival of patients with advanced stages of cancer will lead to more frequent encounters with this kind of finding in routine clinical investigations.

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

2009-04-23T00:00:00Z

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.

Assessment of left main coronary artery atherosclerotic burden using 64-slice CT coronary angiography: Correlation between dimensions and presence of plaques (Article)

2009-04-01T00:00:00Z

Purpose: The aim of this study was to correlate left main (LM) coronary artery dimensions with the presence of atherosclerosis by multidetector-row computed tomography (MDCT) coronary angiography (CA) and to assess coronary atherosclerotic plaques with a semiquantitative method. Materials and methods: Sixty-two consecutive patients (41 men, mean age 60±11) with suspected coronary artery disease underwent 64-MDCT coronary angiography. LM dimensions (length, ostial and bifurcation diameters), quantitative [location, Hounsfield unit (HU) attenuation] and qualitative (composition, shape) analysis of plaques within the LM were performed. All patients underwent conventional CA. Results: Thirty patients (mean age 55±10) without plaques in the LM presented the following average dimensions: length 10.6±6.1 mm, ostial diameter 5.5±0.7 mm, bifurcation diameter 4.9±0.9 mm. LM plaques (n=36) were detected in 32 patients (mean age 64±10) with the following LM average dimensions: length 11.3±4.0 mm, ostial diameter 6.0±1.2 mm and bifurcation diameter 6.0±1.2 mm. Plaques were calcified (40%, mean attenuation 742±191 HU), mixed (43%, mean attenuation 387±94 HU) or noncalcified (17%, mean attenuation 56±14 HU) and were frequently eccentric (77%). Age was significantly different in the two groups (p<0.05). LM diameters of patients with plaques were improved (p<0.05). A moderate correlation was found between the LM bifurcation diameter and the corresponding plaque area (r=0.56). Significant conventional CA lesions of the LM were present in just three patients (5%). Conclusions: Increased LM diameters are associated with the presence of atherosclerosis. MDCT CA indicates relevant features of LM atherosclerotic burden, as rupture and subsequent thrombosis of vulnerable plaques may develop from lesions characterised as nonsignificant at conventional CA.

Prognostic value of computed tomography coronary angiography in patients with suspected coronary artery disease: A 24-month follow-up study (Article)

2009-02-18T00:00:00Z

The aim of this study was to determine the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major cardiac events in patients with suspected coronary artery disease (CAD). A total of 187 consecutive patients (119 men, age 62.5±10.5 years) without known heart disease underwent single-source 64-slice CTCA (Somatom Sensation 64, Siemens) for clinical suspicion of CAD. Patients underwent follow-up for the occurrence of cardiac death, nonfatal myocardial infarction, unstable angina and cardiac revascularization. In total, 2,822 coronary segments were assessed. Forty-two segments (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed absence of CAD in 65 (34.7%) patients, nonobstructive CAD (coronary plaque >50%) in 87 (46.5%) patients and obstructive CAD (>50%) in 35 (18.8%) patients. A total of 20 major cardiac events (3 myocardial infarctions, 16 cardiac revascularizations, 1 unstable angina) occurred during a mean follow-up of 24 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD and three events occurred in the group of nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. CTCA has a 100% negative predictive value for major cardiac events at 24-month follow-up in patients with normal coronary arteries.

Noninvasive evaluation of the celiac trunk and superior mesenteric artery with multislice CT in patients with chronic mesenteric ischaemia (Article)

2008-12-01T00:00:00Z

Purpose. This study sought to assess the role of multislice computed tomography (MSCT) in patients with suspected chronic mesenteric ischaemia (CMI). Materials and methods. Forty-five patients (29 men; mean age 68) underwent MSCT angiography of the abdomen for suspected CMI (main clinical finding: postprandial abdominal pain). The scan protocol was detectors/collimation 16/0.75 mm; feed 36 mm/s; rotation time 500 ms; increment 0.4 mm; 120-150 mAs and 120 kVp. A volume of 80 ml of contrast material was administered through an antecubital vein (rate 4 ml/s), followed by 40 ml of saline (rate 4 ml/s). Images were analysed on the workstation with different algorithms (axial image scrolling, multiplanar reconstructions, maximum intensity projection, volume rendering). Targeted central lumen-line reconstructions (curved reconstructions) were obtained along the celiac trunk (CeT) and superior mesenteric artery (SMA). Vessel occlusions and significant (>50%) stenosis were recorded. Results. Image generation and interpretation required 25 min. Stenosis and/or occlusions were detected in 29 (65%) cases on the CeT and in 32 (71%) on the SMA. Of those lesions (n=61), 44 (49%) were classified as not significant. In 16 (35%) cases, there was a simultaneous stenosis and/or occlusion of the CeT and SMA (confirmed by conventional angiography). In six (13%) cases, there were no lesions affecting the CeT, SMA or their branches (confirmed by clinical follow-up). Conclusions. MSCT angiography can play a major role in the detection of stenosis of the abdominal arteries in patients with suspected CMI.

Prognostic value of 64-slice coronary angiography in diabetes mellitus patients with known or suspected coronary artery disease compared with a nondiabetic population (Article)

2008-08-01T00:00:00Z

Purpose. This study aimed to determine the prognostic value of coronary angiography with multislice computed tomography (MSCT) in a population of diabetic subjects with known or suspected ischaemic heart disease compared with a nondiabetic control population. Materials and methods. Forty-nine patients with type 2 diabetes mellitus (DM) [group 1; mean age 67.7±8.8 years; 32 men; mean body mass index (BMI) 28±3.9] and 49 patients without DM (group 2, with similar demographic and clinical characteristics) were studied with MSCT coronary angiography to exclude the presence of ischaemic coronary artery disease (CAD). Each group comprised 26 patients (53%) with no history of ischaemic coronary disease and 23 patients (47%) with a history of myocardial infarction and/or myocardial revascularisation. Clinical follow-up was performed by analysing correlations between the rate of cumulative cardiac events (cardiac death, nonfatal myocardial infarction, unstable angina, and myocardial revascularisation), the severity of CAD identified on MSCT, and the presence of DM as a cardiovascular risk factor. Results. At mean follow-up of 20 months, univariate analysis of survival showed significant differences between the two groups (group 1 vs. group 2, p=0.046). Moreover, the cumulative cardiac event rate correlated significantly with the presence of significant CAD (>50% stenosis) in both groups (group 1: p=0.003; group 2: p=0.0004). Conclusions. Event-free survival is significantly lower in the diabetic population compared with the normal control population (p=0.046) and is closely correlated with the presence of significant CAD. MSCT is an effective method for stratifying such risk and, together with high diagnostic accuracy, provides additional prognostic value.

Predictive value of chest CT in patients with cystic fibrosis: A single-center 10-year experience (Article)

2008-06-01T00:00:00Z

OBJECTIVE. The objective of our study was to assess the accuracy of one of the most used scoring systems, the Bhalla scoring system, in the detection of lung impairment in patients with cystic fibrosis and in the prediction of cystic fibrosis progression. MATERIALS AND METHODS. From the database of our center, 300 CT examinations performed between 1991 and 2001 were reviewed. Pulmonary function tests performed the same day as radiologic assessment were available. Of this group, 145 examinations were retrospectively included, referring to 87 patients with confirmed cystic fibrosis and a mean age (± SD) of 15.6 ± 8.4 years (range, 9 months-38 years). Thirty patients underwent one CT examination, 56 underwent two examinations, and one patient underwent three examinations. The mean interval between two examinations was 36.5 months. The 145 examinations were independently reviewed by three radiologists who were blinded to the clinical and pulmonary function test results. The CT examinations were assessed using the scoring system proposed by Bhalla and colleagues. RESULTS. CT assessed using the Bhalla scoring system is mildly correlated with functional pulmonary test results and has high interobserver reproducibility. The CT score significantly changed between scans obtained in a mean interval of 36.5 months, whereas functional pulmonary test results did not, suggesting that CT is more sensitive than function tests for detecting small changes. However, the variation in CT scores did not predict progression of functional pulmonary test results or progression of CT findings between scans. CONCLUSION. CT assessment based on the Bhalla scoring system is more sensitive than pulmonary function tests in detecting initial morphologic changes. However, we found no evidence of the predictive value of CT.

Prevalence and characteristics of coronary artery disease in a population with suspected ischaemic heart disease using CT coronary angiography: Correlations with cardiovascular risk factors and clinical presentation (Article)

2008-04-01T00:00:00Z

Purpose. This study was undertaken to describe the correlation between the distribution of coronary artery disease (CAD) in a symptomatic population with suspected ischaemic heart disease, cardiovascular risk factors (RF) and clinical presentation. Materials and methods. We studied 163 patients (mean age 65.5 years; 101 men and 62 women) referred for multidetector computed tomography coronary angiography (MDCT-CA) to rule out CAD. The patients had no prior history of revascularisation or myocardial infarction. We analysed how the characteristics of CAD (severity and type of plaque) can change with the increase in RF and how they are related to different clinical presentations. Results. Patients were divided into three groups according to the number of RF: zero or one, two or three, and four or more. The percentage of coronary arteries with no plaque, nonsignificant disease and significant disease was 55%, 41% and 4%, respectively, in patients with zero or one RF; 27%, 51% and 22%, respectively, in patients with two or three RF; and 19%, 38% and 44%, respectively, in patients with four or more RF. Plaque in patients with nonsignificant disease was mixed in 65%, soft in 18% and calcified in 17%. The percentage of coronaries with no plaque in the three RF groups was 50%, 20% and 0% in patients with typical chest pain and 46%, 24% and 12% in those with atypical pain. The percentage of significant disease in patients with typical pain was 0%, 47% and 86% and in those with atypical pain 4%, 20% and 29%. Conclusions. MDCT plays an important role in the identification of CAD in patients with suspected ischaemic heart disease. Severity and type of disease is highly correlated with RF number and assumes different characteristics according to clinical presentation.

Prevalence of anatomical variants and coronary anomalies in 543 consecutive patients studied with 64-slice CT coronary angiography (Article)

2008-04-01T00:00:00Z

The aim of our study was to assess the prevalence of variants and anomalies of the coronary artery tree in patients who underwent 64-slice computed tomography coronary angiography (CT-CA) for suspected or known coronary artery disease. A total of 543 patients (389 male, mean age 60.5±10.9) were reviewed for coronary artery variants and anomalies including post-processing tools. The majority of segments were identified according to the American Heart Association scheme. The coronary dominance pattern results were: right, 86.6%; left, 9.2%; balanced, 4.2%. The left main coronary artery had a mean length of 112±55 mm. The intermediate branch was present in the 21.9%. A variable number of diagonals (one, 25%; two, 49.7%; more than two, 24%; none, 1.3%) and marginals (one, 35.2%; two, 46.2%; more than two, 18%; none, 0.6%) was visualized. Furthermore, CT-CA may visualize smaller branches such as the conus branch artery (98%), the sinus node artery (91.6%), and the septal branches (93%). Single or associated coronary anomalies occurred in 18.4% of the patients, with the following distribution: 43 anomalies of origin and course, 68 intrinsic anomalies (59 myocardial bridging, nine aneurisms), three fistulas. In conclusion, 64-slice CT-CA provides optimal visualization of the variable and complex anatomy of coronary arteries because of the improved isotropic spatial resolution and flexible post-processing tool.

64-slice computed tomography coronary angiography: Diagnostic accuracy in the real world (Article)

2008-03-01T00:00:00Z

Purpose. This study was done to evaluate the diagnostic accuracy of 64-slice computed tomography coronary angiography (CTCA) for the detection of significant coronary artery stenosis in the real clinical world. Materials and methods. From the CTCA database of our institution, we enrolled 145 patients (92 men, 52 women, mean age 63.4 ± 10.2 years) with suspected coronary artery disease. All patients presented with atypical or typical chest pain and underwent CTCA and conventional coronary angiography (CA). For the CTCA scan (Sensation 64, Siemens, Germany), we administered an IV bolus of 100 ml of iodinated contrast material (Iomeprol 400 mgI/ml, Bracco, Italy). The CTCA and CA reports used to evaluate diagnostic accuracy adopted ≥50% and ≥70%, respectively, as thresholds for significant stenosis. Results. Eleven patients were excluded from the analysis because of the nondiagnostic quality of CTCA. The prevalence of disease demonstrated at CA was 63% (84/134). Sensitivity, specificity and positive and negative predictive values for CTCA on a per-segment, per-vessel, and per-patient basis were 75.6%, 85.1%, 97.6%; 86.9%, 81.8%, 58.0%; 48.2%, 68.1%, 79.6%; and 95.7%, 92.3%, 93.5%, respectively. Only two out of 134 eligible patients were false negative. Heart rate did not significantly influence diagnostic accuracy, whereas the absence or minimal presence of coronary calcification improved diagnostic accuracy. The positive and negative likelihood ratios at the per-patient level were 2.32 and 0.041, respectively. Conclusions. CTCA in the real clinical world shows a diagnostic performance lower than reported in previous validation studies. The excellent negative predictive value and negative likelihood ratio make CTCA a noninvasive gold standard for exclusion of significant coronary artery disease.

Is dual-source CT coronary angiography ready for the real world? (Article)

2008-03-01T00:00:00Z

Influence of intra-coronary enhancement on diagnostic accuracy with 64-slice CT coronary angiography (Article)

2008-03-01T00:00:00Z

We assessed the effect of intra-coronary attenuation on diagnostic accuracy using 64-slice computed tomography coronary angiography (CT-CA). We enrolled 170 patients with suspected coronary artery disease who underwent conventional coronary angiography (CA) and 64-slice CT-CA (100 ml of Iomeprol 400 mg I/ml at 4 ml/s). The study population was divided into two groups (85 patients each based on median attenuation of 326 HU) based on mean arterial attenuation; group 1 with low attenuation and group 2 with high attenuation. Diagnostic accuracy for the detection of significant coronary artery stenosis was determined for both groups using CA as reference standard. Overall, 163 significant stenoses were detected in 1,030 assessable coronary artery segments in group 1 compared with 160 significant stenoses in 1,020 assessable segments in group 2. The average intra-coronary attenuation was significantly (P<0.05) higher for group 2 (388±46 HU) compared with group 1 (291±33 HU). The corresponding sensitivity and specificity values for detection of significant coronary artery stenosis were higher for group 2 (96.3% and 97.6%, respectively) than for group 1 (82.8% and 93.2%, respectively) and were more marked in distal coronary segments than in proximal segments. Higher intra-coronary attenuation on CT-CA results in greater diagnostic accuracy for detection of coronary artery stenosis.

Coronary variants and anomalies: Methodology of visualisation with 64-slice CT and prevalence in 202 consecutive patients (Article)

2007-12-01T00:00:00Z

Purpose. This paper aims to provide the tools for a complete anatomical evaluation of the coronary tree using 64-slice computed tomography (CT) and evaluate the prevalence of anatomical variants and anomalies in a population of 202 consecutive patients. Materials and methods. Two hundred and two patients with suspected coronary artery disease underwent 64-slice CT with a standard protocol. Two observers working in consensus evaluated and collected the data regarding anatomical variants and anomalies of the coronary vessels. Results. In the 202 consecutive patients, the prevalence of anatomical variants was: left dominant circulation (7%), absent left main (5%), presence of intermediate branch (17%), aortic origin of conus branch (13%) and circumflex origin of sinus node branch (15%). Coronary anomalies (origin and course, intrinsic and termination) showed an overall prevalence of 25%. Conclusions. CT is the ideal method for the three-dimensional evaluation of the coronary tree. Anatomical variants and anomalies of the coronary arteries are quite common and should be known and recognised promptly by the operators.

Diagnostic accuracy of 64-slice computed tomography coronary angiography in patients with low-to-intermediate risk (Article)

2007-10-01T00:00:00Z

Purpose. Our aim was to evaluate the diagnostic accuracy of 64-slice computed tomography coronary angiography (MSCT-CA) for detecting significant stenosis (≥50% lumen reduction) in a population of patients at low to intermediate risk. Materials and methods. We studied 72 patients (38 men, 34 women, mean age 53.9±8.0 years) with atypical or typical chest pain and stratified in the low-to intermediate risk category. MSCT-CA (Sensation 64 Cardiac, Siemens, Germany) was performed after IV administration of 100 ml of iodinated contrast material (Iomeprol 400 mgI/ml, Bracco, Italy). Two observers, blinded to the results of conventional coronary angiography (CAG), assessed the MSCT-CA scans in consensus. Diagnostic accuracy for detecting significant stenosis was calculated. Results. CAG demonstrated the absence of significant disease in 70.1% of patients (51/72). No patient was excluded from MSCT-CA. There were 37 significant lesions on 1,098 available coronary segments. Sensitivity, specificity and positive and negative predictive value of MSCT-CA for detecting significant coronary artery on a per-segment basis were 100%, 98.6%, 71.2% and 100%, respectively. All patients with at least one significant lesion were correctly identified by MSCT-CA. MSCT-CA scored 15 false positives on a per-segment base, which affected only marginally the per-p.atient performance (only one false positive). Conclusions. We concluded that 64-slice CT-CA is a diagnostic modality with high sensitivity and negative predictive value in patients at low to intermediate risk.

Spectrum of collateral findings in multislice CT coronary angiography (Article)

2007-10-01T00:00:00Z

Purpose. The aim of the study was to investigate the prevalence of the noncardiac collateral findings during multislice computed tomography coronary angiography (MSCT-CA). Materials and methods. Six hundred and seventy patients undergoing MSCT-CA with 16-slice and 64-slice CT scanners for suspected atherosclerotic disease of the coronary arteries were retrospectively reviewed. All data sets obtained with a large field of view (FOV) were analysed by two radiologists using standard mediastinal and lung window settings. Collateral findings were divided according to clinical importance into nonsignificant, remarkable and compulsory to be investigated. Results. Eighty-five percent of patients revealed coronary artery disease (CAD). Only 138/670 (20.6%) were without any additional finding. An additional 1,234 findings were recorded: nonsignificant 332 (26.9%), mild 821 (66.53%), compulsory for study 81 (6.56%). A total of 81 patients (12.08%) had significant noncardiac pathology requiring clinical or radiological follow-up. Among these, newly discovered pathologies were revealed in two patients (2.46%). Conclusions. A significant number of noncardiac findings might have been missed in MSCT-CA scans; the appropriate approach should be as a team trained in cardiology and radiology.

Imaging techniques for the vulnerable coronary plaque (Article)

2007-08-01T00:00:00Z

The goal of this article is to illustrate the main invasive and noninvasive diagnostic modalities to image the vulnerable coronary plaque, which is responsible for acute coronary syndrome. The main epidemiologic and histological issues are briefly discussed in order to provide an adequate background. Comprehensive coronary atherosclerosis imaging should involve visualization of the entire coronary artery tree and plaque characterization, including three-dimensional morphology, relationship with the lumen, composition, vascular remodelling and presence of inflammation. No single technique provides such a comprehensive description, and no available modality extensively identifies the vulnerable plaque. In particular, we describe multislice computed tomography, which at present seems to be the most promising noninvasive tool for an exhaustive image-based quantification of coronary atherosclerosis.

Follow-up of internal mammary artery stent with 64-slice CT (Article)

2007-08-01T00:00:00Z

We present a case of 81-year-old woman complaining chest pain after minimal efforts who underwent multiple coronary artery bypass grafts (CABGs) during the last 15 years. A significant in-stent re-stenosis was found at ostium of left internal mammary artery (LIMA). A non-invasive CT coronary angiography (CT-CA) was performed after 6-month follow-up. CT-CA is a reliable non-invasive technique for the follow-up of stents in coronary artery bypass grafts.

Influence of convolution filtering on coronary plaque attenuation values: Observations in an ex vivo model of multislice computed tomography coronary angiography (Article)

2007-07-01T00:00:00Z

Attenuation variability (measured in Hounsfield Units, HU) of human coronary plaques using multislice computed tomography (MSCT) was evaluated in an ex vivo model with increasing convolution kernels. MSCT was performed in seven ex vivo left coronary arteries sunk into oil followingthe instillation of saline (1/∞) and a 1/50 solution of contrast material (400 mgI/ml iomeprol). Scan parameters were: slices/ collimation, 16/0.75 mm; rotation time, 375 ms. Four convolution kernels were used: b30f-smooth, b36f-medium smooth, b46f-medium and b60f-sharp. An experienced radiologist scored for the presence of plaques and measured the attenuation in lumen, calcified and noncalcified plaques and the surrounding oil. The results were compared by the ANOVA test and correlated with Pearson's test. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The mean attenuation values were significantly different between the four filters (p<0.0001) in each structure with both solutions. After clustering for the filter, all of the noncalcified plaque values (20.8±39.1, 14.2±35.8, 14.0±32.0, 3.2±32.4 HU with saline; 74.7±66.6, 68.2±63.3, 66.3±66.5, 48.5±60.0 HU in contrast solution) were significantly different, with the exception of the pair b36f-b46f, for which a moderate-high correlation was generally found. Improved SNRs and CNRs were achieved by b30f and b46f. The use of different convolution filters significantly modifief the attenuation values, while sharper filtering increased the calcified plaque attenuation and reduced the noncalcified plaque attenuation.

Usefulness of 64-Slice Multislice Computed Tomography Coronary Angiography to Assess In-Stent Restenosis (Article)

2007-06-05T00:00:00Z

Objectives: This study sought to evaluate the diagnostic accuracy of 64-slice multislice computed tomography (MSCT) coronary angiography in the follow-up of patients with previous coronary stent implantation. Background: Recent investigations have shown increased image quality and diagnostic accuracy for noninvasive coronary angiography with 64-slice MSCT as compared with previous-generation MSCT scanners, but data on the evaluation of coronary stents are scarce. Methods: In 182 patients (152 [84%] male, ages 58 ± 11 years) with previous stent (≥2.5 mm diameter) implantation (n = 192), 64-slice MSCT angiography using either a Sensation 64 (Siemens, Forchheim, Germany) or Aquilion 64 (Toshiba, Otawara, Japan) was performed. At each center, coronary stents were evaluated by 2 experienced observers and evaluated for the presence of significant (≥50%) in-stent restenosis. Quantitative coronary angiography served as the standard of reference. Results: A total of 14 (7.3%) stented segments were excluded because of poor image quality. In the interpretable stents, 20 of the 178 (11.2%) evaluated stents were significantly diseased, of which 19 were correctly detected by 64-slice MSCT. Accordingly, sensitivity, specificity, and positive and negative predictive value to identify in-stent restenosis in interpretable stents were 95.0% (95% confidence interval [CI] 85% to 100%), 93.0% (95% CI 90% to 97%), 63.3% (95% CI 46% to 81%), and 99.3% (95% CI 98% to 100%), respectively. Conclusions: In-stent restenosis can be evaluated with 64-slice MSCT with good diagnostic accuracy. In particular, a high negative predictive value of 99% was observed, indicating that 64-slice MSCT may be most valuable as a noninvasive method of excluding in-stent restenosis.

Diagnostic accuracy of 64-slice CT in the assessment of coronary stents (Article)

2007-06-01T00:00:00Z

Purpose. The purpose of this study was to assess the diagnostic accuracy of 64-slice computed tomography (64-CT) coronary angiography in the detection of coronary in-stent restenosis. Materials and methods. Ninety-five patients (72 men and 23 women, mean age 58±8 years) with previous percutaneous coronary intervention with stenting and suspected restenosis underwent 64-CT (Sensation 64, Siemens). The mean time between stent deployment and 64-CT was 6.1±4.2 months. The scan parameters were: slices 32×2, individual detector width 0.6 mm, rotation time 0.33 s, feed 3.84 mm/rotation, 120 kV, 900 mAs. After the intravenous administration of iodinated contrast material (Iomeprol 400 mgI/ml, Iomeron, Bracco) and a bolus chaser (40 ml of saline), the scan was completed in <12 s. All coronary segments with a stent were assessed on 64-CT by two observers in consensus and judged as: patent, with intimal hyperplasia (lumen reduction of <50%), with in-stent restenosis (≥50%), or with in-stent occlusion (100%). The consensus reading was compared with conventional coronary angiography. Results. Four patients were excluded because of insufficient image quality. In the remaining 91, we assessed 102 stents (31 RCA; 10 LM; 54 LAD; 7 CX). In 14 (13.7%) stents, in-stent restenosis (n=8) or in-stent occlusion (n=6) was found. Intimal hyperplasia was detected in 11 (10.8%) stents. The sensitivity and negative predictive value of 64-CT for in-stent occlusion were 100% and 100%, respectively, whereas for all stenoses, >50% they were 92.9% and 98.7%, respectively. Conclusions. We found that 64-CT has a high diagnostic accuracy for the detection of in-stent restenosis in a selected patient population.

Visual claudicatio: Diagnosis with 64-slice computed tomography (Article)

2007-06-01T00:00:00Z

We present a case of a 78-year-old male referred presented to our institution with amaurosis fugax after walking 20 steps ("visual claudicatio"). Duplex ultrasound was not able to visualize the carotid arteries. Multislice computed tomography (Sensation 64 Cardiac, Siemens, Germany) of the cerebro-vascular circulation was performed from its origin at the level of the aortic arch to the circle of Willis. The investigation demonstrated a complete occlusion of both common carotid arteries at their origin and a severe origo stenosis of both vertebral arteries. An important collateral circulation of the vertebral arteries through the minor vessels of the neck was also displayed. Both comunicans posterior arteries were small but patent. The intra-cranial arteries were patent. Multislice CT of the cerebro-vascular circulation is an optimal tool for a comprehensive evaluation when duplex ultrasound fails.