RESUMO
PURPOSE: This study was undertaken 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 a male and female population. MATERIAL AND METHODS: A total of 1,372 patients (882 men, 490 women; mean age 59.3 ± 11.9 years) in sinus rhythm imaged with CTCA (64-slice technology) and CAG were enrolled. Diagnostic accuracy and likelihood ratios (LR+ and LR-) of CTCA were assessed against CAG for the male and female populations. RESULTS: The prevalence of obstructive disease was 53% (men 58%; women 43%). CAG demonstrated the absence of significant coronary artery disease (CAD) in 47% (men 42%; women 56%), single-vessel disease in 25% (men 36%; women 22%) and multivessel disease in 29% (men 32%; women 23%) of patients. In the per-patient analysis, sensitivity, specificity and positive (PPV) and negative (NPV) predictive values of CTCA were 99% (men 98%; women 100%), 92% (men 92%; women 92%), 94% (men 95%; women 90%) and 99% (men 98%; women 100%), respectively. The per-patient likelihood ratios (LR) in the total population (LR+=12.4 and LR-=0.011), the male (LR+=12.9 and LR-=0.016) and female (LR =11.9 and LR-=0) populations were very good. We observed no significant differences in diagnostic accuracy between male and female populations. CONCLUSIONS: CTCA is a reliable diagnostic modality with high sensitivity and NPV in the female population.
Assuntos
Angiografia Coronária/métodos , Estenose Coronária/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Estenose Coronária/epidemiologia , Feminino , Humanos , Itália/epidemiologia , Funções Verossimilhança , Masculino , Pessoa de Meia-Idade , Revascularização Miocárdica , Valor Preditivo dos Testes , Prevalência , Sistema de Registros , Sensibilidade e Especificidade , Fatores SexuaisRESUMO
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.
Assuntos
Calcinose/diagnóstico por imagem , Angiografia Coronária , Estenose Coronária/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Calcinose/diagnóstico , Calcinose/epidemiologia , Angiografia Coronária/métodos , Estenose Coronária/diagnóstico , Estenose Coronária/epidemiologia , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Revascularização Miocárdica/métodos , Valor Preditivo dos Testes , Prevalência , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Sensibilidade e EspecificidadeRESUMO
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 ± 11 years) 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.
Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Meios de Contraste , Doença da Artéria Coronariana/complicações , Feminino , Seguimentos , Humanos , Iopamidol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de SobrevidaRESUMO
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.
Assuntos
Calcinose/diagnóstico por imagem , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Calcinose/epidemiologia , Doença da Artéria Coronariana/epidemiologia , Estenose Coronária/epidemiologia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais/estatística & dados numéricos , Valor Preditivo dos Testes , Prevalência , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade , Sicília/epidemiologiaRESUMO
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.
Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Placa Aterosclerótica/diagnóstico por imagem , Idoso , Angina Estável/diagnóstico por imagem , Angina Instável/diagnóstico por imagem , Angiografia Coronária , Doença da Artéria Coronariana/patologia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , UltrassonografiaRESUMO
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.
Assuntos
Calcinose/diagnóstico por imagem , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Algoritmos , Calcinose/mortalidade , Doença da Artéria Coronariana/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Análise de SobrevidaRESUMO
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.
Assuntos
Angiografia Coronária , Estenose Coronária/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Síndrome Coronariana Aguda/diagnóstico por imagem , Fatores Etários , Idoso , Estenose Coronária/diagnóstico , Estenose Coronária/epidemiologia , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Revascularização Miocárdica/métodos , Razão de Chances , Valor Preditivo dos Testes , Prevalência , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade , Distribuição por Sexo , Fatores SexuaisRESUMO
PURPOSE: Computed tomography angiography (CTA) is increasingly used for the diagnosis of coronary artery disease (CAD). However, CTA is not commonly used for the assessment of ventricular and atrial function, although functional information extracted from CTA data is expected to improve the diagnostic value of the examination. In clinical practice, the extraction of ventricular and atrial functional information, such as stroke volume and ejection fraction, requires accurate delineation of cardiac chambers. In this paper, we investigated the accuracy and robustness of cardiac chamber delineation using a multiatlas based segmentation method on multicenter and multivendor CTA data. METHODS: A fully automatic multiatlas based method for segmenting the whole heart (i.e., the outer surface of the pericardium) and cardiac chambers from CTA data is presented and evaluated. In the segmentation approach, eight atlas images are registered to a new patient's CTA scan. The eight corresponding manually labeled images are then propagated and combined using a per voxel majority voting procedure, to obtain a cardiac segmentation. RESULTS: The method was evaluated on a multicenter/multivendor database, consisting of (1) a set of 1380 Siemens scans from 795 patients and (2) a set of 60 multivendor scans (Siemens, Philips, and GE) from different patients, acquired in six different institutions worldwide. A leave-one-out 3D quantitative validation was carried out on the eight atlas images; we obtained a mean surface-to-surface error of 0.94 +/- 1.12 mm and an average Dice coefficient of 0.93 was achieved. A 2D quantitative evaluation was performed on the 60 multivendor data sets. Here, we observed a mean surface-to-surface error of 1.26 +/- 1.25 mm and an average Dice coefficient of 0.91 was achieved. In addition to this quantitative evaluation, a large-scale 2D and 3D qualitative evaluation was performed on 1380 and 140 images, respectively. Experts evaluated that 49% of the 1380 images were very accurately segmented (below 1 mm error) and that 29% were accurately segmented (error between 1 and 3 mm), which demonstrates the robustness of the presented method. CONCLUSIONS: A fully automatic method for whole heart and cardiac chamber segmentation was presented and evaluated using multicenter/multivendor CTA data. The accuracy and robustness of the method were demonstrated by successfully applying the method to 1420 multicenter/ multivendor data sets.
Assuntos
Angiografia Coronária/métodos , Processamento de Imagem Assistida por Computador/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Humanos , Imageamento Tridimensional , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
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 and 120 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%.
Assuntos
Angiografia Coronária/instrumentação , Eletrocardiografia , Frequência Cardíaca , Imagens de Fantasmas , Doses de Radiação , Tomografia Computadorizada Espiral , Absorciometria de Fóton , Algoritmos , Angiografia Coronária/métodos , Desenho de Equipamento , Coração/diagnóstico por imagem , Humanos , Modelos Teóricos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Dosimetria TermoluminescenteRESUMO
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 (> or =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.
Assuntos
Angiografia Coronária/métodos , Estenose Coronária/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Meios de Contraste , Estenose Coronária/epidemiologia , Diagnóstico Diferencial , Eletrocardiografia , Feminino , Humanos , Iohexol/análogos & derivados , Funções Verossimilhança , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Valor Preditivo dos Testes , Prevalência , Interpretação de Imagem Radiográfica Assistida por Computador , Sistema de Registros , Sensibilidade e EspecificidadeRESUMO
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 400 mgI/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 (DE(1)-DE(2)) 15 min after administration of 1.25 (DE(1)) and 15 min after additional administration of 2.50 gI/kg (=total 3.75 gI/kg - DE(2)). 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 DE(2) (approximately 6.0 and 3.5, respectively; r(2)=0.90) vs. DE(1) (approximately 4.0 and 2.2, respectively; r(2)=0.85). CONCLUSIONS: The increase of contrast material volume determines a significant improvement in myocardial infarction image quality with DE-MDCT.
Assuntos
Meios de Contraste/administração & dosagem , Iopamidol/análogos & derivados , Infarto do Miocárdio/diagnóstico por imagem , Reperfusão Miocárdica , Tomografia Computadorizada por Raios X , Animais , Modelos Animais de Doenças , Iopamidol/administração & dosagem , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Sus scrofaRESUMO
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 (> or =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 > or =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) 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.
Assuntos
Angiografia Coronária/métodos , Estenose Coronária/diagnóstico , Eletrocardiografia/métodos , Teste de Esforço , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Meios de Contraste , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/fisiopatologia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
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.
Assuntos
Angiografia Coronária/tendências , Doença das Coronárias/diagnóstico por imagem , Tomografia Computadorizada por Raios X/tendências , Cardiologia/educação , Segurança de Equipamentos , Humanos , Doses de Radiação , Radiologia/educaçãoRESUMO
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.
Assuntos
Imagem Cinética por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Disfunção Ventricular Esquerda/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Angiografia Coronária , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Iopamidol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Disfunção Ventricular Esquerda/diagnóstico por imagemRESUMO
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.
Assuntos
Ecocardiografia , Volume Sistólico , Tomografia Computadorizada por Raios X , Função Ventricular Esquerda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
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 (DE(1) and DE(2)). 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. DE(2), areas of DE and no reflow were not significantly different (p>0.05). The SNR and CNR were not significantly different in DE(1) vs. DE(2) (p>0.05). CONCLUSIONS: Tube current does not significantly affect infarction area, image quality or contrast resolution of DE imaging with CT.
Assuntos
Meios de Contraste , Coração/diagnóstico por imagem , Infarto do Miocárdio/diagnóstico por imagem , Reperfusão Miocárdica , Tomografia Computadorizada por Raios X , Animais , Angiografia Coronária , Circulação Coronária , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/terapia , Sus scrofa , Tomografia Computadorizada por Raios X/métodosRESUMO
OBJECTIVES: Autopsy rates worldwide have dropped significantly over the last five decades. Imaging based autopsies are increasingly used as alternatives to conventional autopsy (CA). The aim of this study was to investigate the effect of the introduction of minimally invasive autopsy, consisting of CT, MRI and tissue biopsies on the overall autopsy rate (of CA and minimally invasive autopsy) and the autopsy rate among different ethnicities. METHODS: We performed a prospective single center before-after study. The intervention was the introduction of minimally invasive autopsy as an alternative to CA. Minimally invasive autopsy consisted of MRI, CT, and CT-guided tissue biopsies. Autopsy rates over time and the effect of introducing minimally invasive autopsy were analyzed with a linear regression model. We performed a subgroup analysis comparing the autopsy rates of two groups: a group of western-European ethnicity versus a group of other ethnicities. RESULTS: Autopsy rates declined from 14.0% in 2010 to 8.3% in 2019. The linear regression model showed a significant effect of both time and availability of minimally invasive autopsy on the overall autopsy rate. The predicted autopsy rate in the model started at 15.1% in 2010 and dropped approximately 0.1% per month (ß = -0.001, p < 0.001). Availability of minimally invasive autopsy increased the overall autopsy rate by 2.4% (ß = 0.024, p < 0.001). The overall autopsy rate of people with an ethnic background other than western-European was significantly higher in years when minimally invasive autopsy was available compared to when it was not (22/176 = 12.5% vs. 81/1014 (8.0%), p = 0.049). CONCLUSIONS: The introduction of the minimally invasive autopsy had a small, but significant effect on the overall autopsy rate. Furthermore, the minimally invasive autopsy appears to be more acceptable than CA among people with an ethnicity other than western-European.
Assuntos
Autopsia/métodos , Autopsia/tendências , Adulto , Causas de Morte , Etnicidade/psicologia , Feminino , Humanos , Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Estudos Prospectivos , Tomografia Computadorizada por Raios X/métodosRESUMO
PURPOSE: The application and large-scale evaluation of minimum cost path approaches for coronary centerline extraction from computed tomography coronary angiography (CTCA) data and the development and evaluation of a novel method to reduce the user-interaction time. METHODS: A semiautomatic method based on a minimum cost path approach is evaluated for two different cost functions. The first cost function is based on a frequently used vesselness measure and intensity information, and the second is a recently proposed cost function based on region statistics. User interaction is minimized to one or two mouse clicks distally in the coronary artery. The starting point for the minimum cost path search is automatically determined using a newly developed method that finds a point in the center of the aorta in one of the axial slices. This step ensures that all computationally expensive parts of the algorithm can be precomputed. RESULTS: The performance of the aorta localization procedure was demonstrated by a success rate of 100% in 75 images. The success rate and accuracy of centerline extraction was quantitatively evaluated on 48 coronary arteries in 12 images by comparing extracted centerlines with a manually annotated reference standard. The method was able to extract 88% and 47% of the vessel center-lines correctly using the vesselness/intensity and region statistics cost function, respectively. For only the proximal part of the vessels these values were 97% and 86%, respectively. Accuracy of centerline extraction, defined as the average distance from correctly automatically extracted parts of the centerline to the reference standard, was 0.64 mm for the vesselness/intensity and 0.51 mm for the region statistics cost function. The interobserver variability was 99% for the success rate measure and 0.42 mm for the accuracy measure. Qualitative evaluation using the best performing cost function resulted in successful centerline extraction for 233 out of the 252 coronaries (92%) in 63 additional CTCA images. CONCLUSIONS: The presented results, in combination with minimal user interaction and low computation time, show that minimum cost path approaches can effectively be applied as a preprocessing step for subsequent analysis in clinical practice and biomedical research.
Assuntos
Angiografia Coronária/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Humanos , Fatores de Tempo , Interface Usuário-ComputadorRESUMO
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.
Assuntos
Angiografia Coronária/instrumentação , Eletrocardiografia , Frequência Cardíaca , Imagens de Fantasmas , Doses de Radiação , Tomografia Computadorizada Espiral , Absorciometria de Fóton , Algoritmos , Angiografia Coronária/métodos , Desenho de Equipamento , Coração/diagnóstico por imagem , Humanos , Modelos Teóricos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Dosimetria TermoluminescenteRESUMO
Cardiac computed tomography (CT) is a fast developing technique. In 10 years it developed from investigative tool into a clinical reality. The technology drive has been the key to success for this technique which is to date the only non invasive clinical tool for coronary angiographic assessment. Technical background is quite complex and the newer solutions are aiming at reducing the scan time and the radiation dose while improving temporal resolution, contrast resolution and ultimately image quality. The key technical development has been in the late 1990, the introduction of ECG triggering/gating techniques. Spatial resolution has also been improved reaching sub-millimeter performance. The latest innovations provide fast coverage with >64 slice detectors, high spatial resolution with 0.5 mm slice thickness, high temporal resolution with <100 ms in hardware, and higher contrast resolution with the forthcoming dual-energy solutions. Recently, also dose issues have been exploited and current state of the art technology are able to perform cardiac CT with 1-2 mSv. These improvements put cardiac CT as the most promising clinical tool for the non invasive assessment of coronary arteries.