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1.
Br J Radiol ; 92(1103): 20190465, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31356106

RESUMO

Increased collagen, or fibrosis, is an important marker of disease and may improve identification of patients at risk. In addition, fibrosis imaging may play an increasing role in guiding therapy and monitoring its effectiveness. MRI is the most frequently used modality to detect, visualize and quantify fibrosis non-invasively. However, standard MRI techniques used to phenotype cardiac fibrosis such as delayed enhancement and extracellular volume determination by T1 mapping, require the administration of gadolinium-based contrast and are particularly difficult to use in patients with cardiac devices such as pacemakers and automatic defibrillators. Therefore, such methods are limited in the serial evaluation of cardiovascular fibrosis as part of chronic disease monitoring. A method to directly measure collagen amount could be of great clinical benefit. In the current review we will discuss the potential of a novel MR technique, ultrashort echo time (UTE) MR, for fibrosis imaging. Although UTE imaging is successfully applied in other body areas such as musculoskeletal applications, there is very limited experience so far in the heart. We will review the established methods and currently available literature, discuss the technical considerations and challenges, show preliminary in vivo images and provide a future outlook on potential applications of cardiovascular UTE.


Assuntos
Sistema Cardiovascular/patologia , Angiografia por Ressonância Magnética/métodos , Artefatos , Meios de Contraste , Fibrose/patologia , Gadolínio , Humanos , Fatores de Tempo
2.
J Am Heart Assoc ; 8(6): e007201, 2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30879377

RESUMO

Background The predictive value of coronary artery calcium ( CAC ) has been widely studied; however, little is known about specific characteristics of CAC that are most predictive. We aimed to determine the independent associations of Agatston score, CAC volume, CAC area, CAC mass, and CAC density score with major adverse cardiac events in patients with suspected coronary artery disease. Methods and Results A total of 379 symptomatic participants, aged 45 to 85 years, referred for invasive coronary angiography, who underwent coronary calcium scanning and computed tomography angiography as part of the CORE 320 (Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320 Detector Computed Tomography) study, were included. Agatston score, CAC volume, area, mass, and density were computed on noncontrast images. Stenosis measurements were made on contrast-enhanced images. The primary outcome of 2-year major adverse cardiac events (30 revascularizations [>182 days of index catheterization], 5 myocardial infarctions, 1 cardiac death, 9 hospitalizations, and 1 arrhythmia) occurred in 32 patients (8.4%). Associations were estimated using multivariable proportional means models. Median age was 62 (interquartile range, 56-68) years, 34% were women, and 56% were white. In separate models, the Agatston, volume, and density scores were all significantly associated with higher risk of major adverse cardiac events after adjustment for age, sex, race, and statin use; density was the strongest predictor in all CAC models. CAC density did not provide incremental value over Agatston score after adjustment for diameter stenosis, age, sex, and race. Conclusions In symptomatic patients, CAC density was the strongest independent predictor of major adverse cardiac events among CAC scores, but it did not provide incremental value beyond the Agatston score after adjustment for diameter stenosis.

3.
Circ Cardiovasc Imaging ; 12(2): e007720, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30764641

RESUMO

Background Ongoing advancements of coronary computed tomographic angiography (CTA) continue to challenge the role of invasive coronary angiography (ICA) as the gold standard for the evaluation of coronary artery disease (CAD). We sought to investigate the diagnostic accuracy of 320-slice CTA for detecting obstructive CAD in reference to ICA and nuclear myocardial perfusion imaging using single-photon emission computed tomography. Methods For the CORE320 study (Coronary Artery Evaluation Using 320-Row Multidetector Computed Tomography Angiography and Myocardial Perfusion), 381 patients at 16 centers underwent CTA, nuclear myocardial perfusion imaging by single-photon emission computed tomography, and ICA for the evaluation of CAD. Imaging studies were analyzed in blinded core laboratories, and a stenosis of ≥50% by quantitative coronary angiography was considered obstructive, whereas a stress difference score of ≥1 indicated inducible myocardial ischemia. The area under the receiver operating characteristic curve was used to evaluate diagnostic accuracy. Results Of 381 patients, 229 (60%) had obstructive CAD by quantitative coronary angiography. Diagnostic accuracy of CTA on a per-patient analysis revealed an area under the receiver operating characteristic curve of 0.90 (95% CI, 0.87-0.93). Per-vessel and per-segment analysis revealed lower area under the receiver operating characteristic curve of 0.87 (0.84-0.90) and 0.81 (0.78-0.83), respectively. Median radiation dose was lower for CTA versus ICA: 3.16 (interquartile range, 2.82-3.59) versus 11.97 (interquartile range, 7.60-17.8) mSv ( P<0.001). Accuracy for identifying patients with inducible myocardial ischemia by SPECT-MPI was similar for CTA and ICA (area under the receiver operating characteristic curve, 0.68 versus 0.71 by quantitative coronary angiography and 0.68 by visual angiographic assessment; P>0.05). Furthermore, accuracy for identifying patients who subsequently underwent clinically driven coronary revascularization also was similar for CTA (0.76 [0.71-0.81]) and ICA (0.78 [0.74-0.83]; P=0.20). Conclusions Contemporary CTA accurately identifies patients with obstructive CAD by ICA at lower radiation exposure; however, agreement is lower in vessel- and segment-level analyses. Both CTA and ICA perform similarly for predicting clinically driven revascularization and for detecting myocardial ischemia by myocardial perfusion imaging using single-photon emission computed tomography, suggesting that limitations by both CTA and ICA contribute to variability of stenosis quantification. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT00934037.

4.
J Cardiovasc Comput Tomogr ; 12(3): 212-219, 2018 May - Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29730016

RESUMO

AIMS: To determine the diagnostic accuracy of semi-automatic quantitative metrics compared to expert reading for interpretation of computed tomography perfusion (CTP) imaging. METHODS: The CORE320 multicenter diagnostic accuracy clinical study enrolled patients between 45 and 85 years of age who were clinically referred for invasive coronary angiography (ICA). Computed tomography angiography (CTA), CTP, single photon emission computed tomography (SPECT), and ICA images were interpreted manually in blinded core laboratories by two experienced readers. Additionally, eight quantitative CTP metrics as continuous values were computed semi-automatically from myocardial and blood attenuation and were combined using logistic regression to derive a final quantitative CTP metric score. For the reference standard, hemodynamically significant coronary artery disease (CAD) was defined as a quantitative ICA stenosis of 50% or greater and a corresponding perfusion defect by SPECT. Diagnostic accuracy was determined by area under the receiver operating characteristic curve (AUC). RESULTS: Of the total 377 included patients, 66% were male, median age was 62 (IQR: 56, 68) years, and 27% had prior myocardial infarction. In patient based analysis, the AUC (95% CI) for combined CTA-CTP expert reading and combined CTA-CTP semi-automatic quantitative metrics was 0.87(0.84-0.91) and 0.86 (0.83-0.9), respectively. In vessel based analyses the AUC's were 0.85 (0.82-0.88) and 0.84 (0.81-0.87), respectively. No significant difference in AUC was found between combined CTA-CTP expert reading and CTA-CTP semi-automatic quantitative metrics in patient based or vessel based analyses(p > 0.05 for all). CONCLUSION: Combined CTA-CTP semi-automatic quantitative metrics is as accurate as CTA-CTP expert reading to detect hemodynamically significant CAD.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Circulação Coronária , Vasos Coronários/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Imagem de Perfusão do Miocárdio/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Ásia , Automação , Angiografia por Tomografia Computadorizada/normas , Angiografia Coronária/normas , Doença da Artéria Coronariana/fisiopatologia , Vasos Coronários/fisiopatologia , Europa (Continente) , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/normas , Imagem de Perfusão do Miocárdio/normas , América do Norte , Variações Dependentes do Observador , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Interpretação de Imagem Radiográfica Assistida por Computador/normas , Padrões de Referência , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , América do Sul , Tomografia Computadorizada de Emissão de Fóton Único
5.
Eur J Radiol ; 101: 30-37, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29571798

RESUMO

PURPOSE: Recently, ultra-high-resolution computed tomography (U-HRCT) with a 0.25 mm × 128-row detector was introduced. The purpose of this study was to evaluate the diagnostic performance of coronary CT angiography (CCTA) using U-HRCT. METHODS: This retrospective study included 38 consecutive patients with suspected coronary artery disease (CAD) who underwent CCTA with U-HRCT followed by invasive coronary angiography (ICA). Per-segment diameter stenosis was calculated. Diagnostic performance of CCTA relative to ICA as the reference standard was determined. For segments with >30% diameter stenosis, the correlation and agreement of percent diameter stenosis between CCTA and ICA were calculated. RESULTS: Obstructive CAD was observed in 65 segments (12%) of 51 vessels (45%) in 32 patients (84%) during ICA. The per-patient, vessel, and segment analyses showed a sensitivity of 100% (95% confidence interval [CI], 95%-100%), 96% (95% CI: 89%-99%) and 95% (95% CI: 89%-98%), respectively, and a specificity of 67% (95% CI: 38%-67%), 81% (95% CI: 75%-83%) and 96% (95% CI: 96%-97%), respectively. The percentage of diameter stenosis, as determined by CCTA, demonstrated an excellent correlation with ICA (R = 0.90; 95% CI: 0.83-0.95) and a slight significant overestimation (mean: 4% ±â€¯7%, p < .01), with the agreed range of limits being ±â€¯16%. The median effective radiation dose for CCTA was 5.4 mSv (range: 2.9-18.0 mSv). CONCLUSIONS: CCTA with U-HRCT demonstrated an excellent correlation and agreement with ICA in the quantification of coronary artery stenosis.


Assuntos
Angiografia Coronária/normas , Estenose Coronária/diagnóstico por imagem , Idoso , Angiografia por Tomografia Computadorizada/métodos , Angiografia por Tomografia Computadorizada/normas , Angiografia Coronária/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos
6.
Eur J Cardiothorac Surg ; 54(1): 19-25, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29370354

RESUMO

OBJECTIVES: Preoperative identification of the artery of Adamkiewicz can help prevent postoperative spinal cord injury in patients undergoing thoracic and thoraco-abdominal aortic aneurysm repair. Although several studies have shown the feasibility of evaluating the artery of Adamkiewicz using multidetector row computed tomography (MDCT), no detailed investigations regarding the collateral circulation to the artery of Adamkiewicz have been performed. The purpose of this study was to investigate the collateral circulation to the artery of Adamkiewicz using MDCT in patients with thoracic and thoraco-abdominal aortic aneurysms. METHODS: Our institutional review board approved this study. Sixty-four patients with descending thoracic and thoraco-abdominal aortic aneurysms associated with the occlusion of the segmental artery from which the artery of Adamkiewicz originated were scanned using 64- or 320-detector row computed tomography. Two independent observers evaluated the MDCT images based on the degree of visualization of the artery of Adamkiewicz and its collateral circulation using a 4-point scale. RESULTS: The average visualization score was 2.8 ± 0.6. In 53 of the 64 (83%) patients, image quality was judged to be diagnostic. MDCT demonstrated 75 collateral pathways to the artery of Adamkiewicz in these 53 patients. Sixty-four of the 75 (85%) pathways were collaterals around the spinal column, and the remaining 11 (15%) pathways were collateral arteries in the thoracic wall. CONCLUSIONS: MDCT revealed the collateral pathways to the artery of Adamkiewicz around the spinal column and in the thoracic wall in 83% of our patients with thoracic and thoraco-abdominal aortic aneurysms.

7.
Br J Radiol ; 91(1084): 20170678, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29260893

RESUMO

OBJECTIVE: To assess the accuracy of an iterative reconstruction (IR) technique for coronary artery calcium scoring with reduced radiation dose. METHODS: 163 consecutive patients underwent twofold scanning by 320-row detector CT at 120 kVp. A low-dose scan at 25% tube current but with standard scan length (14 cm) was followed by a standard dose scan with routine tube current but reduced scan length (10 cm). Reduced dose images were constructed using filtered back-projection (FBP) and IR (adaptive iterative dose reduction in three dimensions). The standard dose scan reconstructed with FBP served as the gold standard for comparisons. Image noise and Agatston coronary calcium scores were determined and compared between the groups. RESULTS: Compared with FBP at standard dose, noise at reduced dose increased markedly with FBP but remained low with IR. Mean Agatston score with FBP at reduced dose showed a significant increase as compared with FBP at standard dose. No significant difference was observed when applying IR at reduced dose. At reduced dose, 38 (23.3%) patients were reassigned to a different cardiovascular risk category with FBP but only 8 (4.9%) with IR. Out of 47 patients with a zero Agatston score, 15 patients (31.9%) were false-positive with FBP at reduced dose, but no false positives were found with IR. CONCLUSION: IR allows accurate coronary artery calcium scoring with a radiation dose reduced by 75%. Advances in knowledge: The application of adaptive iterative dose reduction in three dimensions allows the maintenance of accurate Agatston scores and risk stratification at significantly reduced tube current, thus reducing the patient's exposure to ionizing radiation.


Assuntos
Doença das Coronárias/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Calcificação Vascular/diagnóstico por imagem , Idoso , Algoritmos , Feminino , Humanos , Masculino , Doses de Radiação , Medição de Risco
8.
Eur Heart J Cardiovasc Imaging ; 19(2): 127-135, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29045612

RESUMO

The aim of this paper is to provide a guide to the clinical application of the functional computed tomography (CT) techniques fractional flow reserve (CT FFR) and myocardial perfusion (CTP) in patients presenting for the evaluation of coronary artery disease (CAD). Both techniques have recently been introduced to complement coronary CT angiography (CTA) with physiological information. Evidence supporting their diagnostic accuracy accumulates at a fast pace, and both techniques are moving from research tools to clinical applications for specific subgroups of patients. As a consequence, the question that now emerges is how to optimally implement these techniques in the daily clinical workflow to maximize the benefit to patients. Given the inherent differences between both techniques in their underlying physical principles and methodology, as well as the types of pathophysiological information they provide, these techniques are not interchangeable. Rather, within the broad spectrum of patients presenting for CAD evaluation, both CT FFR and CTP may have their own optimized application where the highest benefit at the lowest risk and cost may be achieved. Therefore, we will review the physical principles and available clinical evidence of each technique, and propose how this information can be applied to the individual patient. Moreover, as techniques continue to mature, the combination of coronary CTA with CT FFR and/or CTP likely will become a powerful and accessible diagnostic tool for the detailed characterization of atherosclerotic disease providing a potentially more precise and personalized approach to patients with suspected CAD.

9.
Neuroradiology ; 60(1): 109-115, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29080918

RESUMO

PURPOSE: Preoperative identification of the artery of Adamkiewicz can help prevent postoperative spinal cord injury following thoracic and thoracoabdominal aortic repair. Several studies have demonstrated the feasibility of evaluating the artery of Adamkiewicz using multi-detector row computed tomography (CT), but precise visualization remains a challenge. The present study was conducted to evaluate the usefulness of ultra-high-resolution CT for visualizing the artery of Adamkiewicz with a slice thickness of 0.25 versus 0.5 mm in patients with aortic aneurysms. METHODS: Our institutional review board approved this study. Twenty-four patients with thoracic and thoracoabdominal aneurysms were scanned with beam collimation of 0.25 mm × 128. Images were reconstructed with slice thicknesses of 0.25 and 0.5 mm. The signal-to-noise ratio (SNR) of the aorta and contrast-to-noise ratio (CNR) between the anterior spinal artery and spinal cord were measured. Two independent observers evaluated visualization of the artery of Adamkiewicz and its continuity between the anterior spinal artery and the aorta using a four-point scale. RESULTS: No significant differences in the SNR of the aorta or CNR of the anterior spinal artery were observed between 0.25- and 0.5-mm slices. The average visualization score was significantly higher for 0.25-mm slices (3.58 ± 0.78) than for 0.5-mm slices (3.13 ± 0.99) (p = 0.01). The percentage of patients with nondiagnostic image quality was significantly lower for 0.25-mm slices (8.3%) than for 0.5-mm slices (33.3%) (p = 0.03). CONCLUSION: In patients with aortic aneurysms, ultra-high-resolution CT with 0.25-mm slices significantly improves visualization of the artery of Adamkiewicz compared to 0.5-mm slices.


Assuntos
Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Torácica/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Coluna Vertebral/irrigação sanguínea , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador , Estudos Retrospectivos , Razão Sinal-Ruído
10.
J Comput Assist Tomogr ; 41(2): 242-248, 2017 Mar/Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28288480

RESUMO

OBJECTIVES: The aim of this study is to evaluate the effect of heart rate on exposure window, best phase, and image quality for stress computed tomography perfusion (CTP) in the CORE320 study. METHODS: The CTP data sets were analyzed to determine the best phase for perfusion analysis. A predefined exposure window covering 75% to 95% of the R-R cycle was used. RESULTS: Of the 368 patients included in the analysis, 93% received oral ß blockade before the rest scan. The median heart rate during the stress acquisition was 69 bpm (interquartile range [IQR], 60-77). The median best phase was 81% (IQR, 76-90), and length of exposure window was 22% (IQR, 19-24). The best phase was significantly later in the cardiac cycle with higher heart rates (P < 0.001), and higher heart rates resulted in a small, but higher number of poor quality scans (6%, P < 0.001). The median effective dose of the stress scan was 5.3 mSv (IQR, 3.8-6.1). CONCLUSIONS: Stress myocardial CTP imaging can be performed using prospective electrocardiography triggering, an exposure window of 75% to 95%, and ß-blockade resulting in good or excellent image quality in the majority (80%) of patients while maintaining a low effective radiation dose.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Teste de Esforço , Frequência Cardíaca , Tomografia Computadorizada por Raios X/métodos , Antagonistas de Receptores Adrenérgicos beta 1 , Idoso , Doença da Artéria Coronariana/fisiopatologia , Eletrocardiografia/métodos , Eletrocardiografia/estatística & dados numéricos , Feminino , Humanos , Masculino , Metoprolol , Pessoa de Meia-Idade , Estudos Prospectivos , Tomografia Computadorizada por Raios X/estatística & dados numéricos
11.
Med Phys ; 43(4): 1921, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27036588

RESUMO

PURPOSE: Computed tomography (CT) radiation dose reduction is frequently achieved by applying lower tube voltages and using iterative reconstruction (IR). For calcium scoring, the reference protocol at 120 kVp with filtered back projection (FBP) is still used, because kVp and IR may influence the Agatston score (AS) and volume score (VS). The authors present a two-step method to optimize dose: first, to determine the lowest feasible exposure and highest noise thresholds; second, to define a calibration method that ensures that the AS and VS are similar to the reference protocol. METHODS: AS and VS were measured for an anthropomorphic thoracic phantom that includes a calcium calibration module. The phantom was scanned on a 320-row CT scanner, at tube voltages of 120 kVp using FBP, and 120, 100, and 80 kVp using adaptive iterative dose reduction (AIDR 3D) reconstruction. The minimum CTDIs were determined based on three objective quality criteria. Calibration was performed to estimate adjusted CT number thresholds for the lower kVp acquisitions. Finally, the accuracies of the total and individual insert scores at dose level close to the minimum CTDI level were investigated and compared to low (FBPLD - 120) and high (FBPHD - 120) dose reference protocols (based on ten repeated acquisitions for each group). RESULTS: IR allows the exposure to be reduced by 69% at 120 kVp, with no significant effect on the total scores when averaged over all included dose steps and compared to FBP-120 (AS: 693 vs 699, p = 0.182; VS: 588 vs 587 mm(3), p = 0.569). Also when averaged over ten repeated scans and compared to FBPHD - 120 (AS: 709 vs 704, p = 0.435; VS: 604 vs 601 mm(3), p = 0.479), there is no statistical significant effect. Reducing the peak tube voltage allows even greater dose reductions: 73% at 100 kVp and 76% at 80 kVp. The calibrated CT number thresholds for analysis at 120, 100, and 80 kVp were, respectively, 130, 133, and 160 HU for the Agatston score, and 130, 132, and 140 HU for the volume score. Following the calibration, the mean scores of the four groups with dose variation were not significantly different from the reference protocol, at 100 kVp (AS: 698 vs 699, p = 0.818; VS: 584 vs 587 mm(3), p = 0.365) or at 80 kVp (AS: 698 vs 699, p = 0.996; VS: 586 vs 587 mm(3), p = 0.827). Similarly, there was no significant score difference with FBPLD - 120 during repeated scanning: 100 kVp (AS: 690 vs 694, p = 0.394; VS: 579 vs 585 mm(3), p = 0.168) and 80 kVp (AS: 703 vs 694, p = 0.115; VS: 588 vs 585 mm(3), p = 0.613). Compared to FBPHD - 120 group, the relative score deviation for the accuracy of the 400 and 800 mg/cm(3) HA inserts with 3 and 5 mm diameter is less than 7%. However, the relative deviation of the smaller 1 mm inserts is poorer (up to 41% deviations for scores <3). CONCLUSIONS: With iterative reconstruction using AIDR 3D, deviations of the total Agatston and volume scores remain within 4% of the reference protocol. The 1 mm inserts were detected as calcification, but scores less than ten tend to be underestimated. Following the calibration process, the application of IR in combination with reduced tube voltages allows up to 76% lower radiation dose.


Assuntos
Cálcio/metabolismo , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/metabolismo , Imagem Tridimensional/métodos , Calibragem , Humanos , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Razão Sinal-Ruído , Tomografia Computadorizada por Raios X
12.
Eur Heart J Cardiovasc Imaging ; 16(2): 166-76, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25368207

RESUMO

AIMS: The aim of this study was to investigate the association of left ventricular mass (LVM) with coronary atherosclerosis and myocardial infarction (MI). METHODS AND RESULTS: Patients (n = 338) underwent 320 × 0.5 mm detector row coronary computed tomography (CT) angiography, invasive coronary angiography (ICA), and single-photon emission CT (SPECT) myocardial perfusion imaging. Quantitative coronary atheroma volume was obtained from the CT images for the entire coronary tree (19-segment model) with an arterial contour detection algorithm. Normalized total atheroma volume (NormTAV) was analysed to reflect quantitative total atheroma volume. LVM was measured on myocardial CT images and indexed to height to the power of 2.7 (LVMi). Patients with obstructive coronary artery disease (CAD) were defined as those with ≥50% diameter stenosis by quantitative ICA. Abnormal perfusion defect was defined as ≥1 abnormal myocardial segment by SPECT. The association of LVMi with coronary atherosclerosis and myocardial perfusion defect on SPECT at the patient level was determined with uni- and multivariable linear and logistic regression analyses. Obstructive CAD was present in 60.0% of enrolled patients. LVMi was independently associated with abnormal summed rest score [SRS; odds ratio (OR), 1.07; 95% confidence interval (CI), 1.03-1.09] and summed stress score (OR, 1.04; 95% CI, 1.01-1.07). An increase in LVMi was also independently associated with that in NormTAV (coefficient, 10.44; 95% CI, 1.50-19.39) and SRS ≥1 (OR, 1.05; 95% CI, 1.01-1.10), even after adjusting for cardiovascular risk factors in patients without previous MI. CONCLUSIONS: LVM was independently associated with the presence of coronary artery atherosclerosis and MI.


Assuntos
Técnicas de Imagem Cardíaca , Doença da Artéria Coronariana/diagnóstico , Hipertrofia Ventricular Esquerda/diagnóstico , Isquemia Miocárdica/diagnóstico , Idoso , Algoritmos , Doença da Artéria Coronariana/fisiopatologia , Feminino , Humanos , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/fisiopatologia , Estudos Prospectivos
13.
PLoS One ; 8(7): e67936, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23874471

RESUMO

PURPOSE: Significant obstructive coronary artery disease (CAD) is common in asymptomatic dialysis patients. Identifying these high risk patients is warranted and may improve the prognosis of this vulnerable patient group. Routine catheterization of incident dialysis patients has been proposed, but is considered too invasive. CT-angiography may therefore be more appropriate. However, extensive coronary calcification, often present in this patient group, might hamper adequate lumen evaluation. The objective of this study was to assess the feasibility of CT-angiography in this patient group. METHODS: For this analysis all patients currently participating in the ICD2 trial (ISRCTN20479861), with no history of PCI or CABG were included. The major epicardial vessels were evaluated on a segment basis (segment 1-3, 5-8, 11 and 13) by a team consisting of an interventional and an imaging specialist. Segments were scored as not significant, significant and not interpretable. RESULTS: A total of 70 dialysis patients, with a mean age of 66±8 yrs and predominantly male (70%) were included. The median calcium score was 623 [79, 1619]. Over 90% of the analyzed segments were considered interpretable. The incidence of significant CAD on CT was 43% and was associated with cardiovascular events during follow-up. The incidence of cardiovascular events after 2-years follow-up: 36% vs. 0% in patients with no significant CAD (p<0.01). CONCLUSION: Despite the high calcium scores CT-angiography is feasible for the evaluation of the extent of CAD in dialysis patients. Moreover the presence of significant CAD on CT was associated with events during follow-up.


Assuntos
Cálcio/sangue , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Diálise Renal , Insuficiência Renal Crônica/terapia , Tomografia Computadorizada por Raios X , Idoso , Ensaios Clínicos como Assunto/estatística & dados numéricos , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/epidemiologia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/diagnóstico por imagem , Insuficiência Renal Crônica/epidemiologia , Projetos de Pesquisa
14.
Heart Vessels ; 28(2): 166-72, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22349692

RESUMO

Previous angiographic studies have shown that almost two-thirds of vulnerable plaques are located in non-obstructive lesions. Possibly, the maximum necrotic core (Max NC) area is not always identical to the site of most severe stenosis. Therefore, the purpose of this study was to evaluate the potential difference in location between the maximum necrotic core area and the site of most severe narrowing as assessed by virtual histology intravascular ultrasound (VH IVUS). Overall, 77 patients (139 vessels) underwent VH IVUS. The Max NC site was defined as the cross section with the largest necrotic core area per vessel. The site of most severe narrowing was defined as the minimum lumen area (MLA). Per vessel, the distance from both the Max NC site and MLA site to the origo of the coronary artery was evaluated. In addition, the presence of a virtual histology-thin cap fibroatheroma (VH-TCFA) was assessed. The mean difference (mm) between the MLA site and Max NC site was 10.8 ± 20.6 mm (p < 0.001). Interestingly, the Max NC site was located at the MLA site in seven vessels (5%) and proximally to the MLA site in 92 vessels (66%). Importantly, a higher percentage of VH-TCFA was demonstrated at the Max NC site as compared to the MLA site (24 vs. 9%, p < 0.001). In conclusion, the present findings demonstrate that the Max NC area is rarely at the site of most severe narrowing. Most often, the Max NC area is located proximal to the site of most severe narrowing.


Assuntos
Estenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Placa Aterosclerótica , Ultrassonografia de Intervenção , Idoso , Distribuição de Qui-Quadrado , Angiografia Coronária , Estenose Coronária/patologia , Vasos Coronários/patologia , Feminino , Fibrose , Humanos , Masculino , Pessoa de Meia-Idade , Necrose , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/patologia
15.
Int J Cardiovasc Imaging ; 29(2): 453-61, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23001159

RESUMO

To evaluate the effect of radiation dose reduction on image quality and diagnostic accuracy of coronary computed tomography (CT) angiography. Coronary CT angiography studies of 40 patients with (n = 20) and without (n = 20) significant (≥50 %) stenosis were included (26 male, 14 female, 57 ± 11 years). In addition to the original clinical reconstruction (100 % dose), simulated images were created that correspond to 50, 25 and 12.5 % of the original dose. Image quality and diagnostic performance in identifying significant stenosis were determined. Receiver-operator-characteristics analysis was used to assess diagnostic accuracy at different dose levels. The identification of patients with significant stenosis decreased consistently at doses of 50, 25 and 12.5 of the regular clinical acquisition (100 %). The effect was relatively weak at 50 % dose, and was strong at dose levels of 25 and 12.5 %. At lower doses a steady increase was observed for false negative findings. The number of coronary artery segments that were rated as diagnostic decreased gradually with dose, this was most prominent for smaller segments. The area-under-the-curve (AUC) was 0.90 (p = 0.4) at 50 % dose; accuracy decreased significantly with 25 % (AUC 0.70) and 12.5 % dose (AUC 0.60) (p < 0.0001), with underestimation of patients having significant stenosis. The clinical acquisition protocol for evaluation of coronary artery stenosis with CT angiography represents a good balance between image quality and patient dose. A potential for a modest (<50 %) reduction of tube current might exist. However, more substantial reduction of tube current will reduce diagnostic performance of coronary CT angiography substantially.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Doses de Radiação , Tomografia Computadorizada por Raios X , Idoso , Área Sob a Curva , Reações Falso-Negativas , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença
16.
Diab Vasc Dis Res ; 10(2): 123-34, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22621919

RESUMO

PURPOSE: In diabetes, generalised microvascular disease and coronary artery disease (CAD) are likely to occur in parallel. We used a sidestream dark field (SDF) handheld imaging device to determine the relation between the labial microcirculation parameters and CAD in asymptomatic patients with diabetes. METHODS: SDF imaging was validated for assessment of labial capillary density and tortuosity. Thereafter, mean labial capillary density and tortuosity were evaluated and compared in non-diabetic controls, and in asymptomatic patients with type 1 and type 2 diabetes. In diabetic patients, mean capillary density and tortuosity were compared according to the presence of CAD. RESULTS: Both type 1 and type 2 diabetes were associated with increased capillary density and tortuosity. In diabetes, mean capillary density was an independent predictor of elevated coronary artery calcium (CAC) (p = 0.03) and obstructive CAD on computed tomography angiography (p = 0.01). Using a cut-off mean capillary density of 24.9 (per 0.63 mm(2)) the negative predictive value was 84% and 89% for elevated CAC and obstructive CAD. Likewise, capillary tortuosity was an independent predictor of increased CAC (p = 0.01) and obstructive CAD (p = 0.04). CONCLUSION: Assessment of labial microcirculation parameters using SDF imaging is feasible and conveys the potential to estimate vascular morbidity in patients with diabetes, at bedside.


Assuntos
Doença da Artéria Coronariana/diagnóstico , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 2/complicações , Lábio/irrigação sanguínea , Microscopia/métodos , Adulto , Idoso , Calcinose/diagnóstico por imagem , Capilares/patologia , Estudos de Casos e Controles , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/etiologia , Feminino , Humanos , Masculino , Microcirculação , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X
17.
Int J Cardiovasc Imaging ; 29(1): 221-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22576679

RESUMO

To determine the rate of subsequent invasive coronary angiography (ICA) and revascularization in relation to computed tomography coronary angiography (CTA) results. In addition, independent determinants of subsequent ICA and revascularization were evaluated. CTA studies were performed using a 64-row (n = 413) or 320-row (n = 224) multidetector scanner. The presence and severity of CAD were determined on CTA. Following CTA, patients were followed up for 1 year for the occurrence of ICA and revascularization. A total of 637 patients (296 male, 56 ± 12 years) were enrolled and 578 CTA investigations were available for analysis. In patients with significant CAD on CTA, subsequent ICA rate was 76%. Among patients with non-significant CAD on CTA, subsequent ICA rate was 20% and among patients with normal CTA results, subsequent ICA rate was 5.7% (p < 0.001). Of patients with significant CAD on CTA, revascularization rate was 47%, as compared to a revascularization rate of 0.6% in patients with non-significant CAD on CTA and no revascularizations in patients with a normal CTA results (p < 0.001). Significant CAD on CTA and significant three-vessel or left main disease on CTA were identified as the strongest independent predictors of ICA and revascularization. CTA results are strong and independent determinants of subsequent ICA and revascularization. Consequently, CTA has the potential to serve as a gatekeeper for ICA to identify patients who are most likely to benefit from revascularization and exclude patients who can safely avoid ICA.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Adulto , Idoso , Distribuição de Qui-Quadrado , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Revascularização Miocárdica , Razão de Chances , Seleção de Pacientes , Valor Preditivo dos Testes , Prognóstico , Interpretação de Imagem Radiográfica Assistida por Computador , Sistema de Registros , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Procedimentos Desnecessários
19.
Eur Heart J ; 33(11): 1367-77, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22390913

RESUMO

AIMS: Limited information is available regarding the relationship between coronary vessel dominance and prognosis. Therefore, the purpose of this study was to determine the prognostic value of coronary vessel dominance in relation to significant coronary artery disease (CAD) in patients referred for computed tomography coronary angiography (CTA). METHODS AND RESULTS: The study population consisted of 1425 patients (869 men, 57 ± 12 years) referred for CTA. To evaluate the impact of vessel dominance and significant CAD on CTA on outcome, patients were followed during a median period of 24 months for the occurrence of non-fatal myocardial infarction and all-cause mortality. The presence of a left dominant system was identified as a significant predictor for non-fatal myocardial infarction and all-cause mortality (HR: 3.20; 95% CI: 1.67-6.13, P < 0.001) and had incremental value over baseline risk factors and severity of CAD on CTA. In addition, in the subgroup of patients with significant CAD on CTA, patients with a left dominant system had a worse outcome compared with patients with a right dominant system (cumulative event rates: 9.5% and 35% at 3-year follow-up for a right and left dominant coronary artery system, respectively, log-rank P < 0.001). CONCLUSIONS: The presence of a left dominant system was identified as an independent predictor of non-fatal myocardial infarction and all-cause mortality, especially in patients with significant CAD on CTA. Therefore, the assessment of coronary vessel dominance on CTA may further enhance risk stratification beyond the assessment of significant CAD on CTA.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Idoso , Angiografia Coronária/mortalidade , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/fisiopatologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/mortalidade
20.
Eur Heart J ; 33(8): 1007-16, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22285583

RESUMO

AIMS: Previous studies have used semi-automated approaches for coronary plaque quantification on multi-detector row computed tomography (CT), while an automated quantitative approach using a dedicated registration algorithm is currently lacking. Accordingly, the study aimed to demonstrate the feasibility and accuracy of automated coronary plaque quantification on cardiac CT using dedicated software with a novel 3D coregistration algorithm of CT and intravascular ultrasound (IVUS) data sets. METHODS AND RESULTS: Patients who had undergone CT and IVUS were enrolled. Automated lumen and vessel wall contour detection was performed for both imaging modalities. Dedicated automated quantitative software (QCT) with a unique registration algorithm was used to fuse a complete IVUS run with a CT angiography volume using true anatomical markers. At the level of the minimal lumen area (MLA), percentage lumen area stenosis, plaque burden, and degree of remodelling were obtained on CT. Additionally, mean plaque burden was assessed for the whole coronary plaque. At the identical level within the coronary artery, the same variables were derived from IVUS. Fifty-one patients (40 men, 58 ± 11 years, 103 coronary arteries) with 146 lesions were evaluated. Quantitative computed tomography and IVUS showed good correlation for MLA (n = 146, r = 0.75, P < 0.001). At the level of the MLA, both techniques were well-correlated for lumen area stenosis (n = 146, r = 0.79, P < 0.001) and plaque burden (n = 146, r = 0.70, P < 0.001). Mean plaque burden (n = 146, r = 0.64, P < 0.001) and remodelling index (n = 146, r = 0.56, P < 0.001) showed significant correlations between QCT and IVUS. CONCLUSION: Automated quantification of coronary plaque on CT is feasible using dedicated quantitative software with a novel 3D registration algorithm.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Placa Aterosclerótica/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia de Intervenção/métodos , Idoso , Algoritmos , Estenose Coronária/diagnóstico por imagem , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Calcificação Vascular/diagnóstico por imagem , Remodelação Ventricular/fisiologia
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