RESUMO
Atrial fibrillation is the most common cause of arrhythmia which is responsible for over 15% of ischemic strokes, most of these being secondary to migration of a left atrial appendage (LAA) thrombus. In patient with contraindication to anticoagulant therapy, percutaneous closure system placement may be indicated. Cardiac computed tomography (CT) angiography plays a central role in the initial assessment as well as in the follow-up. The purpose of the pre-implantation cardiac CT angiography is to evaluate the anatomy of the LAA in order to select the most suitable prosthesis and check for any contraindication to device implantation. Image analysis is divided into four steps that include analysis of the approach; search for a thrombus in the LAA; investigation of the anatomy of the LAA (morphology of the LAA, dimensions of the LAA and choice of device) and cardiac and thoracic assessments. Follow-up involves CT examination to check for correct placement of the device and to detect any complications. On the basis of the results of currently available published research, a panel of experts has issued recommendations regarding cardiac CT angiography prior to percutaneous LAA closure device placement, which were further endorsed by the Société française d'imagerie cardiaque et vasculaire diagnostique et interventionnelle (SFICV).
Assuntos
Apêndice Atrial , Fibrilação Atrial , Angiografia , Apêndice Atrial/diagnóstico por imagem , Apêndice Atrial/cirurgia , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/terapia , Angiografia por Tomografia Computadorizada , Humanos , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
OBJECTIVES: To demonstrate non-inferiority of iobitridol 350 for coronary CT angiography (CTA) compared to higher iodine content contrast media regarding rate of patients evaluable for the presence of coronary artery stenoses. METHODS: In this multicentre trial, 452 patients were randomized to receive iobitridol 350, iopromide 370 or iomeprol 400 and underwent coronary CTA using CT systems with 64-detector rows or more. Two core lab readers assessed 18 coronary segments per patient regarding image quality (score 0 = non diagnostic to 4 = excellent quality), vascular attenuation, signal and contrast to noise ratio (SNR, CNR). Patients were considered evaluable if no segment had a score of 0. RESULTS: Per-patient, the rate of fully evaluable CT scans was 92.1, 95.4 and 94.6 % for iobitridol, iopromide and iomeprol, respectively. Non-inferiority of iobitridol over the best comparator was demonstrated with a 95 % CI of the difference of [-8.8 to 2.1], with a pre-specified non-inferiority margin of -10 %. Although average attenuation increased with higher iodine concentrations, average SNR and CNR did not differ between groups. CONCLUSIONS: With current CT technology, iobitridol 350 mg iodine/ml is not inferior to contrast media with higher iodine concentrations in terms of image quality for coronary stenosis assessment. KEY POINTS: ⢠Iodine concentration is an important parameter for image quality in coronary CTA. ⢠Contrast enhancement must be balanced against the amount of iodine injected. ⢠Iobitridol 350 is non-inferior compared to CM with higher iodine concentrations. ⢠Higher attenuation with higher iodine concentrations, but no SNR or CNR differences.
Assuntos
Calcinose/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Estenose Coronária/diagnóstico por imagem , Adulto , Idoso , Meios de Contraste , Doença da Artéria Coronariana/diagnóstico por imagem , Método Duplo-Cego , Feminino , Humanos , Iodo , Iohexol/análogos & derivados , Iopamidol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/métodos , Tomografia Computadorizada por Raios X/métodosRESUMO
The aim of this study was to assess the diagnostic performance of shear wave elastography (SWE) in comparison to B-mode and Doppler ultrasonography in differentiating benign from malignant head and neck lymph nodes (HNLNs). Sixty-two HNLNs from 56 patients were prospectively examined using B-mode, Doppler and SWE. The standard of reference was histopathology or cytology and follow-up. Qualitative malignant criteria (hilum infiltration, cortical hypo-echogenicity, irregular margins, abnormal vessels) were assessed on a five-point scale. Four quantitative parameters were obtained: long axis length, short axis length, short axis/long axis ratio, resistive index and maximum shear elasticity modulus (µmax). Diagnostic performance was analyzed with special emphasis on the sub-centimeter HNLN subgroup. Thirty HNLNs were malignant (48%). µmax intra-observer reproducibility was 0.899 (0.728 in sub-centimeter subgroup). Malignant HNLNs were stiffer (µmax = 72.4 ± 59.0 kPa) compared with benign nodes (µmax = 23.3 ± 25.3 kPa) (p < 0.001). Among the quantitative criteria, µmax had the highest diagnostic accuracy (area under the curve = 0.903 ± 0.042), especially in the sub-centimeter subgroup (area under the curve = 0.929 ± 0.045; p < 0.001) in which the area under the curve was significantly higher compared with the other quantitative criteria (p < 0.05). The additional use of SWE combined with B-mode tended to improve diagnostic accuracy (p > 0.05). SWE is a promising reproducible quantitative tool with which to predict malignant HNLNs, especially sub-centimeter nodes.
Assuntos
Técnicas de Imagem por Elasticidade/métodos , Interpretação de Imagem Assistida por Computador/métodos , Linfonodos/diagnóstico por imagem , Doenças Linfáticas/diagnóstico por imagem , Metástase Linfática/diagnóstico por imagem , Ultrassonografia Doppler/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Módulo de Elasticidade , Feminino , Dureza , Humanos , Aumento da Imagem/métodos , Linfonodos/fisiopatologia , Doenças Linfáticas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Pescoço , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resistência ao Cisalhamento , Adulto JovemRESUMO
PURPOSE: Although arterial spin labeling (ASL) has become a routinely performed method in the rodent heart, its application to the human heart remains challenged by low tissue blood flow and cardiac and respiratory motion. We hypothesized that an alternative steady-pulsed ASL (spASL) method would provide more efficient perfusion signal averaging by driving the tissue magnetization into a perfusion-dependent steady state. METHODS: We evaluated the feasibility of spASL in the human heart by combining pulsed labeling in the aortic root with a balanced steady state free precession sequence. The spASL scheme was applied to 13 subjects under free breathing. Breathing motion was addressed using retrospective image exclusion based on a contour-based cross-correlation algorithm. RESULTS: The measured signal with spASL was due to labeled blood. We found that the perfusion signal was larger than that obtained with the earlier flow-sensitive alternating inversion recovery (FAIR) method. Averaged myocardial blood flow (MBF) over four myocardial regions was 1.28 ± 0.36 mL·g(-1) ·min(-1) . CONCLUSION: spASL was able to quantify MBF in healthy subjects under free breathing. Because quantification with ASL is more direct than with first-pass perfusion MRI, it appears particularly suited for pathologies with diffuse microvascular alterations, MBF reserve, and follow-up studies.
Assuntos
Circulação Coronária/fisiologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Imagem de Perfusão do Miocárdio/métodos , Adulto , Feminino , Humanos , Masculino , Processamento de Sinais Assistido por Computador , Marcadores de Spin , Adulto JovemRESUMO
PURPOSE: 1) To assess the myocardial partition coefficient (λ) of gadolinium quantified using T1 mapping in dilated cardiomyopathy (DCM); and 2) to assess the impact of increased λ on left ventricular (LV) circumferential strain and ejection fraction in DCM. MATERIALS AND METHODS: Seventeen patients with DCM and 11 controls were prospectively included. All patients and controls underwent a 1.5 T MRI using: 1) cine to quantify LV volumes and function; 2) tagging to quantify circumferential strain in mid-LV; 3) T1 mapping before and 9 minutes after contrast injection to quantify R1, ΔR1, and λ; and 4) inversion recovery 3D Flash was used to assess late gadolinium enhancement (LGE) 10 minutes after Gd DOTA injection (0.2 mmol/kg). We used Student's t-test to compare means, Pearson's test for correlation assessment, and a mixed linear model to integrate the dependency between myocardial segments. RESULTS: No difference in median λ was measured between patients with (0.52 [interquartile range = 0.48-0.56]) and without enhancement on LGE (0.51 [0.47-0.54]; P = 0.07). Circumferential strain value measured in each segment was correlated with the λ measured in the corresponding segment (r = 0.55; P < 0.0001). Multivariate analysis revealed a significant link between the λ in each segment and circumferential strain (0.002 ± 0.001; P = 0.009) and also with ejection fraction (-0.001 ± 0.0008; P = 0.04). CONCLUSION: In DCM, λ correlates independently with circumferential strain and ejection fraction, suggesting that there is a link between λ and systolic function.
Assuntos
Cardiomiopatia Dilatada/diagnóstico , Cardiomiopatia Dilatada/metabolismo , Meglumina/farmacocinética , Modelos Cardiovasculares , Compostos Organometálicos/farmacocinética , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/metabolismo , Idoso , Cardiomiopatia Dilatada/complicações , Força Compressiva , Simulação por Computador , Meios de Contraste/farmacocinética , Módulo de Elasticidade , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estresse Mecânico , Volume Sistólico , Resistência à Tração , Distribuição Tecidual , Disfunção Ventricular Esquerda/diagnósticoRESUMO
OBJECTIVE: The aim of the study was to assess the value of in vivo T2 measurements to noninvasively quantify myocardial fibrosis in diabetic mice at 11.75 T. Diabetic cardiomyopathy is characterized by extracellular matrix alteration and microcirculation impairment. These conditions might provide electrical heterogeneity, which is a substrate for arrhythmogenesis. T1 mapping has been proposed to quantify diffuse myocardial fibrosis in cardiac diseases but has several limitations. T2 measurement may represent an alternative for fibrosis quantification at high magnetic field. MATERIALS AND METHODS: A magnetic resonance imaging protocol including in vivo T2 measurements at 11.75 T was performed in 9 male C57BL/6J mice after 8 weeks of streptozotocin-induced diabetes and in 9 control mice. Programmed ventricular stimulation was performed in both groups. T2 measurements were compared with histologic quantification of fibrosis using picrosirius red staining. RESULTS: Myocardial T2 was significantly lower in diabetic mice (13.8 ± 2.8 ms) than in controls (18.9 ± 2.3 ms, P < 0.001). There was a good correlation between T2 and fibrosis area obtained by histopathology (R = 0.947, P < 0.001). During programmed ventricular stimulation, 3 nonsustained ventricular tachycardias were induced in diabetic mice versus none in the control group. CONCLUSIONS: The in vivo T2 relaxation time strongly correlated with myocardial fibrosis area assessed with histologic staining in diabetic mice.
Assuntos
Diabetes Mellitus Experimental/patologia , Fibrose Endomiocárdica/patologia , Imageamento por Ressonância Magnética/métodos , Estreptozocina , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/complicações , Fibrose Endomiocárdica/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Despite improvement in revascularization strategies, microvascular obstruction (MO) lesions remain associated with poor outcome after ST-segment elevation myocardial infarction (STEMI). AIMS: To establish a bedside-available score for predicting MO lesions in STEMI, with cardiac magnetic resonance imaging (CMR) as the reference standard, and to test its prognostic value for clinical outcome. METHODS: Patients with STEMI of<12 hours' evolution treated by percutaneous coronary intervention (PCI) were included. CMR was performed 4-8 days later, to measure myocardial infarction (MI) extent, left ventricular ejection fraction (LVEF) and volumes, and to identify MO lesions. An MO score was built from multivariable logistic regression results and included clinical, angiographic and electrocardiographic criteria. Adverse cardiovascular events were recorded prospectively after STEMI. RESULTS: We analysed data from 112 patients. MO lesions were found in 63 (56%) patients and were associated with larger MI as assessed by higher peak creatine phosphokinase (3755 ± 351 vs 1467 ± 220 IU, p<0.001), lower LVEF (46.7 ± 1.5 vs 53.4 ± 1.6%, p<0.01) and larger MI extent (18.7 ± 1.2 vs 9.0 ± 1.3% LV, p<0.001) on CMR. MO score>4 accurately identified microcirculatory injuries (sensitivity 84%; specificity 82%) and independently predicted the presence of MO lesions on CMR. MO score>4 predicted adverse cardiovascular events during the first year after STEMI (relative risk 2.60 [1.10-6.60], p=0.03). CONCLUSIONS: MO lesions are frequent in PCI-treated STEMI and are associated with larger MIs. MO score accurately predicted MO lesions and identified patients with poor outcome post-STEMI.
Assuntos
Angioplastia Coronária com Balão/efeitos adversos , Doença da Artéria Coronariana/etiologia , Circulação Coronária , Indicadores Básicos de Saúde , Microcirculação , Infarto do Miocárdio/terapia , Angioplastia Coronária com Balão/mortalidade , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/fisiopatologia , Creatina Quinase/sangue , Eletrocardiografia , Feminino , França , Humanos , Estimativa de Kaplan-Meier , Modelos Logísticos , Imagem Cinética por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/fisiopatologia , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Volume Sistólico , Fatores de Tempo , Resultado do Tratamento , Função Ventricular EsquerdaRESUMO
BACKGROUND: Two-dimensional echocardiography images obtained at end-diastole and end-systole and cardiac magnetic resonance (CMR) images obtained at end-diastole represent the three imaging methodologies validated for diagnosis of left ventricular non-compaction (LVNC). No study has compared these methodologies in assessing the magnitude of non-compaction. AIMS: To compare two-dimensional echocardiography with CMR in the evaluation of patients with suspected LVNC. METHODS: Sixteen patients (48+/-17 years) with LVNC underwent echocardiography and CMR within the same week. Echocardiography images obtained at end-diastole and end-systole were compared in a blinded fashion with those obtained by CMR at end-diastole to assess non-compaction in 17 anatomical segments. RESULTS: All segments could be analysed by CMR, whereas only 238 (87.5%) and 237 (87.1%) could be analysed by echocardiography at end-diastole and end-systole, respectively (p=0.002). Among the analysable segments, a two-layered structure was observed in 54.0% by CMR, 42.9% by echocardiography at end-diastole and 41.4% by echocardiography at end-systole (p=0.006). Similar distribution patterns were observed with the two echocardiographic methodologies. However, compared with echocardiography, CMR identified a higher rate of two-layered structures in the anterior, anterolateral, inferolateral and inferior segments. Echocardiography at end-systole underestimated the NC/C maximum ratio compared with CMR (p=0.04) and echocardiography at end-diastole (p=0.003). No significant difference was observed between CMR and echocardiography at end-diastole (p=0.83). Interobserver reproducibility of the NC/C maximum ratio was similar for the three methodologies. CONCLUSION: CMR appears superior to standard echocardiography in assessing the extent of non-compaction and provides supplemental morphological information beyond that obtained with conventional echocardiography.
Assuntos
Miocárdio Ventricular não Compactado Isolado/diagnóstico , Imagem Cinética por Ressonância Magnética , Adulto , Idoso , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Miocárdio Ventricular não Compactado Isolado/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Ultrassonografia , Adulto JovemRESUMO
OBJECTIVES: (1) To determine the accuracy of delayed enhancement multidetector computed tomography (MDCT) in measuring the extent of acute myocardial infarct and no-reflow areas using cardiac magnetic resonance imaging (MRI) as standard of reference and (2) to define the optimum timing between injection and MDCT image acquisition to characterize infarcted myocardium and no-reflow areas after reperfusion therapy. MATERIALS AND METHODS: Nineteen patients were prospectively included after acute myocardial infarction and revascularization. Each patient had an MDCT acquisition before and 5 and 10 minutes after injection of 1.5 mL/kg iodinated contrast medium, and a contrast-enhanced MRI at 5 and 10 minutes after injection of 0.2 mmol/kg gadolinium chelate. We assessed image quality and infarct extent using MDCT and MRI, and we measured parameters related to iodinated contrast media kinetics (DeltaHU and DeltaHU ratio). RESULTS: The areas of hyperenhanced myocardium located on the MDCT corresponded to the occluded vessel located on the coronary angiogram (kappa = 0.9). There were strong correlations between the extent of hyperenhanced infarcted myocardium on MDCT and MRI at 5 minutes (20.4% +/- 2.7% of left ventricle (LV) and 20.9% +/- 2.4%, respectively, R = 0.85; P < 0.0001) and 10 minutes after injection (21.0% +/- 2.9% of LV and 19.4% +/- 2.5%, respectively, R = 0.80; P < 0.0001). However, the correlation between the area of hypoenhanced myocardium measured using MDCT and CMR 5 minutes after injection (R = 0.86; P < 0.0001) was better than the measurement obtained 10 minutes after injection (R = 0.64; P = 0.002). On contrast-enhanced MDCT, 5 minutes after injection, the signal-to-noise ratio was significantly higher than at 10 minutes after injection in LV blood (28 +/- 1 to 21 +/- 1, respectively; P = 0.0007), normal myocardium (18 +/- 1 to 15 +/- 1; P = 0.0009), and hyperenhanced infarcted myocardium (24 +/- 1 to 20 +/- 1; P = 0.004). MDCT image quality was significantly better at 5 minutes (3.2 +/- 0.1) than at 10 minutes (2.8 +/- 0.2, P = 0.01, kappa = 0.4). The DeltaHU ratio increased slightly but significantly between 5 minutes (0.83 +/- 0.01) and 10 minutes (0.93 +/- 0.01; P = 0.01), suggesting a slow wash-in and wash-out of contrast medium in infarcted myocardium. CONCLUSION: In ST segment elevation myocardial infarction patients contrast-enhanced MDCT is an accurate method for characterizing and sizing myocardial infarct and no-reflow. Contrast-enhanced MDCT performed 5 minutes after injection yields a higher signal-to-noise ratio and image quality than the 10 minutes time point with no difference in the extent of infarct measurement.
Assuntos
Imageamento por Ressonância Magnética/métodos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/terapia , Reperfusão/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenômeno de não Refluxo/diagnóstico , Fenômeno de não Refluxo/prevenção & controle , Prognóstico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resultado do TratamentoRESUMO
PURPOSE: To provide evidence that vascular endothelial growth factor (VEGF) genes delivered transendocardially with magnetic resonance (MR) imaging guidance may neovascularize or improve vascular recruitment in occlusive infarction. MATERIALS AND METHODS: All experimental procedures received approval from the institutional committee on animal research. Dogs with permanent coronary artery occlusion were imaged twice (3 days after occlusion for assessment of acute infarction; a mean of 50 days after occlusion +/- 3 [standard error of the mean] for assessment of chronic infarction). A mixture of plasmid VEGF and plasmid LacZ (n = 6, treated animals) or plasmid LacZ and sprodiamide (n = 6, placebo control animals) was delivered to four sites. MR fluoroscopy was used to target and monitor delivery of genes. The effectiveness of this delivery approach was determined by using MR imaging methods to assess perfusion, left ventricular (LV) function, myocardial viability, and infarct resorption. Histologic evaluation of neovascularization was then performed. RESULTS: MR fluoroscopic guidance of injectates was successful in both groups. Treated animals with chronic, but not those with acute, infarction showed the following differences compared with control animals: (a) steeper mean maximum upslope perfusion (200 sec(-1) +/- 32 vs 117 sec(-1) +/- 15, P = .02), (b) higher peak signal intensity (1667 arbitrary units +/- 100 vs 1132 arbitrary units +/- 80, P = .002), (c) increased ejection fraction (from 27.9% +/- 1.2 to 35.3% +/- 1.6, P = .001), (d) smaller infarction size (as a percentage of LV mass) at MR imaging (8.5% +/- 0.9 vs 11.3% +/- 0.9, P = .048) and triphenyltetrazolium chloride staining (9.4% +/- 1.5 vs 12.7% +/- 0.4, P = .05), and (e) higher vascular density (as number of vessels per square millimeter) at the border (430 +/- 117 vs 286 +/- 19, P = .0001) and core (307 +/- 112 vs 108 +/- 17, P = .0001). CONCLUSION: The validity of plasmid VEGF gene delivered with MR fluoroscopic guidance into occlusive infarction was confirmed by neovascularization associated with improved perfusion, LV function, and infarct resorption.
Assuntos
Oclusão Coronária/tratamento farmacológico , Terapia Genética/métodos , Imagem por Ressonância Magnética Intervencionista/métodos , Fator A de Crescimento do Endotélio Vascular/farmacologia , Análise de Variância , Animais , Meios de Contraste/administração & dosagem , Cães , Meglumina/administração & dosagem , Compostos Organometálicos/administração & dosagem , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
The objectives of the study were: (1) to compare the kinetics of a new gadolinium-based low-diffusibility magnetic resonance (MR) contrast medium, P846 and Gd-DOTA in left ventricular (LV) blood and in normal and ischemically injured myocardium using inversion recovery echo-planar imaging (IR-EPI) and (2) to compare the enhancement pattern after injection of P846 with Gd-DOTA, using T1-weighted spin-echo imaging (T1-SE). Sixteen rats were subjected to left descending artery (LAD) occlusion for 30 min, followed by 2.5 h reperfusion. MR imaging was performed before and after administration of the contrast medium in two different groups of animals: one group (n = 8) received 0.05 mmol kg(-1) P846 and the other (n = 8) 0.1 mmol kg(-1) Gd-DOTA. A blipped IR-EPI and a multislice T1-SE were performed before injection and for 90 min after injection. T1-values were derived by fitting regional signal intensity on the IR-EPI images, the R1, DeltaR1 (R(1postcontrast) - R(1precontrast)) and DeltaR1 ratios were calculated in LV blood, normal and injured myocardium. On SE-T(1), the signal intensity ratio (SI) and extent of injury were measured. True infarct size was measured using histochemical staining. Changes in DeltaR(1) were 4.8 times greater with 0.05 mmol kg(-1) P846 than with 0.1 mmol kg(-1) Gd-DOTA in LV blood (6.3 +/- 0.9 vs 0.9 +/- 0.1 s(-1), p < 0.0001), normal (1.7 +/- 0.2 vs 0.34 +/- 0.03 s(-1), p < 0.0001) and ischemically injured myocardium (5.4 +/- 0.4 vs 1.6 +/- 0.1 s(-1), p < 0.0001). MR imaging experiments showed that the signal enhancement with P846 is longer (90 min), which might be explained by a lower diffusion of P846 compared with Gd-DOTA (30 min). P846 differentiates viable and nonviable myocardium. Despite lower gadolinium dose, P846 permits differentiation of viable and nonviable myocardium owing to a high contrast and a long imaging window with conventional t1-weighted SE sequence.