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1.
Medicine (Baltimore) ; 99(46): e23148, 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33181686

RESUMO

To evaluate the perfusion of coronary circulation and its related factors and the difference in the peak filling times in aortic sinus and coronary sinus by coronary computed tomography angiography (CCTA).From January 1 to August 1, 2018, 61 outpatients with angina pectoris were recruited, completed a questionnaire about risk factors and underwent CCTA, which was also used to assess the stenosis of different coronary artery segments.The duration of circulation was 9.50 ±â€Š2.43 seconds in patients with flat T wave, which was shorter than the duration in normal subjects (P = .021). However, other cardiovascular risk factors showed no effect on the duration of circulation. In addition, the duration of circulation was closely related to the peak filling time of coronary sinus [r(s) = 0.681]. We further divided the circulation time difference (delta) values into 3 levels (<6, 6-12, and ≥12 seconds).It showed that the circulation duration (Y) was associated with:Therefore, the cardiac circulation duration was negatively related to the degree of stenosis in the 1 diagonal and proximal LCA.It compensates for the inability of CCTA to assess circulation at rest simply by determining the peak filling time in the aortic sinus and the coronary sinus. Moderate cardiac microcirculation duration was related to a low incidence of clinical symptoms and electrocardiogram disorders, which was determined mainly by the diagonal and left circumflex branch 1 of LCA.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Doença das Coronárias , Vasos Coronários , Circulação Coronária/fisiologia , Doença das Coronárias/diagnóstico , Doença das Coronárias/epidemiologia , Doença das Coronárias/fisiopatologia , Estenose Coronária/patologia , Estenose Coronária/fisiopatologia , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/patologia , Vasos Coronários/fisiopatologia , Eletrocardiografia/métodos , Eletrocardiografia/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio/métodos , Valor Preditivo dos Testes , Medição de Risco , Fatores de Risco , Avaliação de Sintomas/métodos , Avaliação de Sintomas/estatística & dados numéricos
2.
J Stroke Cerebrovasc Dis ; 29(9): 105058, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32807463

RESUMO

OBJECTIVES: Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI) technique used to assess cerebral perfusion. When tissue perfusion is impaired, such as in Moyamoya disease, a hyperintense band called the arterial transit artifact (ATA) may occur, which interferes with accurate measurements on ASL-MRI. In this study, we evaluated the correlation of ATAs with magnetic resonance angiography (MRA) and single-photon emission computed tomography (SPECT) imaging results in Moyamoya disease. The aim of our study was to elucidate the pathophysiology of ATAs and risk factors for high ATA scores. MATERIALS AND METHODS: This retrospective study included 28 patients (56 hemispheres) with Moyamoya disease treated at our institution. MRI, MRA, ASL perfusion, and N-isopropyl-[123I] b-iodoamphetamine (123I-IMP) SPECT were performed. In order to semi-quantitatively evaluate the degree of ATA, the ATA scores were measured according to the number of hyperintense signal bands in the cerebral cortex. The relationship between the ATA scores and clinical and radiological factors were analyzed. RESULTS: Regional cerebral blood flow (rCBF) determined with ASL weakly correlated with that determined by 123I-IMP SPECT (ρ=0.31, p=0.027). There was no significant association between the ATA scores and rCBF values determined with 123I-IMP SPECT (p=0.872, 0.745, 0.743 at PLD1000 (post-labeling delay), 1500, and 2000, respectively). However, there was a significant correlation between ATA scores and MRA scores (ρ=0.427 p=0.001; ρ=0.612 p=0.001; ρ=0.563 p=0.001 at PLD1000, 1500, and 2000, respectively). An analysis of patient background characteristics revealed a significantly higher incidence of high ATA scores in female patients, patients with high MRA scores, and patients with a distinguishable ivy sign. A multivariate analysis confirmed that female sex, high MRA score, and presence of an ivy sign were risk factors for high ATA scores. CONCLUSION: ATA scores were moderately correlated with MRA scores, and presence of an ivy sign was the most predictive factor for high ATA scores. A high ATA score determined using ASL in a patient with Moyamoya disease might suggest an advanced disease stage and a reduction in cerebrovascular reserve capacity.


Assuntos
Artefatos , Angiografia Cerebral/métodos , Artérias Cerebrais/diagnóstico por imagem , Circulação Cerebrovascular , Angiografia por Ressonância Magnética , Doença de Moyamoya/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Marcadores de Spin , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Velocidade do Fluxo Sanguíneo , Artérias Cerebrais/fisiopatologia , Feminino , Humanos , Iofetamina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Doença de Moyamoya/fisiopatologia , Valor Preditivo dos Testes , Compostos Radiofarmacêuticos/administração & dosagem , Reprodutibilidade dos Testes , Estudos Retrospectivos
3.
Br J Radiol ; 93(1113): 20200349, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783626

RESUMO

The aim of this review is to provide an overview of different functional cardiac CT techniques which can be used to supplement assessment of the coronary arteries to establish the significance of coronary artery stenoses. We focus on cine-CT, CT-FFR, CT-myocardial perfusion and how developments in machine learning can supplement these techniques.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Aprendizado de Máquina , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada por Raios X/métodos , Ensaios Clínicos como Assunto , Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária/métodos , Reserva Fracionada de Fluxo Miocárdico , Humanos , Volume Sistólico , Calcificação Vascular/diagnóstico por imagem , Função Ventricular Esquerda
4.
Methodist Debakey Cardiovasc J ; 16(2): 114-121, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32670471

RESUMO

Coronary artery disease (CAD), also known as ischemic heart disease, is a major cause of morbidity and mortality worldwide, and timely noninvasive diagnosis of clinical and subclinical CAD is imperative to mitigate its burden on individual patients and populations. Positron emission tomography (PET) is a versatile tool that can perform relative myocardial perfusion imaging (MPI) with high accuracy; furthermore, it provides valuable information about the coronary microvasculature using rest and stress myocardial blood flow (MBF) and coronary flow reserve (CFR) measurements. Several radiotracers are approved by the US Food and Drug Administration to help with MPI, MBF, and CFR evaluation. A large body of evidence indicates that evaluation of the coronary microcirculation using MBF and CFR provides strong diagnostic and prognostic data in a multitude of patient populations. This review describes the technical aspects of PET compared to other modalities and discusses its clinical uses for diagnosis and prognosis of coronary arterial epicardial and microcirculatory disease.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Microcirculação , Imagem de Perfusão do Miocárdio/métodos , Tomografia por Emissão de Pósitrons , Doença da Artéria Coronariana/fisiopatologia , Humanos , Valor Preditivo dos Testes
5.
Medicine (Baltimore) ; 99(26): e20804, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32590765

RESUMO

The aim of this study was to evaluate the effect of a novel 4-dimensional similarity filter (4DSF) on quantitative and qualitative parameters of low-dose dynamic myocardial computed tomography perfusion (CTP) images.In this retrospective study, medical records of 32 patients with suspected or known coronary artery disease who underwent dynamic myocardial CTP at 80 kV were included. The 4DSF reduces noise by averaging voxels that have similar dynamic behavior after adaptive iterative dose reduction 3D (AIDR3D) and deformable image registration were applied. Qualitative (artefact, contour sharpness, and myocardial homogeneity [1 = poor; 2 = intermediate; 3 = good]) and quantitative measurement (standard deviation [SD] and signal-to-noise ratio [SNR]) were compared between the 4DSF and AIDR3D. Contrast-to-noise ratio (CNR) between ischemic and normal remote myocardium was also assessed using myocardial perfusion magnetic resonance imaging as the reference standard in seven patients.The 4DSF was successfully applied to all the images. Improvement in subjective image quality yielded by 4DSF was higher than that yielded by AIDR3D (homogeneity, 1.0 [3 vs 2]; artefact, 1.5 [3 vs 1.5]; P < .001) in all patients. The 4DSF significantly decreased the SD by 59% (AIDR3D vs 4DSF: 33.5 ±â€Š0.4 vs 13.8 ±â€Š0.4, P < .001), increased the SNR by 134% (AIDR3D vs 4DSF: 4.4 ±â€Š0.2 vs 10.3 ±â€Š0.2, P < .001), and increased the CNR by 131% (AIDR3D vs 4DSF: 1.6 ±â€Š0.2 vs 3.7 ±â€Š0.2, P < .001).The 4DSF improved the qualitative and quantitative parameters of low-dose dynamic myocardial CTP images.


Assuntos
Doença da Artéria Coronariana/diagnóstico , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada por Raios X , Feminino , Humanos , Japão , Masculino , Registros Médicos/estatística & dados numéricos , Pessoa de Meia-Idade , Melhoria de Qualidade , Intensificação de Imagem Radiográfica/métodos , Saúde Radiológica , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/instrumentação , Tomografia Computadorizada por Raios X/métodos
6.
J Cardiovasc Magn Reson ; 22(1): 35, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32418537

RESUMO

BACKGROUND: Cardiovascular magnetic resonance (CMR) studies in patients with implanted cardioverter/defibrillators (ICD) are increasingly required in daily clinical practice. However, the clinical experience regarding the feasibility as well as clinical value of CMR studies in patients with subcutaneous ICD (S-ICD) is still limited. Besides safety issues, image quality and analysis can be impaired primarily due the presence of image artefacts associated with the generator. METHODS: Twenty-three patients with an implanted S-ICD (EMBLEM, Boston Scientific, Marlborough, Massachusetts, USA; MR-conditional) with suspected cardiomyopathy and/or myocarditis underwent multi-parametric CMR imaging. Studies were performed on a 1.5 T CMR scanner after device interrogation and comprised standard a) balanced steady state free precession cine, b) T2 weighted-edema, c) velocity-encoded cine flow, d) myocardial perfusion, e) late-gadolinium-enhancement (LGE)-imaging and f) 3D-CMR angiography of the aorta. In case of substantial artefacts, alternative CMR techniques such as spoiled gradient-echo cine-sequences and wide-band inversion-recovery LGE (wb-LGE) sequences were applied. RESULTS: Successful CMR studies could be performed in all patients without any case of unexpected early termination or relevant technical complication other than permanent loss of the S-ICD system beeper volume in 52% of our patients. Assessment of cine-CMR images was predominantly impaired in the left ventricular (LV) anterior, lateral and inferior wall segments and a switch to spoiled gradient echo-based cine-CMR allowed an accurate assessment of cine-images in N = 17 (74%) patients with only limited artefacts. Hyperintensity artefacts in conventional LGE-images were predominantly observed in the LV anterior, lateral and inferior wall segments and image optimisation by use of the wb-LGE was helpful in 15 (65%) cases. Aortic flow measurements and 3D-CMR angiography were assessable in all patients Perfusion imaging artefacts precluded a meaningful assessment in at least one half of the patients. A benefit in clinical-decision making was documented in 17 (74%) patients in the present study. CONCLUSION: Safe 1.5 T CMR imaging was possible in all patients with an S-ICD, though the majority had permanent loss of the S-ICD beeper volume. Achieving good image quality may be challenging in some patients - particularly for perfusion imaging. Using spoiled gradient echo-based cine-sequences and wb-LGE sequences may help to reduce the extent of artefacts, thereby allowing accurate cardiac assessment. Thus, 1.5 T CMR studies should not be withhold in patients with S-ICD for safety concerns and/or fear of extensive imaging artefacts precluding successful image analysis.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Desfibriladores Implantáveis , Cardioversão Elétrica/instrumentação , Imagem Cinética por Ressonância Magnética , Imagem de Perfusão do Miocárdio/métodos , Miocardite/diagnóstico por imagem , Adulto , Idoso , Artefatos , Cardiomiopatias/fisiopatologia , Cardiomiopatias/terapia , Tomada de Decisão Clínica , Circulação Coronária , Cardioversão Elétrica/efeitos adversos , Feminino , Humanos , Imagem Cinética por Ressonância Magnética/efeitos adversos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio/efeitos adversos , Miocardite/fisiopatologia , Miocardite/terapia , Segurança do Paciente , Valor Preditivo dos Testes , Prognóstico , Desenho de Prótese , Falha de Prótese , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Função Ventricular Esquerda
7.
Cardiovasc Diabetol ; 19(1): 52, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375795

RESUMO

BACKGROUND: The microvascular effects of obesity should be considered in diabetic individuals for elucidating underlying mechanisms and developing targeted therapies. This study aims to determine the effect of obesity on myocardial microvascular function in type 2 diabetes mellitus (T2DM) patients using cardiac magnetic resonance (CMR) first-pass perfusion imaging and assessed significant risk factors for microvascular dysfunction. MATERIALS AND METHODS: Between September 2016 and May 2018, 120 patients with T2DM (45.8% women [55 of 120]; mean age, 56.45 ± 11.97 years) and 79 controls (44.3% women [35 of 79]; mean age, 54.50 ± 7.79 years) with different body mass index (BMI) scales were prospectively enrolled and underwent CMR examination. CMR-derived perfusion parameters, including upslope, time to maximum signal intensity (TTM), maximum signal intensity (MaxSI), MaxSI (-baseline), and SI (baseline), and T2DM related risk factors were analyzed among groups/subgroups both in T2DM patients and controls. Univariable and multivariable linear and logistic regression analyses were performed to assess the potential additive effect of obesity on microvascular dysfunction in diabetic individuals. RESULTS: Compared with controls with comparable BMIs, patients with T2DM showed reduced upslope and MaxSI and increased TTM. For both T2DM and control subgroups, perfusion function gradually declined with increasing BMI, which was confirmed by all perfusion parameters, except for TTM (all P < 0.01). In multivariable linear regression analysis, BMI (ß = - 0.516; 95% confidence interval [CI], - 0.632 to - 0.357; P < 0.001), female sex (ß = 0.372; 95% CI, 0.215 to 0.475; P < 0.001), diabetes duration (ß = - 0.169; 95% CI, - 0.319 to - 0.025; P = 0.022) and glycated haemoglobin (ß = - 0.184; 95% CI, - 0.281 to - 0.039; P = 0.010) were significantly associated with global upslope in the T2DM group. Multivariable logistic regression analysis indicated that T2DM was an independent predictor of microvascular dysfunction in normal-weight (odds ratio[OR], 6.46; 95% CI, 2.08 to 20.10; P = 0.001), overweight (OR, 7.19; 95% CI, 1.67 to 31.07; P = 0.008) and obese participants (OR, 11.21; 95% CI, 2.38 to 52.75; P = 0.002). CONCLUSIONS: Myocardial microvascular function gradually declined with increasing BMI in both diabetes and non-diabetes status. T2DM was associated with an increased risk of microvascular dysfunction, and obesity exacerbated the adverse effect of T2DM.


Assuntos
Circulação Coronária , Diabetes Mellitus Tipo 2/complicações , Cardiomiopatias Diabéticas/diagnóstico por imagem , Imagem Cinética por Ressonância Magnética , Microcirculação , Imagem de Perfusão do Miocárdio/métodos , Obesidade/complicações , Idoso , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/diagnóstico , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/diagnóstico , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Fatores de Risco
8.
J Cardiovasc Magn Reson ; 22(1): 30, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32366254

RESUMO

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is thought to be associated with microvascular dysfunction. Adenosine stress-perfusion cardiovascular magnetic resonance imaging (CMR) is a sensitive method for assessing microvascular perfusion abnormalities. We evaluated the prevalence and clinical characteristics of HCM patients with adenosine-induced perfusion defects on CMR. METHODS: Among 189 consecutive patients with HCM who underwent adenosine-stress perfusion CMR, 115 patients who had clinical, echocardiography, 24-h Holter monitoring and treadmill exercise test data were analyzed. We calculated myocardial perfusion ratio index from the intensity-over-time curve to quantify perfusion defects. The presence and extent of the stress-induced perfusion defect were compared with clinical characteristics, presence and extent of late gadolinium enhancement (LGE), left ventricular (LV) mass index and volume, presence of non-sustained ventricular tachycardia (NSVT) and results of treadmill exercise test. RESULTS: The mean age of enrolled patients was 51.8 ± 11.3 years. Most patients were asymptomatic except 25 subjects presented with New York Heart Association Class II dyspnea and 16 patients with atypical non-exertional chest discomfort. LGE was present in 103 (89.6%) subjects. Adenosine stress-induced perfusion defects were present in 48 (42%) subjects. None of the perfusion defects corresponded with a single or multiple coronary artery territories, showing a multiple patchy pattern in 24 (50.0%), a concentric subendocardial pattern in 20 subjects (41.7%), and as a single blot-like defect in the remaining 4 (8.3%). A perfusion defect was associated with NSVT, LV apical aneurysm, higher LV mass index, and higher LGE volume on univariate analysis. Multivariate analysis revealed female gender (P = 0.008), presence of apical aneurysm and NSVT (P = 0.036 and 0.047, respectively), and LV mass index (P = 0.022) to be independently associated with adenosine stress-induced perfusion defects. CONCLUSIONS: In patients with HCM, adenosine-stress perfusion defects on CMR are present in more than 40% of subjects. This perfusion defect is associated with NSVT, higher LV mass index, and apical aneurysms. The prognostic value of this finding needs further elucidation.


Assuntos
Adenosina/administração & dosagem , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Circulação Coronária , Imagem Cinética por Ressonância Magnética , Microcirculação , Imagem de Perfusão do Miocárdio/métodos , Vasodilatadores/administração & dosagem , Cardiomiopatia Hipertrófica/epidemiologia , Cardiomiopatia Hipertrófica/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Fatores de Risco , Seul/epidemiologia , Função Ventricular Esquerda , Remodelação Ventricular
9.
BMC Cardiovasc Disord ; 20(1): 244, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32450798

RESUMO

BACKGROUND: Although timely coronary intervention can result in markedly improved clinical outcomes of patients with acute coronary syndrome (ACS), non-ST-elevation (NSTE)-ACS is sometimes difficult to accurately diagnose. CASE PRESENTATION: A 52-year-old woman complained of acute chest pain with sudden onset. Both electrocardiography (ECG) and echocardiography showed normal results, and we urgently needed to make a differential diagnosis among critical illnesses such as acute coronary syndrome and nonischemic cardiovascular life-threatening diseases. Contrast-enhanced computed tomography (CT) without ECG synchronization showed evidence of neither aortic dissection nor pulmonary embolism, but regionally reduced contrast enhancement in the posterior myocardium, which were suggestive of myocardial ischemia. Emergency coronary angiography demonstrated severe stenosis of the left circumflex artery, and we achieved favorable revascularization with drug-eluting stent deployment. CONCLUSIONS: We diagnosed a patient with NSTE-ACS in whom contrast-enhanced CT without ECG synchronization was effective for visualization of reduced myocardial perfusion, suggesting ischemic heart disease.


Assuntos
Síndrome Coronariana Aguda/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Síndrome Coronariana Aguda/fisiopatologia , Síndrome Coronariana Aguda/terapia , Circulação Coronária , Stents Farmacológicos , Feminino , Humanos , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/instrumentação , Valor Preditivo dos Testes , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Resultado do Tratamento
10.
Curr Cardiol Rep ; 22(6): 43, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32451746

RESUMO

PURPOSE OF REVIEW: The most pertinent clinical question in post-coronary computed tomography angiography (CCTA) patients is the assessment of the physiological significance of an anatomically identified stenosis. The clinical application of radionuclide MPI using single-photon emission computed tomography (SPECT) versus positron emission tomography (PET) in the evaluation and management of patients with an inconclusive CCTA is reviewed using a case-based approach. RECENT FINDINGS: Recent evidence suggests that CCTA is the most sensitive non-invasive test to exclude angiographic CAD and may be an effective first-line test especially among symptomatic low-intermediate risk patients. However, in the presence of angiographic atherosclerosis, its specificity and positive predictive value for identifying flow-limiting stenosis are modest. Radionuclide myocardial perfusion imaging offers accurate quantitative assessment of myocardial ischemia, which helps with risk stratification and patient management especially the potential need for revascularization. Routine accurate quantifications of myocardial blood flow and flow reserve are major advantages of PET MPI, which are especially useful when used in patients at intermediate-high clinical risk.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Angiografia Coronária , Humanos , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X
11.
Int J Cardiovasc Imaging ; 36(9): 1781-1789, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32399762

RESUMO

We aimed to evaluate the effects of four-dimensional noise reduction filtering using a similarity algorithm (4D-SF) on the image quality and hemodynamic parameter of dynamic myocardial computed tomography perfusion (CTP). Sixty-eight patients who underwent dynamic myocardial CTP for the assessment of coronary artery disease were enrolled. Dynamic CTP was performed using a 320-row CT with low tube voltage scan (80 kVp). Two different datasets of dynamic CTP were reconstructed using iterative reconstruction (IR) alone and a combination of IR and 4D-SF. Qualitative (5-grade scale) and quantitative image quality scores were assessed, and the CT-derived myocardial blood flow (CT-MBF) was quantified. These results were compared between the two different CTP images. The qualitative image quality in CTP images reconstructed with IR and 4D-SF was significantly higher than that with IR alone (noise score: 4.7 vs. 3.4, p < 0.05). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in CTP images reconstructed with IR and 4D-SF were significantly higher than those with IR alone (SNR: 20.6 vs. 9.7; CNR: 7.9 vs. 3.9, respectively; p < 0.05). There was no significant difference in mean CT-MBF between the two sets of CTP images (3.01 vs. 3.03 mL/g/min, p = 0.1081). 4D-SF showed incremental value in improving image quality in combination with IR without altering CT-MBF quantification in dynamic myocardial CTP imaging with a low tube potential.


Assuntos
Algoritmos , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Circulação Coronária , Tomografia Computadorizada Multidetectores , Imagem de Perfusão do Miocárdio/métodos , Interpretação de Imagem Radiográfica Assistida por Computador , Idoso , Doença da Artéria Coronariana/fisiopatologia , Bases de Dados Factuais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Razão Sinal-Ruído
12.
Magn Reson Med ; 84(5): 2871-2884, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32426854

RESUMO

PURPOSE: Cardiovascular magnetic resonance first-pass perfusion for the pixel-wise detection of coronary artery disease is rapidly becoming the clinical standard, yet no widely available method exists for its assessment and validation. This study introduces a novel phantom capable of generating spatially dependent flow values to enable assessment of new perfusion imaging methods at the pixel level. METHODS: A synthetic multicapillary myocardial phantom mimicking transmural myocardial perfusion gradients was designed and manufactured with high-precision 3D printing. The phantom was used in a stationary flow setup providing reference myocardial perfusion rates and was scanned on a 3T system. Repeated first-pass perfusion MRI for physiological perfusion rates between 1 and 4 mL/g/min was performed using a clinical dual-sequence technique. Fermi function-constrained deconvolution was used to estimate pixel-wise perfusion rate maps. Phase contrast (PC)-MRI was used to obtain velocity measurements that were converted to perfusion rates for validation of reference values and cross-method comparison. The accuracy of pixel-wise maps was assessed against simulated reference maps. RESULTS: PC-MRI indicated excellent reproducibility in perfusion rate (coefficient of variation [CoV] 2.4-3.5%) and correlation with reference values (R2 = 0.985) across the full physiological range. Similar results were found for first-pass perfusion MRI (CoV 3.7-6.2%, R2 = 0.987). Pixel-wise maps indicated a transmural perfusion difference of 28.8-33.7% for PC-MRI and 23.8-37.7% for first-pass perfusion, matching the reference values (30.2-31.4%). CONCLUSION: The unique transmural perfusion pattern in the phantom allows effective pixel-wise assessment of first-pass perfusion acquisition protocols and quantification algorithms before their introduction into routine clinical use.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Imagem de Perfusão do Miocárdio/métodos , Desenho de Equipamento , Humanos , Processamento de Imagem Assistida por Computador , Imagens de Fantasmas , Impressão Tridimensional , Reprodutibilidade dos Testes
13.
Clin Nucl Med ; 45(8): 588-593, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32404715

RESUMO

PURPOSE: The aim of the study is to evaluate the impact of myocardial I-metaiodobenzylguanidine (MIBG) in the diagnosis, clinical management, and differential diagnosis of Parkinson disease (PD) and non-PD parkinsonism. METHODS: The study enrolled 41 patients with parkinsonism. An initial diagnosis was reached after thorough clinical and imaging evaluation. After 2 to 5 years of follow-up, a final diagnosis was established. All patients underwent, soon after their initial visit, presynaptic striatal DaT scintigraphy with I-FP-CIT (DaTscan) and I-MIBG myocardial scintigraphy. DaTscan is not specific to distinguish among different types of neurodegenerative parkinsonism. I-MIBG myocardial scintigraphy displays the functional status of cardiac sympathetic nerves, which is reduced in PD/dementia with Lewy bodies (DLB) and normal in atypical parkinsonian syndromes and secondary or nondegenerative parkinsonism. RESULTS: No patients showed adverse effects during or after both scintigraphies. A positive DaTscan was found in all patients in the PD/DLB group (17/17) and in 15 of 24 patients in the non-PD group. Myocardial I-MIBG scintigraphy was associated with lower sensitivity (82% vs 100%) but higher specificity than DaTscan (79% vs 38%) in diagnosis PD/DLB from non-PD parkinsonism. A positive scan result on both techniques, to confirm diagnosis of PD/DLB, significantly improved the specificity of DaTscan, from 38% to 75%, with no reduction in sensitivity. CONCLUSIONS: Myocardial I-MIBG imaging provides complementary value to I-FP-CIT in the proper diagnosis, treatment plan, and differential diagnosis between PD and other forms of parkinsonism.


Assuntos
Imagem de Perfusão do Miocárdio/métodos , Doença de Parkinson/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , 3-Iodobenzilguanidina , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nortropanos , Compostos Radiofarmacêuticos , Tropanos
14.
Int J Cardiovasc Imaging ; 36(7): 1377-1384, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32246388

RESUMO

Transient ischemic dilation (TID), a marker of severe coronary artery disease (CAD), is the post-stress to rest left ventricular (LV) volume ratio quantified using non ECG gated single photon emission computerized tomography (SPECT). Although prone positioning causes physiological reduction of LV volume in normal subjects, we hypothesize this may not occur in TID with underlying severe CAD as cardiac hemodynamics worsen when prone. We aim to evaluate the utility of the non ECG gated supine to prone LV volume ratio (SPLVr) for identifying severe CAD. Retrospective data analysis from 130 patients with TID ratio ≥ 1.21 and both post-stress supine and prone images. SPLVr had a significant negative correlation with summed stress (r = - 0.221, p = 0.011) and rest (r = - 0.292, p = 0.001) scores. Of the 129 cases with follow-up invasive or computed tomography coronary angiography, 52 (40.3%) had severe CAD (left main ≥ 50% stenosis, 3-vessel with ≥ 70% stenosis or 2-vessel with proximal left anterior descending ≥ 70% stenosis). Mean SPLVr was significantly lower in severe CAD cases (1.05 ± 0.14 vs 1.12 ± 0.17, p = 0.012). SPLVr predicted severe CAD on univariate [OR 0.12 (95% CI 0.00-0.35) p = 0.01] but not in multivariate analysis. SPLVr is a novel marker that negatively correlates with extent of perfusion abnormalities and is lower amongst TID patients with severe CAD. Larger studies are needed to assess if SPLVr can reliably identify underlying severe CAD amongst TID cases.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Posicionamento do Paciente , Decúbito Ventral , Volume Sistólico , Decúbito Dorsal , Tomografia Computadorizada de Emissão de Fóton Único , Função Ventricular Esquerda , Idoso , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença
15.
Cardiovasc Diabetol ; 19(1): 42, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-32234045

RESUMO

BACKGROUND: Stress cardiovascular magnetic resonance (CMR) to screen for silent myocardial ischaemia in asymptomatic high risk patients with type 2 diabetes mellitus (DM) has never been performed, and its effectiveness is unknown. Our aim was to determine the feasibility of a screening programme using stress CMR by obtaining preliminary data on the prevalence of silent ischaemia caused by obstructive coronary artery disease (CAD) and quantify myocardial perfusion in asymptomatic high risk patients with type 2 diabetes. METHODS: In this prospective cohort study, we recruited 63 asymptomatic DM patients (mean age 66 years ± 4.4 years; 77.8% male); with Framingham risk score ≥ 20% from 3 sites from June 2017 to August 2018. Normal volunteers were recruited to determine normal global myocardial perfusion reserve index (MPRI). Adenosine stress CMR and global MPRI was performed and measured in all subjects. Positive stress CMR cases were referred for catheter coronary angiography (CCA) with/without fractional flow reserve (FFR) measurements. Positive CCA was defined as an FFR ≤ 0.8 or coronary narrowing ≥ 70%. Patients were followed up for major adverse cardiovascular events. Prevalence is presented as patient numbers and percentage. Mann-Whitney U test was used to compare global MPRI between patients and normal volunteers. RESULTS: 13 patients had positive stress CMR with positive CCA (20.6% of patient population), while 9 patients with positive stress CMR examinations had a negative CCA. 5 patients (7.9%) had infarcts detected of which 2 patients had no stress perfusion defects. 12 patients had coronary artery stents inserted, whilst 1 patient declined stent placement. DM patients had lower global MPRI than normal volunteers (n = 7) (1.43 ± 0.27 vs 1.83 ± 0.31 respectively; p < 0.01). After a median follow-up of 653 days, there was no death, heart failure, acute coronary syndrome hospitalisation or stroke. CONCLUSION: 20.6% of asymptomatic DM patients (with Framingham risk ≥ 20%) had silent obstructive CAD. Furthermore, asymptomatic patients have reduced global MPRI than normal volunteers. TRIAL REGISTRATION: ClinicalTrials.gov Registration Number: NCT03263728 on 28th August 2017; https://clinicaltrials.gov/ct2/show/NCT03263728.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Circulação Coronária , Diabetes Mellitus Tipo 2/epidemiologia , Imagem Cinética por Ressonância Magnética , Infarto do Miocárdio/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Adenosina/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Doenças Assintomáticas , Estudos de Casos e Controles , Angiografia Coronária , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/fisiopatologia , Doença da Artéria Coronariana/terapia , Diabetes Mellitus Tipo 2/diagnóstico , Estudos de Viabilidade , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/terapia , Intervenção Coronária Percutânea/instrumentação , Projetos Piloto , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Stents , Fatores de Tempo , Resultado do Tratamento , Vasodilatadores/administração & dosagem
16.
Phys Med Biol ; 65(14): 145010, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32244234

RESUMO

Myocardial perfusion (MP) PET imaging plays a key role in risk assessment and stratification of patients with coronary artery disease. In this work, we proposed a patch-based artificial neural network (ANN) fusion approach that integrates information from the ML and the post-smoothed ML reconstruction to improve MP PET imaging. The proposed method was applied to images reconstructed from different noise levels to enhance quantification and task-based MP defect detection. Using the XCAT phantom, we simulated three MP PET imaging cases, one with normal perfusion and the other two with non-transmural and transmural regionally reduced perfusion of the left ventricular (LV) myocardium. The proposed ANN fusion technique was quantitatively evaluated in terms of the noise versus bias and noise versus contrast tradeoff, and compared with the post-smoothed ML reconstruction. Using the channelized Hotelling observer, we evaluated the detectability of the non-transmural and transmural defects through the receiver operating characteristic analysis. The quantitative results demonstrated that the ANN enhancement method reduced bias and improved contrast while reaching comparable noise to what the post-smoothed ML reconstruction achieved. Moreover, the ANN fusion technique significantly improved the defect detectability of both the non-transmural and transmural defects. In addition to the simulation study, we further evaluated the proposed method using patient data. Compared with the post-smoothed ML reconstruction, the ANN fusion improved the tradeoff between noise and the mean value on the LV myocardium, indicating its potential clinical application in MP PET imaging.


Assuntos
Imagem de Perfusão do Miocárdio/métodos , Redes Neurais de Computação , Tomografia por Emissão de Pósitrons/métodos , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Imagens de Fantasmas , Curva ROC
17.
Open Heart ; 7(1): e001158, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32153789

RESUMO

Objective: The main objective of the present study was to compare the use of four-dimensional (4D) flow MRI with the habitual sequence (two-dimensional phase-contrast (2DPC) MRI) for the assessment of aortic regurgitation (AR) in the clinical routine. Methods: This was a retrospective, observational cohort study of patients with varying grades of AR. For the purposes of the present study, we selected all the cases with a regurgitant fraction (RF)>5% as determined by 2DPC MRI (n=34). In all cases, both sequences (2DPC and 4D flow MRI) were acquired in a single session to ensure comparability. We compared the results of the two techniques by evaluating forward flow, regurgitant flow and regurgitation fraction. Then, the patients were divided into subgroups to determine if these factors had any influence on the measurements: aortic diameter (≤ vs >38 mm), valve anatomy (tricuspid vs bicuspid/quadricuspid), stenosis (gradient ≥15 vs <15) and region of interest location (aortic valve vs sinotubular junction). Results: No statistically significant differences were observed between the two techniques with Pearson's correlation coefficients (r) of forward flow (r=0.826/p value<0001), regurgitant flow (r=0.866/p value<0001) and RF (r=0.761/p value<0001). Conclusions: The findings of this study confirm the value of 4D flow MRI for grading AR in clinical practice with an excellent correlation with the standard technique (2DPC MRI).


Assuntos
Insuficiência da Valva Aórtica/diagnóstico por imagem , Valva Aórtica/diagnóstico por imagem , Hemodinâmica , Imagem Cinética por Ressonância Magnética , Imagem de Perfusão do Miocárdio/métodos , Adulto , Idoso , Valva Aórtica/fisiopatologia , Insuficiência da Valva Aórtica/fisiopatologia , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença
18.
Intern Med ; 59(11): 1361-1371, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32161215

RESUMO

Objective There is no report on the risk stratification of major cardiac events (MCEs) with a combination of the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score and ischemic reduction detected with rest 201Tl and stress 99mTc-tetrofosmin myocardial perfusion single-photon-emission computed tomography (SPECT) after revascularization in Japanese patients with coronary artery disease (CAD). Methods This was a retrospective study. The patients were followed up to confirm their prognosis for at least one year. Ischemia was evaluated based on the summed difference scores converted to the percentage of the total myocardium Safety Data Sheet (SDS%). The SYNTAX score and SDS% were calculated before and after revascularization. The endpoint was the occurrence of MCEs. Patients Study subjects were 293 patients who had a ≥75% stenotic lesion detected with coronary angiography following confirmation of ≥5% ischemia with SPECT, underwent revascularization, and thereafter received a re-evaluation with SPECT and coronary angiography. Results During the follow-up, 25 patients experienced MCEs of cardiac death (n=2), non-fatal myocardial infarction (n=3), and unstable angina pectoris (n=20). A receiver operating characteristic analysis indicated that the best cut-off values of the residual SYNTAX score and ΔSDS% were 12 and 5%, respectively, for the prediction of MCEs. The patients with a low residual SYNTAX score (<12) and high ΔSDS% (≥5%) had the best prognosis, while those with a high residual SYNTAX score (≥12) and low ΔSDS% (<5%) had the worst prognosis. Conclusion The combination of the residual SYNTAX score and ischemic reduction detected with nuclear cardiology is useful for predicting MCEs after revascularization.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Imagem de Perfusão do Miocárdio/métodos , Complicações Pós-Operatórias/diagnóstico , Prognóstico , Procedimentos Cirúrgicos Torácicos/efeitos adversos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Grupo com Ancestrais do Continente Asiático , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
19.
Korean J Radiol ; 21(4): 462-470, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32193894

RESUMO

OBJECTIVE: To demonstrate that human visual illusion can contribute to sub-endocardial dark rim artifact in contrast-enhanced myocardial perfusion magnetic resonance images. MATERIALS AND METHODS: Numerical phantoms were generated to simulate the first-passage of contrast agent in the heart, and rendered in conventional gray scale as well as in color scale with reduced luminance variation. Cardiac perfusion images were acquired from two healthy volunteers, and were displayed by the same gray and color scales used in the numerical study. Before and after k-space windowing, the left ventricle (LV)-myocardium boarders were analyzed visually and quantitatively through intensity profiles perpendicular the boarders. RESULTS: k-space windowing yielded monotonically decreasing signal intensity near the LV-myocardium boarder in the phantom images, as confirmed by negative finite difference values near the board ranging -1.07 to -0.14. However, the dark band still appears, which is perceived by visual illusion. Dark rim is perceived in the in-vivo images after k-space windowing that removed the quantitative signal dip, suggesting that the perceived dark rim is a visual illusion. The perceived dark rim is stronger at peak LV enhancement than the peak myocardial enhancement, due to the larger intensity difference between LV and myocardium. In both numerical phantom and in-vivo images, the illusory dark band is not visible in the color map due to reduced luminance variation. CONCLUSION: Visual illusion is another potential cause of dark rim artifact in contrast-enhanced myocardial perfusion MRI as demonstrated by illusory rim perceived in the absence of quantitative intensity undershoot.


Assuntos
Artefatos , Coração/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Meios de Contraste/química , Ventrículos do Coração/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador , Imagem por Ressonância Magnética
20.
J Cardiovasc Magn Reson ; 22(1): 14, 2020 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-32028980

RESUMO

BACKGROUND: Myocardial perfusion with cardiovascular magnetic resonance (CMR) imaging is an established diagnostic test for evaluation of myocardial ischaemia. For quantification purposes, the 16 segment American Heart Association (AHA) model poses limitations in terms of extracting relevant information on the extent/severity of ischaemia as perfusion deficits will not always fall within an individual segment, which reduces its diagnostic value, and makes an accurate assessment of outcome data or a result comparison across various studies difficult. We hypothesised that division of the myocardial segments into epi- and endocardial layers and a further circumferential subdivision, resulting in a total of 96 segments, would improve the accuracy of detecting myocardial hypoperfusion. Higher (sub-)subsegmental recording of perfusion abnormalities, which are defined relatively to the normal reference using the subsegment with the highest value, may improve the spatial encoding of myocardial blood flow, based on a single stress perfusion acquisition. OBJECTIVE: A proof of concept comparison study of subsegmentation approaches based on transmural segments (16 AHA and 48 segments) vs. subdivision into epi- and endocardial (32) subsegments vs. further circumferential subdivision into 96 (sub-)subsegments for diagnostic accuracy against invasively defined obstructive coronary artery disease (CAD). METHODS: Thirty patients with obstructive CAD and 20 healthy controls underwent perfusion stress CMR imaging at 3 T during maximal adenosine vasodilation and a dual bolus injection of 0.1 mmol/kg gadobutrol. Using Fermi deconvolution for blood flow estimation, (sub-)subsegmental values were expressed relative to the (sub-)subsegment with the highest flow. In addition, endo-/epicardial flow ratios were calculated based on 32 and 96 (sub-)subsegments. A receiver operating characteristics (ROC) curve analysis was performed to compare the diagnostic performance of discrimination between patients with CAD and healthy controls. Observer reproducibility was assessed using Bland-Altman approaches. RESULTS: Subdivision into more and smaller segments revealed greater accuracy for #32, #48 and # 96 compared to the standard #16 approach (area under the curve (AUC): 0.937, 0.973 and 0.993 vs 0.820, p < 0.05). The #96-based endo-/epicardial ratio was superior to the #32 endo-/epicardial ratio (AUC 0.979, vs. 0.932, p < 0.05). Measurements for the #16 model showed marginally better reproducibility compared to #32, #48 and #96 (mean difference ± standard deviation: 2.0 ± 3.6 vs. 2.3 ± 4.0 vs 2.5 ± 4.4 vs. 4.1 ± 5.6). CONCLUSIONS: Subsegmentation of the myocardium improves diagnostic accuracy and facilitates an objective cut-off-based description of hypoperfusion, and facilitates an objective description of hypoperfusion, including the extent and severity of myocardial ischaemia. Quantification based on a single (stress-only) pass reduces the overall amount of gadolinium contrast agent required and the length of the overall diagnostic study.


Assuntos
Adenosina/administração & dosagem , Doença da Artéria Coronariana/diagnóstico por imagem , Circulação Coronária , Estenose Coronária/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador , Imagem Cinética por Ressonância Magnética , Imagem de Perfusão do Miocárdio/métodos , Adulto , Idoso , Estudos de Casos e Controles , Meios de Contraste/administração & dosagem , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/fisiopatologia , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos/administração & dosagem , Valor Preditivo dos Testes , Estudo de Prova de Conceito , Estudos Prospectivos , Reprodutibilidade dos Testes , Vasodilatadores/administração & dosagem
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