RESUMO
INTRODUCTION: Our aim was to assess the feasibility of using time-resolved 3D phase-contrast (4D flow) MRI to characterize extracranial-intracranial (EC-IC) bypass. METHODS: We enrolled 32 patients who underwent EC-IC bypass (15 men, 17 women; mean age 66.4 years). In all, 16 underwent radial artery graft (RAG) bypass and 16 underwent superficial temporal artery (STA) bypass. 4D flow MRI, time-of-flight (TOF) magnetic resonance angiography (MRA), and computed tomography angiography (CTA) were performed. Bypass patency, flow direction, and blood flow volume (BFV) of each artery were determined by 4D flow MRI. Arterial diameters were measured by TOF-MRA and CTA. We compared RAG and STA bypasses by evaluating the flow direction and BFV of each artery. We evaluated the correlation between arterial diameters (measured by CTA or MRA) and the BFV and the detectability of flow direction (measured by 4D flow MRI) of each artery. RESULTS: 4D flow MRI confirmed the patency of each bypass artery. Flow direction of the M1 segment of the middle cerebral artery and BFV in the bypass artery differed between RAG and STA groups (p < 0.01). BFV in the bypass slightly correlated with the diameters on CTA (p < 0.05, R (2) = 0.287). Of the 29 arteries in the circle of Willis, nine were not depicted on 4D flow MRI. Cutoff values for arterial diameters on CTA and TOF-MRA for detecting the artery on 4D flow MRI were 2.4 and 1.8 mm, respectively. CONCLUSION: 4D flow MRI provided unique information for characterizing EC-IC bypasses, although this detectability is limited when addressing small arteries with slow flow.
Assuntos
Circulação Cerebrovascular , Transtornos Cerebrovasculares/fisiopatologia , Transtornos Cerebrovasculares/cirurgia , Angiografia por Ressonância Magnética/métodos , Artérias Temporais/transplante , Enxerto Vascular/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Transtornos Cerebrovasculares/diagnóstico por imagem , Feminino , Sobrevivência de Enxerto , Humanos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Artéria Radial/transplante , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Grau de Desobstrução VascularAssuntos
Arteriopatias Oclusivas/cirurgia , Artéria Carótida Interna/cirurgia , Revascularização Cerebral/métodos , Aneurisma Intracraniano/cirurgia , Angiografia por Ressonância Magnética/métodos , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/fisiopatologia , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/fisiopatologia , Circulação Cerebrovascular , Estudos de Viabilidade , Feminino , Hemodinâmica , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/fisiopatologia , Masculino , Avaliação de Resultados da Assistência ao Paciente , Radiografia , Reprodutibilidade dos TestesRESUMO
OBJECTIVE: To assess technical feasibility of navigator-gated 3-dimensional (3D) fat-suppressed delayed-enhancement magnetic resonance imaging (DE-MRI) at 3.0 T for simultaneous visualization of myocardial scars and coronary arteries. METHODS: Thirty patients with various myocardial diseases underwent navigator-gated 3D fat-suppressed DE-MRI using a 3.0-T scanner. The ability of this imaging technique to detect myocardial scars was compared with that of 2D DE-MRI. Visualization of the coronary arteries by this MRI technique was scored, and the relationship between myocardial scars and coronary arteries was assessed. RESULTS: Navigator-gated 3D fat-suppressed DE-MRI detected 71 of 75 segments with a myocardial scar. This imaging visualized proximal coronary arteries with an acceptable image quality and demonstrated a relationship between the myocardial scars and coronary arteries in 11 of the patients with scars. CONCLUSION: Navigator-gated 3D fat-suppressed DE-MRI at 3.0 T was feasible for simultaneous visualization of myocardial scars and proximal coronary arteries.