k-t GRAPPA accelerated four-dimensional flow MRI in the aorta: effect on scan time, image quality, and quantification of flow and wall shear stress.
Magn Reson Med
; 72(2): 522-33, 2014 Aug.
Article
em En
| MEDLINE
| ID: mdl-24006309
ABSTRACT
PURPOSE:
The purpose of this study was to evaluate the utility of k-t parallel imaging for accelerating aortic four-dimensional (4D)-flow MRI. The aim was to systematically investigate the impact of different acceleration factors and number of coil elements on acquisition time, image quality and quantification of hemodynamic parameters.METHODS:
k-t accelerated 4D-flow MRI (spatial/temporal resolution = 2.1 × 2.5 × 2.5 mm/40.0 ms) was acquired in 10 healthy volunteers with acceleration factors R = 3, 5, and 8 using 12- and 32-channel receiver coils. Results were compared with conventional parallel imaging (GRAPPA [generalized autocalibrating partial parallel acquisition], R = 2). Data analysis included radiological grading of three-dimensional blood flow visualization quality as well as quantification of blood flow, velocities and wall shear stress (WSS).RESULTS:
k-t GRAPPA significantly reduced scan time by 28%, 54%, and 68%, for R = 3, 5, and 8, respectively, while maintaining image quality as demonstrated by overall similar image quality grading. Significant differences in peak WSS (diff12ch = -5.9%, diff32ch = 18.5%) and mean WSS (diff32ch = 13.9%) were found at the descending aorta for both receiver coils for R = 5 (PWSS < 0.04). Peak velocity differed for R=8 at the aortic root (-7.4%) and descending aorta (-12%) with PpeakVelo < 0.03.CONCLUSION:
k-t GRAPPA acceleration with a 12- or 32-channel receiver coil and an acceleration of 3 or 5 can compete with a standard GRAPPA R = 2 acceleration.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Aorta
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Velocidade do Fluxo Sanguíneo
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Algoritmos
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Interpretação de Imagem Assistida por Computador
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Angiografia por Ressonância Magnética
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Imageamento Tridimensional
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Técnicas de Imagem de Sincronização Cardíaca
Tipo de estudo:
Diagnostic_studies
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article