Physiologic and anatomic assessment of a canine carotid artery stenosis model utilizing phase contrast with vastly undersampled isotropic projection imaging.
AJNR Am J Neuroradiol
; 28(1): 111-5, 2007 Jan.
Article
em En
| MEDLINE
| ID: mdl-17213435
ABSTRACT
BACKGROUND AND PURPOSE:
Noninvasive assessment of the hemodynamic significance of carotid stenosis is often performed with MR angiography and supplemented with carotid Doppler sonography. Phase contrast with vastly undersampled isotropic projection reconstruction (PC-VIPR), a novel MR imaging technique, accelerates phase-contrast MR flow imaging and provides both images of the vessels and measurements of blood-flow velocities. For this study, we determined the accuracy of PC-VIPR blood-flow velocity measurements to determine pressure gradients across an experimental carotid stenosis. MATERIALS ANDMETHODS:
A focal stenosis was surgically created in each common carotid artery of 6 canines. Digital subtraction angiography (DSA) was performed, and the degree of stenosis was determined using the North American Symptomatic Carotid Endarterectomy Trial methodology. A microcatheter was positioned in the carotid artery proximal and distal to the stenosis, and pressures were measured in the vessel through the catheter. PC-VIPR was then performed on a 1.5T MR imaging scanner with parameters producing 0.8-mm isotropic voxel resolution. From the velocity measurements, pressure gradients were calculated from the Navier-Stokes relationship to compare with the pressures measured by a catheter.RESULTS:
Carotid stenoses in the 50%-85% range were produced in the 12 arteries. Pressure gradients across the stenoses ranged from 6 to 26 mm Hg. The pressure gradient calculated from the PC-VIPR data correlated (r = 0.91, P < .0001) with the actual pressure measurements.CONCLUSION:
With PC-VIPR, a novel MR imaging technique, the hemodynamic effect of a stenosis on flow and pressure can be evaluated.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Velocidade do Fluxo Sanguíneo
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Processamento de Imagem Assistida por Computador
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Aumento da Imagem
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Estenose das Carótidas
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Angiografia por Ressonância Magnética
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Modelos Animais de Doenças
Limite:
Animals
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article