The aim of this study was to conduct a flow experiment using a cerebrovascular phantom and investigate whether magnetic resonance angiography (MRA) could replace three-dimensional rotational angiography (RA) and computed tomography angiography (CTA) to construct vascular models for computational fluid dynamics (CFD). We performed MRA and 3D cine phase-contrast (PC) MR imaging with a silicone cerebrovascular phantom of an internal carotid artery-posterior communicating artery aneurysm with blood-mimicking fluid, and controlled flow with a flowmeter. We also obtained RA and CTA data for the phantom.
View Article and Find Full Text PDFBackground: The haemodynamics determined by different approaches for studying fluid dynamics - i.e. computational fluid dynamics (CFD), particle image velocimetry (PIV), and phase-contrast magnetic resonance imaging (PC-MRI) - have rarely been thoroughly compared; nor have the factors that affect accuracy and precision in each method.
View Article and Find Full Text PDFPurpose: Evaluate in vivo hemodynamic and morphological biomarkers of intracranial aneurysms, using magnetic resonance fluid dynamics (MRFD) and MR-based patient specific computational fluid dynamics (CFD) in order to assess the risk of rupture.
Methods: Forty-eight intracranial aneurysms (10 ruptured, 38 unruptured) were scrutinized for six morphological and 10 hemodynamic biomarkers. Morphological biomarkers were calculated based on 3D time-of-flight magnetic resonance angiography (3D TOF MRA) in MRFD analysis.
Purpose: The accuracy of flow velocity and three-directional velocity components are important for the precise visualization of hemodynamics by 3D cine phase-contrast MRI (3D cine PC MRI, also referred to as 4D-flow). The aim of this study was to verify the accuracy of these measurements of prototype or commercially available 3D cine PC MRI obtained by three different manufactures' MR scanners.
Methods: The verification of the accuracy of flow velocity in 3D cine PC MRI was performed by circulating blood mimicking fluid through a straight-tube phantom in a slanting position, such that the three-directional velocity components were simultaneously measurable, using three 3T MR scanners from different manufacturers.
We developed a method of velocimetry based on an optical flow method using quantitative analyses of tagged magnetic resonance (MR) images (tagged MR-optical flow velocimetry, tMR-O velocimetry). The purpose of our study was to examine the accuracy of measurement of the proposed tMR-O velocimetry. We performed retrospective pseudo-electrocardiogram (ECG) gating tagged cine MR imaging on a rotating phantom.
View Article and Find Full Text PDFPurpose: We performed computational fluid dynamics (CFD) for patients with and without paraclinoid internal carotid artery (ICA) aneurysms to evaluate the distribution of vascular biomarkers at the aneurysm initiation sites of the paraclinoid ICA.
Methods: This study included 35 patients who were followed up for aneurysms using 3D time of flight (TOF) magnetic resonance angiography (MRA) and 3D cine phase-contrast MR imaging. Fifteen affected ICAs were included in group A with the 15 unaffected contralateral ICAs in group B.
Introduction: We aim to elucidate the effect of spatial resolution of three-dimensional cine phase contrast magnetic resonance (3D cine PC MR) imaging on the accuracy of the blood flow analysis, and examine the optimal setting for spatial resolution using flow phantoms.
Materials And Methods: The flow phantom has five types of acrylic pipes that represent human blood vessels (inner diameters: 15, 12, 9, 6, and 3 mm). The pipes were fixed with 1% agarose containing 0.