Peter R. Hoskins

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A blood-mimicking fluid (BMF) suitable for use in Doppler flow test objects is described and characterised. The BMF consists of 5 microns diameter nylon scattering particles suspended in a fluid base of water, glycerol, dextran and surfactant. The acoustical properties of various BMF preparations were measured under uniform flow to study the effects of(More)
Pulsatile flow was studied in physiologically realistic models of a normal and a moderately stenosed (30% diameter reduction) human carotid bifurcation. Time-resolved velocity measurements were made using magnetic resonance imaging, from which wall shear stress (WSS) vectors were calculated. Velocity measurements in the inflow and outflow regions were also(More)
OBJECTIVE A more accurate means of prediction of abdominal aortic aneurysm (AAA) rupture would improve the clinical and cost effectiveness of prophylactic repair. The purpose of this study was to determine whether AAA wall distensibility can be used to predict time to rupture independently of other recognized risk factors. METHODS A prospective,(More)
Numerical simulations of pulsatile blood flow in straight tube stenosis models were performed to investigate the poststenotic flow phenomena. In this study, three axisymmetrical and three asymmetrical stenosis models with area reduction of 25%, 50% and 75% were constructed. A measured human common carotid artery blood flow waveform was used as the upstream(More)
Wall-less flow phantoms are preferred for ultrasound (US) because tissue-mimicking material (TMM) with good acoustical properties can be made and cast to form anatomical models. The construction and geometrical stability of wall-less TMM flow phantoms is described using a novel method of sealing to prevent leakage of the blood-mimicking fluid (BMF).(More)
Ultrasound (US) test phantoms incorporating tissue-mimicking materials (TMMs) play an important role in the quality control (QC) and performance testing of US equipment. Three commercially available TMMs (Zerdine from CIRS Inc.; condensed-milk-based gel from Gammex RMI; urethane-rubber-based from ATS Labs) and a noncommercial agar-based TMM, were(More)
PURPOSE To study pulsatile fluid flow in a physiologically realistic model of the human carotid bifurcation, and to derive wall shear stress (WSS) vectors. MATERIALS AND METHODS WSS vectors were calculated from time-resolved 3D phase-contrast (PC) MRI measurements of the velocity field. The technique was first validated with sinusoidal flow in a straight(More)
This study was performed in order to provide quantitative data on the estimation of maximum velocity made using modern Doppler ultrasound systems. This is important since the degree of stenosis within arteries is commonly assessed from the maximum velocity. A string phantom was used as the source of Doppler signals. This enables direct comparison between(More)
We reviewed the simulation and validation of arterial ultrasound imaging and blood flow assessment. The physical process of ultrasound imaging and measurement is complex, especially in disease. Simulation of physiological flow in a phantom with tissue equivalence of soft tissue, vessel wall and blood is now achievable. Outstanding issues are concerned with(More)
A nonplanar wall-less anatomical flow phantom of a healthy human carotid artery is described, the construction of which is based on a lost-core technique described in the companion paper (Part I) by . The core was made by rapid prototyping of an idealized three-dimensional computer model of the carotid artery. Flow phantoms were built using these idealized(More)