Phantoms for studying the acceleration and turbulence of liquids using magnetic resonance imaging.
Magnetic resonance angiography is a relatively new method used to image vascular structure. However, a limitation manifested through signal loss due to non-stable flow makes this technique unreliable for directly visualizing occlusions and estimating the degree of stenosis. In this study, a quantitative approach is developed to understand further the situations where signal loss occurs and a phase mapping technique is used quantitatively to study acceleration in test objects designed to generate flow disturbance. In regions of acceleration the correlation coefficient between magnetic resonance imaging velocity and the inverse of area was r > 0.999 (p < 0.001). The range of acceleration calculated was 6514-63,053 mm s-2 and at maximum acceleration the measured velocity had a systematic error of 4.0(+/- 2.0)% and coefficient of variation of 3.1%. Test objects were devised and utilized for demonstrating non-stable flow and jet formation with comparison being made to predictions from fluid dynamics theory.
Zananiri
F V
FV
Department of Medical Physics & Bioengineering, Bristol General Hospital, UK.
Jackson
P C
PC
Davies
E R
ER
Wells
P N
PN
D000054:Acceleration; D008279:Magnetic Resonance Imaging; D008962:Models, Theoretical; D014783:Viscosity