PHANTOMS FOR STUDYING THE ACCELERATION AND TURBULENCE OF LIQUIDS USING MAGNETIC-RESONANCE-IMAGING

Magnetic resonance angiography is a relatively new method used to imag e vascular structure. However, a limitation manifested through signal loss due to non-stable flow makes this technique unreliable for direct ly visualizing occlusions and estimating the degree of stenosis. In th is study, a quantitative approach is developed to understand further t he situations where signal loss occurs and a phase mapping technique i s used quantitatively to study acceleration in test objects designed t o generate flow disturbance. In regions of acceleration the correlatio n coefficient between magnetic resonance imaging velocity and the inve rse of area was r > 0.999 (p < 0.001). The range of acceleration calcu lated was 6514-63053 mm s-2 and at maximum acceleration the measured v elocity had a systematic error of 4.0(+/-2.0)% and coefficient of vari ation of 3.1%. Test objects were devised and utilized for demonstratin g non-stable flow and jet formation with comparison being made to pred ictions from fluid dynamics theory.