Phase-contrast magnetic resonance imaging evaluates the atherosclerosis

SHIHaobo; YUYifan; LUOYuanfen; MALing; WANGYufeng; OUYANGHanming; CHENMaodong; ZHANGXiangqun

Abstract：ObjectiveTo investigate the feasibility of phase-contrast magnetic resonance imaging (PC-MRI) for hemodynamic analysis in vivo and assessment of arterial hemodynamics-induced atherosclerosis.MethodsThirteen healthy adult rabbits were purchased from the Animal Center of Southern Medical University. Four rabbits were randomly selected as the blank group. The 4 rabbits of blank groups were fed together with 9 other rabbits with high-fat diets after receiving the first experimental data. Thirteen rabbits were given high-fat feeding for 2-6 months as an experimental group. The rabbits were withdrawing 7 mL blood for viscosity test before being anesthetized. Then, the rabbits were fixed on a plate and scanned by the coronal T2WI sequence. The aorta (above the bifurcation of the rabbit renal artery 1 cm.) was selected as the target vessel segment which were scanned by the PC-MRI scan quantitative blood flow measurement techniques. The cross-sectional blood phase and amplitude maps of the abdominal aorta were obtained and selected as the analysis images. The hemodynamic parameters processing software was used to process the phase amplitude maps of the blank group and the experimental group. The wall shear stress (WSS), mean velocity and mean flow-rate were explored.ResultsDuring the high-fat feeding, 3 rabbits died of unexplained, 2 rabbits died of anesthesia, 8 rabbits successfully established the atherosclerotic models, with success rate of 62% (8/13). The blood lipids of the experimental group increased to varying degrees: CHO (52.50±15.39 mmo1/L)、TG (5.19±3.85 mmo1/L)、HDL-C (11.10±5.17 mmo1/L)、LDL-C (33.43±16.40 mmo1/L). Blank group:WSS was (17.03±1.14)×10-2 Pa, mean flow rate was 12.28±2.51 cm/s, mean flow rate was 4.51±1.13 mL/s. Experimental group: WSS was (28.79±3.50)×10-2 Pa, mean flow rate was 22.31±6.24 cm/s, mean flow rate was 5.79±1.89 mL/s. The differences of aortic WSS and the mean flow rate between control group and experimental group were significant (P<0.05).ConclusionThe PC-MRI can be used for hemodynamic analysis in vivo and assessment of atherosclerosis caused by arterial hemodynamic changes.