Investigation On The Value Of Super-resolution Ultrasound Imaging In Evaluating Microflow/function Changes In Local Brain Tissue After Cerebral Microbleeds

Objective Ultrasonic contrast agent microvesicles were prepared,and ultrasonic combined with microvesicles was used to prepare brain microhemorrhage model.Ultrasonic microflow imaging was used to observe the effect of microhemorrhage on microcirculation,and microvascular structure analysis was used to interpret microcirculation imaging results.Methods Ultrasonic contrast agent microbubbles were prepared by ethanol injection.The particle size and concentration of ultrasonic contrast agent were measured by using Kurt counter Multisizer4.In vivo evaluation of ultrasonic microbubble imaging using ultrasonic diagnostic instrument;The model of cerebral microhemorrhage was prepared by combining ultrasonic cavitation with microbubble,and the optimal mechanical index and irradiation time were screened according to the pathological results.Ultrasonic microflow imaging showed microcirculation changes after microhemorrhage.Microvascular structure changes were analyzed by PTAH staining and transmission electron microscopy.Results 1.Characterization of ultrasound contrast agent,1.The micro bubble diameter is 4.977 0.035 um,microscope,micro bubble a few microns of spherical structure,good dispersancy.2.The cell in the body of the imaging effect is good,the cavitation model,5-6 minutes after the cell signal starts to drop 3.MI MI = 1.4 lasts for 20 minutes,the brain surface microscopic H E staining visible micro hemorrhage stove,nerve cell edema increased 4.Ultrasound microflow imaging showed that the decrease in the number of ultrasonic irradiation area left brain microvascular blood flow at a slower pace5.Microvascular structure analysis: the lumen of the microvascular in the irradiation area was filled with PTAH blue-stained material,and the vascular wall was thickened with toluene blue staining,and the microvascular endothelial cell structure disappeared in the irradiation area under transmission electron microscopy.Conclusion 1.The prepared ultrasonic contrast agent microbubbles have stable spherical structure;2.The injection frequency of ultrasonic contrast agent microbubbles in cavitation mode in vivo was 5min/ time;3.Ultrasound combined with microvesicles can cause microhemorrhagic foci in rat brain;4.Ultrasonic microflow imaging showed that the number of cerebral microvessels decreased after microhemorrhage and the blood flow slowed down.5.Microhemorrhage leads to microvascular endothelial cell injury,a few microvascular thrombosis,and the formation of nerve cell edema in the microhemorrhage area...