A Study On Brain Imaging With Multi-angle Plane Waves Compounding

Brain disease has become a major health problem in the world.Many developed countries,including the United States,Japan,Canada,Australia,Australia South and Korea,have put forward their own brain research programs.China has also incorporated brain science and brain research into the“13^th Five-year”program.Knowledge of the brain is the first step in the treatment of brain diseases.Brain imaging is a valuable tool to recognize the brain.It provides a reliable basis for displaying the brain structure,studing the cognitive mechanism of the brain,observing the dynamic changes of the brain,and analyzing the direction of the diagnosis of brain disease.There are many limitations in the mature brain imaging technology,which would impede accurately understand the brain structure and the state of the brain function.The traditional ultrasound imaging technology does not have high frame frequency and the signal sampling points are not enough to imaging the cerebral blood flow.The ultrasonic imaging technology based on multi-angle plane waves compounding has unprecedented spatial and temporal resolution?¹00 mu m,1ms?.The high frame rate allows it to acquire power Doppler imaging of the chronic blood flow of small blood vessels of the brain,and the focus is accurately displayed.In addition,functional imaging technology can also capture transient changes in the brain,thereby helping to study the links and functions of various functional areas in brain activity.In this paper,the Doppler collection platform of the brain blood flow power is set up,and the optimal value of the two important parameters of the plane wave number,the maximum plane wave deflection angle,is determined by the Field_II sound field simulation,the phantom blood vessel and the small animal experiment.The power Doppler image of small animals and primates was successfully obtained by the Doppler power imaging algorithm of cerebral blood flow,and the brain functional experiments of rat whisker stimulation and primate visual stimulation were designed.The corresponding brain functional changes of the primary body perception cortex and visual cortex of the primate animals were obtained by ultrasonic blood flow detection.Although the brain imaging technology based on multi-angle plane waves compounding can achieve high spatial and temporal resolution,the skull has a strong attenuation effect on ultrasound,which leads to the difference in penetration of ultrasound in the case of cranium,and can not distinguish the cerebral blood flow signal and noise signal.In this paper,the thickness of the skull is measured by the double focus thickness measurement.The experiment shows that the method can accurately detect the thickness of the skull,which lays the foundation for the compensation for the ultrasonic transcranial imaging.