Experimental study on the ultrasonic attenuation of the injured brain with special emphasis on the relationship between cerebral edema and cerebral circulation.

In the field of ultrasonic diagnosis, its attenuation property in the brain has been also explored. Investigated are the ultrasonic attenuation of the brain following experimental head injury as well as cerebral circulation and water content of brain, the purpose of which are to analyse the essential mechanism of ultrasonic attenuation as its relationship to the brain edema. I studied the continuous changes of brain by means of epidural air shot, intracarotid oil injection and by extreme reduction of cerebral blood flow. Reduction of ultrasonic attenuation on brain is primarily due to the increased water content of brain tissue, whereasreduction of cerebral blood flow increases ultrasonic attenuation values to some extent.