Studies in ultrasonic echoencephalography. VII. General principles of recording information in ultrasonic B- and C-scanning and the effects of scatter, reflection and refraction by cadaver skull on this information.

Abstract

Some of the factors are considered upon which the presentation of intracranial tomograms by the ultrasonic pulse-echo technique depend. Range resolution is degraded by the increased velocity of the ultrasonic beam in the skull. Azimuth resolution is degraded by refraction when the beam does not strike the skull at normal incidence. Both range and azimuth resolution are degraded for strong reflectors when receiver sensitivity is high. The limitations imposed by these factors on the angle of scan and dynamic range of the receiver system are estimated.