Solid tissue model for the standardization of the echo-ophthalmograph 7200 MA (Kretztechnik).

After discussion of the biologic basis of echographic tissue differentiation and of the required standardization of the ultrasonic diagnostic device by means of tissue models (citrated blood), a technical standard is presented. This solid tissue model, which can be used an unlimited number of times, enables the investigator to determine or check the tissue sensitivity of his instrument at any time easily and quickly. The model consists of a synthetic resin (Wacker Silgel 504) to which a certain number of microbeads (glass beads S-100) are added before it hardens. The acoustic properties of this technical standard correspond to those of the biologic standard (citrated blood) including all important factors such as reflectivity, degree of scattering and sound attenuation.