AbstractConventional signal processing and display of information obtained by ultrasonic scanning results in the loss of low level information which may be diagnostically valuable by demonstrating the internal structure of organs. The use of grey scale echography preserves this information, allowing visualization of the normal tissue patterns and the minimal deviations from these which can indicate early pathology. This technique supplements radioisotope scanning since it has greater resolution. The method may be particularly valuable in evaluating the effect of therapy on liver metastases.