Grey-scale ultrasound in the diagnosis of abdominal mass lesions.

With the introduction of grey-scale imaging, the diagnostic capability of ultrasound has been greatly increased. Previously, ultrasound images were limited to a bistable presentation that did not distinguish between high- and low-level echoes. As a result the images could be interpreted by only a few experienced ultrasonographers. Grey-scale imaging with the use of a television scan converter allows both the strong and the weaker echoes to be displayed, so that both the outline and the internal texture of normal abdominal organs and lesions can be visualized on a single scan. Abnormalities are now more readily identified and their relation to normal organs is more easily appreciated so that the scans can be interpreted not only by the ultrasonographer but also by the clinician. Several cases are presented in which grey-scale ultrasound was used.