ABSTRACT
Ultrasonography (USG) utilizes ultrasonic waves as the information carrier; these are mechanical longitudinal waves of high inaudible frequencies in the approximate range of 1 to 10 MHz, propagating in tissues. A characteristic feature of the USG images is their speckled appearance that theoretically carries certain indirect information on the imaged tissue microstructure; this information is rather hidden under influences of transducer parameters and system adjustment. Due to speckle noise presence, the task of reliable USG image segmentation is more difficult than in other modalities. An often-used and perhaps preferred display mode in three-dimensional USG is a combination of multiplane viewing with three-dimensional rendering of a polyhedron, the walls of which are formed by the two-dimensional tomographic images. Although there were many attempts to quantify or classify the ultrasonic echo signals, the main goal of USG remains the spatial two-dimensional or three-dimensional imaging of anatomy via detected tissue interfaces and of displaying the spatial flow distribution.
