Body-centered visualisation for freehand 3-D ultrasound.

Three-dimensional (3-D) ultrasound (US) data is typically visualised by any-plane slicing, volume rendering or surface rendering. Typical implementations of these techniques do not readily convey the spatial relationship between the visualised data and the patient's body, something that is particularly important when the data are reviewed after the scan has taken place, perhaps by a remote expert who did not even perform the scan. This paper describes a facility to register the 3-D US data to the patient's body and then display the data correctly superimposed on a rendered mannequin (rigid computer model). This way, the user can appreciate the position and orientation of any visualisation with respect to the patient's body. The facility relies on efficient implementation of progressive meshes to manage the level of detail of the mannequin model.