Three dimensional Sample Clauses

Three dimensional ultrasound 3D ultrasound refers to the acquisition of a series of parallel B-mode images by the sequential movement of the transducer or of the ultrasound beam. These images are then saved as a 3D volume of ultrasound information and can be manipulated using a computer processor. In the 1980s three dimensional scanning was restricted to a research setting but by 1989 the first three dimensional scanner became Figure 3 Schematic representation of 3D volume acquisition by transvaginal probe commercially available. This was called the Combison 330 and was launched by Kretztechnik AG (Xxxxxxxxxxx 1993; Xxxxxx et al. 2000). Initially the three dimensional ultrasound volume was obtained by an 180o rotation of the two dimensional scan plane around the long axis of the probe (Xxxx 1999). Although this provided accurate three dimensional images it was limited by merging of all images at the centre. In order to avoid this limitation current 3D probes include a mechanism to deflect the ultrasound beam and avoid merging. Once the 3D volume is acquired it is displayed in three orthogonal planes one representing the original B-mode image and an additional 2 reconstructed planes at right angles to each other. It is possible to then rotate the image around a fixed point of interest as well as to move any of the three planes to obtain views that would not otherwise be possible because of the anatomical constraints of the female pelvis (Xxxx et al. 1997).