3D-endosonography in gastroenterology: methodology and clinical applications

Endoluminal ultrasonography allows detailed imaging of the gastrointestinal wall and adjacent structures. Three-dimensional (3D) imaging may improve visualisation of topographic relations and the nature of pathologic lesions. The objective of this report is to summarise current status of 3D-endosonography and to discuss the possible clinical impact of this new modality. 3D ultrasonographic images are usually generated from a series of digitised two-dimensional ultrasound pictures acquired in a manner that enables registration of their relative spatial position. Such acquisition can be accomplished with different ultrasound probes, but in most cases of endosonography, a controlled pullback of radial-scanning probes has been applied. Digital ultrasound images are obtained by frame grabbing of analogue video recordings or by direct transmission from digital scanners. Dedicated software programs have been developed for 3D reconstruction and visualisation, allowing interactive display and measurements. 3D endosonography provides new possibilities for clinical imaging, but the impact on therapeutic strategies and clinical outcome has yet to be established.