Background: The objective of three-dimensional (3-D) endoscopic ultrasonography (EUS) is to recognize lesions stereoscopically.
Methods and results: We investigated a total of 43 lesions in the upper gastrointestinal (GI) tract by regenerating 3-D images in eight cases of oesophageal cancer, two cases of oesophageal submucosal tumour, two oesophageal varices, two cases of achalasia, 27 gastric cancers, one gastric carcinoid, and one duodenal submucosal tumour. Using a prototype system (Fujinon, Omiya, Japan), we reconstructed 3-D images from conventional EUS images taken by a thin ultrasound probe (Sonoprobe, SP-701, Fujinon) having a radial-linear scanning mode. The basic 3-D images could be obtained in a short period during EUS performed using the conventional thin-ultrasound probe. The acceptable quality level of the reconstructed 3-D images was 37% (57% in the oesophagus, 25% in the stomach and 100% in the duodenum). Deterioration of 3-D images was due to a wobbling of linear scanning mainly caused by peristalsis of the GI tract, cardiac impulses, and respiration.
Conclusions: Our study has proved that the simple and speedy 3-D display system built using the existing linear-radial switchable probe is easily applicable to clinical cases.