Three dimensional endosonography: A new technique of endoscopic ultrasound

A new technique, three dimensional endoscopic ultrasound, is described, which involves software to reconstruct a 3-D image from EUS. An Olympus (EU-M20) instrument and a SUN workstation were used to generate three-dimensional images for display. During the endoscopic ultrasonographic examination, a straight (20 cm), slow (120 sec) and stabilized withdrawal of the instrument through the esophagus was performed, using 7.5 and 12 MHz frequencies and 4, 6, 9 and 12 cm fields of view. The images recorded on videotape were digitized (8 bits depth) and were arranged into a 3-D data set on a Sun Sparcstation-3 using commercial software. Spacing the 2-D images closely together yielded more accurate representations of 3-D structures but also took much longer to generate and to manipulate. Eight patients were studied (2 with normal findings of esophagus, 2 with leiomyoma and 4 with carcinoma of the esophagus). The precise recognition of the layers and adjacent structures provided better assessment of the esophageal and peri-esophageal anatomy and, thus, improved recognition of the origin and the full extent of the lesions. Three dimensional utrasound imaging appears to be a useful procedure in the evaluation of esophageal diseases and should enhance the diagnostic accuracy of the endoscopic ultrasound.