Three-dimensional endoluminal ultrasonography of the ureter.

Endoluminal ultrasonography has been useful in demonstrating the ureteral and periureteral anatomy. Devices now available give cross-sectional images. A computer program is available to reconstruct these images into three-dimensional (3D) representations. Endoureteral sonography was performed using 6.2F endoluminal ultrasound catheters connected to a dedicated ultrasound unit giving cross-sectional images. The images along the segment in the study were collected by advancing the catheter to the most proximal portion and pulling it in antegrade fashion through the segment with a step-pulling device. The images were collected on videotape and reconstructed into 3D representations using a dedicated 3D computer system (Lis 6000-A). Anatomic features studied included ureteral strictures, obstructed ureteropelvic junction, ureteral neoplasms, and the ureterovesical junction. In each case, additional information and appreciation of the structure could be obtained with the 3D reconstruction. Endoluminal ultrasonography has provided an additional dimension to imaging of the ureter. Three-dimensional reconstruction of these images can give additional information regarding the longitudinal appearance of ureteral segments without the need for development of new ultrasound transducers. It can offer appreciation of anatomic features not evident with two-dimensional imaging alone.