[Value of endoluminal high-resolution ultrasound in urology]

The clinical use of endoluminal high resolution ultrasound in urology was investigated in 14 patients using miniature transducer-containing catheters (20 MHz 8 F and 10 MHz 10 F). For imaging the ureter, an 8 F flexible ultrasound probe was used. Using this technique, exact 360 degrees cross sections of the ureter and periureteral tissue were obtained. Differentiation between normal and abnormal structures including embedded stones and aberrant vessels is possible and impacts on surgical approach. Wall thickness of the ureterovesical junction was observed in patients with vesicoureteral reflux compared to the other patients. Therefore, a reliable measurement and differentiation of anatomical structures in the urinary tract was possible. The 20 MHz device revealed a better discrimination of anatomical and pathological structures than the widely used systems with lower frequencies e.g. 10 MHz. However, for the exact staging of superficial urothelial carcinomas, the method failed. Ultrasound devices with higher frequencies, e.g. 30 MHz and more, will most likely allow a more exact staging of these tumours.