[The advantage of a thin flexible ureteroscope with a new real-time processing system].

To observe the upper urinary tract more clearly with a thin flexible endoscope, we developed a novel real-time processing system. This system enhances the parts of the dark cladding around the core by individual strong brightness of each image fiber. The upper urinary tract in eight patients was examined using a thin flexible endoscope with this system at retrograde pyelography or at urological operation. Six patients had hydronephrosis and 2 had filling defects in the renal pelvis or calyx. The endoscope was 0.75 mm in diameter and had 300 pixels of image fiber. The objective portion could be assessed successfully in seven of eight. Significantly finer and colorful image could be obtained with this system compared with the conventional method and the epithelium could be clearly observed. We conclude that this real-time processing system remarkably improves the quality of image obtained with the thin flexible ureteroscope and makes it a more promising modality in the diagnosis and treatment of the upper urinary tract.