[Usefulness of ultrasonography in follow-up of postoperative pelviureteric dilatation in children].

: To determine the availability of ultrasonography in follow-up of postoperative pelviureteric dilatation, 35 children, who had previously been operated on in some part of the urinary tract, were examined by both excretory urography and ultrasonography. Of 59 kidneys shown to be with a dilated collecting system on excretory urography, 58 were correctly detected by ultrasonography, with a sensitivity of 98.3%. The grade of dilatation of the collecting system diagnosed by ultrasonography was corresponded to that by excretory urography in 99 of 123 kidneys [80.5%). At the level of the lower calyx, 40 of 43 ureters which measured 5 mm or greater in diameter on excretory urogram, were detected by ultrasonography. Thirty of 36 ureters posterior to the bladder with a diameter of over 5 mm were also detected by ultrasonography. The diameters of the ureters measured by ultrasonography were well correlated with those on excretory urogram. These results suggest that the availability of ultrasonography is so high that it could substitute for excretory urography in follow-up of postoperative hydronephroureter in children.