... volume and compared with the catheterization volume for the same patients. The sonographic method, with a 97.7% specificity and a negative predictive value of 89.5%, proved to be specific enough to eliminate the necessity of routine catheterization for measuring residual bladder volumes of > 150 cm 3...

... with vaginal delivery were recruited on postpartum day 1, and their bladder volumes were first estimated by ultrasound. Immediately after the ultrasound scans the bladders were catheterized for the true bladder volumes. The ultrasound-estimated bladder volumes were then compared with the catheterized bladder...