Abstract
A procedure has been developed using an intravenous injection of 50μCi of 131I-sodium iodohippurate to measure a renogram and residual urine volume using a scintillation camera interfaced with a PDP 11/45 digital computer. Residual urine is measured 2 hr after injection. The external counting method using a probe for measurement of residual urine has been shown by many investigators to be the most accurate method without catheterization. The scintillation camera method described here for determination of residual urine has many advantages over the probe counting method and is more accurate.