DETECTION OF VESICOURETERAL REFLUX WITH RADIONUCLIDE CYSTOGRAPHY

Abstract

A prospective clinical study in children with urinary tract symptomatology showed that radionuclide cystography with Tc^99m pertechnetate and the gamma camera is better than our conventional roentgenographic cystography in detecting significant vesicoureteral reflux. Reflux was found in 44 of 200 possible renal units (i.e., ureter and/or renal pelvis) by both modalities. In 26 units the correlation was equal. Definite reflux into the renal pelvis was noted in 9 instances only during the radionuclide examination, whereas only 5 instances of such reflux were missed by the radionuclide study. Additional advantages of radionuclide cystography include a marked reduction in radiation dose when compared to the roentgenographic technique. The calculated radiation dose to the bladder wall for a 30 minute examination using 1 mc Tc^99m pertechnetate and 200 cc. of saline is approximately 30 millirads. This is estimated to be between 50 to 100 times less than that of our comparable routine roentgenographic technique. Residual urine volume can be easily calculated and ureteral tonicity and peristalsis may be studied by the radionuclide technique. The resolution of present radionuclide imaging equipment inhibits the visualization of reflux into the distal ureter and the diagnosis of bladder or urethral abnormalities.