For inpatients, a Foley catheter should be placed in the bladder prior to the patient's arrival in Nuclear Medicine. If a pediatric patient requires sedation, this should be arranged in advance. Ordering house staff may be called in by Nuclear Medicine for assistance in setting up an I.V. line and with catheterization.
1 mCi of Tc-99m albumin or sulfur colloid (or Tc-99m O4 ) is mixed with saline and infused in a retrograde manner into the bladder via a Foley catheter. Dose to the bladder is generally less than 0.050 rad. This is considerably less than X ray cystograms.
Variable, depending of Foley size, time to fill bladder and patient's ability to void. Generally the scan takes 25-30 min. with catheter in place.
The radiopharmaceutical instilled allows visualization of the bladder and ureters (if reflux is present). While resolution is less than with fluoroscopic studies, the nuclear study is more sensitive and the radiation dose is much lower. It also allows for quantitative analysis of both the amount of reflux and the post-void residual which is not possible with fluoroscopy.