RATE OF URINARY-BLADDER BLOOD-FLOW EVALUATED BY XE-133 WASHOUT AND RADIOACTIVE MICROSPHERES IN PIGS

Urinary bladder blood flow as measured by the washout of locally injected Xe-133 and by the simultaneously performed radioactive microsphere reference-sample method was studied in pigs. The washout curves were analyzed according to the initial slope, the corrected initial slope and the total curve. The corrected-initial-slope flow rates were not statistically significantly different from the microsphere whole-wall flow rates. The variability between the methods shown by the test-retest difference revealed only a minor lack of agreement. The bladder blood flow tended to decrease after the intravesical pressure had been increased to 20 cmH2O, but the difference was not statistically significant. Washout of locally injected Xe-133 can be used for the evaluation of urinary bladder blood flow in humans and in longitudinal animal studies. The corrected-initial-slope method is recommended for the analysis of washout curves.