Must control bladder fill pre mri; am to stop urination 2hr before, drink 16oz water 1hr before. how long before can i drink, say, 16oz of other fluids and expect most of the excess to have made it to my bladder?

If you stop voiding 2 hours before the test, your bladder should have at least 150 cc by the time the test done. With an extra drink of 16 oz one hour before the test, about 100-150 cc more will be produced so your bladder should be full, around 300 -350 cc, before the test and that volume is adequate for the test. If you want a higher bladder volume, drink the extra fluid 2 hours before the test.