I'm not a doctor, so definitely follow up with the doctor that ordered the test. In the HIDA scan they inject a dye with radioactive tracers that fill up the gallbladder and can be seen with the special camera they use. If the camera sees the gallbladder is filling up, then there is no blockage in the liver.
Then they inject a hormone (CCK) to empty the gallbladder and monitor the progress with the camera. The percentages are how much it has emptied out the radioactive dye. After an hour your gallbladder emptied out 47% of the dye, which is in the acceptable range from everything I've seen. The lowest threshold score of a "low functioning" gallbladder I've seen is 35%, so your gallbladder is considered to be functioning well enough. I recently had a HIDA scan so I've been researching this a lot. Hope this helps.