What is a renal
scan and GFR?
renal scan and GFR (glomerular filtration rate) is a test to look at how well the
kidneys filter blood.
How is the test done?
test is done by a technician called a nuclear medicine technologist. It has four
Your child will be
given a small injection (needle) into a vein in the arm or back of hand. The injection contains a very small amount of
radioactive medicine that mixes with the blood.
Your child will
then lie down on a narrow bed and a special camera will take pictures for 30
minutes right after the injection. This is to see how your child’s kidneys
filter the medicine. In most cases your child can watch a movie as the scan is
will take a blood sample 1.5 hours after the injection.
will take another blood sample 2.5 hours after the injection.
child can leave the department between the scan and the blood samples, but they
must return at the time given by the technologist.
How long does the
test can take about three hours in total. This includes the time to inject your
child, take pictures of their kidneys, and wait for the blood samples to be
special cream (called a topic anesthetic) can be put on your child’s skin to
numb their hand or arm before the injection. If you would like this option,
please arrive at least 30 minutes before your appointment time.
Does my child need
to do anything special to prepare for the test?
child can eat and drink as usual, but they may be asked to drink one or two
glasses of water or juice before the test so they are well hydrated.
children need a blood or urine test before the test. Your doctor’s office will
tell you if your child needs one. The test can be done in the Ambulatory Centre
on the main floor near Shoppers Drug Mart, but it must be done before the renal scan and GFR. Please arrive early to leave enough
time for the test and still be on time for the GFR scan.
Will I be able to
stay with my child during the test?
parent or guardian may stay in the room with the child, but no other children
are allowed. This is to make sure the test is done properly.
When are the
doctor from the nuclear medicine team will send a report to your family doctor
within one or two working days of the test. Please contact your family doctor
to get the results. You will not be able to get the results from the nuclear
How do I contact
the hospital about the scan?
you have any questions or if you need to change your appointment, please call
the Nuclear Medicine Department, The Hospital for Sick Children, at