What is a renogram?
A renogram is a nuclear medicine test of the kidneys. It can be used to see how well each kidney is working and whether urine passes on into the bladder without obstruction.
Is it safe for me to have the test?
For this test it is necessary to inject a small amount of radioactive tracer, called a radiopharmaceutical, in order to take the pictures. The small risk from this (less than a CT scan) is outweighed by the information that will be gained by taking the test. A doctor will have checked the request to make sure this is the appropriate test for you.
If you have any concerns or would like further information, please contact the department where you are having your renogram. If you don’t understand why you need to have this test please speak to the doctor who referred you.
For female patients
If you know that you are pregnant, or there is any chance that you may be pregnant, then please contact the department where you will be having your renogram. Do this as soon as possible as the scan can be postponed if it is not urgent.
Also contact the department if you are breast-feeding, as they may give you special instructions.
Preparation for your test
Unless your doctor has told you to have restricted fluids, please make sure that you drink plenty of non-alcoholic drinks before the renogram. You can eat normally.
If you are taking diuretic medicines please contact the department where you will be having your renogram for particular advice. You can take any other medicine as normal.
You will be asked to go to the toilet to empty your bladder. You will not have to get undressed, but you will be asked to remove any metal objects like braces, jewellery and belts before the test starts.
The pictures are taken by a special machine called a gamma camera. You will be asked to lie on a bed or sit on a special chair with the camera behind your back. There may also be another camera detector in front of you. A small amount of radioactive tracer will be injected into a vein in your arm. You may have had a blood test in the past; this is much the same. The ‘pinprick’ of the needle may hurt a bit but that is all.
You then just have to lie or sit still for about 30 minutes whilst the gamma camera takes a series of pictures of the tracer passing through your kidneys.
Sometimes it is also necessary to give another injection of a diuretic, a substance which makes your kidneys work harder and produce more urine. This may be given before the renogram or in the middle, but you will be able to go to the toilet when you need to. Some more pictures may be taken later after you have been to the toilet.
After your test
The effect of the diuretic will wear off after a few hours, but you may feel the need to go to the toilet more frequently or urgently. Please bear this in mind when you are travelling home or planning your activities for the next few hours. You should continue to drink plenty of fluids in order to replace what has been lost in your urine.
It is very unlikely that you will feel any other side-effects after the scan, but if you think that you have please let the nuclear medicine department know.
After the renogram you may continue all your normal activities unless you have been advised otherwise.
After your scan there will be some radioactivity left in your body but this will not present a significant risk to other people around you. However, for the rest of the day, we suggest that you try to keep any time that you spend within arm’s length of pregnant women, babies and small children as short as possible; but there is no need to stop giving children essential love and care.
The radioactivity in your body will soon disappear.
It is perfectly safe for you to travel abroad after your scan, but many airports and sea ports are now equipped with very sensitive radiation detectors. So it is possible that the very small amount of radioactivity left in your body could set off a detector as you pass through security. Therefore, if you intend to travel abroad within a week following your scan, it could be helpful to take with you something to explain that you have recently had a nuclear medicine scan. This could be your appointment letter or some other official confirmation from the department where you had your scan.
Your renogram pictures will be processed to produce a graph showing how quickly the tracer passes through your kidneys and into your bladder.
The result will be looked at by a specialist doctor, who will issue a report. The report will be sent to the doctor who requested your test rather than to your GP. This is 4 because the doctor who requested your test will have all the results from other tests and will be able to tell you how the result of your renogram affects your care.
Information about you
As part of your care, information will be shared between clinical staff, some of whom you may not meet. It may also be used to help train other staff. Information collected may also be used later on to help the department improve their quality of care, plan services or to research into new developments.
The pictures from your scan may be used to teach other healthcare workers, but your name and all other identification will be removed first. It won’t be possible to identify you from the scan pictures.
All information will be treated as confidential and is not given to anyone who does not need it. If you have any concerns, please discuss these with the department.
All the staff would like to make your visit as pleasant as possible. If you have any concerns please talk to a member of the nuclear medicine staff.
This video, made in the Central Manchester Nuclear Medicine Centre, shows a patient having the Renogram test.
A printable version of this leaflet can be found here