Radiology - Kidney Split Function Test

Nuclear Medicine Department

Please read this leaflet carefully in conjunction with your appointment letter.

If you require any further information, please contact the Nuclear Medicine Department on 0161 206 4861.

Why do I need this test?

Your doctor has asked you to come for a test called a split function glomerular filtration rate to check how well your individual kidneys are working. You can choose to refuse this test, but we strongly recommend that you discuss this with your doctor before making a decision.

Preparation for your tests

You will need to attend the hospital on two separate days, one for a kidney function test, which lasts approximately 4 to 5 hours, and another for a kidney scan which lasts approximately 3 to 4 hours.

Please note that it is vital you attend both these appointments otherwise no result is possible.

Please confirm both of your appointments by leaving a message on our 24-hour answer phone 0161 206 4861.

Preparation – Kidney function test

• On the evening before the test, you should eat and drink as normal. Have nothing more to eat from midnight until after the test has started the next day
• You can only drink water or fruit juice/cordials as normal after 10pm on the day before the test. If you are unsure about this do not hesitate to contact the department
• You must not smoke from midnight the night before the test, until after the test is completed, including e-cigarettes
• If you are on Continuous Ambulatory Peritoneal Dialysis (CAPD), you will need to drain the fluid off that morning and leave the tube capped-off. The Renal Unit may do this for you if necessary. Please ensure that you do this before arriving for the test
• If you are taking any medication, you should continue as normal and bring a list of your current medication with you

Preparation – Kidney scan

There is no special preparation for this appointment, however you should drink plenty before and after your scan.

If you are taking any medication, you should continue as normal.

How are the tests performed?

For both appointments, when you arrive in the department, we will first make sure you have followed the preparation instructions correctly and that we can safely carry on with the tests.

How is the Kidney function test performed?

This appointment allows us to calculate the filtration rate of your kidneys.

You will have a blood sample taken and then be given an injection of a radioactive liquid into a vein, usually in your arm. After this, both arms will be monitored with an instrument capable of detecting radioactivity.

You will have a further two blood samples taken from a different vein, at 2 hours and 4 hours after the radioactive injection. You will be asked to return to the department at set times for this.

During the waiting times between blood samples, you may eat, but only one of the items listed and drink but only from this restricted list below:

Drinks: water, fruit juices and cordials

Food: 2 slices of white toast with jam (no butter) or 2 rich tea or digestive biscuits or 1 piece of fresh fruit (apples, oranges, grapes, watermelon/melon, berries, no bananas).

There are no side effects from the injection; it does not make you sleepy or prevent you from driving a car.

How is the Kidney scan performed?

For this appointment we will take some pictures of your kidneys.

You will be given a small injection of a radioactive liquid into a vein, usually in your arm. This injection circulates around your body and will be absorbed by your kidneys. This allows us to take pictures, called a scan, later on in the day.

During this waiting time you will be able to leave the department and will be free to eat and drink. There are no side effects from the injection; it does not make you sleepy or prevent you from driving a car.

The pictures are usually taken at about 3 hours after your injection. For these, you will normally lie on our bed while the gamma camera performs the scan. Usually there is no need to undress, although we will ask you to remove jewellery, keys or other metallic or bulky objects from your pockets.

The scan takes about 10 minutes but can take longer depending on the individual. Having the scan does not hurt but it is important that you keep still. If you are in pain, please tell us and we will try to make you as comfortable as possible.

Risks and Limitations

If you think you may be pregnant, or you are breastfeeding you must contact us before the test date.

You might get a bruise around the injection/blood sampling sites.

Side effects are not common, but some people may get a skin rash, a headache, upset stomach, vertigo or dizziness soon after the injections.

You will receive a small radiation dose of about 0.4 mSv. To put this in perspective, the average radiation dose received from natural background radiation is just under 3 mSv in one year in the UK.

After the tests

After both test, you can eat as normal and should continue to drink plenty of fluids for the rest of the day. This will help to remove the radioactivity from your body.

Please avoid prolonged close contact with children or pregnant women for the rest of the day. This is to avoid exposing babies and children to unnecessary radiation.

What happens to the results?

A report is sent to the hospital consultant who asked us to do the test. Allow at least 2 weeks after the last appointment for this.

Nuclear medicine staff are not allowed to give patients the result of any tests directly.

Can I bring a friend or relative?

Only essential carers may remain with you. You must let us know before your test date if you require a carer present.

Please, do not bring children or pregnant adults with you as there may be other patients in the department who might expose them to a small but unnecessary amount of radiation.

What if I cannot attend for my appointment?

If you have any questions about your examination or are unable to make the appointment, please telephone the help line on 0161 206 4861. This is a 24-hour answer phone, but it is usually manned Monday to Friday 8.30am to 4pm. If you prefer you can contact us via email at Radio.isotopes@nca.nhs.uk

Please include your name, address, date of birth and hospital number (if known) on all correspondence.

Please help us to cut our waiting lists. If you need to cancel or change your appointment, call us as soon as you can so that we can give it to somebody else.

I need an ambulance, how do I arrange this?

If you need an ambulance contact:
0161 206 7014 – Salford residents
0800 032 3240 – other areas

Please inform the Nuclear Medicine department if you are arriving by ambulance.

Interpreters

If you need a translator for your examination, please contact the Nuclear Medicine department.

Other sources of information

For further information regarding nuclear medicine examinations, visit the British Nuclear Medicine website:
http://www.bnms.org.uk/page/PatientsCarers

If you still have concerns or require further information about this test please contact us at:

Nuclear Medicine Department, Salford Royal Hospital, Stott Lane, Salford M6 8HD
Telephone: 0161 206 4861