Nuclear Medicine DMSA Scan

Authors: Dr Chian Chang*
                            Dr Timothy Cain *

What is a DMSA scan?

DMSA, or dimercaptosuccinic acid, is a radioactive compound (radiopharmaceutical) that when injected into a vein allows images or pictures to be taken of the kidneys. DMSA enters the kidneys and is concentrated in functioning/normal kidney tissue, giving an indication as to how the kidneys are working. It does not provide information as to the internal structure of the kidneys. The gamma rays emitted from the radioisotope allow images of the kidneys to be taken using gamma cameras (See InsideRadiology: Nuclear Medicine for further information).

Why would my doctor refer me to have this procedure?

In children, the test is commonly carried out to look for evidence of damage to the kidneys from previous infections (scars) or evidence of active infection (pyelonephritis).

In adults, reasons for having the test include looking for scars; estimating the function of both kidneys, particularly when planning kidney surgery; or for targeted treatment, such as radiotherapy

How do I prepare for a DMSA scan?

No special preparation is required for this scan. It is recommended that you or your child are well hydrated for the study.

If you are or think you could be pregnant or are breast-feeding, you must inform your doctor beforehand or the nuclear medicine staff at the time of your DMSA scan. They will discuss the radiation precautions with you and the need to temporarily stop breast-feeding.

What happens during a DMSA scan?

The radiopharmaceutical enters into the bloodstream through an injection into a vein.

After the injection, there is a wait period, usually 90 minutes (it can be up to 4 hours) between the injection and having the scan. This allows the radiopharmaceutical to circulate through the bloodstream and accumulate in the kidneys. The delay also allows time for the radiopharmaceutical to clear from other body tissues.

The kidney scan takes about 30 minutes. The staff will likely ask you or your child to empty your/their bladder just before you lie on the scanning bed. It is important to lie as still as possible during this time, as motion will blur the images and affect the quality of the scan.

Carers are allowed in the scan room when their child is being scanned. You can talk or read to your child to help them keep still. Some radiology facilities also have a television to distract your child during the scan.

Rarely, sedation may be required (See InsideRadiology: Making my child’s test or procedure less stressful).

The radiopharmaceutical is eliminated from the body through the urine, and this is helped by drinking plenty of fluids and urinating frequently after the injection. Your urine will not change colour. It is recommended that you wash your hands thoroughly after going to the toilet to remove any isotope.

Babies and children in disposable nappies are required to place soiled nappies into a bag before disposal. Soiled cloth nappies require a thorough wash. There are no harmful effects on the skin, but carers are encouraged to be extra diligent in cleaning baby’s skin and washing their hands thoroughly.

Are there any after effects of a DMSA scan?

There sre no after effects.

How long does a DMSA scan take?

A DMSA scan of the kidneys involves an injection of the radiopharmaceutical into the vein, followed by the scan about 90 minutes to 4 hours after the injection. You can usually leave the hospital or nuclear medicine facility after the injection and return later. You are allowed to eat and drink normally during this time.

The scan takes about 30 minutes. You will not feel any different whilst you are being scanned.

What are the risks of a DMSA scan?

There are no risks involved in the DMSA scan procedure itself.

There is a small amount of ionising radiation that is similar to other routine medical imaging tests (see InsideRadiology: Radiation risk of medical imaging for adults and children).

What are the benefits of a DMSA scan?

A DMSA scan enables the doctor to evaluate the amount of normal functioning tissue of your kidneys. Doctors can measure the relative function of each kidney to see if one kidney functions differently to the other. By carrying out regular DMSA scans, doctors can monitor changes in the kidneys confirming whether or not infection is still present or if there is progression of scarring.

Who does the DMSA scan?

The DMSA scan is carried out by nuclear medicine technologists. The images are then provided to a nuclear medicine specialist (specialist doctor) who reviews them, and provides the findings to your referring doctor.

Where is a DMSA scan done?

Most public and private hospital-based nuclear medicine departments and many private nuclear medicine clinics (usually in radiology practices) carry out this scan.

Who does the DMSA scan?

The DMSA scan is carried out by nuclear medicine technologists. The images are then provided to a nuclear medicine specialist (specialist doctor) who reviews them, and provides the findings to your referring doctor.

Where is a DMSA scan done?

Most public and private hospital-based nuclear medicine departments and many private nuclear medicine clinics (usually in radiology practices) carry out this scan.

When can I expect the result of my DMSA scan?

Most nuclear medicine departments should have a result sent to your referring doctor or GP within 24 hours. On rare occasions, the report may be delayed due to unforeseen circumstances, such as emergencies. The nuclear medicine facility where you are having your scan will be able to advise you in better detail at the time of your scan.

It is important that you discuss the results with your referring doctor.

Further information about a DMSA scan:

This is a simple test that allows the doctor to assess any damage to the kidneys. Regular scans (for example, once a year) are often carried out to monitor any change in the function of the kidneys or their response to treatments you may be having.

*The author has no conflict of interest with this topic.

Page last modified on 14/5/2018.

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