What is a DMSA scan?
A DMSA scan is a nuclear medicine test that takes a “picture” of the kidney tissue. A small amount of a radioactively labeled substance is injected into a vein. This substance collects in healthy kidney tissue. A special camera shows how it is distributed.
What does it show?
- Kidney scars: areas that do not work after a past pyelonephritis,
- the share of each kidney in total function (normally about 45–55%),
- a nonfunctioning kidney (multicystic dysplastic kidney),
- an abnormal position or shape of the kidney.
When is it done?
- to check for kidney scarring after a febrile urinary tract infection: at least 6 months after the infection (after a first infection with a normal ultrasound it is often not needed),
- to monitor the kidneys in reflux,
- to assess the function of each part in a duplex kidney.
How is it done?
- The substance is injected into a vein in the arm or leg with a small needle.
- There is a wait of 2–3 hours, during which the child can eat, drink and play.
- The child lies still under the camera for 30–45 minutes. Young children sometimes need a mild sedative.
Preparation
No special preparation or fasting is needed. Bring a toy, a cartoon and food for your child. After the test, drinking plenty of fluids is advised.
Note for pediatricians and family doctors
DMSA performed during acute pyelonephritis shows inflammatory defects and can be used for diagnosis; to assess permanent scarring, however, the scan should be done at least 6 months after the infection. After a first febrile UTI with a normal ultrasound it is often not needed; an abnormal DMSA can be an indication for VCUG (top-down approach). DMSA is chosen to measure differential function, and MAG3/DTPA to assess obstruction.
What happens at the visit?
- The purpose and timing of the test are set according to the child's infection history.
- The result is assessed together with reflux and ultrasound findings.
Frequently asked questions
Does the radioactive substance harm my child?
The dose used is very small. Part of the substance is held in the kidney tissue and part leaves in the urine, and the radioactivity fades naturally within a few hours. After the test, drinking plenty of fluids and passing urine often is advised.
Related topics
Sources
- EAU Guidelines on Paediatric Urology, 2026.
- Piepsz A et al. Guidelines for 99mTc-DMSA scintigraphy in children. Eur J Nucl Med, 2001.
References to the EAU Paediatric Urology guidelines were checked against the 2026 edition (October 2026).
This information is for educational purposes and does not replace medical advice. Decisions about your child’s treatment are made with the doctor after an examination.
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