DMSA scan

A chemical called Dimercaptosuccinic acid (DMSA) is injected into your child’s body. This chemical is taken into some cells in his or her body, such as those in the kidneys. DMSA is linked to a radioisotope. It emits (gives out), a type of radiation (source of energy) called gamma rays.
During the scan, a special camera picks up the gamma rays and turns them into pictures.

• The kidney cells (living parts) that are ‘active’ take up the DMSA and emit gamma rays. These are shown on the images as ‘hot spots’, and may be bright or in a colour.
• The kidney cells that are less ‘active’ (for example, are damaged) take up less or none of the DMSA, and do not emit as many gamma rays. These are shown on the images as less bright spots, or may not be seen at all.

A DMSA scan gives the same amount of radiation (dose) that we would be exposed to in between 6 months and one year. The radioisotope that is injected into your child’s body becomes inactive after a few hours and is passed out of his or her body in urine or faeces (poo). However, your doctor will carefully consider the risks and benefits of doing this test in your child.

The DMSA scan takes place at all the centres of City Imaging and Clinical Labs.
A radiographer or a technician, a specialist trained in imaging tests, performs the test.

• The radioisotope is injected into a blood vessel, using a needle or a small plastic tube called a cannula. This is usually in the hand, arm or foot. Your child may feel a sharp scratch from the needle. A local anaesthetic, a spray or cream, can be put on your child’s skin before inserting the needle or cannula, to make the area feel numb.
• It takes some time for the radioisotope to reach the kidneys. Your child will wait for about three hours, and then come back to the nuclear medicine department.
• During the scan, your child lies on a scanning bed.
• Your child needs to lie still while a large camera above him or her takes pictures. These show the radioisotope that has been taken up by his or her kidneys.