What is a MAG3 Renal Exam?

A MAG3 renal exam is an imaging test that takes pictures of your child’s kidney. The pictures from the MAG3 renal exam can tell the care team if the structure of your child’s kidneys is normal. The pictures can also tell the care team if there is something blocking the glomeruli (the tubes inside the kidneys).

How Does the MAG3 Renal Exam Take Pictures?

The MAG3 renal exam uses radioisotopes mixed with liquid dye to take pictures. Radioisotopes are a type of radiation that makes very clear and detailed x-rays (pictures) of the body. We use the lowest and safest dose of radioisotopes possible during the exam.

How Long Does the Exam Take?

The exam takes about 2 ½ hours.

Where Will My Child Have the Exam Done?

Your child will have the MAG3 renal exam done in the Department of Nuclear Medicine and Molecular Imaging at Massachusetts General Hospital.

How Should My Child Prepare For the Exam?

  • Follow the care team’s instructions on what to eat and drink before the exam. If you have other questions or concerns, ask the care team.

What Can My Child Expect During the Exam?

  1. Your child will lie flat on the exam table. The MAG3 camera is above the exam table. A nurse will be with your child for the whole exam.
  2. A nurse will put a catheter into your child’s urethra (where urine comes out). This might be uncomfortable at first. Your child should not feel the catheter when it’s in. The catheter is a small tube that lets urine out of the body and into a bag during the test.
  3. Your child will have an IV put in their arm. We will give your child numbing cream so the poke from the needle hurts less. This part can be scary for children. Tell your child that it is okay to feel scared.
  4. We will give the radioisotopes and liquid dye through the IV. This does not hurt, but it might feel cold. We will also give liquid diuretics through the IV, which make your child urinate. The catheter will catch any urine that comes out.
  5. The MAG3 camera will take pictures of your child’s kidneys. The camera does not hurt. Your child might hear the camera make clicking sounds when it takes pictures.

What Should My Child Do After the Exam?

After the exam, your child should rest and drink fluids. Your child can also eat their normal diet after the exam.

When Will I Get the Results?

You should get the results on the same day as the exam. The care team will also send a copy of the results to your child’s doctor after the radiologist (imaging doctor) looks at the pictures. Call your child’s doctor or go to the closest emergency room right away if your child has chest pain or feels weak.

If you have questions, please call the Pediatric Nephrology and Hypertension Program at 617-726-2908.

Rev. 1/2019. Mass General for Children and Massachusetts General Hospital do not endorse any of the brands listed on this handout. This handout is intended to provide health information so that you can be better informed. It is not a substitute for medical advice and should not be used to treatment of any medical conditions.