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What Is Indocyanine Green (ICG)?

Medically reviewed by: Jo Cooke-Barber, MD and Molly Haislip, APRN

Also called: IC Green or Spy Agent Green

What Is Indocyanine Green (ICG)?

Indocyanine green (ICG) is a medical dye doctors use to find and help treat problems in certain parts of the body. The dye changes the way the body parts look under a special light so doctors can see them more easily. ICG lasts for just a short time and is safe for kids.

Why Do Kids Get ICG?

Doctors may use ICG in some tests and procedures for the eyes, heart, lungs, liver, bowels, and lymphatic system (part of the immune system). For example, doctors may use it:

How Is ICG Given?

Kids get ICG in the hospital. It may be injected with a syringe or given through an intravenous line (IV), which is a soft tube placed in a vein. How and where doctors give ICG depends on which part of the body they need to look at. 

Kids may get ICG hours before a procedure or in the operating room. The doctor will let you know when your child will get ICG and if they need to come in before surgery for it.

How Does ICG Work?

After ICG is injected, it travels through blood to find proteins in plasma (a yellowish fluid in blood) and sticks to them. The areas that doctors are trying to view have these plasma proteins. Doctors then use special lenses and cameras to see ICG, which looks green in a certain light.

ICG helps doctors clearly see which areas they need to treat.

Does ICG Have Any Side Effects?

Most kids who get ICG do well and don’t notice any side effects. There’s a low risk of allergic reaction, like itching and hives. Sometimes ICG can stain skin green where it’s injected, but the skin will return to its normal color.

ICG has iodine in it, which might cause problems for kids with an iodine allergy and some other illnesses. Tell your doctor if your child has a medicine, dye, or food allergy. A kid who’s at risk for an allergic reaction to ICG may need medicines like antihistamines or steroids to help prevent a serious reaction.

If your child has any side effects, the hospital staff is prepared to treat them right away.

What Else Should I Know?

ICG has been used for a long time and is safe for kids. Talk with your child’s doctor if you have questions about it.

Medically reviewed by: Jo Cooke-Barber, MD and Molly Haislip, APRN
Date reviewed: August 2023