Overview

Contrast dyes are usually given to people having an MRI or CT scan. They make areas of the body show up more clearly and in greater detail on the scan. This improves the quality of our pictures.

We give you the contrast dye as an injection into a vein in your arm or hand.

If the contrast injection leaks out from the vein to the tissues under your skin, this is called extravasation. It can cause a stinging feeling, but this usually wears off after about 30 minutes. You might also have some swelling in your arm or hand.

In most cases, this is a minor injury and does not need any treatment.

If you have extravasation

If there is a leak, the health professional doing your scan (a radiographer) massages your arm and raises it above your head. They might also put a cold compress (a thick, soft piece of cloth) on the area.

If possible, the radiographer will continue with the scan. To do this, you might need another contrast injection. The radiographer will talk to you about this. 

If the extravasation is severe, a doctor will examine you before you leave the hospital. They will tell you if you need any more treatment.

If you have swelling

If you have swelling in your hand or arm when you have left hospital after your scan, there are things you can do to help. 

• Raise your arm as much as you can. At night, keep your arm raised on 2 pillows. Keep doing this until the swelling has gone down.
• Use an ice pack or a bag of frozen vegetables on the swelling. Wrap the ice pack or frozen vegetables in a clean tea towel first. Do not put ice directly on your skin or leave the ice pack on for more than 15 minutes at a time.
• You can massage the area where the contrast has gone into the tissue.
• If the area is painful, take your usual painkillers. Always follow the instructions on the packet.