What is a gastrointestinal bleeding scan?
Sometimes you may experience bleeding from your gastrointestinal tract. No matter what investigations have been performed, the source of the bleeding cannot be determined. This has dire consequences where recurring significant blood loss is involved.
Red blood cells or human serum albumin (a blood protein) should only remain inside the blood vessels of the gut. Suppose we label these with a radioactive substance that emits gamma rays. In that case, we can image the blood supply of the gastrointestinal tract using a particular machine called a gamma camera.
Any abnormal focal collection of this tracer that moves over time can be considered positive for a bleed and guides the surgeon or gastroenterologist to investigate further. This test is highly accurate but still requires an active bleed. If no bleeding is visible per rectum, the likelihood of a positive result is diminished as with all other investigations.
What can be expected to happen?
Your own blood will be drawn and labelled with a radioactive substance. This may take a while.
At injection (on the imaging bed), you will immediately be imaged first for blood flow and then be continuously scanned for up to 90 minutes.
The second series of images can be acquired approximately 4-6 hours after injection.
Should the need arise (e.g. the bleeding rate is very slow), a third image can be performed 24 hours afterwards.
