(radioactive gas inhaled into lungs)
(radioactive albumen carried to lungs)
The perfusion scan involves an intravenous injection (IV) of radioactive albumin. As the blood carries the albumin through them, this will be visible while scanning the lungs as the blood carries the albumin through them.
The ventilation scan involves scanning the lungs while the patient inhales slightly radioactive gas through a mask that is placed over the nose and mouth. This gas also appears visible in the X-ray.
Pictures are taken for both scans, and when compared, may reveal the source of a blood clot. Test results are usually ready within a few hours.