Final answer:
A PET Scan (Positron Emission Tomography) is used to inhale radioactive air into the lungs and inject radioactive contrast intravenously to diagnose conditions such as pulmonary embolus by tracing radiopharmaceuticals within the body.
Step-by-step explanation:
The test in which radioactive air is inhaled into the lungs followed by intravenous injection of radioactive contrast to assess for pulmonary embolus is known as a PET Scan (Positron Emission Tomography). PET scans utilize radiopharmaceuticals to reveal metabolic and physiological functions within tissues, and by tracing these substances, medical professionals can diagnose and monitor various health conditions, including pulmonary embolus.
For a PET scan, a positron-emitting radioisotope is attached to a substance used by the part of the body being investigated. Once administered, the PET scanner detects gamma ray emissions, which, along with a computer, generates images that provide diagnostic information regarding both structure and function. While such radiopharmaceuticals are short-lived, they are essential for the procedure because they enable the visualization of the physiological processes in real-time.