A nuclear lung scan is performed by injecting a radioactive substance and then using a special scanner to visualize blood flow and/or air movement in the lungs. The scan often involves two parts: a perfusion scan and a ventilation scan, which can be done separately or together.
Here's a breakdown of the process:
1. Perfusion Scan
- A health care provider injects a small amount of radioactive albumin (a protein) into a vein, usually in your arm. These particles are tiny and travel to the lungs.
- You are then positioned on a movable table that slides under a scanner. The scanner detects the radioactive particles in your lungs.
- As blood flows through the lungs, the scanner creates images showing where the radioactive particles are located. This helps identify any areas where blood flow may be reduced or blocked. Areas with normal blood flow will show up clearly, while areas with reduced or absent blood flow will appear as "cold spots."
2. Ventilation Scan (Optional, but often done together)
- For the ventilation scan, you will inhale a radioactive gas or aerosol through a mask or mouthpiece. This allows doctors to see how air is moving in and out of your lungs.
- The scanner then takes images of your lungs as you breathe, highlighting areas where air is flowing normally and identifying areas where airflow is obstructed or reduced. Areas with good ventilation will show the radioactive gas or aerosol, while areas with poor ventilation will not.
Combined Perfusion and Ventilation (V/Q) Scan
The combination of the perfusion and ventilation scans, often called a V/Q scan, gives doctors a comprehensive picture of lung function. By comparing the images from both scans, they can determine if any abnormalities are due to problems with blood flow, airflow, or both. This is especially useful for diagnosing conditions like pulmonary embolism (blood clot in the lungs).
What to Expect During the Scan
- The procedure is generally painless. You may feel a slight pinch when the radioactive material is injected.
- You will need to remain still during the scanning process to ensure clear images.
- The entire scan usually takes between 30 minutes and an hour.
- The amount of radiation you are exposed to is minimal and considered safe.
