The lung scan is also know as a V/Q scan. This procedure looks for blood clots to your lungs (pulmonary embolism).
You may be required to have a chest X-ray, or if you have had one, you may be asked to bring the films along. The doctors find a chest X-ray helpful in interpreting the lung scan pictures.
The lung scan has two parts to it, ventilation and perfusion. The ventilation looks at the airflow to your lungs. You will be asked to breathe in a radioactive gas. Pictures will be taken at various angles around your chest. The perfusion looks at the blood flow to your lungs. You will receive an injection of a radioactive tracer into a vein in your arm. Pictures will be taken at various angles around your chest.