Lung Ventilation-Perfusion Scan / Vq Scan

Also called a pulmonary ventilation/perfusion scan, a VQ (ventilation/perfusion) scan uses radioactive material to evaluate the blood flow (perfusion) and airflow (ventilation) in the lungs. The primary purpose of a VQ scan is to diagnose blood clots called pulmonary embolism. Blood clots in the lungs may cause symptoms such as sudden shortness of breath, pain in and around the chest and coughing.