CT pulmonary angiography (CTPA) is a medical imaging procedure that uses computed tomography (CT) to visualize the blood vessels in the lungs, specifically the pulmonary arteries. It is commonly used to diagnose or rule out pulmonary embolism, which is a potentially life-threatening condition where a blood clot, usually from the deep veins of the legs, travels to the lungs and blocks the pulmonary arteries.

During a CTPA, a contrast dye is injected into a vein in the arm, and a CT scanner takes multiple cross-sectional images of the chest. These images are then reconstructed by a computer to create detailed 3D images of the pulmonary arteries, allowing radiologists to assess for the presence of blood clots or other abnormalities.

CTPA is a highly sensitive and specific imaging modality for diagnosing pulmonary embolism and is often preferred over other imaging methods, such as ventilation-perfusion (V/Q) scans or Doppler ultrasound. It is non-invasive and typically performed on an outpatient basis. However, like any medical procedure, it does carry some risks, including potential allergic reactions to the contrast dye and exposure to ionizing radiation from the CT scan.

CTPA is typically ordered when a patient presents with symptoms suggestive of pulmonary embolism, such as sudden onset of chest pain, shortness of breath, rapid heartbeat, or coughing up blood. It is also used as a follow-up imaging study to monitor the progress of a known pulmonary embolism or to assess the response to treatment.

It’s important to note that CTPA should be ordered and interpreted by qualified healthcare professionals, and the decision to undergo this procedure should be made based on a thorough clinical evaluation and consideration of the risks and benefits. Your healthcare provider will be able to provide you with more information about CTPA and whether it is appropriate for your specific medical condition.