Depending on your medical history, your doctor will perform a thorough physical examination and order imaging tests of the lungs and of the leg veins. Be sure to let your doctor know if you have had any symptoms, such as those listed above.
Imaging tests include:
- Chest x-ray: Not an ideal test for the diagnosis of pulmonary embolism but it may rule out an enlarged heart or pneumonia as a cause of your symptoms. If the chest X-ray is normal, you may need further testing.
- Computed Tomography Scan - Angiogram (CTA): It is a very accurate study and the most commonly used one for the diagnosis of pulmonary embolism. This comes at the cost of the need for radiation and intravenous dye (iodinated contrast) that may be harmful for the kidneys, especially in patients with impaired renal function.
- Echocardiogram (echo): This test detects abnormalities in the size or function of the heart, which may be a sign of pulmonary embolism and give information about its severity.
- Ventilation Perfusion Lung Scanning (VQ Scan): This test scans for abnormal blood flow through the lungs after a radioactive tracer has been injected and you breathe a radioactive gas. It is rarely used in contemporary practice.
- Ultrasound of the leg veins (Duplex or Triplex): It is simple, fast, non-invasive and accurate in the diagnosis of venous thrombosis (blood clots) of the legs. If positive it may aid in the diagnosis of pulmonary embolism; if negative additional tests will be needed.
- Pulmonary Angiography: It is an invasive imaging study done in a surgical environment as it requires vein access through a groin or neck puncture. It requires radiation and intravenous contrast. In contemporary practice, it is not routinely recommended for diagnosis. It will eventually be used as part of your treatment if clot busters’ (thrombolysis) are going to be used for your treatment.
Additional tests include:
- Blood tests: D-dimer test measures the levels of a substance that is released when a blood clot breaks up. It is usually high in people with pulmonary embolism. Troponin and BNP (brain natriuretic peptide – hormone) levels if elevated indicate heart damage that may be related to a severe pulmonary embolism.
- Arterial blood gas analysis: Low oxygen levels may suggest pulmonary embolism.
- Electrocardiogram (EKG, ECG): The electrical activity of the heart is recorded with this test. EKG results will mainly help rule out a heart attack, but sometimes may be diagnostic of a pulmonary embolism.