Pulmonary embolism - Diagnosis

How ist pulmonary embolism diagnosed?

Besides analysis of the clinical history and a physical exam, the doctor will ask you about current symptoms.  The doctor focuses on possible risk factors and signs of a thrombosis. The first signs can be detected sometimes by listening to the heart and lung. Some labratory values also indicate this disease:

  • Blood gases:  The oxygen level in the blood is reduced
  • Coagulation values indicate certain risk factors
  • D-Dimers: If this value is increased, this indicates an increased degradation of blood coagulation

An X-ray and an ECG exam serve more for the exclusion of other diseases. An ultrasound exam can reveal indications for the stress of the right heart;  sometimes also a larger blood clot can be observed. Via a pulmonary scintigraphy, during which radioactive marked substances are injected, the blood flow and aeration of the lung can be estimated and put in relation to each other. Certain images suggest a pulmonary embolism, but no definitive diagnosis can be made based on these.

The CT angiography is especially designed to diagnose a pulmonary embolism. An X–ray contrast agent is injected into the vein, where it accumulates more and more. Larger blood clots can be displayed this way.  Smaller thrombosis in the marginal areas cannot be displayed, and for this, a catheter should be inserted through the artery (pulmonalis angiography).