The most common test for pulmonary embolism is a venous phase CT angiogram. This quick and accurate test provides all the information needed for initial treatment. Unfortunately, the need for contrast dye makes the test risky in patients with renal dysfunction.
A VQ scan is an alternative test but does not distinguish between acute and chronic pulmonary embolism. An echocardiogram is important to look at the function of the right heart and see if any thrombus is present in the heart that could cause additional compromise to the lung circulation and may constitute an indication for emergency surgery.