Which diagnostic test is considered the gold standard for detecting pulmonary embolism?

The gold standard for detecting pulmonary embolism is widely recognized as the CT angiogram. This imaging technique allows for visualizing blood flow in the pulmonary arteries and can identify the presence of clots in a highly sensitive and specific manner. The CT angiogram uses contrast material and advanced imaging technology to create detailed images of the blood vessels, making it possible to pinpoint obstructions caused by emboli.

In contrast, while the D-dimer test is a useful blood test that can indicate the presence of an abnormal clotting process in the body, it is not specific and can yield false positives due to various benign conditions. The V/Q lung scan evaluates the ventilation and perfusion of the lungs and is an alternative method for assessing pulmonary embolism, but it is less definitive and has been largely replaced by CT angiography in many clinical situations. X-ray imaging also plays a role in evaluating patients with suspected pulmonary issues, but it typically does not provide sufficient detail to diagnose pulmonary embolism effectively. Thus, the CT angiogram stands out as the most definitive and accurate test for this condition.