What is the next step for a patient with suspected pulmonary embolism after a normal chest X-ray?

In cases of suspected pulmonary embolism (PE), the next appropriate step after obtaining a normal chest X-ray is helical CT pulmonary angiography. This imaging modality is specifically designed to visualize the pulmonary vasculature and can detect the presence of blood clots in the pulmonary arteries.

A normal chest X-ray does not rule out a pulmonary embolism, as standard radiographic imaging is often inconclusive regarding this diagnosis. Therefore, more advanced imaging techniques are necessary to confirm or exclude the presence of a PE. Helical CT pulmonary angiography is highly sensitive and specific for detecting pulmonary emboli and is typically the preferred initial diagnostic tool in clinical practice due to its rapid acquisition of images and high diagnostic accuracy.

Other methods such as MRI or contrast venography are less commonly used for diagnosing pulmonary embolism. MRI is generally not the first-line imaging choice for PE due to its limited availability and the potential for longer examination times, which may not be suitable for an acute condition. Contrast venography, while used for evaluating deep vein thrombosis (DVT), is not routinely employed for PE diagnosis.

In summary, helical CT pulmonary angiography stands out as the most effective next step for confirming a pulmonary embolism following a normal chest X-ray, owing to