Which diagnostic tool can confirm the presence of pulmonary embolism?

CT pulmonary angiography is considered the gold standard for diagnosing pulmonary embolism due to its high sensitivity and specificity for detecting clots in the pulmonary arteries. This imaging technique involves the use of contrast material and high-resolution imaging to visualize the blood vessels in the lungs. It allows for direct visualization of the pulmonary arteries and can easily identify whether any emboli are present.

Other imaging modalities, while useful in certain contexts, do not provide the same level of confirmation for pulmonary embolism. For instance, X-rays are often used to rule out other conditions but are not sensitive enough to detect small blood clots. Ultrasound may be used to detect deep vein thrombosis, which can lead to pulmonary emboli, but it does not visualize the pulmonary arteries directly. MRI can provide detailed images of soft tissues and blood vessels but is not typically used for diagnosing pulmonary embolism due to practical considerations like the need for rapid diagnosis, the use of contrast agents, and availability.

Therefore, CT pulmonary angiography's ability to directly show emboli in the pulmonary circulation is what confirms the presence of pulmonary embolism effectively.