This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Pulmonary embolism is best diagnosed by – 
Select and explain. 
A. USG, B. X-ray chest, C. Ventilation – Perfusion scan, D. CT scan
D: CT scan
Answer: D: CT scan 
Explanation: No option is absolutely correct.
The pulmonary angiography has traditionally been considered as the gold standard test for pulmonary embolism. But, now a days CT contrast (MDCTA) is the investigation of choice.
Amongst the given options, lung V/Q scan is the best option as it is the 2nd choice of the investigation after MDCTA.