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: Medicine
[{'content': 'Best investigation when there is clinical suspicion of pulmonary embolism in a patient is- \nSelect and explain. \nA. D-Dimmer Assay, B. Multidetector CT angiography, C. Doppler ultrasound, D. Catheter angiography', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (Multidetector CT Angiography): For patients with strong clinical suspicions/high likehood of DVT. Imaging tests are obligatory. CT scan with intravenous contrast (Multidetector CT Angiography) is the test of choice for the diagnosis of PE. Invasive catheter based pulmonary Angiography is highly specific but reserved for patients with unsatisfactory chest CT or those who require an interventional procedure like catheter directed thrombolysis or embolectomy.', 'role': 'assistant'}]