This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brain Imaging: Anatomy, Trauma, and Tumors, Subject name: Radiology
Which of the following shows biconvex shape on CT- 
Select and explain. 
A. Epidural hematoma, B. Subdural hematoma, C. Both, D. None
A: Epidural hematoma
Answer: A: Epidural hematoma 
Explanation: Ans. is 'a' i.e., Epidural hematoma o Biconvex (lens shaped or lenticular) hyperdense(2/3rd) or mixed density lesion( 1 /3rd) - Epidural hematomao Crescent (concao-convex) hyperdense (<2 weeks) or isodense (2-4 weeks) or hypodense (>4 weeeks) lesion - subdural hematoma