This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Surgery
Shape of post traumatic Epidural hematoma is 
Select and explain. 
A. Biconvex hyperdense, B. Biconvex hypodense, C. Biconcave hyperdense, D. Biconcave hypodense
A: Biconvex hyperdense
Answer: A: Biconvex hyperdense 
Explanation: (A) Biconvex hyperdense > Epidural hematoma. Head CT after traumatic brain injury reveales a classic biconvex hyperdensity diagnostic of an epidural hematoma (arrow). There is mass effect and midline shift to the left.> Epidural Hematoma: The CT classically will show a hyperdense lesion (hematoma) that is biconvex or lens-shaped secondary to its position between the dura and the skull.