Extradural hematoma CT scan finding is
**Core Concept**
Extradural hematoma is a life-threatening medical emergency characterized by the accumulation of blood in the extradural space, which is the space between the inner surface of the skull and the dura mater. This condition typically results from a traumatic injury, such as a head injury, that leads to the tearing of blood vessels and subsequent bleeding.
**Why the Correct Answer is Right**
The CT scan finding of an extradural hematoma typically shows a biconvex or lenticular-shaped hyperdensity in the extradural space, which is due to the accumulation of acute blood. This finding is often associated with a thin layer of brain tissue between the hematoma and the skull, which is a characteristic feature of extradural hematomas. The presence of this thin layer of brain tissue is due to the fact that extradural hematomas do not typically cross the subarachnoid space, unlike subdural hematomas.
**Why Each Wrong Option is Incorrect**
* **Option A:** is incorrect because extradural hematomas do not typically show a crescent-shaped hyperdensity on CT scan, which is more characteristic of subdural hematomas.
* **Option B:** is incorrect because extradural hematomas do not typically show a midline shift on CT scan, unless the hematoma is large and has caused significant mass effect.
* **Option C:** is incorrect because extradural hematomas do not typically show a rounded or oval-shaped hyperdensity on CT scan, which is more characteristic of subdural hematomas.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that extradural hematomas are often associated with a lucid interval, where the patient may initially appear to be conscious and alert, but then rapidly deteriorate due to increasing intracranial pressure.
**Correct Answer: C.**