<prompt> Which of the following is not true about non contrast CT scan in head injury?Subdural hematoma increase in density over lesional CT scans over weeksExtra dural haematomas are usually lens shapedAcute subdural hematoma appears as crescent shadow of increased densitySubarachnoid haemorrhage appears as areas of increased density in basilar cisterns  <response>: Ans. Subdural hematoma increase in density over lesional CT scans over weeks 