You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which of the following is associated with old chronic trauma? and explain in detail?
Sub Dural hematoma is due to venous bleed and is usually seen due to stretching of bridging veins and there is a slow collection of blood due to venous pressure being low and can be seen in patients with old chronic trauma. it shows Concavo-Convex or Crescentic or Banana shaped on CT. Large crescentic collection of acute blood along the right hemisphere representing an acute SDH. Note mass effect, dilation of the contralateral ventricle due to CSF outflow obstruction, and subfalcine herniation (arrow). Blood also extends into interhemispheric region.