A: Hyperdensities generally refer to blood and in these areas are usually either SDH or SAH. The falx separates the right side of the cerebrum from the left side and the tentorium separates the cerebrum from the cerebellum. When blood is described as being “along the tentorium” we code it to the cerebrum unless they clearly indicate either cerebellum or that it is “infratentorial” or in the posterior fossa. We always code to cerebrum if we aren”t sure of the location. The correct code is 140629.3 ( Page 45 of AIS dictionary )