Does a finding of subacute blood or high protein fluid collection on a mri of the brain indicate a mass?

Radiologist will call the lesion a mass if the lesion has features of a mass. Blood or fluid collection in the brain does not show as a mass by MRI.

Radiologists routinely use software programs to detect blood vs. spinal fluid and often can provide an estimate of the duration of bleeding. A structural mass, such as a tumor is readily distinguishable.