A white spot on a brain MRI, referred to as white matter or a brain lesion, shows an area of injury or disease, but can result in a number of diagnoses, according to the Mayo Clinic. The potential diagnoses range from harmless and controllable to possibly life threatening.
White or dark spots on a CT brain scan could indicate conditions such as aneurysms, encephalitis, multiple sclerosis or traumatic brain injury, notes the Mayo Clinic.
If a white or drak spot on the brain is not a result of a previous condition, a physician requires further testing or analysis, explains the Mayo Clinic. The physician may refer a patient to a specialist, such as a neurologist. Additional testing may include a CT scan, drawing blood and other laboratory tests to help diagnose the cause of the white matter.