How They’re Diagnosed
The type of MRI process that reveals these lesions is often referred to as T2-weighted MRI. MRIs use interwoven magnetic fields to create images of the all of the tissues inside a body, and are most often used to make the soft tissues appear in higher contrast than surrounding areas.
T2-weighted MR imaging uses specific settings for two factors of the imaging process: echo time and repetition time. Lesions show areas where the tissue contains more fluid than normal for the tissue type and pools of free water. It is also possible for the data from a T2 MRI to be adjusted so that the free water is not highlighted and the focus is on high concentrations of water within the tissue. This is known as a FLAIR sequence.
Common Causes
Scientists and doctors are not always sure about the exact diagnostic meaning of hyperintense lesions. They are usually a sign of some sort of larger condition, but not always. Lesions may appear many years before a larger problem actually develops in a person. Still, in most cases, they are a sign of a degenerative or autoimmune condition.
Multiple Sclerosis, a disease in which the protective coating around the body’s main nerves deteriorates, is one of the most common causes, particularly for lesions that occur along the spinal cord. Lesions in certain parts of the brain can be a sign of dementia, though this is most common in old age. Type II Diabetes and the Human Immunodeficiency Virus (HIV) and related Acquired Immunodeficiency Syndrome (AIDS) may cause spots on the liver, colon, and brain, among other places, and cancers of all forms may also be to blame.