Modic changes are found often in MR imaging. They are signal intensity changes in the vertebral body right next to the endplates of damaged discs. Vertebral endplates are the fibrocartilage portions of the intervertebral disc. The end-plate is a possible source of disc-related low back pain.

The word modic comes from the doctor who first wrote about these changes in 1988 (Michael T. Modic, MD, professor of radiology and neurology at Case Western in Cleveland).

There are three kinds of modic changes. Type 1 is a decreased signal intensity and means there's edema or swelling in the area. Type 1 modic changes can also mean there's a tumor or infection.

Type 2 modic changes are the most common type reported on MRIs. With Type 2 modic changes there is an increase in the MRI signal. It means the first layer of bone under the cartilage is starting to turn to fat. It's a sign that the problem has been there for awhile. Type 1 modic changes can convert into Type 2 changes.

Type 3 modic changes occur with bone sclerosis, a hardening of the bone. As the body tries to heal the damaged disc, extra bone cells are formed. The defective bone growth results in sclerosis.

Modic changes on MRI have been linked with discogenic back pain but pain can occur where no modic changes are seen.