Bone marrow is heterogeneous on MRI images when it does not have the same appearance throughout. Bone marrow is the tissue inside bones that forms the various blood cell types.
Bone cysts are fluid-filled lesions with a fibrous lining. They are common, benign (non-cancerous), and mainly seen in childhood. These lesions are usually asymptomatic (do not cause symptoms) and found incidentally (on passing when looking for something else).
Images show evidence of a previous bone fracture that is healing/has healed.
A previous bone fracture that is now healed. No further follow-up or evaluation is needed for this finding.
The acromioclavicular joint (AC joint), is the point where the clavicle (collarbone), meets the acromion (the highest part of the scapula [shoulder bone]). The AC joint allows for raising the arm over the head as well as moving the arm across the body. AC joint osteoarthritis is a type of shoulder arthritis that involves degenerative (wear-and-tear) changes to the cartilage and other structures in the acromioclavicular joint. These degenerative changes can cause pain, stiffness, and weakness in the front of the shoulder.
A cervical rib is an extra rib that is present at birth and forms above the first (top-most) rib, growing from the base of the neck just above the collarbone. It may grow on one side or both (bilateral) and may reach down to attach to the first rib (a fully formed bony rib) or may not be fully formed (a thin strand of tissue fibers). These are usually asymptomatic (do not cause symptoms) but can occasionally be a cause of thoracic outlet syndrome (a group of disorders that occur when blood vessels or nerves are compressed in the space between the collarbone and the first rib). Symptoms of thoracic outlet syndrome include pain in the shoulders and neck, numbness, weakness, and coldness in the fingers.
