Bone bruising was a phenomenon that was not observed prior to magnetic resonance imaging, according to the International Society of Arthroscopy, Knee Surgery & Orthopaedic Sports Medicine. Bone marrow edema and bone bruising appear the same on MRI.

Bone marrow is a soft spongy material that is located inside of the bones. Bone marrow is necessary for the transition that stem cells make to become one of the types of blood cells (red blood cells, platelets or white blood cells).

The human skeleton is composed mainly of a substance called bone, and there are primarily four types of cells that make up bone. These are the osteoprogenitor cells, osteoblasts, osteoclasts and osteocytes. Their names all start with the prefix “osteo,“ which is the Greek word for "bone."