Bone Marrow Conversion and Reconversion

Chapter 75 discusses bone marrow conversion and reconversion. The bone marrow is one of the largest organs in the body and it changes in composition throughout life. There is a normal conversion of hematopoietic bone marrow to fatty marrow with age. Various stressors or diseases can cause a reversal of this process or marrow reconversion. Marrow reconversion is often incidentally detected on MRI. Its imaging characteristics are important to distinguish from pathologic marrow infiltrative processes. Characteristic locations of marrow reconversion and the presence of focal or microscopic fat on MRI are useful features, but biopsy may still be required to exclude malignancy. Treatment is specific to the underlying disorder.