Fat component in the normal bone marrow will be replaced by leukemic cells in patients with Leukemia. The infiltration/replacement of the marrow will result in typical appearance on MRI T1 sequence where the abnormal marrow appears darker than the adjacent muscles or disks (in case of lumbar MRI studies). Additionally, the abnormal bone marrow will appear show higher signal intensity on the fluid-sensitive sequences. Leukemia can also presents as lucent metaphyseal bands classically in pediatric patients.