**3.7 Bone marrow disorders**

Non-invasive imaging techniques have been used in the past for visualization the functional activity of the bone marrow compartment. Imaging with radiolabelled compounds may allow different bone marrow disorders to be distinguished. These imaging techniques, almost all of which use radiolabelled tracers, such as 99mTc-nanocolloid, 99mTc-sulphur colloid (99mTc-SC), 111In-chloride, and radiolabelled white blood cells (99mTc-WBC), have been used in nuclear medicine for several decades. The results support that the radiolabelled agents can be alternatives to bone marrow scan.
