Dopamine D2 receptor imaging and measurement with SPECT.

Only recently it has become possible to label and visualize dopamine D2 receptors in the living human brain using an [123I]labeled ligand and the SPECT technique. Iodobenzamide (S(-)IBZM) is a substance with high affinity and high specificity for D2 receptors and was used in controls and in patients with different extrapyramidal disorders. After the i.