SPECT Imaging of Dopamine D2/3 Receptors

Single-photon emission computed tomography acquisition has previously been described (Wulff et al., 2015 (link)). In short, SPECT images were acquired using a Siemens Symbia T2 series SPECT-CT scanner, with the [¹²³I]-Iodobenzamide ([¹²³I]-IBZM) as the radioactive ligand, because of its dopamine D_2/3R selectivity (Kung et al., 1990 (link); Barnas et al., 2001 (link)). After 180 min of rest, a CT scout and 2 × 30 min tomography were performed. CT-scout and tomography were performed to optimize positioning in the scanner and for attenuation correction. Patients underwent both baseline and follow-up SPECT scans, whereas controls only underwent baseline SPECT to minimize their exposure to radiation. At follow-up, the individual dose of amisulpride was administered 3 h prior to the scan, and s-amisulpride was measured prior to and at 60, 120, 150, 180, 210, and 240 min after administration. The mean s-amisulpride during SPECT-scan was calculated.