Inveon preclinical μpet spect ct system

An anaesthetized rat (with 1.5–2.5 % isoflurane) was immobilized in a multimodal animal carrier unit (MACU; medres®—medical research GmbH, Cologne, Germany) and maintained at a body temperature of 37 °C throughout the whole experiment. [¹⁸F]FE@SNAP (47.64 ± 1.23 MBq) was injected as a bolus via the lateral tail vein, and dynamic PET imaging (Siemens Inveon preclinical μPET/SPECT/CT system) was performed over 60 min. Immediately afterwards, T1-weighted high-resolution axial, coronary and sagittal brain MRI scans were performed using a Bruker BioSpec 94/30 USR small-animal MR system (Bruker BioSpin GmbH, Karlsruhe, Germany).

Ten‐ to twelve‐week‐old male rats (397 ± 67 g) were anesthetized using 1.5–2% isoflurane with oxygen (1.5–2 L/min) and immobilized. Animals were warmed with a 37 °C positioning bed, except for imaging with [¹⁸F]FDG. Tracers (75.56 ± 5.48 MBq [¹⁸F]FDG (radiochemical purity >98%) or 82.7 ± 8.9 MBq [¹¹C]SNAP‐7941 (molar activity: 44.33 ± 29.63 GBq/μmol; radiochemical purity >99%) as well as SNAP‐7941 (15 mg/kg body weight (BW)), CL316,243 (2 mg/kg BW), or the respective vehicles were injected into the lateral tail vein. The total volume applied did not exceed 1 milliliter. After a μCT scan of 7 min, dynamic PET imaging was acquired on a Siemens Inveon preclinical μPET/SPECT/CT system. Sixty minutes after [¹⁸F]FDG injection, SNAP‐7941 (n = 4) or vehicle (n = 4) was injected, and the PET scan was continued for another 60 minutes. For scans with [¹¹C]SNAP‐7941, CL316,243 (n = 6), SNAP‐7941 (n = 6), or vehicle (n = 4) was administered 15 min after tracer application, respectively. The total PET acquisition time was 45 minutes. Differences between [¹⁸F]FDG and [¹¹C]SNAP‐7941 in PET acquisition time are due to the half‐lives of the respective nuclides (carbon‐11: 20.3 min; and fluorine‐18: 109.8 min) and the tracers’ equilibrium at 60 min ([¹⁸F]FDG) and 15 min ([¹¹C]SNAP‐7941) after application. Figure 2 shows the timeline of small animal imaging.