PET/CT Imaging

MicroPET/CT images were acquired with an Albira PET/SPECT/CT small animal imaging system (Bruker Biospin Corporation, Woodbridge, CT, USA). Healthy 10-week-old female BALB/c mice (Envigo, Horst, The Netherlands) (*n* = 4) were pre-treated by intraperitoneal injection of 250 µL corresponding to 4 mg of alendronate-TCO or 2.5 mg alendronate alone, respectively. Pre-treated mice were retro-orbitally injected with radiolabeled tracer in a dose of 5–10 MBq corresponding to 1–2 µg of conjugate per animal 5 h after the pre-treatment. Anaesthetized (2% isoflurane (FORANE, Abbott Laboratories, Abbott Park, IL, USA)) animals were placed in a prone position in the Albira system before the start of imaging. Static PET/CT images were acquired over 30 min starting 1 h p.i.. A 10-min PET scan (axial FOV 148 mm) was performed, followed by a double CT scan (axial FOV 2 × 65 mm, 45 kVp, 400 µA, at 400 projections). Scans were reconstructed with the Albira software (Bruker Biospin Corporation, Woodbridge, CT, USA) using the maximum likelihood expectation maximization (MLEM) and filtered back projection (FBP) algorithms. After reconstruction, acquired data was viewed and analyzed with PMOD software (PMOD Technologies Ltd., Zurich, Switzerland).
