Inveon micro pet spect ct

The animals were anesthetized with ketamine/xylazine and euthanized via transcardial perfusion using 4% PFA (4 (link)). Maxillae were hemisected and micro-focus computed tomography (µCT) images were obtained using a Siemens Inveon Micro-PET/SPECT/CT (Siemens, Ann Arbor, MI) at a 9 µm spatial resolution. Siemens Inveon Research Workplace 4.2 software was used for image acquisition and processing, 2-D and 3-D image viewing, and quantitative analysis. Unless otherwise indicated, bone loss was evaluated from the buccal side. To assess the levels of periodontal bone loss, four linear measurements were taken following 3-D reconstruction of the µCT scans. Bone loss was evaluated on the distal side of the distobuccal root of the first molar (M1), the mesial side of the mesiobuccal root of the second molar (M2), the distal side of the distobuccal root of M2, and the distal side of the distobuccal root of the third molar (M3). Unless otherwise indicated, distances from the cement-enamel junction (CEJ) to the most apical site of bone destruction were measured. Four measurements were averaged to obtain the distance from the CEJ.

Dynamic PET measurements with different radiofluorinated 2-nitroimidazole derivatives on a patient scanner (Biograph™ mCT, 128 S, Siemens, Erlangen, Germany) were performed to characterize the hypoxic status of small (0.8 ± 0.5 cm³) and very large (4.4 ± 2.8 cm³) H-, HI- and AT1-tumors prior to irradiation. For this, 15-53 MBq of [¹⁸F]fluoromisonidazole ([¹⁸F]FMISO) were injected into the tail vein of the animals and PET images were recorded over a time period of 60 min using a 28-frame protocol (for details, see [16 (link)]). In total, this study included 30 tumors (10 AT1, 12 HI and 8 H).
Additional static measurements in 12 HI-tumors (diameter 16 mm) were performed on a PET/CT (Inveon Micro-PET/SPECT/CT, Siemens Medical Solutions, Knoxville, USA) before and 2, 9, and 21d after carbon ion or photon irradiation, respectively. In these measurements, 38-52 MBq [¹⁸F]fluoroazomycin arabinoside ([¹⁸F]FAZA) were administered into the tail vein and images were evaluated at 2 h post-injection.