Inveon acquisition workplace iaw

After harvesting, the femoral specimens were scanned using a special imaging system (XPERT; Kubtec Co., Stratford, CT) designed for small animals. To provide a preliminary assessment of scaffolds degradation and new bone formation, the lateral X-ray films of each group (n = 4) were recorded at 45 kV and 100 μA. All of the films were recorded using a high-resolution camera (DMLA; Leica, Wetzlar, Germany). Repair effect of femoral defect was evaluated by micro-computed tomography (micro-CT; Inveon™ CT scanner, Siemens, Berlin, Germany) and all specimens were scanned vertically along the long bone axis covering the entire distal femur with a current of 80 mA and a voltage of 80 kV. That’s how the region of interest (ROI; 6.5 × 5.0 × 5.0 mm) was traced manually and virtually 3D reconstructed. For quantitative analysis, the newly formed bone (NB) volume-to-total volume (BV/TV), material residual/total volume (RV/TV) and trabecular number (Tb.N) were calculated using Inveon Acquisition Workplace (IAW; Siemens, Berlin, Germany).

For small-animal PET imaging, the different ⁶⁸Ga-labeled PSMA ligands (0.5 nmol, 20 MBq in approximately 100 µL 0.9% saline) were injected into C4-2 tumor bearing mice. The dynamic PET was recorded in a small animal PET scanner (Siemens Inveon D-PET). The standardized uptake values (SUVs) were obtained from conventional (non-dynamic) PET images. The formula for the SUV was $\text{SUV}=\frac{\mathit{activity}\mathit{in}\mathit{ROI} \left(\frac{\mathit{Bq}}{\mathit{ml}}\right) \times \mathit{animal}\mathit{weight} \left(g\right)}{\mathit{injected}\mathit{dose}\left(\mathit{Bq}\right)}$
Manual delineation of the respective appropriate whole organ (heart, kidneys, bladder, tumor, with an approximate volume of 100–500 µL) yielded the volumes of interest (VOIs). For this purpose, whole organs or parts of the organ/tissue (liver and muscle) were used. The images were reconstructed based on the procedure: OSEM 3D/SP MAP with 16 subsets, two iterations, and an image x-y size: 256, image z size: 161. The data were not modified with a post-processing filter. Analysis of the images and time-activity curves (TACs) was conducted on the Inveon™ Acquisition Workplace (IAW) from Siemens IRW 4.1. Dynamic PET scans were performed 0–60 min p.i., and images were reconstructed in three time frames of 20 min (0–20 min, 20–40 min, and 40–60 min) for visual display. A static PET scan was generated at 1 h post injection. The mean SUVs were plotted over time in order to compare the different radiotracers.