Inveon micro pet ct animal scanner

The early effects of different treatments were evaluated using micro PET/CT scans and all images were analyzed by using an Inveon micro PET/CT animal scanner (Siemens, Germany). Mice were fasted for 12 h and then anesthetized by intraperitoneal injection with 1% pentobarbital (5 ml/kg). Mice were then placed in the center of the scanner, intravenously injected with 200–300 μCi FDG, and then scanned. PET/CT images were exported one h after injection of 18F-FDG trace. The parameters used for PET/CT scanning were as follows: 80 kV, 500 μA, slice thickness of 1.5 mm, and 10 min per bed position.
The image plane with the largest tumor appearance on the PET/CT fusion image was selected for analysis, and the irregular region of interest (ROI) covering the entire tumor was manually drawn. ROIs were also drawn on the paraspinal muscles. The tracer uptake value in both the tumor and muscle tissue was determined in the attenuation-corrected transaxial tomographic slices by calculating the standard uptake value (SUV), and was measured by means of ROI. The 18F-FDG maximum SUV of each lesion was obtained from the selected ROI and then compared to the SUVs of the contralateral paraspinal muscles to calculate the tumor/muscle (T/M) ratio.

Glucose uptake in overnight-fasted mice was determined at 10 weeks post-transplantation by micro [¹⁸ F]FDG PET/CT images obtained with an Inveon micro PET/CT animal scanner (Siemens, Germany). Mice were anaesthetized with 1% pentobarbital (5 mL/kg), administered an intravenous injection of 100–200 µCi [¹⁸ F]FDG and positioned in the centre PET field of the view ring. PET/CT images (80 kV; 500 µA; 1.5-mm slice thickness) were acquired 30 min post-[¹⁸ F]FDG administration. For quantitative analysis, volumes of interest (VOIs) were drawn on PET images for the liver, abdominal subcutaneous white adipose tissue, skeletal muscle (triceps brachii), and heart myocardium. All in vivo images were analysed using PMOD software (PMOD Technologies, Zurich, Switzerland) and Inveon Research Workplace (IRW) software (Siemens Medical Solutions, Knoxville, TN). Four to six mice were used from each group.

[¹⁸F]FEPPA radiosynthesis and control quality were performed as previously described [19 (link)]. [¹⁸F]FEPPA radiochemical purity was more than 99% and its molar activity at the end of synthesis was 183 ± 80 GBq/µmol. During radiotracer administration and image acquisition, mice were anesthetized with 2.5% and 1–1.5% isoflurane in oxygen at 0.8–1.5 L/min and 0.4–0.8 L/min respectively for induction and maintenance. PET/CT studies investigating brain inflammation were performed after the injection of [¹⁸F]FEPPA diluted in 150 µL saline (10 MBq) into the lateral tail vein of mice. The injection was made on an Inveon micro PET/CT animal scanner (Siemens Medical Solutions^®, Saint-Denis, France) with a spatial resolution of 1.4 mm full width at half-maximum at the center of the field of view. Dynamic mod-list PET acquisitions of the whole-body mice were performed from the time of the radiotracer injection until 60 min after the injection (n = 12 FL and 12 KO Cx43) and followed by a 3-min duration CT acquisition. PET data were reconstructed using 3-dimensional ordered-subset expectations maximization algorithm into a 128 × 128 image matrix (21 frames: 3 × 5, 3 × 15, 4 × 30, 3 × 60, 2 × 120, 4 × 300, 2 × 900 s and were corrected for random, scatter and decay events.