Affiliation:
1. CERMEP
2. Universite Claude Bernard Lyon 1
Abstract
Abstract
Background: The low throughout of small animal positron emission tomography (PET) images acquisitions represents a substantial limitation. The aims of this study were (i) to design an low-cost support for whole-body PET scanning of two lying rats, and (ii) to study its impact on brain image quantification.
Methods: A dual holder system compatible with the Siemens INVEON PET scanner was conceived and produced using a 3D printer. The developed system allows to overlap the two INVEON beds, 5 cm apart. Two cone masks can deliver gas anesthesia through the scanner’s head side, and the tail veins of both rats are freely accessible on the back side of the scanner, allowing the radiotracer injection before or during the scans. Ear and tooth bars immobilize the rats’ head on a stereotactic position. Six experiments of two cylindrical phantoms per session (50 ml tubes filled with different 18F activity) were scanned solo, on upper or lower bed and duo, on both beds. Four experiments were performed on 8 Sprague Dawley male rats (330 ± 66 g). For each experiment, two rats fasted for 4 hours, received a [18F]FDG dose (34.5 ± 5.5 kBq) and underwent 4 imaging conditions, starting 20 minutes after radiotracer injection: (1) One rat only for a solo test scan (2) repeated for a solo retest, (3) two rats simultaneously for a duo test, (4) repeated for a duo retest.
Results: Accuracy of concentration measurement was 5.09% for one phantom in the FOV, and 4.35% for two phantoms measured simultaneously. Ratio concentration between phantoms reached an accuracy of 6.59% for separated measures, and 5.77% for simultaneous measures.
In vivo distribution profiles showed no difference between solo and duo uptakes. ROI quantification in the whole brain showed same test-retest variability for solo and duo measurement (both at 3%). The quantified test-retest bias was 8% in solo and 4% in duo, and the ICC were comparable in solo and duo (0.984 versus 0.982).
Conclusions: Our results showed that simultaneous scans of two rats in INVEON does not affect quantification. The dual support system will allow us to reduce protocol costs and duration.
Publisher
Research Square Platform LLC
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