Speaker
Description
The MERMAID (Multi-Emission Radioisotopes – Marine Animal Imaging Device) project aims to develop a dedicated PET/CT scanner for functional imaging of adult zebrafish. The system consists of four rotating detector modules arranged in pairs and provides a field of view (FOV) of 2.5 cm (diameter) and 6 mm (axial length). To extend the axial FOV, a motorized stage is integrated for bed placement and automatic bed positioning during the scan. Radioactive decay is compensated for during the measurement, and randoms are estimated using the singles-rate method. A dedicated list-mode MLEM reconstruction algorithm was developed in-house, including random and parallax compensation. 3D printing of radioactive resin was used to construct a downscaled NEMA NU-4-like image quality (IQ) phantom, used for IQ evaluation. The percentage standard deviation (uniformity) reached a local minimum of 10.65% at iteration 7. At iteration 20, the spill-over ratio (SOR) was 0.19 (SOR) while the recovery coefficient varied from 0.21 (rod diameter=1.0 mm) to 1.19 (rod diameter=2.5 mm). Additionally, in vivo scans of adult zebrafish were carried out, after intraperitoneal injection of 18F-FDG and a 30-minute incubation time. The fish were immobilized within a dedicated fish chamber with continuous freshwater and anesthesia flow. In the reconstructed images, several organs could be visualized, including the brain and swim bladder. Future work includes the integration of a CT scanner for attenuation correction and anatomical guidance, as well as the addition of four further PET modules to improve sensitivity and extend the axial field of view.
| Track | PSMR |
|---|---|
| Presentation type | Oral |