Imaging Ability of the Compton Imaging System (Gri+) for Thyroid Phantom Filled with 99mTc

Nuclear medicine imaging utilises the γ - ray emitted from radiotracers to investigate physiological bodily functions. The distribution of radiotracer material in the body is commonly imaged using a single-photon emission computed tomography (SPECT) system [1]. However, SPECT systems display inherent limitations with respect to spatial resolution and sensitivity because a SPECT system consists of a scintillation detection system equipped with a mechanical collimator. The University of Liverpool has developed an electronically collimated Compton camera imaging system with an angular resolution of 4.12°. The current study investigated the imaging ability of the Compton camera imaging system in medical applications by imaging a thyroid phantom, which was designed to mimic the real anatomical geometry of the human thyroid and which was filled with
^99m
Tc solution (10 MBq). The phantom was imaged from different angular projections, and Compton images were reconstructed using analytical image reconstruction and tomographic reconstruction codes. The system has successfully visualised and distinguished the two thyroid lobes. The 3D image produced from a multi-angular projection shows that the system can image the phantom with an accuracy of 5 mm, and the elongation artefact has been reduced. Further analyse is warranted to determine whether Compton imaging is a promising modality for future nuclear medicine applications and whether it will significantly reduce the radiation dose delivered to patients.