Assessment of a novel small field of view medical hybrid gamma camera

Small field of view (SFOV) gamma detection and imaging technologies for monitoring in vivo tracer uptake are rapidly expanding and being introduced for bed-side imaging and image guided surgical procedures. The Hybrid Gamma Camera (HGC) has been developed, at the University of Leicester, to enhance the localisation of targeted radiopharmaceuticals during surgical procedures, for example in sentinel lymph node (SLN) biopsies, and for bed-side imaging in small organ gamma imaging procedures such as lacrimal scintigraphy and thyroid scintigraphy. In this thesis, prototype medical phantoms including anthropomorphic three-dimensional printed phantoms have been designed, constructed, and evaluated using representative modelled medical scenarios to study the capability of the HGC to detect SLNs and image small organs. Furthermore, the results of the first clinical feasibility study of the HGC has been discussed. The HGC was used to perform non-invasive hybrid gamma-optical imaging procedures on patients attending their routine scint32igraphic imaging appointments in a nuclear medicine clinic. Various quantitative and qualitative assessments have been conducted on different phantom configurations including simulating targeted tissues at several depths and using different radioactivity concentrations. Two generations of the HGC have been utilised, having two different thicknesses of columnar CsI(Tl) scintillator, and two pinhole collimator diameters (0.5 mm and 1.0 mm). Additionally, the behaviour of the HGC at a range of imaging distances and acquisition times has been examined. All of these factors were considered to judge the detection limitations of the HGC. The results demonstrate that the HGC was ideally suited for small organ imaging. The HGC capability to detect low activity uptake in small SLNs indicates its usefulness as an intraoperative imaging system during surgical SLN procedures. The ability of the HGC to utilise both pinhole collimators enhances its practicality and improves its ability to meet the needs of SFOV gamma imaging