Development of a hybrid portable medical gamma camera

A novel small field of view medical gamma camera - the Compact Gamma Camera (CGC) - has been developed at the University of Leicester to provide portable, high-resolution gamma imaging for applications in nuclear medical imaging. The suitability of this camera for medical imaging is investigated through Monte Carlo simulation, phantom studies and preliminary clinical testing. Quality assurance protocols are adapted for use with small field of view gamma cameras. These protocols are then used to provide a full characterisation of the CGC. The CGC is found to compare favourably to other small field of view systems in development. Phantom studies are described which show that the CGC is well suited to intraoperative imaging, particularly for use in sentinel lymph node biopsy. A Monte Carlo model is described that is designed to simulate the response of a pinholecollimated, scintillator-based gamma camera. The model is shown to accurately model sensitivity and spatial resolution. Previously derived analytical models are shown to be unsuitable for modelling finite source profiles and a new analytical model is described which addresses this shortcoming. This model is used to define appropriate test source sizes for the characterisation of small field of view systems. A modified version of the CGC - the Hybrid Compact Gamma Camera (HCGC) - is described which includes an optical imager in a coaligned configuration. The HCGC allows for functional and anatomical images to be obtained simultaneously. The use of hybrid optical-gamma imaging is novel in small field of view cameras and offers new possibilities for assisting surgeons in localising the site of uptake in procedures such as sentinel node detection.