The principle of the Compton camera allows the accurate localisation of a gamma-ray source through the reconstruction of interaction sequences in position and energy sensitive detectors. The Liverpool imaging group are investigating the feasibility of a Compton imaging system for applications in diagnostic nuclear medicine.

As the well defined kinematics of Compton scattering facilitates electronic collimation of gamma rays incident upon a detection system, the need for physical collimation in current Single Photon Emission Computed Tomography (SPECT) systems becomes redundant. This rise in imaging efficiency holds the potential to reduce scan time thus minimising patient dose and/or increasing patient throughput.

The Liverpool imaging group, in collaboration with the Nuclear Physics Group at the STFC Daresbury Laboratory, are developing a Compton camera utilising position sensitive semiconductor detectors and state of the art digital electronics. Pulse Shape Analysis (PSA) techniques will be used to improve the intrinsic spatial resolution of the detectors while the use of Cone-beam reconstruction techniques will allow accurate, quantitative reconstruction of source distributions.

Monte-Carlo simulations have been conducted in the GEANT4 environment in order to devise a detector configuration which maximises the number of easily reconstructable gamma-ray interactions. The established optimum geometry has been granted funding and is expected at the University of Liverpool within the calendar year.

Members of the group involved in the development of the Compton SPECT system are: Prof. Paul Nolan, Prof. John Simpson, Dr. Andy Boston, Dr. Helen Boston, Dr Laura Harkness, Dr Daniel Judson, Dr David Scraggs, Janet Sampson, Anthony Sweeney and Jamie Dormand.

Further details of the ProSPECTUs project can be found on the STFC Daresbury webpage.