Abstract
The method described appears to be a simple and useful application to existing nuclear medicine techniques using a widely available gamma camera. It permits comparison or simultaneous imaging with injected tracers in the same geological conditions. For example the 140 keV energy of 99Tcm can be easily discriminated from the 181 keV energy of the 90 degrees scattered radiation. Although the performance of the system in terms of spatial resolution and density gradient discrimination is limited, it could provide a medium-resolution method of detecting the overall distribution of the lung density and it could be suitable for monitoring changes of lung pathology. Computerisation of the gamma camera leads to the possibility of performing quantitative analysis of lung density and correcting for the attenuation of the primary and secondary beams, utilising the data from multiple parallel sections.