Energy-weighted acquisition of scintigraphic images using finite spatial filters

Energy weighted acquisition (EWA) is a technique for improving image contrast by correcting for some of the blurring effects of Compton scattering within the patient. We outline image formation theory as it applies to energy weighting and present a pre-processing implementation that acquires images with real-number energy-dependent weighting functions of finite spatial extent. The effect of scattered radiation on quantitative accuracy, with and without EWA, is demonstrated with sheet and point sources at various depths. A planar phantom and a clinical 201TI study demonstrate enhanced contrast and edge definition. The performance of EWA in SPECT is shown by 99mTc and 123I phantom studies and a clinical 125I study.