Medical Radioisotope Scanning

Abstract

5 1. IXTRODUCTIOS RADIOISOTOPE scanning is an exploratory technique performed in an attempt to determine and visualize the distribution of radioactivity in the body. It is becoming rapidly accepted throughout the world because it is sometimes the only method, and often a powerful additional method, of tackling many diagnostic problems in clinical practice.

The effect of energy and source location on gamma camera intrinsic and extrinsic spatial resolution: an experimental and Monte Carlo study

“…Accurate quantification of gamma camera images is a requirement for absorbed radiation dose calculations (Bardies et al 2006) and a prerequisite for quantitative evaluation of biodistribution studies of systemically administered diagnostic and therapeutic radiopharmaceuticals (Zanzonico et al 1989, Siegel et al 1999, Siantar et al 2002. The accuracy with which spatial heterogeneity of uptake can be determined is limited by gamma camera spatial resolution (Mallard 1965, Leichner and Kwok 1992, Rosenthal et al 1995, Bardies et al 2006. Monte Carlo modelling has been shown to be a useful tool for studying quantitative accuracy in nuclear medicine imaging (Ljungberg andStrand 1989, Zaidi 1999).…”

“…The two main factors that determine the spatial resolution of a system are (i) the collimator design and (ii) the accuracy with which scintillation events can be localized, which is limited by statistical variation in the number of scintillation photons produced. This gives rise to variations in the PM-tube positioning signals (Anger 1958, Mallard and Myers 1963, Mallard 1965, Svedberg 1972. The degree of impact that scattering of photons within the crystal have on R intrinsic is dependent on the energy of the photons being imaged (Anger 1964).…”