A Review of Activity Quantification by Planar Imaging Methods

Abstract

Objective: The purpose of this paper is to provide information on the nature and magnitude of the problems encountered in activity quantification by planar imaging in nuclear medicine and provide an understanding of several methods of activity quantification.

Methods: This paper presents a critical examination of several methods that have been applied or proposed for use in the quantification of radioactivity in the body using planar images in nuclear medicine. Outlined in this paper are the uses and limitations of each method in quantifying activity in the body, along with errors associated with each method, and suggestions for improving the accuracy of activity quantification.

Results: Absorption and scatter of gamma photons in the body have significant influence on the accuracy of activity quantification.

Conclusion: Accurate activity quantification will require the use of a method that can adequately correct for errors including those due to source inhomogeneity, the presence of nontarget organ activity, and for overlapping discrete regions of activity uptake.