Direct reconstruction of functional parameters for dynamic SPECT

Abstract

A bs tra c t We have developed a dynamic SPECT method which allows the prevalent rotating camera systems to be used. In this method, the parameters of the time-activity curve in each pixel are recovered directly from the projection data, without first reconstructing a series of static images. Preliminary test results show that we can accurately recover time-activity curves for a simple model based on activity values expected for myocardial viability studies with fatty acid tracers.

The stability analysis of dynamic SPECT systems

“…In many medical imaging studies, the distribution of some physical property of interest in the object (phantom, animal or patient) is time-dependent [1,7,10]. For example, the distribution function in fatty acid myocardial viability studies is assumed to be [5] g(x , y, t) ≡ A(x , y)e −λ(x ,y)t + B (x , y)e −η(x ,y)t + C (x , y) (1.1) in a two-dimensional image.…”

“…A simplified model was applied by [7] for the study of myocardial viability using labeled fatty acids where …”

Quantitative dynamic SPECT tomography

“…The reconstruction of dynamic parameters was discussed in [4][6]. There are two approaches to the reconstruction.…”

“…The reason is that the projection data is a Poisson process in time, which means that a relatively long time is needed in order to achieve a good signal-to-noise ratio. It was demonstrated in [4], that this technique could give distorted images. One way to overcome this difficulty [4], is by estimating the dynamic parameters directly from the projections.…”

“…It was demonstrated in [4], that this technique could give distorted images. One way to overcome this difficulty [4], is by estimating the dynamic parameters directly from the projections. The method in [4] is based on a priori information about the number of exponentials which are present in the dynamic model.…”