Registration Of Beta-cit Dopamine Transporter Spect Images

Abstract

This work outlines a method for quantification of nigrostriatal dopaminergic neurons by means of SPECT using the cocaine derivative [123I] β-CIT (123I-labelled 2β-carbomethoxy-3β-(4-iodophenyl) tropane (β-CIT))as a radiotracer which binds with high affinity to the dopamine receptors. It has been validated (1) that the calculation of a simple ratio of specific/non-specific displaceable binding during a period of binding-equilibrium in the striatum about 20 hrs after the administration of a bolus injection of the tracer gives a strong and reliable index of the binding potential of dopamine uptake sites. Previous studies [2] have shown that the dopaminergic deficit in patients with Parkinson's disease (PD) can clearly be visualized and quantified by using the method for calculation of binding potential. In the current study, the data demonstrate that the dopaminergic nerve cell loss in PD (and in other disorders presenting with a dopaminergic lesion) can be quantified using [123I] beta-CIT and SPECT. Such quantification makes early diagnosis of PD possible. Also included is a description of the role of neurotransmitters, their effects on brain functions and neurotransmitter imaging techniques. This description is followed by more detailed explanation of various components of a typical functional human brain mapping analysis including image reconstruction, image registration, image standardization and statistical analysis. The advantages and limitations of each component of the analysis are also described in detail to provide the context in which this work was undertaken.