ABSTRACT
This chapter presents the physics and engineering of each technique and describes applications to anatomy, perfusion, metabolism, chemical content, and neuroreceptors in in vivo studies of the Alzheimer's disease (AD) brain. It explains the physical principles underlying six noninvasive imaging modalities and summarizes how these modalities are being used to study the AD patient’s brain. The intent is to give the readers an explanation of what the different methods can measure and how they have contributed to characterization of AD. Noninvasive studies of brain anatomy changes in AD started in the mid 1970s after the introduction of X-ray computed tomography. Emission computed tomography involves detection of photons from radionuclide distributions in the body after injection of a radionuclide. Single photon emission computed tomography dates from the early 1960s, when the idea of emission transverse section tomography was presented by K. Kuhl and D. Edwards.
