Foundations of Medical Imaging and Signal Recording - Biomedical Signal Analysis: Contemporary Methods and Applications - page 15

Figure 1.8
SPECT brain study. (Image courtesy Dr. A. Wismuller, Dept. of Radiology,
University of Munich.)
localization in 3-D space and is used to provide functional images of
organs. Its main applications are in functional cardiac and brain imaging.
Figure 1.8 is an image of a SPECT brain study.
PET is a technique having no analogy to other imaging modalities.
The radionuclides employed for PET emit positrons instead of γ -rays.
These positrons, antiparticles of electrons, are measured and their posi-
tions are computed. The reconstruction is produced by using algorithms
of filtered backprojection. The imaging equation in PET is similar to
that in SPECT, with one difference: The limits of integration for the