Positron emission tomography

Abstract

The developments in positron emission tomography (PET) are reviewed with an emphasis on instrumentation for clinical PET imaging. After a brief summary of positron imaging before the advent of computed tomography, various improvements are highlighted including the move from PET scanners with septa to fully 3D scanners, changes in the preferred scintillators, efforts to improve the energy discrimination, and improvements in attenuation correction. Time-of-flight PET imaging is given special attention due to the recent revival of this technique, which promises significant improvement. Besides technical instrumentation efforts, other factors which influenced the acceptance of clinical PET are also discussed.

Instrumentation for Time-of-Flight Positron Emission Tomography

“…During a PET scan, a short-life radioactive tracer isotope of known quantity incorporated into a biomolecule with an affinity to the area of interest is administrated into the living subject [4]. The most widely used radiopharmaceutical is the fluoro-deoxyglucose (FDG) as it gives information regarding glucose consumption at the cellular level [5].…”

De l’imagerie médicale à la thérapie guidée par l’image

“…Les principes mis en jeu en imagerie nucléaire (tomographie d'émis-sion monophotonique, TEMP, ou à positons, TEP) sont radicalement différents de ceux de l'IRM [9]. Ils sont fondés sur l'utilisation d'un traceur composé d'un vecteur moléculaire comportant un isotope radioactif qui permet de localiser la distribution de la molécule au sein de l'organisme (une imagerie 3D du corps entier est aujourd'hui disponible) sans modifier ses propriétés biologiques.…”

Machine Learning for Functional Brain Mapping

“…During the scanning session, the conditions are presented in a predetermined fashion in one of a number of ways. Influenced by positron emission tomography (PET) imaging where extended stimulation periods are required in order to produce stable activations Muehllehner & Karp (2006), fMRI studies often utilize experimental paradigms which alternate extended periods of stimuli being 'on' or 'off' (see figure 1D; Turner et al (1998)). This so called block design is appealing due to ease of presentation and analysis, as well as to the relatively high signal-to-noise ratios achieved.…”