This talk is on the fundamental principles of
positron emission tomography, or PET imaging.
My name is Osama Mawlawi, and I'm
an associate professor at the Department of Imaging Physics at the University of Texas
MD Anderson Cancer Center in Houston, Texas.
In this talk, we will cover PET signal detection,
processing, and image generation.
We will also cover factors affecting PET image resolution,
sensitivity and contrast, as well as quantification.
We will also discuss the data acquisition schemes such as static,
dynamic and gated, and cover scanner designs and their current status vis-a-vis
the dedicated scanners that are out there, as well as
the PET/CT scanners that are currently available from different manufacturers.
We will finish by giving a brief discussion
of radiation exposure using PET/CT imaging.
What is PET imaging?
PET is a functional imaging modality as compared to a structural modality.
By 'functional', we mean that the resulting images
show us biological processes such as blood-flow,
glucose metabolism, or receptor density.
Directly off the bat,
we can see that the PET image is not characterized by
high resolution as compared to their MR and CT counterparts seen on this slide.
However, what is unique about PET imaging is that it can give us
specific information about the underlying biological process.
For example, the image in the bottom left shows
the PET image of a patient undergoing visual stimulation.
The visual stimulation causes blood to rush to the occipital cortex,
which is involved in processing visual information.
The PET image captures this process, and also indicates the extent of blood flow
by also providing information about the intensity of the signal in the occipital region.
Similar information can be extracted from PET images on glucose metabolism,
receptor density, and other biological processes,
for example in the image in the middle of glucose metabolism,
we can assess whether there are any
laterality differences between the left and right hemisphere of this patient study.
Also in the image on the right,
we can see whether the patient is suffering from any neurological disorder,
by assessing the receptor densities in different parts of the brain.
This information is very helpful for physicians to
manage their patient in a superior manner.