By Dr Ananya Mandal, MD
The nuclear imaging process enables a dataset of one or more images to be obtained. In a multi-image data set, a time sequence often referred to as a dynamic data set is represented by an array of images that are generated as a radiopharmaceutical agent passes through targeted areas of the body and emits radiation.
The data set may also be called a cardiac gated time sequence or a spatial sequence, where the gamma-camera is moved relative to the patient.
The agent is administered to the patient orally or intravenously. The amount of radiopharmaceutical used is carefully selected to ensure the patient is exposed to the least amount of radiation needed to obtain accurate results. A process called single emission photon tomography (SPECT) is then used to generate the images.
The SPECT process involves the use of a rotating gamma-camera to generate images which are then reconstructed to show a “slice” of the patient in a given position. A group of parallel slices creates a slice-stack, which is a 3-D image of how the radionuclide is distributed in the patient.
To provide quantitative analysis for each specific imaging technique used in nuclear imaging, the computer used can require millions of lines of source code. Kinetic models can be used to provide further analysis of time sequences and one example is a Patlak plot.
Reviewed by Sally Robertson, BSc
Last Updated: Jan 11, 2015