Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body.
A bone scan or bone scintigraphy is a nuclear medicine imaging technique of the bone. It can help diagnose a number of bone conditions, including cancer of the bone or metastasis, location of bone inflammation and fractures, and bone infection (osteomyelitis).
[18F]Fluorodeoxyglucose (INN), or fluorodeoxyglucose F 18, also commonly called fluorodeoxyglucose and abbreviated [18F]FDG, 2-[18F]FDG or FDG, is a radiopharmaceutical, specifically a radiotracer, used in the medical imaging modality positron emission tomography (PET). Chemically, it is 2-deoxy-2-[18F]fluoro-D-glucose, a glucose analog, with the positron-emitting radionuclide fluorine-18 substituted for the normal hydroxyl group at the C-2 position in the glucose molecule.
Molecular imaging is a field of medical imaging that focuses on imaging molecules of medical interest within living patients. This is in contrast to conventional methods for obtaining molecular information from preserved tissue samples, such as histology. Molecules of interest may be either ones produced naturally by the body, or synthetic molecules produced in a laboratory and injected into a patient by a doctor. The most common example of molecular imaging used clinically today is to inject a contrast agent into a patient's bloodstream and to use an imaging modality to track its movement in the body. Molecular imaging originated from the field of radiology from a need to better understand fundamental molecular processes inside organisms in a noninvasive manner.
Oxygen-18 is a natural, stable isotope of oxygen and one of the environmental isotopes.
Glutamate carboxypeptidase II (GCPII), also known as N-acetyl-L-aspartyl-L-glutamate peptidase I, NAAG peptidase, or prostate-specific membrane antigen (PSMA) is an enzyme that in humans is encoded by the FOLH1 gene. Human GCPII contains 750 amino acids and weighs approximately 84 kDa.
Preclinical imaging is the visualization of living animals for research purposes, such as drug development. Imaging modalities have long been crucial to the researcher in observing changes, either at the organ, tissue, cell, or molecular level, in animals responding to physiological or environmental changes. Imaging modalities that are non-invasive and in vivo have become especially important to study animal models longitudinally. Broadly speaking, these imaging systems can be categorized into primarily morphological/anatomical and primarily molecular imaging techniques. Techniques such as high-frequency micro-ultrasound, magnetic resonance imaging (MRI) and computed tomography (CT) are usually used for anatomical imaging, while optical imaging, positron emission tomography (PET), and single photon emission computed tomography (SPECT) are usually used for molecular visualizations.
Emission computed tomography (ECT) is a type of tomography involving radioactive or emissions. Types include positron emission tomography (PET) and Single-photon emission computed tomography (SPECT).
Brain positron emission tomography is a form of positron emission tomography (PET) that is used to measure brain metabolism and the distribution of exogenous radiolabeled chemical agents throughout the brain. PET measures emissions from radioactively labeled metabolically active chemicals that have been injected into the bloodstream. The emission data from brain PET are computer-processed to produce multi-dimensional images of the distribution of the chemicals throughout the brain.
Radiofluorination is the process by which a radioactive isotope of fluorine is attached to a molecule and is preferably performed by nucleophilic substitution using nitro or halogens as leaving groups. Fluorine-18 is the most common isotope used for this procedure. This is due to its 97% positron emission and relatively long 109.8 min half-life. The half-life allows for a long enough time to be incorporated into the molecule and be used without causing exceedingly harmful effects. This process has many applications especially with the use of positron emission tomography (PET) as the aforementioned low positron energy is able to yield a high resolution in PET imaging.
Desmethoxyfallypride is a moderate affinity dopamine D2 receptor/D3 receptor antagonist used in medical research, usually in the form of the radiopharmaceutical [F-18]-desmethoxyfallypride (DMFP(18F)) which has been used in human studies as a positron emission tomography (PET) radiotracer.
Metabolic trapping refers to a localization mechanism of synthesized radiocompounds in the human body. It can be defined as the intracellular accumulation of a radioactive tracer based on the relative metabolic activity of the body's tissues. It is a basic principle of the design of radiopharmaceuticals as metabolic probes for functional studies or tumor location.
18F-FMISO or fluoromisonidazole is a radiopharmaceutical used for PET imaging of hypoxia. It consists of a 2-nitroimidazole molecule labelled with the positron-emitter fluorine-18.
Dihydrotetrabenazine or DTBZ is an organic compound with the chemical formula C19H29NO3. It is a close analog of tetrabenazine. DTBZ and its derivatives, when labeled with positron emitting isotopes such as carbon-11 and fluorine-18, are used as PET radioligands for examining VMAT2.
PET radiotracer is a type of radioligand that is used for the diagnostic purposes via positron emission tomography imaging technique.
A PSMA scan is a nuclear medicine imaging technique used in the diagnosis and staging of prostate cancer. It is carried out by injection of a radiopharmaceutical with a positron or gamma emitting radionuclide and a prostate-specific membrane antigen (PSMA) targeting ligand. After injection, imaging of positron emitters such as gallium-68 (68Ga), copper-64 (64Cu), and fluorine-18 (18F) is carried out with a positron emission tomography (PET) scanner. For gamma emitters such as technetium-99m (99mTc) and indium-111 (111In) single-photon emission computed tomography (SPECT) imaging is performed with a gamma camera.
Peter J. H. Scott FRSC CChem is a British and American chemist and radiochemist who is a professor of radiology, professor of pharmacology and professor of medicinal chemistry, as well as a core member of the Rogel Cancer Center at the University of Michigan in the United States. He is Chief of Nuclear Medicine and director of the University of Michigan Positron Emission Tomography (PET) Center, and runs a research group developing new radiochemistry methodology and novel PET radiotracers.
Arterial input function (AIF), also known as a plasma input function, refers to the concentration of tracer in blood-plasma in an artery measured over time. The oldest record on PubMed shows that AIF was used by Harvey et al. in 1962 to measure the exchange of materials between red blood cells and blood plasma, and by other researchers in 1983 for positron emission tomography (PET) studies. Nowadays, kinetic analysis is performed in various medical imaging techniques, which requires an AIF as one of the inputs to the mathematical model, for example, in dynamic PET imaging, or perfusion CT, or dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).
Gallium (68Ga) gozetotide or Gallium (68Ga) PSMA-11 sold under the brand name Illuccix among others, is a radiopharmaceutical made of 68Ga conjugated to prostate-specific membrane antigen (PSMA) targeting ligand, Glu-Urea-Lys(Ahx)-HBED-CC, used for imaging prostate cancer by positron emission tomography (PET). The PSMA targeting ligand specifically directs the radiolabeled imaging agent towards the prostate cancerous lesions in men.
