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.
Single-photon emission computed tomography is a nuclear medicine tomographic imaging technique using gamma rays. It is very similar to conventional nuclear medicine planar imaging using a gamma camera, but is able to provide true 3D information. This information is typically presented as cross-sectional slices through the patient, but can be freely reformatted or manipulated as required.
A radioactive tracer, radiotracer, or radioactive label is a synthetic derivative of a natural compound in which one or more atoms have been replaced by a radionuclide. By virtue of its radioactive decay, it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling or radiotracing is thus the radioactive form of isotopic labeling. In biological contexts, experiments that use radioisotope tracers are sometimes called radioisotope feeding experiments.
A radioligand is a radioactive biochemical substance, in particular, a ligand that is radiolabeled. Radioligands are used for diagnosis or for research-oriented study of the receptor systems of the body, and for anti-cancer radioligand therapy.
Ketanserin (INN, USAN, BAN) (brand name Sufrexal; former developmental code name R41468) is a drug used clinically as an antihypertensive agent and in scientific research to study the serotonergic system; specifically, the 5-HT2 receptor family. It was discovered at Janssen Pharmaceutica in 1980. It is not available in the United States.
Neuroimaging is the use of quantitative (computational) techniques to study the structure and function of the central nervous system, developed as an objective way of scientifically studying the healthy human brain in a non-invasive manner. Increasingly it is also being used for quantitative research studies of brain disease and psychiatric illness. Neuroimaging is highly multidisciplinary involving neuroscience, computer science, psychology and statistics, and is not a medical specialty. Neuroimaging is sometimes confused with neuroradiology.
The 5-HT2A receptor is a subtype of the 5-HT2 receptor that belongs to the serotonin receptor family and is a G protein-coupled receptor (GPCR). The 5-HT2A receptor is a cell surface receptor, but has several intracellular locations.
RTI(-4229)-55, also called RTI-55 or iometopane, is a phenyltropane-based psychostimulant used in scientific research and in some medical applications. This drug was first cited in 1991. RTI-55 is a non-selective dopamine reuptake inhibitor derived from methylecgonidine. However, more selective analogs are derived by conversion to "pyrrolidinoamido" RTI-229, for instance. Due to the large bulbous nature of the weakly electron withdrawing iodo halogen atom, RTI-55 is the most strongly serotonergic of the simple para-substituted troparil based analogs. In rodents RTI-55 actually caused death at a dosage of 100 mg/kg, whereas RTI-51 and RTI-31 did not. Another notable observation is the strong propensity of RTI-55 to cause locomotor activity enhancements, although in an earlier study, RTI-51 was actually even stronger than RTI-55 in shifting baseline LMA. This observation serves to highlight the disparities that can arise between studies.
(–)-2β-Carboisopropoxy-3β-(4-iodophenyl)tropane is a stimulant drug used in scientific research, which was developed in the early 1990s. RTI-121 is a phenyltropane based, highly selective dopamine reuptake inhibitor and is derived from methylecgonidine. RTI-121 is a potent and long-lasting stimulant, producing stimulant effects for more than 10 hours after a single dose in mice which would limit its potential uses in humans, as it might have significant abuse potential if used outside a medical setting. However RTI-121 occupies the dopamine transporter more slowly than cocaine, and so might have lower abuse potential than cocaine itself.
Ioflupane (123I) is the international nonproprietary name (INN) of a cocaine analogue which is a neuro-imaging radiopharmaceutical drug, used in nuclear medicine for the diagnosis of Parkinson's disease and the differential diagnosis of Parkinson's disease over other disorders presenting similar symptoms. During the DaT scan procedure it is injected into a patient and viewed with a gamma camera in order to acquire SPECT images of the brain with particular respect to the striatum, a subcortical region of the basal ganglia. The drug is sold under the brand name Datscan and is manufactured by GE Healthcare, formerly Amersham plc.
DaT Scan commonly refers to a diagnostic method, based on SPECT imaging, to investigate if there is a loss of dopaminergic neurons in striatum. The term may also refer to a brand name of Ioflupane (123I) tracer used for the study. The scan principle is based on use of the radiopharmaceutical Ioflupane (123I) which binds to dopamine transporters (DaT). The signal from them is then detected by the use of single-photon emission computed tomography (SPECT) which uses special gamma-cameras to create a pictographic representation of the distribution of dopamine transporters in the brain.
Altanserin is a compound that binds to the 5-HT2A receptor. Labeled with the isotope fluorine-18 it is used as a radioligand in positron emission tomography (PET) studies of the brain, i.e., studies of the 5-HT2A neuroreceptors. Besides human neuroimaging studies altanserin has also been used in the study of rats.
DASB, also known as 3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile, is a compound that binds to the serotonin transporter. Labeled with carbon-11 — a radioactive isotope — it has been used as a radioligand in neuroimaging with positron emission tomography (PET) since around year 2000. In this context it is regarded as one of the superior radioligands for PET study of the serotonin transporter in the brain, since it has high selectivity for the serotonin transporter.
Gated SPECT is a nuclear medicine imaging technique, typically for the heart in myocardial perfusion imagery. An electrocardiogram (ECG) guides the image acquisition, and the resulting set of single-photon emission computed tomography (SPECT) images shows the heart as it contracts over the interval from one R wave to the next. Gated myocardial perfusion imaging has been shown to have high prognostic value and sensitivity for critical stenosis.
Setoperone is a compound that is a ligand to the 5-HT2A receptor. It can be radiolabeled with the radioisotope fluorine-18 and used as a radioligand with positron emission tomography (PET). Several research studies have used the radiolabeled setoperone in neuroimaging for the studying neuropsychiatric disorders, such as depression or schizophrenia.
Iofetamine, brand names Perfusamine, SPECTamine), or N-isopropyl-(123I)-p-iodoamphetamine (IMP), is a lipid-soluble amine and radiopharmaceutical drug used in cerebral blood perfusion imaging with single-photon emission computed tomography (SPECT). Labeled with the radioactive isotope iodine-123, it is approved for use in the United States as a diagnostic aid in determining the localization of and in the evaluation of non-lacunar stroke and complex partial seizures, as well as in the early diagnosis of Alzheimer's disease.
Iomazenil is an antagonist and partial inverse agonist of benzodiazepine and a potential treatment for alcohol use disorder. The compound was introduced in 1989 by pharmaceutical company Hoffmann-La Roche as an Iodine-123-labelled SPECT tracer for imaging benzodiazepine receptors in the brain. Iomazenil is an analogue of flumazenil (Ro15-1788).
Nifene is a high affinity, selective nicotinic α4β2* receptor partial agonist used in medical research for nicotinic acetylcholine receptors, usually in the form of nifene (18F) as a positron emission tomography (PET) radiotracer.
Preclinical or small-animal Single Photon Emission Computed Tomography (SPECT) is a radionuclide based molecular imaging modality for small laboratory animals. Although SPECT is a well-established imaging technique that is already for decades in use for clinical application, the limited resolution of clinical SPECT (~10 mm) stimulated the development of dedicated small animal SPECT systems with sub-mm resolution. Unlike in clinics, preclinical SPECT outperforms preclinical coincidence PET in terms of resolution and, at the same time, allows to perform fast dynamic imaging of animals.
Theranostics, also known as theragnostics, is a technique in personalised medicine and nuclear medicine where a one radioactive drug is used to identify (diagnose) and a second radioactive drug is used to treat cancerous tumors.
(what is this?) (verify) 
