Iofetamine (123I)

A radiopharmaceutical used in brain imaging

Chemical structure of Iofetamine (123I)

Iofetamine (123I), also known as N-isopropyl-p-iodoamphetamine (IMP), is a radiopharmaceutical agent used primarily in nuclear medicine for brain imaging. It is a derivative of amphetamine and is labeled with the radioactive isotope iodine-123.

Chemical properties

Iofetamine is a lipophilic compound, which allows it to cross the blood-brain barrier efficiently. The presence of the iodine-123 isotope enables it to be detected using single-photon emission computed tomography (SPECT), a type of nuclear imaging technique.

Mechanism of action

Once administered, iofetamine (123I) is taken up by the brain tissue, where it is distributed in proportion to the regional cerebral blood flow. This property makes it useful for assessing cerebral perfusion and identifying areas of altered blood flow, which can be indicative of various neurological disorders.

Clinical applications

Iofetamine (123I) is used in the evaluation of several neurological conditions, including:

• Stroke: To assess the extent of brain tissue affected by ischemia.
• Epilepsy: To localize epileptogenic foci by identifying regions of altered perfusion.
• Dementia: To evaluate patterns of cerebral blood flow that may be characteristic of different types of dementia.

Administration and imaging

The compound is typically administered intravenously. After administration, imaging is performed using a SPECT camera, which detects the gamma rays emitted by the decay of iodine-123. The resulting images provide information about the distribution of blood flow in the brain.

Safety and side effects

Iofetamine (123I) is generally well-tolerated. However, as with any radiopharmaceutical, there is a small risk of radiation exposure. The use of iodine-123, which has a relatively short half-life, helps to minimize this risk. Common side effects are rare but may include mild allergic reactions.

Related pages

• Radiopharmaceuticals
• Single-photon emission computed tomography
• Cerebral blood flow
• Nuclear medicine