Thallium-201 scintigraphy
Thallium-201 (Th-201) is a radiopharmaceutical used for scintigraphy, primarily of the myocardium. The element thallium is treated by the body as an analog of potassium; it is produced in a cyclotron by bombarding thallium-203 with protons.
Characteristics
- thallium is a monovalent cation
- usually employed in the form of a chloride salt
- photon energy: 68-80 keV (a smaller amount of γ-rays at 137 and 167 keV)
- physical half life: 73 hours
- biological half life
- rest: 3 minutes
- exercise: 30 seconds
- normal distribution: myocardium, skeletal muscle, GI tract, liver, kidneys
- excretion: renal
- target organ: kidneys
- pharmacokinetics:
- miscellaneous facts:
- more background noise than MUGA
- thallium-201 cerebral SPECT can be used to differentiate toxoplasmosis vs lymphoma (increased uptake in lymphoma, decreased in toxoplasmosis)
Uses, doses and timings
Cardiac scan
