Isotopes Used in SPECT
Out of the isotopes used in SPECT and for taking planar images (scintigraphy) the Tc-99 isotope of technetium is the most widespread. Generally Tc is produced in so-called technetium generators.
The first 99Mo-99mTc generator was built in 1957. 99Mo can be produced in reactors through neutron activation. 99Mo decays to 99mTc with a half-life of 67 hours. 99mTc is especially suitable for isotope diagnostics as its half-life is 6 hours and its gamma energy is 140 keV. Furthermore, it can easily be bound to several molecules (e.g. phosphonate, tetrafosmin, etc.), thus there is no difficulty in producing a radiopharmaceutical. It is favourable that the activity of the generator can remain high for a relatively long time.
A technetium generator and the decay scheme of Mo-99
Other SPECT isotopes:
- Tl-201: myocardial perfusion studies
- In-111: prostate cancer
- Ga-67: infection or lymphoma
- I-123: thyroid
- Xe-133: lung
The last two isotopes mentioned are used for planar imaging only. The tendency is to perform as many examinations using technetium as possible.
Sidebar
Site Language: English
Theme: Tikinewt