Fundamental study for myocardial imaging using 201Tl, 123I and 99mTc nuclides

Fundamental study for myocardial imaging using 201Tl, 123I and 99mTc nuclides has been performed. (1) Changes of energy spectra were studied in each radial position on data acquisition of SPECT. The energy spectra in 123I with a LEHR collimator were greatly influenced by scatterer into the range of photopeak. (2) 99mTc with a LEHR collimator was found to be the best system in spatial resolution. The spatial resolution in 123I with a LEHR collimator was better than that in 201Tl with same collimator. Furthermore, with increasing scatterer, 123I with a MEHS collimator was shown superior resolution than that in 123I with a LEHR collimator. (3) The best detectability of cold region in septal area in planar image was recognized in 99mTc with a LEHR collimator, 123I with MEHS, 201Tl with LEHR, and 123I with LEHR, in turn. On the other hand, as to the detectability of cold region in septal area in SPECT image, 123I with a LEHR or MEHS collimator was shown better result than that in 201Tl with a LEHR collimator. (author)