Phantom studies were employed to determine whether the enhanced energy resolution (9.7% FWHM) of a new high-resolution, three-headed single-photon emission computed tomograph might permit the simultaneous acquisition of 99mTc and 123I. Various window widths (15% and 10%) and positions (centered and asymmetric to the photopeak) were used to examine cross- contamination between these two isotopes. Brain phantom experiments using a 15% centered 99mTc window in conjunction with a 10% asymmetric 123I window (upper half of the 123I photopeak) demonstrated that approximately 95% of observed counts were derived from the isotope of interest. Shifting the 123I window from asymmetric to centered resulted in a significant increase in contamination of the 123I window. Shifting the 99mTc window from centered to asymmetric did not significantly alter image quality for 99mTc. Separate experiments employing vials with varying isotope concentrations demonstrated that quantitative recovery from mixed 99mTc and 123I sources was equivalent to that from matched single-isotope sources (r2 ≥ 0.90).
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Nuclear Medicine|
|State||Published - Jan 1 1992|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging