An investigation of dual energy transmission measurements in simultaneous transmission emission imaging
- Univ. of Utah, Salt Lake City, UT (United States)
- Univ. of North Carolina, Chapel Hill, NC (United States)
In order to perform accurate attention correction of SPECT data in nonuniform media, some prior knowledge of the attenuation distribution within the object is required. Transmission computed tomography provides a way of estimating the attenuation distribution within the object of interest. In this study the authors investigate the feasibility of acquiring dual energy transmission projection data using a conventional gamma camera. Transmission projection data are acquired, simultaneously with {sup 99m}Tc emission data, using the two major photopeaks of {sup 153}Gd, at 44 keV and 99 keV. The degree of contamination of the data in the 44 keV window, by scattered 99 keV transmission photons, is investigated using Monte Carlo simulations. A modified scaling method is proposed to convert the two attenuation maps, obtained from transmission data acquired at 44 keV and 99 keV, to one appropriate for {sup 99m}Tc. This attenuation map is compared to one produced by scaling the 99 KeV attenuation map, for the attenuation correction of {sup 99m}Tc SPECT images. The use of dual energy transmission imaging is shown to improve the quantitative accuracy of the reconstructed SPECT images compared to a single scale factor method. However, for situations where a dual scaling factor method is possible, this is shown to perform as well as the dual energy method. Dual energy transmission imaging is shown to be more effective at visualizing areas of bone, particularly in regions near the edge of the untruncated field of view.
- OSTI ID:
- 194803
- Report Number(s):
- CONF-941061--
- Journal Information:
- IEEE Transactions on Nuclear Science, Journal Name: IEEE Transactions on Nuclear Science Journal Issue: 6Pt2 Vol. 42; ISSN 0018-9499; ISSN IETNAE
- Country of Publication:
- United States
- Language:
- English
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