PT  - JOURNAL ARTICLE
AU  - Vines, Douglass C.
AU  - Ichise, Masanori
AU  - Liow, Jeih-San
AU  - Toyama, Hiroshi
AU  - Innis, Robert B.
TI  - Evaluation of 2 Scatter Correction Methods Using a Striatal Phantom for Quantitative Brain SPECT
DP  - 2003 Sep 01
TA  - Journal of Nuclear Medicine Technology
PG  - 157--160
VI  - 31
IP  - 3
4099  - http://tech.snmjournals.org/content/31/3/157.short
4100  - http://tech.snmjournals.org/content/31/3/157.full
SO  - J. Nucl. Med. Technol.2003 Sep 01; 31
AB  - Objective: Scatter correction is an important factor in quantitative SPECT. In this study, we evaluated 2 methods of scatter correction for brain SPECT. The first is based on thresholding the energy spectrum (ES), and the second is based on a modification of the transmission-dependent convolution subtraction (TDCS) method. Methods: SPECT imaging of a skull striatal phantom was performed using a triple-head camera with and without scatter correction. The striatal compartments were filled with 123I, and the brain shell cavity (background) was filled with varying concentrations of 123I to obtain striatal-to-background ratios of 2, 5, 10, 15, 20, and 25 to 1, respectively, which were considered to be the expected ratios. SPECT-measured ratios of striatal-to-background counts were determined with scatter correction (both ES and TDCS methods) and without scatter correction and were then compared with the expected ratios. Results: Without scatter correction, measured striatal-to-background ratios were underestimated by an average of 41.7%, compared with the expected ratios. The ES method of scatter correction underestimated the striatal-to-background ratios by an average of 27.4%, a significant improvement (P < 0.04) over those without scatter correction. With the TDCS method of scatter correction, the ratios were underestimated by only 3.3% (P < 0.03). TDCS ratios were significantly (P < 0.04) higher than ES ratios and were nearly identical to the expected ratios. Conclusion: These results suggest that scatter correction significantly improves the striatal-to-background ratios. The TDCS method appears to correct scatter more effectively than does the ES method for the striatal phantom, thus providing more accurate quantification.