Local threshold segmented attenuation correction with emission data subtraction for PET thorax imaging
- Mallinckrodt Inst. of Radiology, St. Louis, MO (United States); and others
This work was undertaken to provide fast, accurate attenuation correction for PET thorax imaging by combining the techniques of localized threshold segmented attenuation correction (LTS) and emission subtraction (EMS). Emission subtraction consists of subtracting a fraction (5-8%) of the emission scans from the transmission scans. Segmentation of the resulting transmission images was then performed. The LTS technique implements an optimal threshold method on localized histograms from low-count, (200K/slice, 2-3 min) post-injection, transmission images. Theoretical values of attenuation coefficient are assigned to corresponding regions. Emission images are then reconstructed using attenuation correction factors computed by forward-projecting segmented transmission images. Chest phantom studies showed that for emission activity at or below 0.3 {mu}Ci/ml, using LTS technique alone provides results equivalent to standard, pre-injection, (1.5-2M/slice, 10-15 min) measured method. By applying emission subtraction, the limitation (0.3 {mu}Ci/ml) is virtually removed. The LTS technique in conjunction with emission subtraction gives the best results of both techniques. Noise difficulties normally seen with short transmission scans and with emission subtraction are avoided with LTS. Use of short transmission scans easily offsets additional processing time, thus increases scanner throughput. The technique has been applied on both chest phantom and cardiac FDG studies. The results were found linearly correlated to those using standard, pre-injection, measured attenuation correction method.
- OSTI ID:
- 197924
- Report Number(s):
- CONF-940605--
- Journal Information:
- Journal of Nuclear Medicine, Journal Name: Journal of Nuclear Medicine Journal Issue: Suppl.5 Vol. 35; ISSN JNMEAQ; ISSN 0161-5505
- Country of Publication:
- United States
- Language:
- English
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