Abstract
Purpose: Our goal was to evaluate the influence of spatially heterogeneous background activity on 'hot object' quantitation in brain emission CT. Method: We studied the effects of spatially heterogeneous background activity on hot object quantitative recovery in simulations of both spheres and realistic brain distributions (utilizing human MRI data). Results: Significant underestimation of object activity concentration was seen for both cortical and subcortical hot objects, with increasing underestimation for increasing hot object/surrounding gray matter contrast. Significant 'spill-in' of counts from surrounding activity was present. Conclusion: Hot objects are significantly influenced by both 'spill-out' and 'spill-in.' Qualitative and quantitative analyses of such objects must explicitly consider both spill-out and spill-in; this implies a correction scheme that goes beyond simple division of the observed value by a conventional recovery coefficient.
Original language | English (US) |
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Pages (from-to) | 680-687 |
Number of pages | 8 |
Journal | Journal of computer assisted tomography |
Volume | 20 |
Issue number | 4 |
DOIs | |
State | Published - 1996 |
Keywords
- Magnetic resonance imaging, physics and instrumentation
- Quantitation
- Recovery coefficients
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging