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Updated: Aug 5, 2026
14:58
Quantifying X-Ray Fluorescence Data Using MAPS
Published on: February 17, 2018
Effects of the attenuation map used in the Chang algorithm on quantitative SPECT results
1Department of Diagnostic Radiology, University of Maryland Medical Center, Baltimore 21201-1595, USA.
Journal of Nuclear Medicine Technology
|October 2, 1998
Summary
Accurate attenuation maps are crucial for quantitative SPECT imaging using the Chang algorithm. Errors in map size or position significantly impact image accuracy, especially for symmetric structures like the brain.
Area of Science:
- Nuclear Medicine
- Medical Imaging Physics
Background:
- Quantitative SPECT imaging relies on accurate attenuation correction.
- The Chang algorithm is a widely used method for attenuation compensation.
Purpose of the Study:
- To evaluate the impact of attenuation map errors on SPECT quantitation using the Chang algorithm.
- To assess the sensitivity of the Chang algorithm to inaccuracies in attenuation map size, position, and pixel size.
Main Methods:
- Simulated 3D head phantom projection data with uniform attenuation.
- Image reconstruction using filtered backprojection and the Chang algorithm with varied attenuation maps.
- Quantitative comparison of reconstructed images against phantom data.
Main Results:
- Accurate Chang algorithm application yielded <10% deviation and <5% asymmetry.
- Small errors (0.64 cm) in attenuation map size or position caused significant quantitative inaccuracy (>10% deviation/asymmetry).
Conclusions:
- The Chang algorithm's accuracy is highly dependent on precise geometric parameters of the attenuation map.
- Even minor errors in attenuation map geometry can severely distort quantitative SPECT results for symmetric organs like the brain.
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