Program Information
Quantitative Evaluation of Transmission Properties of Breast Tissue Equivalent Materials Under Compton Scatter Imaging Setup
K Yang*, C Geng , X Li , B Liu , Massachusetts General Hospital, Boston, MA
Presentations
TU-C1-GePD-I-6 (Tuesday, August 1, 2017) 9:30 AM - 10:00 AM Room: Imaging ePoster Lounge
Purpose: To accurately evaluate x-ray transmission properties of breast tissue equivalent materials for the potential implementation of Compton scatter imaging.
Methods: X-ray transmission properties of breast tissue equivalent materials (CIRS, 012A) were evaluated for three different breast compositions based on glandular/adipose percentage (3070, 5050, and 7030). Two initial validations were carried out using primary x-ray beam at 80 kVp with both experimental measurement (ion chamber with narrow beam setup) and analytical calculation (Spektr toolkit). The tungsten-anode x-ray spectrum was first validated by measuring and calculating the transmission through increasing thickness of 1100 Aluminum filters. Then the elemental compositions of breast tissue equivalent phantoms were validated by comparing the calculated and measured x-ray transmission. The above validated information was therefore used for the evaluation of the transmission properties of breast tissue equivalent phantoms under Compton scatter imaging setup, in which Compton scattered photons from a 5050 phantom was used as the imaging source and a GOS based linear detector array (DT) as the detector. The same study was performed through three independent approaches: analytical calculation, experimental measurement, and Monte Carlo simulation (GEANT4). For all three methods, the scattered x-ray photon transmission as a function of tissue thickness were determined and fit into 1st order exponential functions. Effective attenuation coefficients were then determined and compared.
Results: With the incident primary x-ray spectrum and phantom materials accurately validated, the transmission curves determined from all three methods for Compton scatter imaging matched reasonably well, with a maximum difference
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