Mammographic x-ray spectra measured by Compton spectroscopy using a high resolution Schottky CdTe detector

Area of Science:

• Medical Physics
• Radiological Imaging
• Spectroscopy

Background:

• Accurate x-ray spectra analysis is crucial for quality assurance (QA) and quality control (QC) in mammography.
• Clinical measurement of diagnostic x-ray spectra is challenging due to high photon fluence rates causing pulse pile-up.
• Compton spectroscopy is explored as a solution for spectral analysis under these conditions.

Purpose of the Study:

• To evaluate the suitability of Compton spectroscopy for mammographic x-ray spectra analysis.
• To compare spectra obtained via Compton spectroscopy with those measured directly.
• To assess if spectral broadening from Compton spectroscopy impacts QA/QC evaluations.

Main Methods:

• Utilized Compton spectroscopy with a Schottky CdTe detector to measure x-ray spectra.
• Employed Klein-Nishina formula for energy correction and reconstruction of scattered photons.
• Compared attenuation curves derived from Compton spectroscopy data with those from direct measurements using Hubbell's coefficients and aluminum attenuators.

Main Results:

• Attenuation curves from Compton spectroscopy spectra closely matched those from corrected, directly measured spectra.
• Spectral broadening from Compton spectroscopy did not hinder accurate spectral shape estimation for QA/QC.
• Measured attenuation curves with aluminum attenuators aligned with theoretical calculations.

Conclusions:

• Compton spectroscopy provides a practical approach for diagnostic x-ray spectra analysis in mammography.
• The method's spectral broadening is tolerable for QA/QC purposes, allowing reliable spectral shape evaluation.
• The study validates Compton spectroscopy as a useful tool for radiographic system quality control.