High-rate x-ray spectroscopy in mammography with a CdTe detector: a digital pulse processing approach

Area of Science:

• Medical Physics
• Instrumentation
• Radiological Imaging

Background:

• Direct measurement of mammographic X-ray spectra is challenging due to high fluence rates and detector limitations.
• Accurate spectral information is crucial for optimizing mammography imaging and radiation dose.

Purpose of the Study:

• To develop and evaluate a novel detection system for high-rate X-ray spectroscopy in mammography.
• To overcome limitations of existing systems in measuring X-ray spectra under clinical conditions.

Main Methods:

• Utilized a Cadmium Telluride (CdTe) detector coupled with a digital pulse processing (DPP) system.
• Employed a 14-bit, 100 MHz digitizer for signal processing, including pile-up inspection and pulse height analysis.
• Tested the system's response using monoenergetic sources, a molybdenum anode X-ray tube, and clinical mammography setups.

Main Results:

• The detection system achieved excellent performance up to 512 kcps with an energy resolution of 4.08% FWHM at 22.1 keV.
• Mammographic X-ray spectra measured under clinical conditions showed a low number of pile-up events, even at high photon counting rates (up to 453 kcps).
• High accuracy was confirmed by the agreement of attenuation curves and half-value layer values with simulated and ionization chamber measurements.

Conclusions:

• The developed detection system is highly effective for high-rate X-ray spectroscopy in mammography.
• It offers a valuable tool for both laboratory research and advanced quality control applications in mammography.