X-ray spectroscopy and dosimetry with a portable CdTe device

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2007-02, Vol.571 (1), p.373-377
• Main Authors: Abbene, Leonardo, La Manna, Angelo, Fauci, Francesco, Gerardi, Gaetano, Stumbo, Simone, Raso, Giuseppe
• Format: Article
• Language: English
• Subjects: CdTe detectors; Exposure; HVL; X-ray spectroscopy
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2006.10.112

X-ray spectra and dosimetry information are very important for quality assurance (QA) and quality control (QC) in medical diagnostic X-ray systems. An accurate knowledge of the diagnostic X-ray spectra would improve the patient dose optimization, without compromising image information. In this work, we performed direct diagnostic X-ray spectra measurements with a portable device, based on a CdTe solid-state detector. The portable device is able to directly measure X-ray spectra at high photon fluence rates, as typical of clinical radiography. We investigated on the spectral performances of the system in the mammographic energy range (up to ∼40 keV). Good system response to monoenergetic photons was measured (energy resolution of 5% FWHM at 22.1 keV). We measured the molybdenum X-ray spectra produced by a mammographic X-ray unit (GE Senographe DMR) at 28 kV and 30 kV under clinical conditions. The results showed the good reproducibility of the system and low pile-up distortions. Preliminary dosimetric measurements have been regarded as exposure and half value layer (HVL) values obtained from direct measurements and from measured X-ray spectral data, and a good agreement between exposure attenuation curves and the HVL values was obtained. The results indicated that the portable device is suitable for mammographic X-ray spectroscopy under clinical conditions.