Design and image-quality performance of high resolution CMOS-based X-ray imaging detectors for digital mammography

作者：Cha B K^*; Kim J Y; Kim Y J; Yun S; Cho G; Kim H K; Seo C W; Jeon S; Huh Y

来源：Journal of Instrumentation, 2012, 7: C04020.

DOI：10.1088/1748-0221/7/04/C04020

• X-ray detectors
• Scintillators, scintillation and light emission processes (solid, gas and liquid scintillators)
• Scintillators and scintillating fibres and light guides
• X-ray radiography and digital radiography (DR)

In digital X-ray imaging systems, X-ray imaging detectors based on scintillating screens with electronic devices such as charge-coupled devices (CCDs), thin-film transistors (TFT), complementary metal oxide semiconductor (CMOS) flat panel imagers have been introduced for general radiography, dental, mammography and non-destructive testing (NDT) applications. Recently, a large-area CMOS active-pixel sensor (APS) in combination with scintillation films has been widely used in a variety of digital X-ray imaging applications. We employed a scintillator-based CMOS APS image sensor for high-resolution mammography. In this work, both powder-type Gd2O2S:Tb and a columnar structured CsI:Tl scintillation screens with various thicknesses were fabricated and used as materials to convert X-ray into visible light. These scintillating screens were directly coupled to a CMOS flat panel imager with a 25 x 50 mm(2) active area and a 48 mu m pixel pitch for high spatial resolution acquisition. We used a W/Al mammographic X-ray source with a 30 kVp energy condition. The imaging characterization of the X-ray detector was measured and analyzed in terms of linearity in incident X-ray dose, modulation transfer MTF), noise-power spectrum (NPS) and detective quantum efficiency (DQE).

• 出版日期2012-4