X-ray characterization of CMOS imaging detector with high resolution for fluoroscopic imaging application

Abstract

This paper introduces complementary metal-oxide semiconductor (CMOS) active pixel sensor (APS)-based X-ray imaging detectors with high spatial resolution for medical imaging application. In this study, our proposed X-ray CMOS imaging sensor has been fabricated by using a 0.35 pm 1 Poly 4 Metal CMOS process. The pixel size is 100 mu m x 100 mu m and the pixel array format is 24 x 96 pixels, which provide a field-of-view (FOV) of 9.6 mm x 24 mm. The 14.3-bit extend counting analog-to digital converter (ADC) with built-in binning mode was used to reduce the area and simultaneously improve the image resolution. Both thallium-doped Cs! (Cst:TI) and Gd2O2S:Tb scintillator screens were used as converters for incident X-rays to visible light photons. The optical property and X-ray imaging characterization such as X-ray to light response as a function of incident X-ray exposure dose, spatial resolution and X-ray images of objects were measured under different X-ray energy conditions. The measured results suggest that our developed CMOS-based X-ray imaging detector has the potential for fluoroscopic imaging and cone-beam computed tomography (CBCT) imaging applications. (C) 2013 Elsevier B.V. All rights rescrved.