Curved digital X-ray detectors
Albert J. J. M. van Breemen, M.E. Simon, O. Tousignant, Santhosh Shanmugam, Jan-Laurens van der Steen, Hylke B. Akkerman, Auke Jisk Kronemeijer, Walter Ruetten, Rob Raaijmakers, Lex Alving, Jan W. M. Jacobs, Paweł E. Malinowski, Florian De Roose, Gerwin H. Gelinck
Abstract
Abstract A curved image sensor on plastic foil has been developed for cone beam computed tomography (CBCT) X-ray imaging. The image sensor of about 6 × 8 cm 2 size has been built on a thin polyimide foil with an indium gallium zinc oxide (IGZO) backplane and an organic photodetectors (OPD) frontplane. A flexible cesium iodide (CsI) scintillator has been attached to the optical sensor with 480 × 640 pixels of 126 µm size. Dark current density of the OPD was low with less than 10 −7 mA/cm 2 at −2 V, while an external quantum efficiency (EQE) of about 50% was reached in the visible wavelength range matched to the scintillator output. The image quality of the digital X-ray detector allowed for 3D reconstruction images of a bone phantom on a rotating stage with a lab setup. The curved detector with 32 cm curvature radius opens up the path for very compact CBCT gantries with largely reduced footprint.