In nowadays, digital X-ray imaging sensors with indirect detection type have been widely used in many medical imaging applications. These conventional indirect X-ray imaging detectors are based on the combination of a thin-film transistor (TFT) panel with different scintillating screens such as CsI, GOS materials. However, the digital radiography system using TFT-based X-ray imaging detectors are expensive and very limited to access in less developed countries.
In this work, we have designed and developed the inexpensive and compact X-ray imaging system with scintillating screens and a consumer-grade digital camera for medical X-ray imaging tasks. A latest digital single-lens reflex camera (DSLR) such as EOS 90D (Canon) consists of CMOS array with a 22.3mm x 14.8mm active area with 6960 x 4640 pixels and 14bit depth. Different high-resolution commercial scintillation materials such as columnar CsI:Tl and powder Gd2O2S:Tb(GOS) were used to evaluate the preliminary imaging quality. The various design parameters such as scintillator type, the f-number of lens and ISO setting number were optimized for excellent image quality at low X-ray exposure condition.
For preliminary evaluation and optimization of the X-ray image device characterization, different design parameters are selected and tested. The typical imaging performance such as the light response to X-ray dose (Sensitivity), signal-to-noise-ratio (SNR) and modulation transfer function (MTF), phantom imaging was measured and investigated under practical X-ray equipment with 60-90kVp tube voltage and various tube current. The experimental results with a commercial DSLR image camera using scintillating screens showed the potential possibilities to robust high-quality image at lower cost.