Performance of low-cost X-ray area detectors with consumer digital cameras

Abstract

We constructed X-ray detectors using consumer-grade digital cameras coupled to commercial X-ray phosphors. Several detector configurations were tested against the Varian PaxScan 3024M (Varian 3024M) digital flat panel detector. These include consumer cameras (Nikon D800, Nikon D700, and Nikon D3X) coupled to a green emission phosphor in a back-lit, normal incidence geometry, and in a front-lit, oblique incidence geometry. We used the photon transfer method to evaluate detector sensitivity and dark noise, and the edge test method to evaluate their spatial resolution. The essential specifications provided by our evaluation include discrete charge events captured per mm 2 per unit exposure surface dose, dark noise in equivalents of charge events per pixel, and spatial resolution in terms of the full width at half maximum (FWHM) of the detector's line spread function (LSF). Measurements were performed using a tungsten anode X-ray tube at 50 kVp. The results show that the home-built detectors provide better sensitivity and lower noise than the commercial flat panel detector, and some have better spatial resolution. The trade-off is substantially smaller imaging areas. Given their much lower costs, these home-built detectors are attractive options for prototype development of low-dose imaging applications.

A universal moiré effect and application in X-ray phase-contrast imaging

“…Figure 5a shows a reference image without any sample. It appears stretched in the vertical direction due to an oblique incident angle of 4.5° of the beam on the detector screen for improved efficiency and vertical resolution 18 . The grating G 3 was slightly rotated around the beam axis to cause the inclination of the fringes from being horizontal.…”

Cost-effective micro-CT system for non-destructive testing of titanium 3D printed medical components

“…Fig 1 describes the schematics of the frame and the internal components of the low-cost, micro-CT system. The configuration of the x-ray source, phosphor screen, and the camera-lens assembly is similar to the tilted-screen front-lit configuration described by Panna et al [ 18 ] with the addition of a 2 mm thick lead plate placed in between the rotary stage and the camera to prevent direct interactions between the camera CMOS sensor and any primary or scattered x-rays. The camera-lens assembly was mounted to the frame with a sliding gantry plate that allowed camera-to-screen adjustments.…”

“…Recent advancements in full-frame CMOS imaging technology have shown promise in reaching the light sensitivity, field-of-view size, and spatial resolution required for computed tomography [ 17 ]. Panna et al [ 18 ] have demonstrated the use of consumer-grade, digital cameras that are lens-coupled to x-ray phosphor screens as a viable way of constructing high-definition medium-sized x-ray detectors. They also demonstrated that by placing the digital camera in front of the phosphor screen, in a front-lit tilted configuration, these lens-coupled detectors are less susceptible to diffusion and attenuation of light in the phosphor, and are able to perform as well as modern digital flat-panel detectors.…”

Enhancing Tabletop X-Ray Phase Contrast Imaging with Nano-Fabrication

“…The interferometer consisted of a tungsten-anode x-ray tube operating at 40 kVp/1.0 mA (Source-Ray Inc., NY, US), three phase-mask gratings of 1:1:1 or 2:1:2 pitch ratios with the central grating pitch of 200 nm, an x-ray detector consisting of a GdOS phosphor screen and a digital camera with a wide-aperture lens 32 (Nikon D800 SLR, Japan). The grating lines were oriented horizontally.…”