The x‐ray light valve: A low‐cost, digital radiographic imaging system—Spatial resolution

Abstract

An x-ray light valve ͑XLV͒ coupled with an optical scanner has the potential to meet the need for a low-cost, high quality digital imaging system for general radiography. The XLV/scanner concept combines three well-established, and hence, low-cost technologies: An amorphous selenium ͑a-Se͒ layer as an x-ray-to-charge transducer, a liquid crystal ͑LC͒ cell as an analog display, and an optical scanner for image digitization. The XLV consists of an a-Se layer and LC cell in a sandwich structure which produces an optical image in the LC layer upon x-ray exposure. The XLV/scanner system consists of an XLV in combination with an optical scanner for image readout. Here, the effect of each component on the spatial resolution of an XLV/scanner system is investigated. A theoretical model of spatial resolution of an XLV is presented based on calculations of the modulation transfer function ͑MTF͒ for a-Se and a LC cell. From these component MTFs, the theoretical MTF of the XLV is derived. The model was validated by experiments on a prototype XLV/scanner system. The MTF of the scanner alone was obtained by scanning an optical test target and the MTF of the XLV/scanner system was measured using x rays. From the measured MTF of the scanner, the theoretical MTF of the XLV/scanner system was established and compared with the experimental results. Good general agreement exists between experimental and theoretical results in the frequency range of interest for general radiography, although the theoretical curves slightly overstate the measured MTFs. The experimental MTF of the XLV was compared with the MTF of two clinical systems and was shown to have the capability to exceed the resolution of flat-panel detectors. From this, the authors can conclude that the XLV has an adequate resolution for general radiography. The XLV/scanner also has the potential to eliminate aliasing while maintaining a MTF that exceeds that of a flat-panel imager.

Characteristics of a robust and portable large area X-ray fluorescence imaging system

“…The spatial resolution of the presented system depends primarily on the pixel size of the system, which corresponds to the scan pitch, and on the spot size, that is, the effective size of the primary beam delivered to the sample surface in each step. The spot size can be controlled during the experiments by using different collimators.…”

Artificial intelligence and radiomics in the diagnosis of intraosseous lesions of the gnathic bones: A systematic review

“…This could potentially eliminate the necessity for a preliminary incisional biopsy before proceeding with the chosen treatment such. 3 Accurate diagnosis of different types of cysts and intraosseous tumors in the maxillofacial region is a challenging task, it is mainly due to their similar and common presentations in conventional panoramic dental x-rays. 4 Additionally, it is rare to find incidentally this type of lesions, they are almost always discovered when the patient consults for a feeling of dissatisfaction or increase in volume in the area.…”

“…The key consideration is whether these methods can reliably and accurately offer swift diagnoses based solely on the images. This could potentially eliminate the necessity for a preliminary incisional biopsy before proceeding with the chosen treatment such 3 …”