A Novel Stationary CT Scheme Based on High-Density X-Ray Sources Device

Abstract

With the introduction of cold electron sources such as nanotubes, X-ray sources became small in size so that many sources are installed in array to form stationary CT, which brings benefits of simplicity in mechanism and fast response. However, the nanotube-based X-ray source is still singly packaged and hence density of X-ray sources is limited, which introduces severe sparse-view artifacts and could not be used in practice. With the invention of X-ray sources device based on ZnO nanowires as cold electron emitters, a large amount of X-ray sources is first integrated in a flat panel device. In this study, we design a stationary CT architecture using high-density sources devices, called HD-SCT, and develop corresponding reconstruction algorithm. Specifically, several flat panel detectors and X-ray sources devices are spliced together to form a source-detector plate. Multiple source-detector plates are organized as a polygon that encloses object to complete CT scanning. In HD-SCT, X-ray sources are close to object which can significantly decrease CT device volume. The X-ray beam emitted by each source just cover part of object and the spot sources alternately light to completely scan object. Simultaneously, we propose a reconstruction method for the specific configuration which adopts an iterative algorithm to resolve the reconstruction based on alterative part projections, as well as a novel correction process of projection completion for the shadowed area of placing X-ray source devices. To validate the design of the proposed HD-SCT, we execute a series of simulation experiments, which show that the proposed HD-SCT and corresponding reconstruction method effectively remove the artifacts caused by the embed X-ray source device. The results also disclose that with the increase of density of X-ray sources, the resolution of reconstruction has been dramatically improved, which demonstrates the practical value of introducing high-density X-ray sources device into stationary CT design. INDEX TERMS Stationary CT scheme, high-density X-ray sources devices, source-detector plate, iterative reconstruction.

Generalized‐equiangular geometry CT: Concept and shift‐invariant FBP algorithms

“…23 Duan also designed a stationary CT system with high-density source devices, arranged in a polygonal shape. 24 In this work, we observe a new and interesting CT geometry with favorable potential in real applications, when exploring the ring-based stationary CT and comparing it with the existing fourth-generation CT and the newly proposed CO-planar Transmission and Emission Guidance for Radiotherapy, as shown in the Figure 1.…”

“…For instance, in previous studies, stationary CT systems usually have a dualring or polygonal-shaped source and detector. [21][22][23][24]26,27 Figure 3a illustrates a stationary CT system with polygonal source arrays and circular detector arrays, which could be useful for fast CT scan in security inspection. 37 Another possible application scenario could be GEGCT with a non-convex multi-segment source array (as shown in Figure 3b), which can accommodate more source points to improve the view sampling of stationary CT with distributed source or allow more flexible positions of the source when scanning irregular objects.…”

Optimization of a multi-source rectangular x-ray CT geometry for inline inspection

“…Field emission based vacuum X-ray tubes with carbon nanotubes (CNTs) or nanowires as the electron source have shown to be valuable multi-sources for use in rotation-free CT geometries. [11][12][13] Fixed-gantry configurations of triangular, rectangular (more specifically L-shaped) and hexagonal shape were studied using these linear X-ray source arrays for applications beyond safety inspection, e.g. health innovation.…”

“…health innovation. 9,11,12,[14][15][16][17] The X-ray foci were evenly distributed throughout the array to maximize the coverage area and were scanned sequentially to obtain multi-view projections. 9,16 Intuitively, this equidistant distribution is the natural choice (unless there is prior knowledge of the objects to be inspected).…”

Fully Vacuum-Sealed Diode-Structure Addressable ZnO Nanowire Cold Cathode Flat-Panel X-ray Source: Fabrication and Imaging Application

“…Each micro-Xray source can have a focus spot in micron meter, which is helpful for improving the imaging quality. The addressable flat-panel X-ray source is expected to further develop new imaging methods by controlling the localized emission of X-rays, thereby achieving low dose, fast, and conformal CT imaging [29,30]. Otto Zhou et al reported a small-size multiple-pixel X-ray source device using CNTs cold cathode, which is composed of a 5 × 10 pixel array [31].…”