Industrial X-Ray Computed Tomography

By Simone Carmignato, W. Dewulf, Richard Leach. 2018

239 citations recorded by the source corpus.

The concept of industrial computed tomography (CT) is introduced in this chapter. CT is defined, and the history of CT scanning is outlined. As part of the history, the conventional tomography technique is explained. The development of CT is documented, outlining the initial experiments that lead to the development of modern CT. An overview of the current state of CT scanning is then presented, outlining the five main generations of clinical CT scanner and the two main types of scanner used in industrial CT. The industrial requirements of CT are then discussed, and the content of the following chapters is briefly outlined. Computed tomography is defined as an imaging method in which the object is irradiated with X-rays or gamma rays and mathematical algorithms are used to create a cross-sectional image or a sequence of such images (VDI/VDE 2009). The word tomography itself comes from the Greek tomos, meaning a ‘slice’ or ‘section’, and graphien, meaning ‘to write’. In the process of tomography, X-ray radiography is used to take a large number of radiographic projections, which are then reconstructed using a mathematical algorithm to form a slice image of the object being scanned (Hsieh 2009). These reconstructed slices can then be stacked to form a three-dimensional (3D) representation of the object that can be used in a wide array of applications. The tomographic technique was originally developed as a novel method of clinical visualisation, due to the advantage presented by the technology when compared to traditional two-dimensional (2D) radiography, which compresses a 3D volume into a 2D projection. 2D radiography, therefore, carries the caveat that, due to overlapping structures, locating a feature within a wider object becomes difficult due to the ambiguity regarding the depth of the feature. It is also the case that more dense structures overlapping a feature of interest may obscure that feature entirely, for example in the case of patient jewellery (see Fig. 1.1), or when a bone lies along the same X-ray path as a cancerous tumor, the tumor can be completely obscured by the presence of the bone. A. Thompson (&) R. Leach Faculty of Engineering, University of Nottingham, NG7 2RD Nottingham, UK e-mail: Adam.Thompson@nottingham.ac.uk © Springer International Publishing AG 2018 S. Carmignato et al. (eds.), Industrial X-Ray Computed Tomography, https://doi.org/10.1007/978-3-319-59573-3_1 1 1.1 History of X-ray Computed Tomography Since the discovery of X-rays and the inception of X-ray imaging, there have been many developments in X-ray technologies that have eventually resulted in the industrial CT scanners available today. This section provides a concise history of conventional and computed tomography, and examines the progress of the technologies that have evolved into that which is seen in modern scanners. The initial experiments that defined modern CT are explored, and key developments over time are documented. 1.1.1 X-ray Tomography Prior to the invention of modern computing, there existed a version of tomographic technology that did not require the complex computation that allows today’s computed tomography (CT) scanners to function. Conventional tomography was conceived initially in 1921 by André Bocage (Bocage 1921; Hsieh 2009), in a patent describing a method of attaining slice images of an object by blurring structures above and below the plane of interest. Bocage used the simple setup of an X-ray source, an object and a detector, in this case a piece of X-ray film. For his experiment, Bocage synchronously translated the X-ray source and the detector linearly in opposite directions, in order to blur the structures that lay outside of the focal plane of the system. To understand how Bocage’s method works, two points Fig. 1.1 Left An example X-ray radiograph taken by William Röntgen of his wife’s hand, showing the finger bone concealed beneath the subject’s wedding ring (NASA 2007). Right The basic X-ray acquisition setup (Hsieh 2009) 2 A. Thompson and R. Leach

Subfields: Biomedical Engineering, Radiology, Nuclear Medicine and Imaging

View Paper: https://www.semanticscholar.org/paper/340b2e5da91690ca80d06bc812b77772dd5a1d4b

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Biomedical Engineering

  1. Richard Leach

In Radiology, Nuclear Medicine and Imaging

  1. Richard Leach

Citations in the corpus