X-ray Vision: Diagnostic X-rays and CT Scans
Suzanne Amador Kane, Boris A. Gelman in Introduction to Physics in Modern Medicine, 2020
Radiography that produces digital images that can be processed, stored and displayed on computers is called digital radiography. Several technologies are used in digital radiography. One is computed radiography (CR), not to be confused with computed tomography discussed in Section 5.11. In CR a latent image is created on plates coated with so-called storage phosphors, materials such as europium-doped barium fluoride, which exhibit photo-stimulated luminescence. Absorbed x-ray photons excite electrons that are trapped in impurities within the storage phosphor. The distribution of these trapped electrons represents the stored latent image. To convert the latent image into a digital image a scanning laser is used to illuminate the storage phosphor plate. The laser beam causes the trapped electron to escape and emit visible photons, which are guided into a photomultiplier tube.
Introduction to Three-Dimensional Biomedical Imaging
Richard A. Robb in Three-Dimensional Biomedical Imaging, 2017
Digital radiography is discussed in Chapter 2, and generally refers to the acquisition of conventional X-ray projection images in numerical form, readily permitting digital display, format manipulations, and mathematical analyses of the image data by computer. Although not strictly a three-dimensional imaging method, one relatively simple but very useful form of digital radiography is subtraction angiography, wherein selected pairs of angiographic images are subtracted to eliminate stationary overlying structures and thus enhance the differences between them, namely, the presence and distribution of X-ray contrast material in the circulation. Such techniques make possible the visualization of circulating volumes of blood in any organ of the body using relatively noninvasive (i.v.) injections of contrast material.
Introduction to medical imaging
David A Lisle in Imaging for Students, 2012
In the past, X-ray films were processed in a darkroom or in freestanding daylight processors. In modern practice, radiographic images are produced digitally using one of two processes, computed radiography (CR) and digital radiography (DR). CR employs cassettes that are inserted into a laser reader following X-ray exposure. An analogue-digital converter (ADC) produces a digital image. DR uses a detector screen containing silicon detectors that produce an electrical signal when exposed to X-rays. This signal is analysed to produce a digital image. Digital images obtained by CR and DR are sent to viewing workstations for interpretation. Images may also be recorded on X-ray film for portability and remote viewing. Digital radiography has many advantages over conventional radiography, including the ability to perform various manipulations on the images including: Magnification of areas of interest (Fig. 1.2)Alteration of densityMeasurements of distances and angles.
Approaching complexity: systems biology and ms-based techniques to address immune signaling
Published in Expert Review of Proteomics, 2020
Joseph Gillen, Caleb Bridgwater, Aleksandra Nita-Lazar
The intact, three-dimensional investigation of biologically relevant structures is a near ideal goal for many physiological questions. Throughout history the increasing power to visualize has crept from digital radiography, X-ray, computed tomography, nuclear imaging and so on. All these methods with their varying strengths and weaknesses. With increasing computational power, and mass spectrometry’s ability to record hundreds or thousands of proteomic, metabolomic, or lipidomic datum in every sample the multi-omic, three-dimensional composition and distribution from biological samples can be reconstructed with greater accuracy than ever before. The technique of mass spectrometry imaging (MSI) is dependent on selectively ionizing the surface of a biological surface that has had minimal sample prep and directly injecting ionized analytes into a mass spectrometer for analysis and replicating this process throughout a predetermined area on the surface of the biological sample. This method allows researchers to render an incredibly rich image of the analyte distribution across a surface. This rastering across sample surfaces, and repetition of this process through multiple slices of the same biological sample allow 3-D rendering of molecular distribution within tissues. MSI files from a singular plane of a biological sample can contain hundreds if not thousands of sample positions which form a rich map of the biochemical topography across the sample.
Can adaptive post-processing of storage phosphor plate panoramic radiographs provide better image quality? A comparison of anatomical image quality of panoramic radiographs before and after adaptive processing
Published in Acta Odontologica Scandinavica, 2019
Björn Svenson, Magnus Båth, Reet Karlsson
Panoramic radiography has long been a technique for imaging teeth and jaws [1]. Digital panorama techniques have been developed over the past 10 years, and images can be achieved with either an indirect digital technology such as storage phosphor plate (SPP) technology or direct digital technology such as charged coupled device (CCD) or complementary metal oxide semiconductor (CMOS). There are a number of advantages to digital radiography [2,3], one being that image processing makes it possible to improve image quality [4–7]. It is well known that for the detection of pathological changes diagnostically acceptable representation of normal anatomy is required. Optimal image quality is fundamental to clinical confidence in digital radiography. To achieve this, different techniques have been recommended, such as adjustment of contrast and density, change of kV, and use of filters for the processing of the digital images [8,9]. The effect of image filters for enhancement of the panoramic image quality has been investigated in some studies [7,10,11] and some have applied external image post-processing [4,7,12]. Digital post-processing with sharpening and median filters significantly improved diagnostic image quality [4,7,13] and can improve diagnostic quality significantly in terms of radiographic density and contrast [5].
Dentists’ use of digital radiographic techniques: Part I – intraoral X-ray: a questionnaire study of Swedish dentists
Published in Acta Odontologica Scandinavica, 2018
Björn Svenson, Katri Ståhlnacke, Reet Karlsson, Anna Fält
Basically, there are two types of digital imaging technologies available for intraoral digital radiography, the indirect technique comprising storage phosphor plate (SPP) and the direct technique. The direct technique comprises a charged coupled device (CCD) and complementary metal oxide semiconductor (CMOS), which in this paper will be referred to as solid-state detectors (SSDs). The SPP technology is in a number of countries the most common choice for intraoral digital techniques, and about two-thirds of dentists have chosen an SPP system [2,4,7–9] to replace analogue technology with digital. The quality of the digital images should be at least as good as with film, and in addition, there should be some advantages to using digital technology.
Related Knowledge Centers
- Contrast
- Dental Radiography
- Picture Archiving & Communication System
- Selenium
- Radiography
- Scintillator
- Photostimulated Luminescence
- Picture Archiving & Communication System
- CT Scan
- 3D Reconstruction
- Laser