WordNet

the process of making a radiograph; producing an image on a radiosensitive surface by radiation other than visible light (同)skiagraphy
photography that uses other kinds of radiation than visible light
relating to or performed with the fingers; "digital examination"
displaying numbers rather than scale positions; "digital clock"; "digital readout"
of a circuit or device that represents magnitudes in digits; "digital computer"
one of the elements that collectively form a system of numeration; "0 and 1 are digits" (同)figure
a finger or toe in human beings or corresponding body part in other vertebrates (同)dactyl

PrepTutorEJDIC

放射線写真法・X線写真術
指の / 数字の;計数型の / (タイプライターなどの)鍵(けん),キー
(手足の)指 / アラビア数字(0から9までの一つ;0を除くこともある)
レントゲン写真 / 〈人体など〉‘を'レントゲン写真にとる

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/01/04 13:59:49」(JST)

wiki en

Digital radiography is a form of X-ray imaging, where digital X-ray sensors are used instead of traditional photographic film. Advantages include time efficiency through bypassing chemical processing and the ability to digitally transfer and enhance images. Also less radiation can be used to produce an image of similar contrast to conventional radiography.

Instead of X-ray film, digital radiography uses a digital image capture device. This gives advantages of immediate image preview and availability; elimination of costly film processing steps; a wider dynamic range, which makes it more forgiving for over- and under-exposure; as well as the ability to apply special image processing techniques that enhance overall display of the image.

1 Detectors
- 1.1 Flat Panel Detectors
- 1.2 High-density Line-scan Detectors
2 Radiological examinations
- 2.1 Medical
  - 2.1.1 Dental
  - 2.1.2 Rest of the Body Digital Radiography
- 2.2 Industrial Usage of X-Rays
  - 2.2.1 Aerospace
  - 2.2.2 Security
3 Digital radiographic systems
4 Invention
5 Historical milestones for digital intraoral sensors
6 Historical milestones for digital panoramic systems
7 See also
8 External links

Detectors[edit]

There are two major variants of digital image capture devices: flat panel detectors (FPDs) and high-density line-scan solid state detectors.

Flat Panel Detectors[edit]

FPDs are further classified in two main categories:

1. Indirect FPDs. Amorphous silicon (a-Si) is the most common material of commercial FPDs. Combining a-Si detectors with a scintillator in the detector’s outer layer, which is made from caesium iodide (CsI) or gadolinium oxysulfide (Gd₂O₂S), converts X-rays to light. Because of this conversion the a-Si detector is considered an indirect imaging device. The light is channeled through the a-Si photodiode layer where it is converted to a digital output signal. The digital signal is then read out by thin film transistors (TFTs) or fiber-coupled CCDs. The image data file is sent to a computer for display.

2. Direct FPDs. Amorphous selenium (a-Se) FPDs are known as “direct” detectors because X-ray photons are converted directly into charge. The outer layer of the flat panel in this design is typically a high-voltage bias electrode. X-ray photons create electron-hole pairs in a-Se, and the transit of these electrons and holes depends on the potential of the bias voltage charge. As the holes are replaced with electrons, the resultant charge pattern in the selenium layer is read out by a TFT array, active matrix array, electrometer probes or microplasma line addressing.

High-density Line-scan Detectors[edit]

A high-density line-scan solid state detector is composed of a photostimulable barium fluorobromide doped with europium (BaFBr:Eu) or caesium bromide (CsBr) phosphor. The phosphor detector records the X-ray energy during exposure and is scanned by a laser diode to excite the stored energy which is released and read out by a digital image capture array of a CCD.

Radiological examinations[edit]

Medical[edit]

Medical Uses for Digital Radiography (DR) can be broken into two subcategories, Dental, and the rest of the body.

Dental[edit]

Main article: Dental radiography

The radiological examinations in dentistry may be classified into intraoral – where the film or sensor is placed in the mouth, the purpose being to focus on a small region of the oral-maxillofacial region and extraoral where the film or sensor is placed outside the mouth aiming to visualize the entire oral maxillofacial region. Extraoral imaging is further divided into orthopantomogram, showing a section, curved following more or less mandible shape, of the whole maxillofacial block and cephalometric analysis showing a projection, as parallel as possible, of the whole skull.

Digital radiography in dentistry provides the clinician with the ability to store their images on a computer. This provides two key advantages over film in the form of full screen images that can be enhanced and zoomed in on, aiding diagnostics and providing easier patient communication, as well as allowing dental offices to communicate images electronically, allowing for simpler referrals and, where applicable, easier insurance claim submission.

Rest of the Body Digital Radiography[edit]

(This is an expanding and changing field of science, and subject to revision)

Digital Radiography is replacement of the former Analog methods of detection, with the almost instantaneous development of images on a digital display, instead of the former methods of film and the associated delay in time and chemistry consumption.

Industrial Usage of X-Rays[edit]

Aerospace[edit]

Aerospace is an industry that has experienced great growth in recent decades. Non Destructive Testing (NDT) in aerospace has a special driver of its own due to the high levels of human traffic involved; the crash of a civil or military airliner has the ability to cause loss of life reaching catastrophic proportions. Therefore, strict NDT specifications have been set to detect very small cracks and defects in engine turbo discs, blades and airframe structures, in both production and ongoing maintenance.

Security[edit]

Digital Radiography (DR) has existed in various forms (for example, CCD and amorphous Silicon imagers) in the security X-ray inspection field for over 20 years and is rapidly replacing the use of film for inspection X-rays in the Security and NDT fields. DR has opened a window of opportunity for the aerospace NDT industry due to several key advantages including excellent image quality, high POD, portability, environmental friendliness and immediate imaging.^[1]

Digital radiographic systems[edit]

Digital dental radiography comes in two forms: direct, that connect directly to the computer via USB and provides immediate images, and indirect (photostimulable phosphor plates, or PSP) which uses plates that are radiated and then digitally scanned.

Direct digital sensors represent a significant initial investment, but in addition to the convenience of digital images, provide instant images that can reduce the time the patient spends in the dental chair. They also reduce the need for the constant purchase of film and the necessary development chemicals. Early systems used CCD sensor technology, but changed to Amorphous Silicon (aSi:H) sensors following their introduction in early 1998-9.

Indirect digital imaging (also termed Computed Radiography) utilizes a reusable plate in place of the film. After X-ray exposure the plate (sheet) is placed in a special scanner where the latent formed image is retrieved point by point and digitized, using laser light scanning. The digitized images are stored and displayed on the computer screen. This method is halfway between old film-based technology and current direct digital imaging technology. It is similar to the film process because it involves the same image support handling but differs in that the chemical development process is replaced by scanning. This is not much faster than film processing and the resolution and sensitivity performances are contested. PSP has been described as having an advantage of fitting within any pre-existing equipment without modification because it replaces the existing film; however, it includes extra costs for the scanner and replacement of scratched plates.

Invention[edit]

In the early 1960s, while developing compact, lightweight, portable equipment for the onboard nondestructive testing (NDT) of naval aircraft, Frederick G. Weighart^[2] and James F. McNulty^[3] at Automation Industries, Inc., then, in El Segundo, California co-invented the apparatus, which produced the world’s first digital radiograph, a fluoroscope image. Square wave signals were detected by the pixels of a cathode ray tube to create the image.

Historical milestones for digital intraoral sensors[edit]

1987 – RVG (radiovisiography), Trophy Radiology (France) introduced the world's first intraoral X-rays imaging sensor. Trophy Radiology patented it under the restricted name radiovisiography (other companies use the phrase digital radiography) and continues to produce intraoral sensors today under the Carestream Dental name, which is used under license by Carestream Health. Carestream Dental has released a wireless version of their RVG intraoral sensor named the RVG 6500.
1992 – Sens-a-Ray of Regam Medical System AB (Sundsvall, Sweden) is introduced. The company went out of business and their technology was purchased by Dent-X, recently renamed to ImageWorks (USA).
1993 – VisualX of Gendex-Italy (subsidiary of USA company).
1994 – CDR of Schick Technologies, USA. Schick were the first company to offer three film-like sizes of sensor, as well providing the significant breakthroughs of CMOS-APS technology (1998), USB connectivity (1999), the first sensors without cables (2003) and the first sensors with replaceable cables (2008). They launched their second generation of CMOS-APS chips in 2009. Schick merged with Sirona (Germany) in 2006 and is now part of Sirona Dental Systems, LLC.
1995 – SIDEXIS of Sirona, DEXIS of ProVison Dental Systems, Inc. (renamed DEXIS, LLC following its acquisition by Danaher Corp.), DIGORA (PSP solution) of Soredex (Finland)

Today there are many other products available under a lot of different names (rebranding is quite usual for this type of product).

Historical milestones for digital panoramic systems[edit]

1995 – DXIS, the first dental digital panoramic X-rays system was introduced by Signet (France). DXIS targets to retrofit all the panoramic models.
1997 – SIDEXIS, of Siemens (currently Sirona, Germany) offered for Ortophos Plus panoramic unit, DigiPan of Trophy Radiology (France) offered for the OP100 panoramic made by Instrumentarium (Finland).
1998–2004 – many panoramic manufacturers offered their own digital system.
2005 – SCAN300FP, of 'Ajat' (Finland) is the latest innovation offered. It shows the feature to acquire many hundreds of mega bytes of image information at high frame rate and to reconstruct the panoramic layer by intensive post acquisition computing like a computed tomography. The main advantage is the ability to reconstruct focused differently. The drawback is the low signal/noise ratio of primary information which involves much software work for correction. Also the ability to reconstruct various layers raises the importance of the geometrical distortions already high in dental panoramic radiography. Since 2008 the SCAN300FP system is available in Ajat ART PLUS and ART PLUS C system.

External links[edit]

Applications in the field of Digital radiography

^ "http://www.vidisco.com/node/273". Digigital Radiography. Vidisco. Retrieved 2012-09-27.
^ U.S. Patent 3,277,302, titled “X-Ray Apparatus Having Means for Supplying An Alternating Square Wave Voltage to the X-Ray Tube”, granted to Weighart on October 4, 1964, showing its patent application date as May 10, 1963 and at lines 1-6 of its column 4, also, noting James F. McNulty’s earlier filed co-pending application for an essential component of invention
^ U.S. Patent 3,289,000, titled “Means for Separately Controlling the Filament Current and Voltage on a X-Ray Tube”, granted to McNulty on November 29, 1966 and showing its patent application date as March 5, 1963

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 関節痛の画像診断技術による評価 imaging techniques for evaluation of the painful joint
2. 消化性潰瘍の診断 diagnosis of peptic ulcer disease
3. 非小細胞肺癌のイメージング imaging of non small cell lung cancer
4. 指神経ブロック digital nerve block
5. 爪の手術の原則および概要 principles and overview of nail surgery

English Journal

Comparative study between mobile computed radiography and mobile flat-panel radiography for bedside chest radiography: impact of an antiscatter grid on the visibility of selected diagnostically relevant structures.

Lehnert T, Naguib NN, Wutzler S, Bauer RW, Kerl JM, Burkhard T, Schulz B, Larson MC, Ackermann H, Vogl TJ, Balzer JO.Author information From the *Department of Diagnostic and Interventional Radiology, Clinic of Johann Wolfgang Goethe University Frankfurt, Frankfurt, Germany; †Department of Radiology, Alexandria University Hospital, Alexandria, Egypt; Departments of ‡Trauma, Hand, and Reconstructive Surgery, and §Biostatistics and Mathematical Modeling, Clinic of Johann Wolfgang Goethe University Frankfurt, Frankfurt; and ∥Department for Radiology and Nuclear Medicine, Catholic Clinic Mainz, Mainz, Germany.AbstractOBJECTIVES: The objective of this study was to evaluate the diagnostic performance of 2 different imaging systems in adult bedside chest radiography and the impact on the visibility of selected diagnostically relevant structures in the images acquired with these systems, with and without an antiscatter grid.
Investigative radiology.Invest Radiol.2014 Jan;49(1):1-6. doi: 10.1097/RLI.0b013e3182a56654.
OBJECTIVES: The objective of this study was to evaluate the diagnostic performance of 2 different imaging systems in adult bedside chest radiography and the impact on the visibility of selected diagnostically relevant structures in the images acquired with these systems, with and without an antiscat
PMID 24019019

Medical imaging, PACS, and imaging informatics: retrospective.

Huang HK.Author information Departments of Radiology and Biomedical Engineering, IPI Lab, University of Southern California, 734 West Adams Blvd, Suite KER 313, Los Angeles, CA, 90089-7725, USA, berniehkhuang@gmail.com.AbstractHistorical reviews of PACS (picture archiving and communication system) and imaging informatics development from different points of view have been published in the past (Huang in Euro J Radiol 78:163-176, 2011; Lemke in Euro J Radiol 78:177-183, 2011; Inamura and Jong in Euro J Radiol 78:184-189, 2011). This retrospective attempts to look at the topic from a different angle by identifying certain basic medical imaging inventions in the 1960s and 1970s which had conceptually defined basic components of PACS guiding its course of development in the 1980s and 1990s, as well as subsequent imaging informatics research in the 2000s. In medical imaging, the emphasis was on the innovations at Georgetown University in Washington, DC, in the 1960s and 1970s. During the 1980s and 1990s, research and training support from US government agencies and public and private medical imaging manufacturers became available for training of young talents in biomedical physics and for developing the key components required for PACS development. In the 2000s, computer hardware and software as well as communication networks advanced by leaps and bounds, opening the door for medical imaging informatics to flourish. Because many key components required for the PACS operation were developed by the UCLA PACS Team and its collaborative partners in the 1980s, this presentation is centered on that aspect. During this period, substantial collaborative research efforts by many individual teams in the US and in Japan were highlighted. Credits are due particularly to the Pattern Recognition Laboratory at Georgetown University, and the computed radiography (CR) development at the Fuji Electric Corp. in collaboration with Stanford University in the 1970s; the Image Processing Laboratory at UCLA in the 1980s-1990s; as well as the early PACS development at the Hokkaido University, Sapporo, Japan, in the late 1970s, and film scanner and digital radiography developed by Konishiroku Photo Ind. Co. Ltd. (Konica-Minolta), Japan, in the 1980-1990s. Major support from the US National Institutes of Health and other federal agencies and private medical imaging industry are appreciated. The NATO (North Atlantic Treaty Organization) Advanced Study Institute (ASI) sponsored the International PACS Conference at Evian, France, in 1990, the contents and presentations of which convinced a half dozen high-level US military healthcare personnel, including surgeons and radiologists, that PACS was feasible and would greatly streamline the current military healthcare services. The impact of the post-conference summary by these individuals to their superiors opened the doors for long-term support of PACS development by the US Military Healthcare Services. PACS and imaging informatics have thus emerged as a daily clinical necessity.
Radiological physics and technology.Radiol Phys Technol.2013 Dec 6. [Epub ahead of print]
Historical reviews of PACS (picture archiving and communication system) and imaging informatics development from different points of view have been published in the past (Huang in Euro J Radiol 78:163-176, 2011; Lemke in Euro J Radiol 78:177-183, 2011; Inamura and Jong in Euro J Radiol 78:184-189, 2
PMID 24311236

Dose audit for patients undergoing two common radiography examinations with digital radiology systems.

Inal T, Ataç G.Author information Department of Electrical-Electronics Engineering, Ankara University School of Engineering, Ankara, Turkey.AbstractPURPOSEWe aimed to determine the radiation doses delivered to patients undergoing general examinations using computed or digital radiography systems in Turkey. MATERIALS AND METHODSRadiographs of twenty patients undergoing posteroanterior chest X-ray and of 20 patients undergoing anteroposterior kidney-ureter-bladder radiography were evaluated in five X-ray rooms at four local hospitals in the Ankara region. Currently, almost all radiology departments in Turkey have switched from conventional radiography systems to computed radiography or digital radiography systems. Patient dose was measured for both systems. The results were compared with published diagnostic reference levels (DRLs) from the European Union and International Atomic Energy Agency. RESULTSThe average entrance surface doses (ESDs) for chest examinations exceeded established international DRLs at two of the X-ray rooms in a hospital with computed radiography. All of the other ESD measurements were approximately equal to or below the DRLs for both examinations in all of the remaining hospitals. Improper adjustment of the exposure parameters, uncalibrated automatic exposure control systems, and failure of the technologists to choose exposure parameters properly were problems we noticed during the study. CONCLUSIONThis study is an initial attempt at establishing local DRL values for digital radiography systems, and will provide a benchmark so that the authorities can establish reference dose levels for diagnostic radiology in Turkey.
Diagnostic and interventional radiology (Ankara, Turkey).Diagn Interv Radiol.2013 Dec 4. doi: 10.5152/dir.2013.12122. [Epub ahead of print]
PURPOSEWe aimed to determine the radiation doses delivered to patients undergoing general examinations using computed or digital radiography systems in Turkey. MATERIALS AND METHODSRadiographs of twenty patients undergoing posteroanterior chest X-ray and of 20 patients undergoing anteroposterior kid
PMID 24317331

Japanese Journal

DRシステムにおけるDQE測定時の各因子の測定精度に関する検討

國友博史,小山修司,東出了 [他]
日本放射線技術学会雑誌 70(7), 653-661, 2014-07
NAID 40020172811

軟X線画像法による飽和粘土の水分量推定

廣住豊一,岡島賢治,伊藤良栄 [他]
土壌の物理性 = Journal of the Japanese Society of Soil Physics (127), 3-9, 2014-07
NAID 40020170815

Digital Radiographyにおける線量指標の標準化 : Exposure Indexについて

國友博史
日本小児放射線技術 : 日本小児放射線技術研究会雑誌 (39), 38-42, 2014-03
NAID 40020050186

Related Pictures

★リンクテーブル★

リンク元	「デジタルラジオグラフィー」「デジタルX線撮影」「radiographic image enhancement」
関連記事	「radiography」「digit」「radiograph」「digital」