Encyclopedia > Digital Imaging and Communications in Medicine
Digital Imaging and Communications in Medicine (DICOM) is a standard for handling, storing, printing, and transmitting information in medical imaging. It includes a file format definition and a network communications protocol. The communication protocol is an application protocol that uses TCP/IP to communicate between systems. DICOM files can be exchanged between two entities that are capable of receiving image and patient data in DICOM format. The National Electrical Manufacturers Association (NEMA) holds the copyright to this standard [1]. It was developed by the DICOM Standards Committee, whose members [2] are also partly members of NEMA [3]. Medical imaging designates the ensemble of techniques and processes used to create images of the human body (or parts thereof) for clinical purposes (medical procedures seeking to reveal, diagnose or examine disease) or medical science (including the study of normal anatomy and function). ...
A file format is a particular way to encode information for storage in a computer file. ...
This article concerns communication between pairs of electronic devices. ...
The Internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet runs. ...
The National Electrical Manufacturers Association or NEMA is a U.S.-based association, which was created on September 1, 1926, when the Associated Manufacturers of Electrical Supplies and the Electric Power Club merged. ...
DICOM enables the integration of scanners, servers, workstations, printers, and network hardware from multiple manufacturers into a picture archiving and communication system. The different devices come with DICOM conformance statements which clearly state the DICOM classes they support. DICOM has been widely adopted by hospitals and is making inroads in smaller applications like dentists' and doctors' offices. An image as stored on a picture archiving and communication system (PACS) The same image following contrast adjustment, sharpening and measurement tags added by the system In medical imaging, picture archiving and communication systems (PACS) are computers or networks dedicated to the storage, retrieval, distribution and presentation of images. ...
For the town in the Republic of Ireland, see Hospital, County Limerick. ...
Parts of the DICOM Standard
The DICOM standard is divided into related but independent parts:[4]
The links below are to the 2007 version published in December 2006
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A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to...
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A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to...
“PDF†redirects here. ...
A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to...
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MiB redirects here. ...
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A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to...
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A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to...
History
 Front page of ACR/NEMA 300, version 1.0, which was released in 1985 DICOM is the third version of a standard developed by American College of Radiology (ACR) and National Electrical Manufacturers Association (NEMA). Image File history File links No higher resolution available. ...
Image File history File links No higher resolution available. ...
The American College of Radiology (ACR), founded in 1923, is a non-profit professional medical organization composed of diagnostic radiologists, radiation oncologists, interventional radiologists, nuclear medicine physicians, and medical physicists. ...
The National Electrical Manufacturers Association or NEMA is a U.S.-based association, which was created on September 1, 1926, when the Associated Manufacturers of Electrical Supplies and the Electric Power Club merged. ...
In the beginning of the 1980s it was almost impossible for anyone other than manufacturers of computed tomography or magnetic resonance imaging devices to decode the images that the machines generated. Radiologists wanted to use the images for dose-planning for radiation therapy. ACR and NEMA joined forces and formed a standard committee in 1983. Their first standard, ACR/NEMA 300, was released in 1985. Very soon after its release, it became clear that improvements were needed. The text was vague and had internal contradictions. negron305 Cat scan redirects here. ...
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Varian Clinac 2100C Linear Accelerator Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ...
In 1988 the second version was released. This version gained more acceptance among vendors. The image transmission was specified as over a dedicated 50-pin DICOM cable. The first commercial equipment supporting ACR/NEMA 2.0 was presented at the annual meeting of RSNA in 1990 by GE Healthcare and a company named Vortech (later purchased by Eastman Kodak). Many soon realized that the second version also needed improvements. Several extensions to ACR/NEMA 2.0 were created, like Papyrus (developed by the University Hospital of Geneva, Switzerland) and SPI, (Standard Product Interconnect, driven by Siemens Medical Solutions and Philips Medical Systems). The Radiological Society of North America (RSNA), founded in 1915, has the purpose to promote and develop the highest standards of radiology and related sciences through education and research. The society publishes the journals Radiology and RadioGraphics. ...
GE Healthcare is a $14 billion (USD) unit of General Electric. ...
Eastman Kodak Company (NYSE: EK) is an American multinational public company which produces photographic materials and equipment. ...
Geneva (pronunciation //; French: Genève //, German: //, Italian: Ginevra //, Romansh: Genevra) is the second most populous city in Switzerland (after Zürich), and is the most populous city of Romandy (the French-speaking part of Switzerland). ...
Siemens Medical Solutions (Siemens Med) is a supplier to the healthcare industry headquartered in Erlangen, Germany and Malvern, Pennsylvania. ...
Koninklijke Philips Electronics N.V. (Royal Dutch Philips Electronics Ltd. ...
In 1992 the third version of the standard was released. Its name was then changed to DICOM. New service classes were defined, network support added and the Conformance Statement was introduced. Officially, the latest version of the standard is still 3.0, however, it has been constantly updated and extended since 1992. Instead of using the version number the standard is often version-numbered using the release year, like "the 2007 version of DICOM".
DICOM Data Format DICOM differs from other data formats in that it groups information into data sets. That means that a file of an X-Ray of a chest, for example, actually contains the patient ID within the file, so that the image can never be separated from this information by mistake. Image File history File links Dicom_mr. ...
A data set (or dataset) is a collection of data, usually presented in tabular form. ...
A DICOM data object consists of a number of attributes, including items such as name, ID, etc., and also one special attribute containing the image pixel data (i.e. logically, the main object has no "header" as such - merely a list of attributes, including the pixel data). A single DICOM object can only contain one attribute containing pixel data. For many modalities, this corresponds to a single image. But note that the attribute may contain multiple "frames", allowing storage of cine loops or other multi-frame data. Another example is NM data, where an NM image by definition is a multi-dimensional multi-frame image. In these cases three- or four-dimensional data can be encapsulated in a single DICOM object. Pixel data can be compressed using a variety of standards, including JPEG, JPEG Lossless, JPEG 2000, and Run-length encoding (RLE). LZW (zip) compression can be used for the whole data set (not just the pixel data) but this is rarely implemented. JPG redirects here. ...
JPEG Lossless Compression is a means of compressing images such that the original image can be recovered exactly - so called Reversible Compression. ...
JPEG 2000 is a wavelet-based image compression standard. ...
Run-length encoding (RLE) is a very simple form of data compression in which runs of data (that is, sequences in which the same data value occurs in many consecutive data elements) are stored as a single data value and count, rather than as the original run. ...
LZW (Lempel-Ziv-Welch) is an implementation of a lossless data compression algorithm created by Abraham Lempel and Jacob Ziv. ...
The same basic format is used for all applications, including network and file usage, but when written to a file, usually a true "header" (containing copies of a few key attributes and details of the application which wrote it) is added.
DICOM Services DICOM consists of many different services, most of which involve transmission of data over a network, and the file format below is a later and relatively minor addition to the standard.
Store The DICOM Store service is used to send images or other persistent objects (structured reports, etc.) to a PACS or workstation. An image as stored on a picture archiving and communication system (PACS) The same image following contrast adjustment, sharpening and measurement tags added by the system In medical imaging, picture archiving and communication systems (PACS) are computers or networks dedicated to the storage, retrieval, distribution and presentation of images. ...
Storage Commitment The DICOM storage commitment service is used to confirm that an image has been permanently stored by a device (either on redundant disks or on backup media, e.g. burnt to a CD). The Service Class User (SCU), a modality or workstation, etc., uses the confirmation from the Service Class Provider (SCP), an archive station for instance, to make sure that it is safe to delete the images locally.
Query/Retrieve This enables a workstation to find lists of images or other such objects and then retrieve them from a PACS. An image as stored on a picture archiving and communication system (PACS) The same image following contrast adjustment, sharpening and measurement tags added by the system In medical imaging, picture archiving and communication systems (PACS) are computers or networks dedicated to the storage, retrieval, distribution and presentation of images. ...
Modality Worklist This enables a piece of imaging equipment (a modality) to obtain details of patients and scheduled examinations electronically, avoiding the need to type such information multiple times (and the mistakes caused by retyping).
Modality Performed Procedure Step A complementary service to Modality Worklist, this enables the modality to send a report about a performed examination including data about the images acquired, beginning time, end time, and duration of a study, dose delivered, etc. It helps give the radiology department a more precise handle on resource (acquisition station) use. Also known as MPPS, this service allows a modality to better coordinate with image storage servers by giving the server a list of objects to send before or while actually sending such objects.
Printing The DICOM Printing service is used to send images to a DICOM Printer, normally to print an "X-Ray" film. There is a standard calibration (defined in DICOM Part 14) to help ensure consistency between various display devices, including hard copy printout.
Off-line Media (DICOM Files) The off-line media files correspond to Part 10 of the DICOM standard. It describes how to store medical imaging information on removable media. Except for the data set containing, for example, an image and demography, it's also mandatory to include the File Meta Information.
DICOM restricts the filenames on DICOM media to 8 characters (many people wrongly use 8.3, but this is not legal). No information must be extracted from these names (PS10:6.2.3.2). This is a common source of problems with media created by developers who did not read the specifications carefully. This is a historical requirement to maintain compatibility with older existing systems. It also mandates the presence of a media directory, the DICOMDIR file, that provides index and summary information for all the DICOM files on the media. The DICOMDIR information provides substantially greater information about each file than any filename could, so there is less need for meaningful file names.
There is also an ongoing media exchange test and "connectathon" process for CD media and network operation that is organized by the IHE organization. IHE is an initiative by healthcare professionals and industry to improve the way computer systems in healthcare share information. ...
Application areas Examples of Modalities supported in DICOM are: In music, modality is the subject concerning certain diatonic scales known as modes (e. ...
A colposcopy or colcoscopy is a diagnostic procedure in which a colposcope is utilized to examine an illuminated, magnified view of the cervix, vagina, and vulva. ...
// Computed Radiography (CR) uses very similar equipment to conventional radiography except that in place of a film to create the image, an imaging plate is used. ...
A sterile flexible cystoscope in an operating theatre Hello this is a Message to Dad Quit Reading this stuff :) . Endoscopy of the urinary bladder via the urethra is called cystoscopy. ...
negron305 Cat scan redirects here. ...
Digital Subtraction Angiography (DSA) is the procedure to visualize blood vessels with contrast medium in a bony environment by subtracting the pre-contrast image (the mask) from the image with contrast medium. ...
An echocardiogram. ...
Endoscopic images of a duodenal ulcer A flexible endoscope. ...
Fluorescein angiography, or fluorescent angiography, is a technique for examining the circulation of the retina. ...
The ophthalmoscope, invented by Hermann von Helmholtz, is an instrument used to examine the eye. ...
Laparoscopic surgery, also called keyhole surgery (when natural body openings are not used), bandaid surgery, or minimally invasive surgery (MIS), is a surgical technique. ...
ÃMagnetic Resonance Angiography is the imaging of blood vessels using Magnetic Resonance Imaging. ...
Mammography. ...
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Shown above is the bone scintigraphy of a young woman. ...
Image of a typical positron emission tomography (PET) facility Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three-dimensional image or map of functional processes in the body. ...
A modern fluoroscope. ...
Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ...
This article is about the infrared imaging technique. ...
For other uses, see Ultrasound (disambiguation). ...
Patient about to undergo an angiogram, image courtesy of WHO. Angiography or arteriography is a medical imaging technique in which an X-ray picture is taken to visualize the inner opening of blood filled structures, including arteries, veins and the heart chambers. ...
Lead II An electrocardiogram (ECG or EKG, abbreviated from the German Elektrokardiogramm) is a graphic produced by an electrocardiograph, which records the electrical voltage in the heart in the form of a continuous strip graph. ...
See also - DICOM Conformance statement
- DICOM Data dictionary
- DICOM Media Storage Application Profile
- DICOM Security profile
- DICOM Service class
- DICOM Service Object Pair
References - ^ DICOM brochure
- ^ MEMBERS of the DICOM STANDARDS COMMITTEE
- ^ NEMA Members
- ^ (2006) "6.1 DIMSE Services", Digital Imaging and Communications in Medicine (DICOM) Part 1: Introduction and Overview. National Electrical Manufacturers Association, 11.
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