|If a Picture Is Worth 1,000 Words, then Pervasive, Ubiquitous Imaging Is Priceless
Committee E07 on Nondestructive Testing is developing standards, practices and guides for a variety of industrial uses. Its Subcommittee E07.11 on Digital Imaging and Communication in Nondestructive Evaluation (DICONDE) is guiding the evolution of standards designed to exploit a universally compatible image data format.
What Is DICONDE?
DICONDE is an evolving standard that provides a way for nondestructive evaluation (NDE) manufacturers and users to share image data. It is based on the American College of Radiology (ACR)/National Electrical Manufacturers Association (NEMA) standard, DICOM (Digital Imaging and Communications in Medicine). The DICONDE standard encompasses all NDE specific imaging methods and technologies, such as infrared thermography, ultrasound, computed radiography, computed tomography, eddy current, and acoustic emission, and harmonizes these with the DICOM standard as unique imaging modalities.
A dictionary that describes all the necessary syntax, attributes and data elements for users to acquire, store, archive, transmit and receive image data in a way that is universally compatible.
A universally available image data viewer, permitting pervasive and ubiquitous image data display.
A system that describes destinations where images may be stored.
A database, allowing users to subsequently search for image data, using a variety of criteria.
A method of communication, exploiting commonly employed networking protocol in a way that allows users to transmit and receive data through networks and the Internet.
A system that describes how to use optical media to archive image data (CD-read only, CD-read/write, DVD, DVD-R/W, magneto optical).
A multi-faceted file format that allows users to include reports in a variety of formats (such as a word processing document or a recording of a persons voice).
The History of the DICOM Standard
When digital medical image sources were introduced in the 1970s, computers were used to process these images after their acquisition. This activity led ACR and NEMA to form a joint committee to create a standard means of sharing images. This committee, formed in 1983, published the ACR-NEMA Standards Publication No. 300-1985 after two years of effort.
Up to this point, most devices stored images exclusively in a proprietary format. They could transfer files over a network or on removable media. Although the preliminary versions of the ACR-NEMA effort (Version 2.0 was published in 1988) created standardized terminology and a structural framework for data, the potential of a standard method of communicating digital image information was not realized until the release of version 3.0 of the standard in 1993, Digital Imaging and Communications in Medicine (DICOM).
The DICOM standard now specifies a network protocol exploiting TCP/IP (transmission control protocol/Internet protocol), defines the operation of service classes beyond the simple transfer of data, and has created a language for uniquely identifying information objects as they interact in a network environment. DICOM is also designed to support a multi-part document so that users could include additional data elements in the future.
As the DICOM Web site describes, DICOM defines Information Objects not only for images but also for patients, studies, reports, and other data groupings. With the enhancements made in DICOM (Version 3.0), the Standard delivers on its promise not only of permitting the transfer of medical images in a multi-vendor environment, but also facilitating the development and expansion of picture archiving and communication systems (PACS) and interfacing with medical information systems.
Practical Applications of the DICONDE Standard
Acquiring image data from a variety of sources, NDT operations can spool data off to multiple destinations. These may include:
Diagnostic workstations, where personnel perform data review and interpretation tasks;
File servers, where the image data may be stored;
Archive systems that provide stable media thats immune to the destructive effects of electro-magnetic interference;
Plotters and printers that allow NDT personnel to provide hard copy for additional perspective; and
Remote sites that may be required to perform additional testing as goods age with time and usage, allowing direct comparisons between original and subsequent quality of manufactured goods.
Here is a practical application example: An image of a weld is created digitally. The weld is a critical part of a hydraulic system that controls the airplanes ability to take off, maneuver, and land. NDT personnel review the image of the weld and approve the part for usage in final assembly of aircraft. The image is stored on a file server, where it is subsequently archived for posterity and potential retrieval, should review be required years later. A copy of the image is also sent to the customer via a secure, private network where local NDT personnel can use the image to compare with other, subsequently acquired images as to when to replace the part after significant wear and tear occur.
Effective exploitation of this emerging standard requires the continuous, sustained support of those who design, manufacture and employ NDE imaging systems. This process will allow ASTM to properly maintain the data dictionaries and structures for all NDE-specific imaging methods. Individuals wishing to participate, please contact the author. //
Copyright 2003, ASTM