DICOM committee ponders next moves
The recent publication of the 1998 version of the DICOM standard capped an eventful year for the DICOM committee (PNN 11/98). Many important new features were added, including the modality work list and performed-procedure step, which allows imaging modalities to fetch scheduling information, patient demographics, and other exam information (PNN 7/98). Another important addition to the standard-the gray-scale display function-provides consistent hard-copy and soft-copy presentation of the images.As the standard continues to move forward, the DICOM committee faces ongoing challenges in deciding where to focus its resources. Many topics are being discussed for possible inclusion in the standard, and the committee must weigh the importance of each potential addition. The immediate relevance of topics may be difficult to predict, as seen by some of the additions to DICOM that might have been premature.
For example, the radiation therapy objects and services provide for exchange of therapy planning images, dose plans, and all other radiation therapy information. Despite these additions, most users either don't seem to be aware of these new standards or don't care.
The same applies to the images generated using "visible light," such as endoscopy, microscopy, and pathology. A standard proposal was generated more than a year ago, but few implementations have occurred.
Despite the challenging task of prioritizing items for inclusion in the standard, the committee can look to cases where vendors are implementing proprietary solutions for exchanging information.
Topics meeting this criterion include 3-D image object information as well as MRI data generated by new acquisition techniques such as spectroscopy. The ability to exchange radiologist work-list information between various workstations is also drawing vendor attention. Working groups are tackling this item, however, and results may be seen within the next year.
Another difficult decision faced by the committee is whether to begin standardization work on technology that is still evolving. For example, there are still several incompatible write formats for digital versatile disks (DVD), a technology that is beginning to hit the market (PNN 11/98). The committee runs the risk of picking the wrong format, which could go the way of Betamax.
This problem also arose with the committee's decision last year to hold off on incorporating a wavelet compression standard, despite widespread agreement that the current JPEG algorithms in DICOM produce blocking artifacts and are perceived by some experts as inferior to wavelet schemes. Although there was some disagreement on the committee, it voted to wait for the JPEG 2000 committee to define a wavelet compression scheme, which is scheduled for a 2000 release as an International Standards Organization (ISO) standard (PNN 11/97).
