Saturday, October 4, 2008

A little PACS history

There has been a lot of discussion lately about certain PACS features and how long the ideas have been known to the community.

A good "snapshot" of features is available in the military specification for the MDIS (Medical Diagnostic Image Support) system, what later became the Siemens Gammasonics, Lockheed Martin, Loral and finally GE PACS - the precursor of the first "Centricity PACS". You can find a link to a scanned, OCR'd copy of the MDIS RFP here. This document is dated 28 March 1990.

If one turns, for example, to the Soft Copy Image Display (SCID) requirements in section 4.4, one will see such features as have been taken for granted since the early days of PACS and are now ubiquitous:
  • Pictorial Patient Directory. The workstation shall display the images from a patient's master "folder" and individual image subfolders (e.g., chest, bone, GI). Anatomic region subcategories shall be possible within each subfolder (e.g., elbow, ankle). Single or multiple images shall be easily selectable for full resolution viewing.
  • Worklist. The workstation shall automatically generate a worklist of unread exams to enable each radiologist to review the amount of the work ready for their review. The worklist can be created by radiologist or type of workstation (e.g. CT review workstation) at each as determined at each site.
  • Image Rearrangement and Display. The workstation shall display multiple reduced resolution images on a selected monitor with the ability to easily rearrange these images on the same monitor. It shall also allow rearrangement of the images easily from monitor to monitor on the same workstation.
  • Image Paging. Quick paging through multiple user selected images of an exam displayed on a single monitor shall be provided.
  • Default Display Protocol. This required function displays the images of a patient study in a user-selectable default protocol, activated each time the individual user logs on the workstation. The default display shall be modality and body part specific. It shall be a site-specific requirement- i.e. each MDIS site shall be capable of setting their own parameters.
    (For example - a patient has new and previous posterioranterior (PA) and lateral chest studies to be interpreted. The radiologist viewing the study prefers to view the PA images on the central two monitors and the lateral images on theouter two monitors of a four monitor workstation. The radiologist also prefers to view the lateral images with the anterior border of the chest closest to the left monitor edge, the new PA images on the right central monitor, and the previous PA image on the left central monitor.)
    Additionally, the images shall automatically be presented in an upright as well as correct right/left orientation.
  • Image Enhancements Defaults. The workstation shall include user selectable image enhancement defaults for grayscale window and leveling, variable edge enhancement, and inverse video, activated each time the individual user logs on the workstation.
This document is well worth a read for those who are students of PACS history, but also for those who are seeking to establish the state of knowledge and understanding of PACS concepts in the late 1980's (the document is from the beginning of 1990, and presumably there were earlier drafts well before that describing the same concepts).

I am not sure exactly who the authors of this document were, or I would give them credit here, but I intend to research that a little further amongst some of my older colleagues (:)). Indeed, I think I will begin a little "PACS History" section in my FAQ, and start to accumulate links to documents that describe the early days, or at least references to papers and conference proceedings where the copyright is held by some publisher. Anyone who wants to contribute links or documents, please feel free to email me.

PS. I have to say that I am most impressed by Acrobat 9 Mac's OCR capabilities, which I rarely use. The original scanned paper PDF of the hand-typed MDIS RFP document that I submitted for OCR, primarily to index it for searching, also allows me to cut and past the above paragraphs with only a few edits for punctuation and without a single meaningul error; most impressive.


lapo.bertini said...

Dear David.
Great. PACS history. I think this is one good effort which I support. Being on PACS since early 90s, this's something that will take me down memory lane once again. I'll gladly contribute. Lapo

David Clunie said...

The PACS History web site is now up and running ... see

Patricia said...

Dear David,

I'm working in the my thesis about digital pathology. Do you know any open source project that has DICOM supplement 122?



SBG23 said...

"...also allows me to cut and "past" the above paragraphs with only a few edits for punctuation and without a single meaningul error; most impressive."

I couldn't help but notice the irony of the "past" and "meaningul"
error...still impressive though.

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hyip said...

A PACS is a guide for digital revolution. I'll gladly contribute for this. It also allows rearrangement of the images easily from monitor to monitor on the same workstation.

HYIP monitor said...

Does anybody know what types of images PACS currently supports aside from US, MR, PET, CT, ENDO, MG, DR and CR?

I am writing an essay about the purpose of PACS and I will be glad of any assistance.

Thanks in advance.

scandoc said...

thanks for ur post....wish u could get some images from the old pacs mdis monitor.....