Sunday, September 21, 2008

PACS State-Of-The-Art, Circa 1985

PACS has existed in some form or another for quite a while. Today, we are rather jaded with the multitude of options out there. Do we go with Windows or Linux or Unix for the back end? Do we use 2 MP flat-panel monitors, or 3 MP or even 5 MP's? Gigabit Ethernet to the desktop is a given in most places, so in-house transmission times are almost negligible. And so it goes.

There was a time, however, when this was almost science fiction, and the assemblage of disparate components into what we call a PACS was the goal of a handful of visionaries around the world.

Long before my trip to UCSF to visit Bernie Huang in 1992, as described in a previous post, there were a number of centers developing functioning digital departments. I recently stumbled across an article from the University of Kansas by Arch Templeton, M.D., Samuel Dwyer, Ph.D, et. al., documenting such an effort.
Looking back, the problems of film seem almost funny today:

In most radiology departments, digitally formatted radiographic information is recorded, used, and stored as analog images on multiformat film, manually assembled in individual patient jackets and retained in a central film file. . . Sequential (one at a time) access to film jackets results in limiting the diagnostic information to one user or display site at a time.

And the solution?
The solution is a peripheralized (not centralized) computer based system that can capture, display and archive all digitally formatted image and alphanumeric data generated during a patient's hospital stay. The system must have on-line access, fast communication links, and high utilization capabilities. It must be bidirectionally integrated to an appropriate long term archiving system.
Here is what they envisioned, and ultimately built:

The interesting historical note here is that the system was indeed built as a series of nodes, with relatively independent architecture. Contrast that to today's PACS with a central web-style arrangement. For long-term storage, there were various options, including magnetic tape, or magnetic disks. The old Winchester-type sealed disks were available in 450 MB capacity for about $15,000 per drive, or one could splurge on a 1GB drive for $130,000! Other options included optical disks ($8,000 for the drive, $150 for the 4GB disk). There was such a thing as linear optical tape (drive cost: $80,000-$100,000, 50GB tape reel cost: $2500). The article even discusses laser-sensitive x-ray film which could store 1MB/cm2, or 238 MB on a 14 x 17 sheet!

We've definately come a long way, baby.


Anonymous said...

DR Systems has become a serial litigator on its "idea" patent 5,452,416. They currently have Fuji, Siemens, Kodak, Emageon, eRad, and NovaRad in court. The bigger guys are fighting, but I have no doubt that the small-fry have paid or will pay their pound of flesh.

Anonymous said...

DYnamic, Amicas, and Merge have all paid the piper. Great reputation DR Sys has in the industry....sure they invented hanging protocols.