I was traveling in Europe in a rental car when I had to stop for gas. I had rented a European car, as a matter of fact, one of the “real” Volvos before they were acquired by Ford and became just another bland car brand. I was looking for the handle to open the gas cover but could not locate it. I was looking at all the common places in the door, under the dashboard, on the floor, all locations I had ever seen the gas door handle. Unfortunately, I could not find anything that looked like it. No, problem I thought, I’ll just ask the gas station attendant. In this case, the attendant was inexperienced and had no clue where it could be. So, here I was, almost without gas, having no clue on how to get access to the gas tank. The good news was that after desperately looking for another 10 minutes or so, another driver helped me out. The handle was hidden in the pocket of the driver’s door.
The lesson learned here is that prior to driving a car, or using any type of equipment or device, you should at least read the manual and familiarize yourself with all of the needed features and functions. The same applies for connecting medical devices to a PACS system. The worst thing to do is to connect a device and “see what happens”.
Every medical device that supports DICOM has a DICOM conformance statement, which is available on-line at the company’s website. For some reason, the hospital IT vendors are a little bit more protective about HL7 specifications, but I am sure you can get those on request as well. Still it is amazing how few people actually look at these specifications. I would not buy a 10 or 20 thousand dollar car without at least looking at the specifications to see what the options, features, and functions are; yet some people in charge of purchasing devices worth hundreds of thousands of dollars do just that.
Interface specifications are critical as they specify the features of a device. For example, an ultrasound device may have an export feature for DICOM structured reports with measurements that can be imported directly into the radiology report. It is important to know which reports are supported. Other important features to know about are whether an X-ray machine exports a dose report, and in what format, and what type of file compression is supported, if any. You should also know details on how to configure the work list to make sure it can be configured to filter only procedures performed on that device or in that department. For HL7 specifications, it is important to know what the options are with regard to orders and results to be exchanged.
Now, reading an interface specification can be a little bit overwhelming at first. I have seen a DICOM conformance statement of 450 pages, so you can imagine that this is not something you want to print out and read cover to cover. The trick is practice, practice, practice, and study upfront so you are prepared when there are problems and you need to find the information quickly.
Here is a system for using these manuals that may help. First look at the beginning pages because these provide the so-called SOP class specifications, which would specify the type of services and images and other objects that are supported. For example, does the system support the measurements and dose information as mentioned above. This section also includes the image key for presentation states with annotations and markers. Next look at the section covering the different compression schemes, specified as so-called transfer syntaxes. Bookmark the sections on error handling and configuration as you will likely need to refer to that section frequently. The third section to examine is the one covering exchange media support (CD, DVD, or other) in case the PACS is down and you need a back-up. That way, at least the images can be burned to a CD and transported over your “sneaker net” to a radiologist for reading the CT’s from the ER. I also always look at the attributes supported in the work list and the values of critical attributes in a DICOM header such as series descriptions, body parts, etc.
A famous saying says, “Real men (or women) don’t read manuals,” hopefully, this is not true for “real” system administrators that support these complex and expensive devices. It is important to study these in detail so that you will not be stranded in the middle of nowhere without knowing how to fuel up your device (or car).
(Next blog entry deals with the need for band-aids, only as a last resort)
Herman Oosterwijk, VP, OTech Media