Digital Imaging and Communications in Medicine (DICOM)

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Chapter 9 DICOM Associations
Do not try to solve the problem yourself by talking to your DICOM providers
X and Y independently. This will most likely start a long finger-pointing
contest, loaded with countless confusing details that cloud the issues and make
the real solution difficult to identify. Do not get caught in the middle. Instead,
call both DICOM companies responsible for the noncommunicating units, put
them in direct touch with each other (better still, make both of them come
onsite on the same day), give them your deadline, and withdraw from the conversation
until they produce a working solution. Remember, if either of them
tells you that “it is not possible”, the problem is definitely their fault. Standard
DICOM ensures that any two devices that are supposed to talk to each other,
will talk to each other.
Second, ensure that your DICOM software or device can generate a clear
DICOM connection status and detailed error log in a format comprehensible
by an average human being. Ideally, you would take this precaution before you
buy your software or device. Ask the salesperson to show how you can view
this information. More likely, he won’t know or care, so ask him to come back
only when he finds out. If anything goes wrong with the association establishment,
clear, understandable, and well-recorded error messages are critical for
any troubleshooting effort. One cannot troubleshoot a black box, and confusing
error/transaction logs can make this work even more difficult. Logs saying
nothing more than “invalid message received” without explaining exactly why,
where, and what was invalid are useless.
Piling studies
Many facilities configure their scanners (CT, MR, and so on) to send studies
to their DICOM servers automatically. Many technologists working on
those scanners become used to the automated workflow and do not check
the status of sent studies. And many scanner manufacturers do not really
display much of this status.
What happens then if the DICOM server goes down? If nothing in the
scanner interface warns the users, the error might not be noticed immediately,
and it might not even be noticed for a long time. Quite often, the
unsent studies will pile up on the scanners, and when the pile is finally
discovered, its size can easily reach the scale of a major problem.
The same issue applies to the connection status display. When your DICOM
application sends or receives data on the network, it should provide a clear
progress display for each transaction. It could be a graphical progress interface,
or it could be a simple counter such as “Sending 85%... 95%... Completed successfully”,
but it should be there. Watching this progress is essential for identifying
problems in real time, and not after every single radiologist in your department
has complained about them. I have been in many situations where it