Duplicate Studies

[DataTrade]

I am having a problem when they are resending a study from the modality, that it is creating a duplicate on OnePacs. If an image is pushed, shouldn't the system recognize that they study was already pushed? I am assuming there is some unique idenitfier for this. Maybe they are changing something that is causing the problem? Please advise.

[admin]

It definitely recognizes the study as the same as before. They must be changing an identifier somewhere. Otherwise it would not show up as a duplicate.

Images are identified in DICOM by a UID number (unique identifier). If they push an image again without changing the UID, it will not show up as a duplicate. They must be changing that somehow. For example if they duplicate the image on the modality or apply some post-processing to it, it could make a new instance with a new UID.

[DataTrade]

I just received more information. It looks like the study is not duplicating, but the images within the study are duplicating if it is repushed. Any ideas?

[DataTrade]

Even more information. I pulled up the image information on the duplicate images. Just as an FYI, they are duplicated on the Gateway as well. It appears that the SOP Class UID is the same for both images. But, the SOP Instance UID is different, even though it is the same image. There are no settings in the Konica unit that are being changed prior to re-pushing the study out.

We beleive that every study that has been re pushed has been duplicated. We have also test doing it a third time and in fact, a third image gets added. As you can see, this is a major issue when it comes to storage.

[admin]

This is odd behavior. It's not supposed to do this. Can you get the logs from the gateway and message them to the "admin" account on OnePacs?

The logs are here:

C:/onepacs/gateway/server/default/log/server.log

Post a note after you send them please. Thanks

[justin]

SOP Class UID will often remain the same. This just defines the "type" of image.

SOP Instance UID should be unique per image. Your modality is likely generating a unique UID when it's resending. A simple way to determine this is to check the prefix of the SOP Instance UID. For example, if the original and duplicate both begin with 1.2.392.123456 (or something similar) then you know they were generated by the same entity. Let us know what you find or send us the logs and we can take a look.

All UIDs generated by OnePacs will begin with 1.3.6.1.4.1.29854.

Thanks,

Justin

[DataTrade]

Hey guys, I just send a message to admin, but can't see where to attach a file. I am assuming you do not want me to attach it here, correct?

[justin]

Please send via the OnePacs Messaging system.

http://wiki.onepacsforums.com/doku.php? ... gingsystem

Thanks,

Justin

[DataTrade]

Done. It was sent.

[justin]

The logs indicate that your modality is generating SOP Instance UIDs on-the-fly at the time the images are sent to the gateway.

There is a date/time component in the UID that appears to be based on the transmission time:

2012-04-05 11:02:47,135 INFO XXXXXXX->ONEPACS_XXX (ActiveAssoc-XXXX) [org.dcm4cheri.net.FsmImpl] received [pc-3] 1:C_STORE_RSP
class: 1.2.840.10008.5.1.4.1.1.1.1/Digital X-Ray Image Storage - For Presentation
inst: 1.2.XXX.XXXX.XXX.XXX.XXXXX.20120405.110140.XXXXX/?
status: 0

SOP Instance UIDs should be static. That is they should be the same each time they are transmitted to us (unless of course they were reconstructed and thus different images). There is probably a config setting on your device to do this.



Justin