Retrieve Enhanced MR as MR Images

[focus]

Hello,

We have developed a viewer that doesn't support yet Enhanced MR studies, as we use dcmtk to retrieve studies the users can retrieve Enhanced MR studies, but when they try to visualize our viewer hangs up. The problems is with the libraries we use to visualize the Images.

The presentation context that offers the PACS to retrieve Enhanced these studies is:

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Presentation Context ID: 1
SOP Class: Enhanced MR Image Storage[1.2.840.10008.5.1.4.1.1.4.1]
	SCU Role: Implicit
	Transfer Syntax(proposed): Implicit VR Little Endian[1.2.840.10008.1.2]

Is There a way to change the Storage SOP Class and use alternative SOP Class to retrieve the study ? We would like to use MRImageStore SOP Class to retrieve these Studies.

Or there is some manner to change de Storage SOPClass of the images after haven been retrieved.

Thanks for your help.

[Michael Onken]

Hi,

you could use storescp's configuration file option to exactly specify the SOP classes and transfer syntaxes to be negotiated:

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-xf   --config-file  [f]ilename [p]rofile: string
          use profile p from config file f

DCMTK ships with an example file in dcmnet/etc, look for storescp.cfg.

DCMTK does not contain any converter from enhanced image objects to the "old format". The enhanced versions contain lots of more information. A converter from enhanced to "normal" should be possible. Maybe you can check the gdcm toolkit, which has a tool named gdcmtar, which as far as I know does the conversion (never tried it myself). See gdcmtar page.

Best regards,
Michael

[focus]

Thanks for your reply.

We have create our own dcmAllStorageSOPClassUIDs (dcmAllStorageSOPClassUIDs is a const char[] list that defines the accepted SOPs from dcmtk) without Enhanced SOP classes, and then when we receive a store request with an Enhanced SOP class we reject it, because PACS only presents one Presentation Context that is

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Presentation Context ID: 1
SOP Class: Enhanced MR Image Storage[1.2.840.10008.5.1.4.1.1.4.1]
   SCU Role: Implicit
   Transfer Syntax(proposed): Implicit VR Little Endian[1.2.840.10008.1.2]

The problem is that we don't want to reject it, we would like to renegotiate the SOP class that the images are sent and change it to no enhanced SOP classes.

If PACS send us images with Enhanced MR SOP class is there a way to say to PACS "we don't support Enhanced MR Storage SOP but we support MR Image Storage SOP Class ,please PACS change the SOP class" ?

Reading DICOM documenation I haven't found anything about the possibility to renegotiate SOP Class, I suppose that is not possible to renegotiate the SOP Class in which images will be send, no ?

I believe that The only way to do this It will be that PACS send as the storage request with two Presentation Context ? One with Enhanced MR SOP Class that we will reject it and another with MR SOP Class that we will accept. Is it correct?

Thanks


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[Michael Onken]

Hi,

there is no possibility in DICOM to re-negotiate in terms of giving the requestor the hint that you prefer the old kind of object. The idea is generally to let the requestor propose anything that it is possible to send and let the receivor choose from those possiblities one or more supported SOP classes/transfer syntaxes. So you are right: The requestor must propose the old SOP class.

Best regards,
Michael