Adding elements as a sequence???

Firstly, I am very new to learning the LeadTools Dicom framework, so please forgive me if I am using incorrect terminology for my question, I'll do the best I can.

I am building a dataset for performing a Modality Worklist CFind. I am using DVT to validate the CFind request I am making. I seem to have everything correct except for this ScheduledProcedureStepSequence element, and it's related elements.

The DVT script seems to expect ScheduledStationAETitle (0040 0001), ScheduledProcedureStepStartDate (0040 0002), and CTModality (0008 0060) to be part of a sequence under ScheduledProcedureStepSequence (0040 0100). If you are familiar with DVT, the script looks like this:

RECEIVE C-FIND-RQ "Modality Worklist - FIND" (
(0x00000002, "Modality Worklist Information Model - FIND SOP Class")

(0x00100010, "*") # Patient's Name
(0x00100020, "") # Patient ID
(0x0020000D, "") # Study Instance UID
(0x00400100, SQ,
>(0x00400001, "DVT") # Scheduled Station AE Title
>(0x00400002, AUTOSET) # Scheduled Procedure Step Start Date
>(0x00080060, "CT") # CT Modality
)
)

part of my post was cut off... continued here...


So I have attempted multiple approaches to inserting a sequence. Inserting the Scheduled Procedure step module, inserting the above elements with the "Sequence" flag of InsertElement set to true, etc. Nothing I've tried seems to work.

Any help you can provide would be much appreciated. Thanks!

Additionally, I am using v1.5 of the lead tools SDK, working in C#.

Thanks!

I'm afraid that I'm not familiar with DVT. What does it do exactly? How are you using it with LEADTOOLS?
If it’s a test MWL SCP, try to use our MWL SCU demo with DVT to see if you face the same problem.
Also, try to use your application with our MWL SCP demo to see if the problem occurs.

Can you create a small sample project (not your full application) that only shows the problem and put it in a ZIP or RAR file.
You can either attach your project here (don't include serials/unlock keys and don't use the 'Preview' feature) or send it to support@leadtools.com and mention this forum post.

Thank you for the reply Adam.

DVT is the Dicom Validation Tool
http://www.dvtk.org/
Your MWL SCU demo also fails when used against the DVT script I am using.

But lets leave that behind as it's really not that important.


Can you simply point me to an example, or explain what the Sequence boolean flag for DicomDataset.InsertElement is for or how it would be used? For reference, here is the documentation for InsertElement.
http://www.leadtools.com/Help/LEADTOOLS/v15/DH/DI/Leadtools.Dicom~Leadtools.Dicom.DicomDataSet~InsertElement(DicomElement,Boolean,DicomTagType,DicomVRType,Boolean,Int32).html

I attached a sample dicom file, see the Scheduled Procedure Step Sequence element? How do I insert that element and it's child items into a DicomDataset that I create.

Thanks!

Your dataset wasn't attached.  Here's some general guidelines for attaching files to our forum:

1.) Zip the file(s) up.
2.) Make sure it is less than 5 MB.  If it is larger, please send an email to support@leadtools.com and we'll send you FTP instructions.
3.) Remove ANY AND ALL unlock codes and LEADTOOLS DLLs.
4.) Do not click the preview button, the attachment will not show up when you post it.

If you do not wish to post your file(s) on the forum since they are publically viewable, please send an email to support@leadtools.com and make sure that you include a link to this forum post.

sorry, I'll try again.

and I'll try again, I received an error on posting my last reply

I continue to receive errors when I attempt to attach the zip file containing my dicom dataset.
So here is a link to it hosted online.

http://dl.getdropbox.com/u/78912/Dicom_14_27_897.zip

Thanks!

I have used the code below to add the elements as a sequence and child to the sequence. Does this do what you want? If not, please explain the problem in the results.

ds.Load(file, DicomDataSetLoadFlags.None);
DicomElement element = ds.FindFirstElement(null, DicomTagType.ScheduledProcedureStepSequence, true);
if (element == null)
{
element = ds.InsertElement(null, false, DicomTagType.ScheduledProcedureStepSequence, true, 0);
element = ds.InsertElement(element, true, DicomTagType.ScheduledStationAETitle, false, 0);
element = ds.InsertElement(element, false, DicomTagType.ScheduledProcedureStepStartDate, false, 0);
}

That is close but not quite right.

The tag sequence structure in the example I attached above is this:

0040:0100 - Scheduled Procedure Step Sequence
ffee:e000 - Item
0040:0001 - Scheduled Station AE Title
0040:0002 - Scheduled Procedure Step Start Date


Using your code I get:

0040:0100 - Scheduled Procedure Step Sequence
0040:0001 - Scheduled Station AE Title
0040:0002 - Scheduled Procedure Step Start Date


These are not the same.
I attempted to modify your code and insert the DicomTagType.Item, like this


DicomElement element = ds.FindFirstElement(null, DicomTagType.ScheduledProcedureStepSequence, true);
if (element == null)
{
element = ds.InsertElement(null, false, DicomTagType.ScheduledProcedureStepSequence, true, 0);
element = ds.InsertElement(element, true, DicomTagType.Item, false, 0);
element = ds.InsertElement(element, true, DicomTagType.ScheduledStationAETitle, false, 0);
element = ds.InsertElement(element, false, DicomTagType.ScheduledProcedureStepStartDate, false, 0);
}

Executing that code gives me an Insufficient Memory error at the line inserting the ScheduledProcedureStepStartDate.

Any further suggestions?

the indenting of the elements did not carry through the post, so here they are again

My example file:

0040:0100 - Scheduled Procedure Step Sequence
----ffee:e000 - Item
--------0040:0001 - Scheduled Station AE Title
--------0040:0002 - Scheduled Procedure Step Start Date


Results with your code:

0040:0100 - Scheduled Procedure Step Sequence
----0040:0001 - Scheduled Station AE Title
----0040:0002 - Scheduled Procedure Step Start Date

The DicomTagType.Item should be passed with the sequence flag set to true:
One way is:
element = ds.InsertElement(null, false, DicomTagType.ScheduledProcedureStepSequence, true, 0);
element = ds.InsertElement(element,true, DicomTagType.Item, true, 0);
ds.InsertElement(element, true, DicomTagType.ScheduledStationAETitle, false, 0);
ds.InsertElement(element, true, DicomTagType.ScheduledProcedureStepStartDate, false, 0);

Another way is:
element = ds.InsertElement(null, false, DicomTagType.ScheduledProcedureStepSequence, true, 0);
element = ds.InsertElement(element,true, DicomTagType.Item, true, 0);
element = ds.InsertElement(element, true, DicomTagType.ScheduledStationAETitle, false, 0);
element = ds.InsertElement(element, false, DicomTagType.ScheduledProcedureStepStartDate, false, 0);

Thank you Adam, I actually came to the solution yesterday and forgot to post back here. I appreciate your assistance, your help definitely pushed me towards the solution.

What is the purpose of inserting Item as a middle layer between ScheduledProcedureStepSequence tag and ScheduledStationAETitle ?
Why cannot we simply add ScheduledStationAETitle directly as the direct child of ScheduledProcedureStepSequence ?

This is due to the encoding rules of a sequence as defined in the DICOM specification.

See PS 3.5 section, 7.5 Nesting of Data Sets, 7.5.1 Item Encoding Rules, 7.5.2 Delimitation of the Sequence of Items.

I have also attached an image from the DICOM Specification showing an example: