One of the challenges of creating a DICOM message is how to implement putting data in the correct place. Part of it is by inserting the data in the specific DICOM tags, while the other is to insert binary data such as a picture - In this article I will explain both.

To create a DICOM message, you can either use the  EnsLib.DICOM.File class (to create a DICOM file) or the  EnsLib.DICOM.Document class (to create a message that can be sent to PACS directly). In either case, the SetValueAt method will allow you to add your data to the DICOM tags.

A DICOM message consists of two constituent parts, CommandSet and the DataSet.
The CommandSet contains DICOM elements which contain details about the characteristics of the DataSet, while the DataSet contains the data itself - patient's demographic, image etc.

To update the tags in the CommandSet or the DataSet, simply state the value and the name of the property you wish to update using the SetValueAt method:

set tstatus=tDoc.SetValueAt("1.2.840.10008.5.1.4.1.1.7","CommandSet.MediaStorageSOPClassUID")
set tstatus=tDoc.SetValueAt("1.2.392.200059.1.11.11084587.3.35820032317.2.1.56","CommandSet.MediaStorageSOPInstanceUID") 
set tstatus=tDoc.SetValueAt("1.2.276.0.7230010.3.0.3.6.4","CommandSet.ImplementationClassUID") 
set tstatus=tDoc.SetValueAt("OFFIS_DCMTK_364","CommandSet.ImplementationVersionName") 
set tstatus=tDoc.SetValueAt("Morgan^Gina^G","DataSet.PatientName") 
set tstatus=tDoc.SetValueAt("2751","DataSet.PatientID")
set tstatus=tDoc.SetValueAt("19810816","DataSet.PatientBirthDate")	
set tstatus=tDoc.SetValueAt("F","DataSet.PatientSex") 

	set tstatus=tDoc.SetValueAt("Olympus","DataSet.Manufacturer")		
	set tstatus=tDoc.SetValueAt("Olympus","DataSet.(0008,0070)") 

Once the message is created and transferred to PACS as a document, you can see its data as part of the trace (note that binary data cannot be seen):

In order to add the binary data for the image, it is more complicated that just putting the data in a specific tag, because it needs to be structured in a specific way and measured appropriately. This is why after updating the tags and saving the document, we need to open it as a simple binary file and add the image data at the end of it in a specific manner.

The image is part of the PixelData property in tag (7FE0,0010).

This tag is a sequence - DICOM allows a DataSet to contain other nested DataSets, which are encoded as “sequences”. The point of this structure is to allow repeating groups of data, so whilst such sequences often only contain a single DataSet, the format is defined such that each sequence consists of a set of DataSets.

This structure can be used in recursion, and some DICOM scenarios might use sequences nested 5 or 6 deep.

The demo shows a sample of creating a DICOM document with an image in it. The patient's demographic and other details are just for the sake of teh sample. To run this demo, simply put a JPG file in a directory, configure the directory name in the 'FileStorageDirectory' property in the business operation's settings:

and run the Business Process. After its completion, you'll see a new dcm file in the same directory where your JPG file was. open it in a DICOM viewer and you'll see the DICOM tags as well as the image in it:

Here is a quick demo showing the whole process:

Look for the demo files and instruction in Open Exchange:

https://openexchange.intersystems.com/package/DICOM--Image-Demo

Keren.

In a project I'm working on we need to store some arbitrary XML in the database. This XML does not have any corresponding class in IRIS, we just need to store it as a string (it's relatively small and can fit in a string).
Since there are MANY (millions!) of records in the database I decided to reduce as much as possible the size without compressing. I know that some XML to be stored is indented, some not, it varies.
To reduce the size I decided to minify  the XML, but how do I minify an XML document in IRIS?
I searched across all the classes/utilities and I could not find a ready made code/method, so I had to implement it and it turned out to be fairly simple in IRIS using %XML.TextReader class, frankly simpler than I expected.

Since this can be useful in some other context, I decided to share this little utility with the Developer Community.
I've tested with some fairly complex XML documents and works fine, here is the code.

/// Minify an XML document passed in the XmlIn Stream, the minified XML is returned in XmlOut Stream
/// If XmlOut Stream is passed, then the minified XML is stored in the passed Stream, otherwise a %Stream.TmpCharacter in returned in XmlOut.
/// Collapse = 1 (default), empty elements are collapsed, e.g. <tag></tag> is returned as <tag/>
/// ExcludeComments = 1 (default), comments are not returned in the minified XML
ClassMethod MinifyXML(XmlIn As %Stream, ByRef XmlOut As %Stream = "", Collapse As %Boolean = 1, ExcludeComments As %Boolean = 1) As %Status
{
	#Include %occSAX
	Set sc=$$$OK
	Try {
		Set Mask=$$$SAXSTARTELEMENT+$$$SAXENDELEMENT+$$$SAXCHARACTERS+$$$SAXCOMMENT
		Set sc=##class(%XML.TextReader).ParseStream(XmlIn,.reader,,$$$SAXNOVALIDATION,Mask)
		#dim reader as %XML.TextReader
		If $$$ISERR(sc) Quit
		If '$IsObject(XmlOut) {
			Set XmlOut=##class(%Stream.TmpCharacter).%New()
		}
		While reader.Read() {
			Set type=reader.NodeType
			If ((type="error")||(type="fatalerror")) {
				Set sc=$$$ERROR($$$GeneralError,"Error loading XML "_type_"-"_reader.Value)
				Quit
			}
			If type="element" {
				Do XmlOut.Write("<"_reader.Name)
				If Collapse && reader.IsEmptyElement {
					; collapse empty element
					Do XmlOut.Write("/>")
					Set ElementEnded=1
				} Else {
					; add attributes
					For k=1:1:reader.AttributeCount {
						Do reader.MoveToAttributeIndex(k)
						Do XmlOut.Write(" "_reader.Name_"="""_reader.Value_"""")
					}
					Do XmlOut.Write(">")
				}
			} ElseIf type="chars" {
				Set val=reader.Value
				Do XmlOut.Write($select((val["<")||(val[">")||(val["&"):"<![CDATA["_$replace(val,"]]>","]]]]><![CDATA[>")_"]]>",1:val))
			} ElseIf type="endelement" {
				If $g(ElementEnded) {
					; ended by collapsing
					Set ElementEnded=0
				} Else {
					Do XmlOut.Write("</"_reader.Name_">")
				}
			} ElseIf 'ExcludeComments && (type="comment") {
				Do XmlOut.Write("<!--"_reader.Value_"-->")
			}
		}
	} Catch CatchError {
		#dim CatchError as %Exception.SystemException
		Set sc=CatchError.AsStatus()
	}
	Quit sc
}

P.S.: anyone know if there is other/simpler way to minify XML in IRIS?