Patient With Special Characters

[venkat.g...@gmail.com]

I have one question to DICOM experts to understand

Can Patient ID/MRN DICOM tag can have Special Characters like for example ";" character.

I have did some research in the standard like


I kept, ; in the Patient ID in sample Images for Patient ID DICOM tag and perform DICOM compliance check with ( Dclunie's dciodverify and DVT Media validation), it didn't throw any error.
That tells that, having ";" in Patient ID is very much possible/valid to keep, DICOM is not saying it is a violation in theory

Patient ID ( as it is LO VR type)


I want to know, is it valid to keep the special character ";" in the Patient ID and should we allow and show the images in the viewer?

Appreciate your quick respone!

[David Clunie]

Yes.

The characters permitted are defined by the LO VR definition, which
you can find at:

http://dicom.nema.org/medical/dicom/current/output/chtml/part05/sect_6.2.html

In short, anything except control characters are permitted, recognizing
that backslash ('\') has a special meaning.

So, there is no reason for you to treat ";" any differently from any other
character, since it is valid for this VR.

David

[venkat.g...@gmail.com]

Thanks David for quick Response!.

Actually, we have seen that in certain Hospital Region, they have divided the facilities/hospitals divided into domains.


Which are better DICOM Tags to identify specific studies are arrived from specific domains/organizations.

I was thinking, Patient ID is main item and Accession Number and Issuer of Accession number is better way to represent from which facility/domain the study arrived to organize properly.

Is my understanding is correct, would you correct me and suggest better way of getting this kind of information from any DICOM tags.

[David Clunie]

Hi Ven

I assume this is related to your previous question about special
characters because you have examples of sites stuffing a textual
identity domain disambiguator in with the patient ID value. Using
a prefix or suffix to qualify Patient ID or Accession Number is a
not uncommon ad hoc way of avoiding collisions when institutions
merge or interact (though the 16 character SH VR of Accession
Number makes this harder, compared to the 64 character LO limit
for Patient ID).

A "better" way to address this is using the mechanisms described in
the Multiple Image Manager/Archive (MIMA) profile:

http://www.ihe.net/technical_frameworks/#radiology

In short, this specifies the use (including mapping and defaults) for
these attributes (amongst others):

- Issuer of Patient ID (0010,0021)
- Issuer of Accession Number Sequence (0008,0051)
- Other Patient IDs Sequence (0010,1002)
- Institution Name (0008,0080)
- Institution Code Sequence (0008,0082)

By the way, it is important to consider two potentially distinct ways
in which this information can be used:

- to communicate the identity domain in which the identifier is defined
- to communicate in what domain the instance was acquired/created

One cannot assume that because an identifier in a particular domain is
present in an object, that it was acquired in that domain, because it
may have been coerced (e.g., into the local domain) during ingestion
(etc.). Hence the use of Institution Code Sequence in MIMA.

The MIMA profile also describes the concept of an AE title based mapping
for when the sending system lacks support for these attributes, i.e., the
receiving system adds the issuer information (etc.) based on (configured)
knowledge about where an object came from.

David

PS. Related to this is IHE CP-RAD-222, work in progress, which addresses
the Acquisition Modality populating these de novo (with SWF.b, unrelated
to MIMA), by adding an Enterprise Identity Option, requiring the presence
(and query support for) Issuer of Patient ID and Issuer of Accession Number
Sequence.