2 AETitle Questions (spaces and foreign characters)

[jsl...@atl.com]

1) The DICOM Standard indicates that spaces are not allowed
before or after the AETitle, but doesn't say if they are
allowed within a Title. For Example: "MY TITLE" Is this legal?

2) The DICOM Standard says that the AETitle uses the "Default
Character Repertoire", excluding LF, FF, CR and ESC. The
character repertoire is composed exclusively of the English
alphabet. What about foreign Characters?

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[Steve Moore]

jsl...@atl.com wrote:

> 1) The DICOM Standard indicates that spaces are not allowed
> before or after the AETitle, but doesn't say if they are
> allowed within a Title. For Example: "MY TITLE" Is this legal?
>

I believe that spaces inside an AE title are allowed, but would probably

be disruptive. My advice is that you should be prepared to accept
them from someone else, but that your equipment should not produce
them (as the goal is to make integration simple).

>
> 2) The DICOM Standard says that the AETitle uses the "Default
> Character Repertoire", excluding LF, FF, CR and ESC. The
> character repertoire is composed exclusively of the English
> alphabet. What about foreign Characters?
>

I believe the Default Repertoire is limited as your leadup
implies.

Steve Moore
Mallinckrodt Institute of Radiology

[David Clunie]

jsl...@atl.com wrote:

> 1) The DICOM Standard indicates that spaces are not allowed
> before or after the AETitle, but doesn't say if they are
> allowed within a Title. For Example: "MY TITLE" Is this legal?

It is not correct to say that leading and trailing spaces are not
allowed, they may be present but must be ignored. That is,
"MYAE" and " MYAE " are the same AE title.

Yes, spaces are allowed and are significant. That is "MY AE" and
"MYAE" are different but both valid AE titles.

I would try to avoid configuring AE's with spaces, but your app
should allow them, since you may not have control over what the
other guy does. If he uses spaces then you will need to be able
to enter them to match. Just as if he uses lowercase you can't
restrict your config to just upper case.

From Part 5 Table 6.2-1 DICOM VALUE REPRESENTATIONS for VR AE:

"A string of characters with leading and trailing spaces (20H)
being non-significant. The value made of 16 spaces, meaning
"no application name specified", shall not be used. Default
Character Repertoire excluding control characters LF, FF, CR
and ESC."

There are similar rules for the hardwired PDU stuff in Part 8.

> 2) The DICOM Standard says that the AETitle uses the "Default
> Character Repertoire", excluding LF, FF, CR and ESC. The
> character repertoire is composed exclusively of the English
> alphabet. What about foreign Characters?

Nothing beyond 7 bit ASCII (aka ISO 646). So no funky accents
from ISO IR 100 (ISO 8859-1). From Part 5:

"6.1.2.1 Default character repertoire
The default repertoire for character strings in DICOM shall be the
Basic G0 Set of the International Reference Version of ISO 646:1990
(ISO-IR 6). See Annex E for a table of the DICOM default repertoire
and its encoding.

Note: This Basic G0 Set is identical with the common character set
of ISO 8859."

Notice that this means theoretically that characters like "!@#$%^&*()"
and so on are all legal in AE titles (blech).

david
--
David A. Clunie mailto:dcl...@comview.com
Development Director, Medical Imaging Products http://www.comview.com/
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