Requirements for StudyUID in Modality Worklist Results

There are strict rules for UID formatting and usage. If these are not followed, then some modality equipment may refuse to accept MWL results containing "bad" UIDs. Not all equipment is equally "fussy", and in particular, most equipment will not check for leading zeros, but GE equipment nearly always does (there is sound logic for this, as they would be "outputting" faulty UIDs themselves is they accepted your bad UID).

The most common reasons for StudyUIDs not being accepted by modalities in Modality Worklist return results are:

  • Invalid StudyUID formatting including:
    • Leading "0"s in a component.
Each component must be capable of being represented unambiguously as either a string or an integer, so this UID is OK
1.2.826.0.1.3680043
The 0 is on its own and unambiguous
But this is not:
1.2.827.0.1.03680043
The leading zero in 03680043 is superfluous and illegal.
  • StudyUID in the wrong attribute (it must be a top level attribute, not within a sequence)

Further cautions and information about StudyUID in MWL results:

  • Obviously, the UID returned must be different for different studies
  • Less obvious, and often done wrongly, is the requirement that the same UID should be returned for each request for the same information, so creating UIDs "on the fly" when responding to MWL requests is not acceptable

For more details on UIDs, see UID_Rules

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