DICOM Attribute

SOP Instance UID (0008,0018)

Keyword
SOPInstanceUID
VR
UI
VM
1

Definition

Uniquely identifies the SOP Instance. See for further explanation. See also .

From NEMA PS3.3 §C.12.1.

Attribute Metadata

Tag
(0008,0018)
Keyword
SOPInstanceUID
Name
SOP Instance UID
Value Representation (VR)
UI
Value Multiplicity (VM)
1
Status
Active
Source
NEMA PS3.6 (table_6-1)

This attribute is part of the current DICOM Standard. Its value representation is UI with multiplicity 1.

Used in 3 Modules

This attribute uses the UI Value Representation. Multiplicity 1 governs how many values may be encoded.

Integration Notes

Real-world integration guidance for engineers implementing this attribute in Mirth Connect, FHIR gateways, HL7 v2 bridges, and cloud DICOM services. Authoritative source data where available; reference examples and operational notes where they add value.

FHIR Mapping

  • ImagingStudy.series.instance.uid (0008,0018)

Source: HL7 FHIR R5 ImagingStudy (CC0).

HL7 v2 Equivalent

No standard HL7 v2 equivalent published for this attribute. Imaging-only attributes (Image Pixel data, technical acquisition parameters, modality-specific values) typically have no HL7 v2 carrier.

Cloud DICOM Support

  • AWS HealthImaging Required
  • Azure DICOM Required
  • Google Cloud Healthcare Required

SOP Instance UID is required on Store and is the Instance-level QIDO-RS matching key. Drives WADO-RS instance retrieval on all three platforms.

Per-vendor source URLs and verification date in src/content/dicom/cloud-support.json#_meta. Status taxonomy: required (mandated on Store), queryable (QIDO-RS matching key), preserved (stored as-is), promoted (AWS top-level metadata), unsupported (stripped/rejected).

Real-World Sample Values

  • 1.3.6.1.4.1.5962.1.1.1.1.1.20040119072730.12322 CT_small.dcm
  • 1.3.6.1.4.1.5962.1.1.4.1.1.20040826185059.5457 MR_small.dcm
  • 1.2.840.1136190195280574824680000700.3.0.1.19970424140438 ExplVR_BigEnd.dcm

Extracted from pydicom test fixtures (MIT, de-identified).

Mirth Connect Example

Build WADO-RS retrieval URL from SOP Instance UID — Common bridge pattern when forwarding DICOM references to a FHIR ImagingStudy

Common bridge pattern when forwarding DICOM references to a FHIR ImagingStudy.endpoint or to a viewer.

// (0008,0018) SOP Instance UID — use to construct WADO-RS instance retrieval URL
var wadoBase = configurationMap.get('WADO_RS_BASE'); // e.g. https://dicomweb.example.org/wado-rs
var studyUid  = String(msg.dataset.attr.(@tag == '0020000D').value);
var seriesUid = String(msg.dataset.attr.(@tag == '0020000E').value);
var instanceUid = String(msg.dataset.attr.(@tag == '00080018').value);
var wadoUrl = wadoBase + '/studies/' + studyUid + '/series/' + seriesUid + '/instances/' + instanceUid;
channelMap.put('wado_url', wadoUrl);

Reference only — validate before production. Snippets are starting points, not turnkey solutions. Always test against your channel's specific message structure and your facility's interface specification. See Mirth Connect User Guide + NEMA PS3.6 + your vendor conformance statement for authoritative specification.

Common Operational Errors

Operational error patterns for the most-queried tags will be added as coverage expands.

DICOM Integration Services

Saga IT builds production DICOM integrations across Mirth Connect, FHIR gateways, and cloud imaging platforms. If you're working with SOPInstanceUID or the broader (0008,0018) context: