HL7 IPC Segment: Imaging Procedure Control Segment

The IPC (Imaging Procedure Control) segment carries the DICOM-aligned identifiers needed to coordinate an imaging procedure step between an information system and a modality worklist. It binds the HL7 order (Accession, Requested Procedure ID) to the DICOM world (Study Instance UID, Scheduled Procedure Step ID), and optionally specifies modality, protocol, and the scheduled station.

IPC is the bridge segment between an imaging order placer and the DICOM Modality Worklist (MWL): the first four fields are mandatory because they uniquely identify the procedure step the modality will perform.

Used in

IPC carries DICOM imaging procedure control in OMI (imaging order) messages. It appears once per scheduled procedure step within the imaging-order group, after ORC/OBR.

Field-by-field reference

The table below lists every field defined for IPC in HL7 v2.5.1, in segment order. The Seq column is the field identifier (e.g. IPC-1). The Data Type column links to the corresponding v2 data-type reference. Req marks whether the field is required by the standard. Repeat indicates whether the field may repeat in a single IPC instance. Table # references the HL7 user- or HL7-defined table when one is well-established.

Seq	Name	Data Type	Length	Req	Repeat	Table #	Description
IPC-1	Accession Identifier	ei	—	R	—	—	Accession assigned by the placer system
IPC-2	Requested Procedure ID	ei	—	R	—	—	Identifier of the requested procedure
IPC-3	Study Instance UID	ei	—	R	—	—	DICOM Study Instance UID for the exam
IPC-4	Scheduled Procedure Step ID	ei	—	R	—	—	DICOM Scheduled Procedure Step identifier
IPC-5	Modality	ce	—	O	—	—	DICOM modality code for the step
IPC-6	Protocol Code	ce	—	O	Y	—	Imaging protocol applied to the step
IPC-7	Scheduled Station Name	ei	—	O	—	—	Station scheduled to perform the step
IPC-8	Scheduled Procedure Step Location	ce	—	O	Y	—	Location where the step is scheduled
IPC-9	Scheduled AE Title	st	—	O	—	—	DICOM Application Entity Title of station

Examples

Minimal IPC

The four required identifiers form a minimal IPC. Real-world Study Instance UIDs and SPS IDs follow DICOM UID syntax (a rooted dotted-decimal string).

IPC|ACC-2026-0009921^^HOSP-ELM^EI|REQ-77410^^HOSP-ELM^EI|1.2.840.114350.2.357.3.798268.2.20260610.094512^^HOSP-ELM^DICOM|SPS-0001^^HOSP-ELM^EI

Fully-populated IPC

IPC|ACC-2026-0009921^^HOSP-ELM^EI|REQ-77410^^HOSP-ELM^EI|1.2.840.114350.2.357.3.798268.2.20260610.094512^^HOSP-ELM^DICOM|SPS-0001^^HOSP-ELM^EI|CT^Computed Tomography^DCM|CT-CHEST-WO^CT Chest without contrast^L~CT-LOWDOSE^Low-dose protocol^L|CT-SCANNER-02^^HOSP-ELM^EI|RAD.CT.ROOM2^Radiology CT Room 2^L|HOSP_CT02

Annotated breakdown

IPC
 |1 Accession Identifier        = ACC-2026-0009921 (placer accession, EI)
 |2 Requested Procedure ID      = REQ-77410        (requested procedure, EI)
 |3 Study Instance UID          = 1.2.840.114350.2.357.3.798268.2.20260610.094512
                                                   (DICOM UID, EI)
 |4 Scheduled Procedure Step ID = SPS-0001         (DICOM SPS ID, EI)
 |5 Modality                    = CT  (DICOM modality, DCM table)
 |6 Protocol Code               = CT-CHEST-WO ~ CT-LOWDOSE  (repeats)
 |7 Scheduled Station Name      = CT-SCANNER-02
 |8 Scheduled Procedure Step
     Location                   = RAD.CT.ROOM2 Radiology CT Room 2
 |9 Scheduled AE Title          = HOSP_CT02  (DICOM AE Title)

In context: IPC inside an OMI imaging order

OMI^O23 carries an imaging order group with one ORC, one OBR, and one or more IPC segments — one IPC per Scheduled Procedure Step that the modality worklist should expose.

MSH|^~&|EHR|HOSP-ELM|RIS|RAD-DEPT|20260610094500||OMI^O23^OMI_O23|MSG00078|P|2.5.1
PID|1||MRN-552108^^^HOSP-ELM^MR||PARK^MIA^E||19880922|F
PV1|1|O|RAD^^^HOSP-ELM||||A455^GREEN^OWEN^^^^MD
ORC|NW|PL-77410^HOSP-ELM|||SC||^^^20260610100000^^R||20260610094500|||A455^GREEN^OWEN^^^^MD
OBR|1|PL-77410^HOSP-ELM||71260^CT CHEST WITHOUT CONTRAST^C4|||20260610100000||||||Cough, rule out infiltrate|||A455^GREEN^OWEN^^^^MD
IPC|ACC-2026-0009921^^HOSP-ELM^EI|REQ-77410^^HOSP-ELM^EI|1.2.840.114350.2.357.3.798268.2.20260610.094512^^HOSP-ELM^DICOM|SPS-0001^^HOSP-ELM^EI|CT^Computed Tomography^DCM|CT-CHEST-WO^CT Chest without contrast^L|CT-SCANNER-02^^HOSP-ELM^EI|RAD.CT.ROOM2^Radiology CT Room 2^L|HOSP_CT02

In context: multi-step imaging procedure

A single study with two scheduled procedure steps (e.g. non-contrast then contrast-enhanced) repeats IPC under the same OBR, each with a distinct SPS ID but a shared Study Instance UID.

ORC|NW|PL-77411^HOSP-ELM|||SC||^^^20260611080000^^R||20260611073000|||A455^GREEN^OWEN^^^^MD
OBR|1|PL-77411^HOSP-ELM||74177^CT ABDOMEN PELVIS W CONTRAST^C4|||20260611080000||||||Abdominal pain|||A455^GREEN^OWEN^^^^MD
IPC|ACC-2026-0009934^^HOSP-ELM^EI|REQ-77411^^HOSP-ELM^EI|1.2.840.114350.2.357.3.798268.2.20260611.073001^^HOSP-ELM^DICOM|SPS-0001^^HOSP-ELM^EI|CT^Computed Tomography^DCM|CT-AP-NONCON^CT Abdomen/Pelvis non-contrast^L|CT-SCANNER-01^^HOSP-ELM^EI|RAD.CT.ROOM1^Radiology CT Room 1^L|HOSP_CT01
IPC|ACC-2026-0009934^^HOSP-ELM^EI|REQ-77411^^HOSP-ELM^EI|1.2.840.114350.2.357.3.798268.2.20260611.073001^^HOSP-ELM^DICOM|SPS-0002^^HOSP-ELM^EI|CT^Computed Tomography^DCM|CT-AP-CONTRAST^CT Abdomen/Pelvis with contrast^L|CT-SCANNER-01^^HOSP-ELM^EI|RAD.CT.ROOM1^Radiology CT Room 1^L|HOSP_CT01

Notes and gotchas

All four identifier fields (IPC-1 through IPC-4) are required. A Modality Worklist consumer that cannot find any one of them will typically reject the worklist item.
Study Instance UID and Scheduled Procedure Step ID are DICOM UIDs. Use a registered root and keep them globally unique; never recycle a UID across procedures.
IPC-6 (Protocol Code) and IPC-8 (Scheduled Procedure Step Location) repeat — useful when a step uses more than one protocol or a logical location resolves to several rooms.
IPC-9 (Scheduled AE Title) carries the DICOM AE Title — typically uppercase, up to 16 characters — used by the modality when querying the worklist.
A single OBR may carry multiple IPC segments when the requested procedure has more than one scheduled procedure step.

FHIR mapping

No segment-level ConceptMap is published in the v2-to-FHIR IG for IPC. Conceptually, IPC content lands across two FHIR resources: IPC-1 Accession Identifier and IPC-2 Requested Procedure ID populate ServiceRequest.identifier, while IPC-3 Study Instance UID maps to ImagingStudy.identifier (DICOM UID system) and IPC-4 Scheduled Procedure Step ID maps to ImagingStudy.series.identifier (or a workflow-step extension). IPC-5 Modality maps to ImagingStudy.modality.

Official sources

HAPI v2.5.1 IPC javadoc — accessed 2026-06-10
HAPI HL7v2 v2.5.1 API index — accessed 2026-06-10
HL7 v2.5.1 product brief — accessed 2026-06-10

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