HL7 ORI_O24 Imaging Order Response

The imaging filler answers the OMI order and returns the identifiers that matter.
HL7 message structure ORI_O24 groups and segments from HL7 v2.5.1 Hide structure

These are the generated groups and segments for the version selected at the top of the page. The article explains the workflow, and this panel follows the chosen HL7 version.

Message Structure

SegmentNameRequiredRepeatable
MSH
 Message Header Yes No
MSA
 Message Acknowledgment Yes No
ERR
 Error No Yes
SFT
 Software Segment No Yes
NTE
 Notes and Comments No Yes
ORI_O24.RESPONSE
 Response group No No
ORI_O24.PATIENT
 Patient group No No
PID
 Patient Identification Yes No
NTE
 Notes and Comments No Yes
ORI_O24.ORDER
 Order group Yes Yes
ORC
 Common Order Yes No
ORI_O24.TIMING
 Timing group No Yes
TQ1
 Timing/Quantity Yes No
TQ2
 Timing/Quantity Relationship No Yes
OBR
 Observation Request Yes No
NTE
 Notes and Comments No Yes
IPC
 Imaging Procedure Control Segment Yes Yes

ORI_O24 is the application response to an OMI_O23 imaging order. It tells the placer whether the imaging order message was accepted and, when useful, returns order, accession, study, or procedure-step identifiers that the placer should store.

The message has the familiar response shape: MSH, MSA, optional ERR, then optional patient/order detail. For imaging, IPC is the segment that makes the response more than a generic order acknowledgment.

A small ORI response example

MSH|^~\&|RIS|CITYHOSP|EHR|CITYHOSP|20260718101503||ORI^O24^ORI_O24|ORI240001|P|2.5.1 MSA|AA|OMI230001 PID|1||123456^^^CITYHOSP^MR||Smith^Jane^Anne^^Ms^^L ORC|OK|IMG440001^EHR|ACC20260718001^RIS||||||20260718101503 OBR|1|IMG440001^EHR|ACC20260718001^RIS|CTHEAD^CT Head without contrast^L|||20260718110000 IPC|ACC20260718001|STUDY20260718001|PROC20260718001|STEP20260718001|CTROOM1

What systems do with it

A RIS or imaging workflow manager usually sends ORI_O24 back to the order placer. The placer may use it to display accepted/rejected state, store the accession number, update scheduling, or correlate later reports and image links with the original order.

If the order is rejected, ERR should explain the real reason. A vague reject for an imaging order can strand the user between the EHR, RIS, modality worklist, and scheduling desk.

How to read the structure

MSA acknowledges the OMI message control ID. ORC carries order status and identifiers. OBR echoes the ordered procedure. IPC returns imaging-specific identifiers and can repeat when the order maps to several imaging procedures or steps.

When the response includes patient/order detail, treat it as correlation data. The response is not the final radiology report and should not be filed as a result.

Implementation traps

Do not discard the filler or accession identifier. If the placer loses it, later report filing, image links, cancellations, and status updates become much harder to match.

Also agree whether ORI is sent synchronously on the same connection or later as a separate application response. That affects retry behavior and whether the sender waits for ORI or only for a basic ACK.

Reference notes

HL7 describes ORI_O24 as the application acknowledgment to an OMI message. See HL7 Europe ORI_O24 and the related OMI_O23 imaging order description.