2:Appendices Volume 2 Appendices (HL7 Segments, Message Templates)

Digital Pathology Ordering & Workflow (DPOW)
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Digital Pathology Ordering & Workflow (DPOW), published by IHE Pathology and Laboratory Medicine Technical Committee. This guide is not an authorized publication; it is the continuous build for version 0.1.0-current built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/IHE/PaLM.DPOW/ and changes regularly. See the Directory of published versions

Appendix A - Common HL7 Message Segments for DPOW Transactions
Appendix B - Message Examples
Namespace Additions for Volume 2

This page collects the Volume 2 appendices for the DPOW profile: the message abstract syntax and the common HL7 v2 message segment definitions (Appendix A).

All DPOW transactions leverage a constrained profile of HL7 OML^O21. The OML^O21 (Laboratory Order) message initiates each transaction; ORL^O22 (Laboratory Order Response) is the application acknowledgement.

Key aspects of OML^O21 / ORL^O22:

Trigger event: any change to a laboratory order (new order, cancellation, update)
Designed for specimen-centric workflows where specimen/container information is embedded within the ORC/OBR segment group
Supports complex orders with multiple specimens, containers, and test requests
ORL^O22 is the direct response from the filler to the placer

Work Item WI-DPOW-01 - Message Structure Validation. The DPOW message abstract syntax and segment usage require formal validation against the normative HL7 v2.5.1 OML^O21 / ORL^O22 structure by the PaLM TC HL7 working group before Trial Implementation.

Appendix A - Common HL7 Message Segments for DPOW Transactions

The following segment definitions apply to all DPOW transactions. Usage codes: R Required, RE Required but may be empty, O Optional, C Conditional, X Not supported.

Message Abstract Syntax

Every DPOW transaction uses a constrained HL7 v2.5.1 OML^O21 message; the response is ORL^O22. The trees below give the abstract syntax for each message profile - identified by MSH-21 - showing each segment and segment group with its cardinality [min..max] (0 = optional, * = repeatable). Indentation shows segment-group nesting, following the standard OML^O21 groups (PATIENT, PATIENT_VISIT, ORDER, TIMING, OBSERVATION_REQUEST, OBSERVATION, SPECIMEN). Message profiles that share the same abstract syntax are listed together. The overall structure and the placement of the pre-adopted PRT segment is subject to validation (see WI-DPOW-01).

Physical Asset Registration - DPOW-SPECIMEN^IHE, DPOW-BLOCK^IHE, DPOW-SLIDE^IHE (Physical Asset Registration [LAB-100])

MSH                       [1..1]
PATIENT                   [1..1]
  PID                     [1..1]
  PATIENT_VISIT           [0..1]
    PV1                   [1..1]
ORDER                     [1..1]
  ORC                     [1..1]
  TIMING                  [0..1]
    TQ1                   [1..1]
  OBSERVATION_REQUEST     [1..1]
    OBR                   [1..1]
    NTE                   [0..*]
    PRT                   [0..*]   pathologist / participants
    SPECIMEN              [1..1]
      SPM                 [1..1]
      OBX                 [0..*]   fixative / embedding / stain
      SAC                 [0..1]
      NTE                 [0..*]

Case Update - DPOW-CASE-UPDATE^IHE (Case Update [LAB-101])

MSH                       [1..1]
PATIENT                   [1..1]
  PID                     [1..1]
ORDER                     [1..1]
  ORC                     [1..1]
  OBSERVATION_REQUEST     [1..1]
    OBR                   [1..1]
    NTE                   [0..*]   case-level comments

Place Work Order - DPOW-PLACE-WO^IHE (Place Work Order [LAB-102])

MSH                       [1..1]
PATIENT                   [1..1]
  PID                     [1..1]
  PATIENT_VISIT           [0..1]
    PV1                   [1..1]
ORDER                     [1..1]
  ORC                     [1..1]   ORC-1 = NW
  TIMING                  [0..1]
    TQ1                   [1..1]
  OBSERVATION_REQUEST     [1..1]
    OBR                   [1..1]
    NTE                   [0..*]

Accept Work Order - DPOW-ACCEPT-WO^IHE (Accept Work Order [LAB-103])

MSH                       [1..1]
PATIENT                   [1..1]
  PID                     [1..1]
ORDER                     [1..1]
  ORC                     [1..1]   ORC-5 = CM
  OBSERVATION_REQUEST     [1..1]
    OBR                   [1..1]
    SPECIMEN              [1..1]
      SPM                 [1..1]   SPM-2.1 placer / SPM-2.2 filler identifier

Image Availability Notification - DPOW-IMAGE-NOTIF^IHE (Image Availability Notification [LAB-104])

MSH                       [1..1]
PATIENT                   [1..1]
  PID                     [1..1]
ORDER                     [1..1]
  ORC                     [1..1]
  OBSERVATION_REQUEST     [1..1]
    OBR                   [1..1]
    SPECIMEN              [1..1]
      SPM                 [1..1]
      OBX                 [0..*]   Study / Series Instance UID (Value Type RP)

Acknowledgement - ORL^O22 (response to all DPOW transactions)

MSH                       [1..1]
MSA                       [1..1]
ERR                       [0..*]
PATIENT                   [0..1]
  PID                     [1..1]
ORDER                     [0..*]
  ORC                     [1..1]   e.g., ORC-1 = OK (accepted) / UA (cannot fulfil) for [LAB-102]

A.1 MSH Segment

SEQ	DT	Usage	Card	Element Name
9	MSG	R	[1..1]	Message Type
12	VID	R	[1..1]	Version ID (2.5.1)
21	EI	R	[1..1]	Message Profile Identifier

SEQ

DT

Usage

Card

Element Name

9

MSG

R

[1..1]

Message Type

12

VID

R

[1..1]

Version ID (2.5.1)

21

EI

R

[1..1]

Message Profile Identifier

MSH-21 SHALL reference the applicable DPOW transaction:

IHE DPOW Transaction Transaction Name MSH-21 Value

LAB-100 (specimen) Physical Asset Registration - Specimen DPOW-SPECIMEN^IHE

LAB-100 (block) Physical Asset Registration - Block DPOW-BLOCK^IHE

LAB-100 (slide) Physical Asset Registration - Slide DPOW-SLIDE^IHE

LAB-101 Case Update DPOW-CASE-UPDATE^IHE

LAB-102 Place Work Order DPOW-PLACE-WO^IHE

LAB-103 Accept Work Order DPOW-ACCEPT-WO^IHE

LAB-104 Image Availability Notification DPOW-IMAGE-NOTIF^IHE

IHE DPOW Transaction	Transaction Name	MSH-21 Value
LAB-100 (specimen)	Physical Asset Registration - Specimen	`DPOW-SPECIMEN^IHE`
LAB-100 (block)	Physical Asset Registration - Block	`DPOW-BLOCK^IHE`
LAB-100 (slide)	Physical Asset Registration - Slide	`DPOW-SLIDE^IHE`
LAB-101	Case Update	`DPOW-CASE-UPDATE^IHE`
LAB-102	Place Work Order	`DPOW-PLACE-WO^IHE`
LAB-103	Accept Work Order	`DPOW-ACCEPT-WO^IHE`
LAB-104	Image Availability Notification	`DPOW-IMAGE-NOTIF^IHE`

A.2 ORC Segment

SEQ	DT	Usage	Card	Element Name	Example
1	ID	R	[1..1]	Order Control	NW, XO, CA
2	EI	O	[0..1]	Placer Order Number	PL12345
3	EI	O	[0..1]	Filler Order Number	FL098756
5	ID	O	[0..1]	Order Status	IP
15	DTM	O	[0..1]	Order Effective Date/Time	20250526094900
25	CWE	O	[0..1]	Order Status Modifier	Final^Final^99DPOW
34	CWE	O	[0..*]	Order Workflow Profile	(see value set below)
35	ID	O	[0..1]	Action Code	U
38	EI	RE	[0..1]	Filler Order Group Number	S25.0001

SEQ

DT

Usage

Card

Element Name

Example

1

ID

R

[1..1]

Order Control

NW, XO, CA

2

EI

O

[0..1]

Placer Order Number

PL12345

3

EI

O

[0..1]

Filler Order Number

FL098756

5

ID

O

[0..1]

Order Status

IP

15

DTM

O

[0..1]

Order Effective Date/Time

20250526094900

25

CWE

O

[0..1]

Order Status Modifier

Final^Final^99DPOW

34

CWE

O

[0..*]

Order Workflow Profile

(see value set below)

35

ID

O

[0..1]

Action Code

U

38

EI

RE

[0..1]

Filler Order Group Number

S25.0001

ORC-34 Order Workflow Profile - Proposed Value Set

Pre-adoption note: ORC-34 was introduced in HL7 v2.9. Its use in DPOW (targeting HL7 v2.5.1) is a pre-adoption. Implementations SHALL declare support for this field.

Pre-adoption note: ORC-38 (Filler Order Group Number) was introduced in HL7 v2.9. Its use in DPOW (targeting HL7 v2.5.1) is a pre-adoption to carry the case accession number for DPIA alignment; implementations SHALL declare support for this field.

Value	Display Name	Comment
IMAGE	Image	LIS-driven workflow and reporting
PACS-WORKFLOW	PACS Workflow	PACS-driven workflow and reporting on LIS
PACS-REPORTING	PACS Reporting	PACS-driven workflow and reporting

Value

Display Name

Comment

IMAGE

Image

LIS-driven workflow and reporting

PACS-WORKFLOW

PACS Workflow

PACS-driven workflow and reporting on LIS

PACS-REPORTING

PACS Reporting

PACS-driven workflow and reporting

A.3 OBR Segment

SEQ	DT	Usage	Card	Element Name	Example
2	EI	O	[0..1]	Placer Order Number	PL12345
3	EI	O	[0..1]	Filler Order Number	FL098756
4	CWE	R	[1..1]	Universal Service Identifier	687891.024^Digital AP Study^L
13	CWE	O	[0..*]	Relevant Clinical Information	-
25	ID	O	[0..1]	Result Status	-
31	CWE	O	[0..*]	Reason for Study	-

SEQ

DT

Usage

Card

Element Name

Example

2

EI

O

[0..1]

Placer Order Number

PL12345

3

EI

O

[0..1]

Filler Order Number

FL098756

4

CWE

R

[1..1]

Universal Service Identifier

687891.024^Digital AP Study^L

13

CWE

O

[0..*]

Relevant Clinical Information

-

25

ID

O

[0..1]

Result Status

-

31

CWE

O

[0..*]

Reason for Study

-

A.4 SPM Segment

SEQ	DT	Usage	Card	Element Name	Example
2	EIP	O	[0..1]	Specimen Identifier	S25.0001.A.01.01
2.1	EI	O	[0..1]	Placer Assigned Identifier	(DAWM temp ID for work orders)
2.2	EI	O	[0..1]	Filler Assigned Identifier	S25.0001.A.01.01 (PAWM definitive ID)
3	EIP	O	[0..*]	Specimen Parent IDs	S25.0001.A.01
4	CWE	R	[1..1]	Specimen Type	TISS^Tissue^HL70487
6	CWE	O	[0..*]	Specimen Additives	(see OBX-5)
7	CWE	O	[0..1]	Specimen Collection Method	INCBIO^Incisional biopsy^L
8	CWE	O	[0..1]	Specimen Source Site	80248007^Breast structure^SCT
9	CWE	O	[0..*]	Specimen Source Site Modifier	7771000^Left^SCT
14	ST	O	[0..*]	Specimen Description	Left breast incisional biopsy
17	DTM	O	[0..1]	Specimen Collection Date/Time	20230822073025
18	DTM	O	[0..1]	Specimen Received Date/Time	20230822100052
20	ID	O	[0..1]	Specimen Availability	Y (available) / N (de-associated)
25	CQ	O	[0..1]	Specimen Current Quantity	1^number&UCUM
27	CWE	O	[0..1]	Container Type	(see SPM-27 value set)
30	CX	O	[0..*]	Accession ID	S25.0001

SEQ

DT

Usage

Card

Element Name

Example

2

EIP

O

[0..1]

Specimen Identifier

S25.0001.A.01.01

2.1

EI

O

[0..1]

Placer Assigned Identifier

(DAWM temp ID for work orders)

2.2

EI

O

[0..1]

Filler Assigned Identifier

S25.0001.A.01.01 (PAWM definitive ID)

3

EIP

O

[0..*]

Specimen Parent IDs

S25.0001.A.01

4

CWE

R

[1..1]

Specimen Type

TISS^Tissue^HL70487

6

CWE

O

[0..*]

Specimen Additives

(see OBX-5)

7

CWE

O

[0..1]

Specimen Collection Method

INCBIO^Incisional biopsy^L

8

CWE

O

[0..1]

Specimen Source Site

80248007^Breast structure^SCT

9

CWE

O

[0..*]

Specimen Source Site Modifier

7771000^Left^SCT

14

ST

O

[0..*]

Specimen Description

Left breast incisional biopsy

17

DTM

O

[0..1]

Specimen Collection Date/Time

20230822073025

18

DTM

O

[0..1]

Specimen Received Date/Time

20230822100052

20

ID

O

[0..1]

Specimen Availability

Y (available) / N (de-associated)

25

CQ

O

[0..1]

Specimen Current Quantity

1^number&UCUM

27

CWE

O

[0..1]

Container Type

(see SPM-27 value set)

30

CX

O

[0..*]

Accession ID

S25.0001

SPM-6 SHALL NOT be used. Fixative, embedding medium, and staining information SHALL be conveyed in OBX-5 (CWE) segments (see A.10).

SPM-4 SHALL use TISS or an appropriate SCT code. SPM-5 SHOULD NOT be used.

SPM-8 SHOULD use SNOMED CT codes for body structure (e.g., 80248007^Breast structure^SCT).

SPM-9 SHOULD use SNOMED CT codes for laterality (e.g., 7771000^Left^SCT).

SPM-18 carries the scan date/time exclusively in [LAB-104] (Image Availability Notification). In all other DPOW transactions it retains its standard HL7 meaning of Specimen Received Date/Time.

SPM-20 is used in [LAB-104] to indicate image availability (Y) or de-association (N).

SPM-27 Container Type - Value Set

Value	Display Name	Used for
CONTAINER	Specimen Container	Specimen / container registration
CASSETTE	Block Cassette	Block registration
GLASS	Glass Slide	Slide registration

Value

Display Name

Used for

CONTAINER

Specimen Container

Specimen / container registration

CASSETTE

Block Cassette

Block registration

GLASS

Glass Slide

Slide registration

A.5 SAC Segment

SEQ	DT	Usage	Card	Element Name	Example
2	EI	O	[0..1]	Accession Identifier	S25.0001
3	EI	O	[0..1]	Container Identifier	S25.0001.A
4	EI	O	[0..1]	Primary Container Identifier	S25.0001
7	DTM	O	[0..1]	Registration Date/Time	20230822093007
8	CWE	O	[0..1]	Container Status	R^Process Completed^HL70370
15	CWE	O	[0..*]	Location	HISTO-LAB-01^Histology Lab A1^L
48	CWE	O	[0..1]	Container Material	WSI

SEQ

DT

Usage

Card

Element Name

Example

2

EI

O

[0..1]

Accession Identifier

S25.0001

3

EI

O

[0..1]

Container Identifier

S25.0001.A

4

EI

O

[0..1]

Primary Container Identifier

S25.0001

7

DTM

O

[0..1]

Registration Date/Time

20230822093007

8

CWE

O

[0..1]

Container Status

R^Process Completed^HL70370

15

CWE

O

[0..*]

Location

HISTO-LAB-01^Histology Lab A1^L

48

CWE

O

[0..1]

Container Material

WSI

SAC-48 pre-adoption: SAC-48 (Container Material) is a field introduced in HL7 v2.9.1. Its use in DPOW (targeting HL7 v2.5.1) is a pre-adoption. Implementations SHALL declare support for this field.

SAC-48 Container Material - Value Set

Value	Display Name	Comment
WSI	Whole Slide Image	Glass slides eligible for or already scanned
OTH	Other	Non-scannable or non-eligible specimens

Value

Display Name

Comment

WSI

Whole Slide Image

Glass slides eligible for or already scanned

OTH

Other

Non-scannable or non-eligible specimens

A.6 NTE Segment (Notes and Comments)

SEQ	DT	Usage	Card	Element Name	Example
2	ID	O	[0..1]	Source of Comment	L
3	FT	O	[0..*]	Comment	Malignant region painted in yellow
4	CWE	O	[0..1]	Comment Type	BLOCK^Block comment^99DPOW

SEQ

DT

Usage

Card

Element Name

Example

2

ID

O

[0..1]

Source of Comment

L

3

FT

O

[0..*]

Comment

Malignant region painted in yellow

4

CWE

O

[0..1]

Comment Type

BLOCK^Block comment^99DPOW

NTE-4 Comment Type - Proposed Value Set

Value	Display Name	Context
(empty)	Order-level remark	After ORC
SBOX	Specimen box comment	After SAC
BLOCK	Block comment	After SAC

Value

Display Name

Context

(empty)

Order-level remark

After ORC

SBOX

Specimen box comment

After SAC

BLOCK

Block comment

After SAC

A.7 TQ1 Segment (Timing/Quantity)

SEQ	DT	Usage	Card	Element Name	Example
2	CQ	O	[0..1]	Quantity	1
7	DTM	O	[0..1]	Start Date/Time	20230822103000
8	DTM	O	[0..1]	End Date/Time	20230824103000
9	CWE	O	[0..1]	Priority	R^Routine^HL70485

SEQ

DT

Usage

Card

Element Name

Example

2

CQ

O

[0..1]

Quantity

1

7

DTM

O

[0..1]

Start Date/Time

20230822103000

8

DTM

O

[0..1]

End Date/Time

20230824103000

9

CWE

O

[0..1]

Priority

R^Routine^HL70485

A.8 PRT Segment (Participation)

Pre-adoption note: PRT is a v2.7+ segment. Implementations targeting HL7 v2.5.1 SHOULD use OBR-32 (Principal Result Interpreter) for the reading pathologist instead.

SEQ	DT	Usage	Card	Element Name	Example
1	EI	O	[0..1]	Participation Instance ID	1151651916348
2	ID	R	[1..1]	Action Code	AD
4	CWE	R	[1..1]	Participation	PI^Primary Interpreter^HL70443
5	XCN	O	[0..*]	Participation Person	path01^SMITH^JACQUELINE
9	PL	O	[0..1]	Participation Organization	HospA

SEQ

DT

Usage

Card

Element Name

Example

1

EI

O

[0..1]

Participation Instance ID

1151651916348

2

ID

R

[1..1]

Action Code

AD

4

CWE

R

[1..1]

Participation

PI^Primary Interpreter^HL70443

5

XCN

O

[0..*]

Participation Person

path01^SMITH^JACQUELINE

9

PL

O

[0..1]

Participation Organization

HospA

A.9 PID Segment (Patient Identification)

SEQ	DT	Usage	Card	Element Name	Example
3	CX	R	[1..*]	Patient Identifier List	1234567890^^^MyHospHIS&1.2.3.4.5&ISO
5	XPN	R	[1..*]	Patient Name	SMITH^MARY
7	DTM	O	[0..1]	Date/Time of Birth	19000101
8	CWE	O	[0..1]	Administrative Sex	F
29	DTM	O	[0..1]	Patient Death Date and Time
30	ID	O	[0..1]	Patient Death Indicator	N

SEQ

DT

Usage

Card

Element Name

Example

3

CX

R

[1..*]

Patient Identifier List

1234567890^^^MyHospHIS&1.2.3.4.5&ISO

5

XPN

R

[1..*]

Patient Name

SMITH^MARY

7

DTM

O

[0..1]

Date/Time of Birth

19000101

8

CWE

O

[0..1]

Administrative Sex

F

29

DTM

O

[0..1]

Patient Death Date and Time

30

ID

O

[0..1]

Patient Death Indicator

N

A.10 OBX Segment

OBX is used in two distinct contexts in DPOW.

A.10.1 OBX for Specimen Preparation Metadata ([LAB-100])

One or more OBX segments SHALL follow the SPM segment in [LAB-100] to convey fixative (specimen level), embedding medium (block level), and staining (slide level) information. This replaces the former use of SPM-6 and aligns with DPIA (IHE PaLM DPIA Rev 1.4, Section 3 and Appendix A.2).

SPM-6 SHALL NOT be used for this purpose in DPOW (consistent with DPIA).

SEQ	DT	Usage	Card	Element Name	Notes
1	SI	R	[1..1]	Set ID	Sequential, starting at 1
2	ID	R	[1..1]	Value Type	CWE
3	CWE	R	[1..1]	Observation Identifier	See Table A.10.1-1
4	varies	O	[0..1]	Observation Sub-ID	Used to group multiple OBX segments for the same preparation step (e.g., H&E components). Common value links segments.
5	CWE	R	[1..1]	Observation Value	SCT code for the specific substance (fixative, medium, or stain)
11	ID	R	[1..1]	Observation Result Status	F

SEQ

DT

Usage

Card

Element Name

Notes

1

SI

R

[1..1]

Set ID

Sequential, starting at 1

2

ID

R

[1..1]

Value Type

CWE

3

CWE

R

[1..1]

Observation Identifier

See Table A.10.1-1

4

varies

O

[0..1]

Observation Sub-ID

Used to group multiple OBX segments for the same preparation step (e.g., H&E components). Common value links segments.

5

CWE

R

[1..1]

Observation Value

SCT code for the specific substance (fixative, medium, or stain)

11

ID

R

[1..1]

Observation Result Status

F

Table 2:A.10.1-1: Standard OBX-3 Codes for Specimen Preparation (aligned with DPIA)

Preparation Type OBX-3 Code OBX-3 Display Coding System Level

Fixative 430864009 Tissue fixative SCT Specimen

Embedding medium 430863003 Embedding medium SCT Block

Stain 397165007 Stain SCT Slide

Preparation Type	OBX-3 Code	OBX-3 Display	Coding System	Level
Fixative	`430864009`	Tissue fixative	SCT	Specimen
Embedding medium	`430863003`	Embedding medium	SCT	Block
Stain	`397165007`	Stain	SCT	Slide

When a stain uses more than one substance (e.g., H&E), one OBX segment SHALL be sent per substance, and all segments for that stain SHALL share a common value in OBX-4 to group them.

OBX-3 (Observation Identifier) declares which preparation attribute the segment carries, and OBX-5 (Observation Value) carries the specific substance. For example, a formalin-fixed, paraffin-embedded, H&E-stained slide is conveyed as:

OBX|1|CWE|430864009^Tissue fixative^SCT||431510009^Formalin^SCT||||||F
OBX|2|CWE|430863003^Embedding medium^SCT||311731000^Paraffin wax^SCT||||||F
OBX|3|CWE|397165007^Stain^SCT|1|12710003^Hematoxylin stain^SCT||||||F
OBX|4|CWE|397165007^Stain^SCT|1|36879007^Water soluble eosin stain^SCT||||||F

A.10.2 OBX for Image Availability ([LAB-104])

OBX segments following the SPM in [LAB-104] convey Study and Series Instance UIDs linking the notification to the DICOM study. Because each value is a DICOM UID reference rather than free text, the Value Type (OBX-2) is RP (Reference Pointer) and OBX-5 carries the UID as the reference pointer.

SEQ	DT	Usage	Card	Element Name	Example
1	SI	R	[1..1]	Set ID	1
2	ID	R	[1..1]	Value Type	RP
3	CWE	R	[1..1]	Observation Identifier	StudyInstanceUID^^DCM
5	RP	O	[0..1]	Observation Value	1.2.3.4.5.1234567890
11	ID	R	[1..1]	Observation Result Status	F

SEQ

DT

Usage

Card

Element Name

Example

1

SI

R

[1..1]

Set ID

1

2

ID

R

[1..1]

Value Type

RP

3

CWE

R

[1..1]

Observation Identifier

StudyInstanceUID^^DCM

5

RP

O

[0..1]

Observation Value

1.2.3.4.5.1234567890

11

ID

R

[1..1]

Observation Result Status

F

Appendix B - Message Examples

Worked message examples are deferred pending validation of the message structure against the normative HL7 v2.5.1 OML^O21 / ORL^O22 definition (see WI-DPOW-01). Message content is specified by the Message Abstract Syntax and the segment definitions in Appendix A.

Namespace Additions for Volume 2

No new namespace additions at this time. The PaLM registry of OIDs is located at the IHE PaLM Google Drive.

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