Anatomical location

It’s really a long thread and I might not see the whole picture. Anyway:

The problem discussed seems to be related to the laterality and if we want right, left and bilateral classification. I think it’s great to have the possibility to express laterality this way. For some use-cases you want to express a phenomen using the bilateral qualifier. If you talk about the elbow and the extenstion is limited both in right and left elbow - you might say it is bilateral. That’s fine.

Laterality is not the only problem with location. It get’s even worse when you go into the compositional nature of anatomical location. When you talk about pain in the knee. And you find that the patient locates the pain to the proximal part of patella. How would you express this in the data?

I think there are several ways to store such information in the data. Which in turn makes it harder to reuse the information. For human it will be no problem to read and understand. For machines you need some kind of AI to reason over the data. Very soon you’ll see that you left the situation with simple AQL and reuse. You need more complex reasoning on the content. That’s fine with me. But someone has to take the cost one day :slight_smile:

And the to come back to laterality. If you express redused extension in the elbow using right and left, or using the bilateral qualified doesn’t really matter. The software has to reason about anatomical location any way.

That’s my five cents on this topic. Hope I didn’t misundertand everything…

Hi Bjorn,

The key question here is I guess whether we need separate archetypes one for where the location is single and fairly precise, and another for where bilateral is allowed and for other broad locations like x-ray + ‘Chest’ .

I agree about the deeper challenges of anatomical location but Ithink we should steer well clear of trying to go down that road - if that is needed I would absolutely point people to SNOMED-CT , both as solution and as a pointer to the complexity. At that, level anatomy is a biomedical truth and for me, very much the strength of an ontological approach.

IMHO we only need one archetype for anatomical location.

About the deeper challenges:
Yes you need a terminology or ontological vocabulary.I think that’s obvious, unless we are thinking about modelling the core body parts with openEHR archetypes. When using terminologies you need to think careful about the information model in the archetype versus the combined (pre-/post coordinated) expressions in the terminology used. This is what we discuss the most internally - which granularity to use for a given use-case. I guess that is outside the scope of this thread.

This might be an issue/challenge what our two-level modelling method has to deal with as the method push pretty much complexity into domain content modelling. One component of the challenge is that it would be difficult to determine the scope of an archetype in order to produce it as a separate and reasonable “max data set”.

I agree. Other than the current discussion, I am pretty happy with e approach to anatomical location. Arguably laterality could be pushed to SNOMED but lateraility is a very common attribute and many implementers with not have access to SNOMED legally, or have the tech capacity to use it right now.

The issue that Bjorn brings up is if/when we want to get more smart about using detailed knowledge of anatomical relationships and terminology to do smarter processing. To me that just replicates work that has been done in various ontologies elsewhere. The representation is kinda ugly in SNOMED-CT but that mostly reflects the complexity - not something I’d want to ‘own’

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The key question to me is still understanding the use cases for bilateral. I think clinicians often talk about things being bilateral without wanting for a second that it be recorded that way. Then there are registries and questionnaire where data gets messy for no good reason but just the reality we have to grapple with. Then diagnoses or reporting bilateral findings for tests or ordering bilateral procedures.

If we understand the use cases then bilateral options might need to be represented in various ways. One possiblity is a higher level archetype - it was just thinking out loud and the challenge will be to clearly explain how to use it. This possibility for confusion is a good reason to not consider it as a solution, but at the same time doesn’t justify munging/shoehorning ‘bilateral’ into the Anatomical Location CLUSTER that has been deliberately and, IMO, very successfully modelled explicitly as a single site. In most situations multiple sites for physical exam and test results should be represented by using multiple instances of the single site, which is pure & correct for most EHR data. It is the registries and legacy data where semantics have often not been considered carefully that cause us grief.

Perhaps another more viable interim solution is to specialise Anatomical Location for the messy data, while preserving the published archetype to support best practice.

Personally, I’ve not come across the need to record ‘bilateral’ very often, or I’ve demonstrated how it’s not good data modelling. I have had the use case where audiology testing had to be done on the left ear, right ear or both simultaneously and it was modelled into the archetype directly with absolutely no need for ‘anatomical location’ CLUSTER.

I don’t have enough background use cases to make an informed decision at present… I suspect that more possible situations than we suspect will be managed as per the ‘audiology test’ method. And so our challenge is to identify the outliers.

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Some examples of use of bilteral

This is the Genomics England Cancer schema that asked for ‘bilateral’ as part of an ‘imaging event’ whfor which we wanted to use the ‘Imaging report’ archetype.

Anatomical Site *IMAGING CODE (NICIP) and/or *IMAGING CODE (SNOMED CT) and/or *CANCER IMAGING MODALITY and IMAGING ANATOMICAL SITE and ANATOMICAL SIDE (IMAGING) is required. A classification of the part of the body that is the subject of an Imaging Or Radiodiagnostic Event. 0…1 No imagingAnatomicalSite IMAGING ANATOMICAL SITE
Anatomical Side The side of the body that is the subject of an Imaging or Radiodiagnostic Event. 0…1 No anatomicalSide(imaging) Enumerations L:Left R:Right M:Midline B:Bilateral 8:Not applicable 9:Not Known ANATOMICAL SIDE (IMAGING)

SNOMED terms where bilateral is used…

Now if you have SNOMED license you may be ok but even then there is no guarantee that the particular core anatomical site has a pre-coordinated term which includes ‘bilateral’ .

These would be used in contexts of

Diagnoses 425414000 | Bilateral renal artery stenosis (disorder) |
Procedures 287662009 | Bilateral vasectomy (procedure) |
Sign/symptoms 12241791000119109 | Bilateral red eyes (disorder) |
Imaging 43204002 | Bilateral mammography (procedure) |

Now I wouldn’t necessarily defend the use of bilteral in all these situations, but for good or bad, we are often not in a position to force change, technically or clinically.

So my question back is what would be the practical down side of simply adding ‘bilateral’ to the current valueset, given that it can be excluded again at template-level if local circumstances can enforce more semantically precise recording e.g for something like ‘bilateral hip replacement’.

I’m still not clear what practical issue we are trying to solve/avoid by adhering to the current scope of the archetype.


Can you provide examples of expected data here for an imaging request or a report?

  • Bilateral what?
  • Midline what?

This link gives me a finding that the patient is on oxygen…

Totally agree. I wonder if specialising the current for this purpose might be a solution? Where bilateral is part of existing data but really is not good modelling, and certainly not how we’d choose to promote as valid for future modelling.
This is a real tension - reality vs good data design - and how we choose to represent it.

The revision that we reverted tried to do that but we had to change all of the semantics, so much so that the archetype lost it’s integrity - definitions made no sense. Literally part of the archetype is designed for a single location and some parts for more than one. I couldn’t get it to make enough sense so that I could explain it credibly to others.
You are welcome to try again. Maybe you’ll be more successful. Or think about specialising and adding your ‘bilateral’ to the existing model to support your use cases.
I think that in most cases, this modelling is the result of poor data design in existing systems. I’m still not seeing many examples where bilateral is best practice representation of the data.
And I’m increasingly inclined to agree with Sam’s early suggestions that precoordinating left and right to appropriate anatomical location is probably good modelling, similarly for bilateral. So maybe the solution is not just for the information model, but an example of the grey zone, where we need to find the semantic sweetspot, using terminology as well. We have not done so before but we could consider requesting SNOMED codes here.
Midline is actually modelled in the ‘Anatomical line’ attribute.

Oops sorry for the duff link - the SCT browser was not doing what I expected. If you search for bilateral, you get a long list of codes e.g. …

I think the main question to ask is what is the purpose of these concepts? I believe we need to conceptually differentiate between

  1. uniquely identifiable anatomical locations
  2. body site designations where it’s
    a. unimportant to uniquely identify specific locations, or
    b. the designations will be further specified at a later point, for example when a planned procedure is changed into a set of specific orders

I think these SNOMED CT concepts are only useful for item 2.

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I agree in principle but I’m still not sure how you really know in practice whether to use (1) or (2), or the actual benefit (or dis-benefit of using different archetypes). What is it that worries you about using the same archetype?

I am building a GP system. I need ot be able to record diagnoses where sometimes the body site is uniquely specific ‘Left’ and other times it may be ‘Bilateral’ - which should I use (1) or (2)? What do I tell the developers? I actually do not know exactly if anyone will use ‘bilateral’ but we know people do.

Similalrly with a bofdy site for an imaging test - this might be quite specific and a good candidatefor (1) but in other circumstances, folks might ask for ‘bilateral mamography’ .

I cannot predict ahead of time whether to use (1) or (2). So in practice, I am always going to use (2), since it is a superset of (1). If there are situations where bilateral is clearly not applicable, well for that template, we just constrain it out.

Same goes for anatomical path reports, or surgical procedures ‘Bilateral vasectomy’

Now the one place where I can see that (2) might always be inapplicable is when describing an examination but I’m struggling to understand what goes wrong if I use (2) with ‘bilteral’ constrained out.

Heather’s suggestion of specialisation does help but I’d still be using (2) in the vast majority of cases, simply because in practice you often cannot be sure that (1) only applies.

Looking at the SNOMED example you provided - structures usually are recorded as both in the preferred/FSN, although bilateral is often available as a synonym. I certainly don’t usually talk or record body sites as bilateral ears or bilateral hips, rather both ears or hips. ‘Both palatine tonsils’ is not an option, only ‘bilateral palatine tonsils’ but I’d suggest that’s a SNOMED issue and an outlier - at least it is plural! ‘Bilateral middle ear’, singular, makes less sense.

Recording ‘Bilateral pneumonia’ is different to recording ‘Pneumonia’ in the left and right lungs. Currently the Problem/Diagnosis archetype allows recording of:

  1. Diagnosis name = “Pneumonia” | Body site (0…*) = left lung ( SCTID: 44029006) +/- right lung ( SCTID: 3341006)
  2. Diagnosis name = “Pneumonia” | Body site (0…*) = both lungs ( SCTID: 74101002)
  3. Diagnosis name = “Pneumonia” | Structured body site SLOT/CLUSTER.anatomical_location (0…*) - Body site name = Lung | Laterality = left or right
  4. Diagnosis name = “Pneumonia” | Structured body site SLOT/CLUSTER.anatomical_location (0…*) - Body site name = Lung | Specific site = Base of right lung ( SCTID: 51785002) Laterality = left ( SCTID: 7771000) or right ( SCTID: 24028007)
  5. Diagnosis name = “Pneumonia” | Structured body site SLOT/CLUSTER.anatomical_location (0…*) - Body site name = Lung | Specific site = Base of lung ( SCTID: 10024003) Laterality = left or right

So we can record Pneumonia found in the left lung, right lung (#1) or both lungs (per #2), but we don’t record pneumonia in ‘bilateral lungs’ at least not in common parlance. But adding ‘bilateral’ or ‘both’ to the ‘Laterality’ data element in anatomical location is not actually helping you record ‘Bilateral pneumonia’ as an entity.
I propose we should a qualifier of ‘Side’ for the Problem/Diagnosis name in the Problem/diagnosis archetype with the values Left/Right/Bilateral, if it is not available as a pre-coordinated diagnosis term (see green box in mind map, below). And CLUSTER.anatomical_location remains unchanged as a the way to record details about a single body site.

I think it is the same in principal for Procedure (see mind map) - I propose we should a qualifier of ‘Side’ for the Procedure name in the Procedure archetype with the values Left/Right/Bilateral, if it is not available as a pre-coordinated procedure term

Re Service request - at present we don’t really have any way of addressing a side eg to order bilateral mammography if this is not already available as a pre-coordinated term. We do have SCTID: 43204002 for Bilateral mammography, so not a good example, but we need a way to represent those that aren’t pre-coordinated. We could do the same thing, but it makes little sense to see Side and Body site in a Service request in the broadest sense, but perhaps makes more sense if we specialise it for Procedures/Investigations etc and add Side and Body site to align with my proposal for ACTION.procedure.

CLUSTER.specimen correctly carries one anatomical site per specimen, so needs no further modification.

Lab findings (eg in CLUSTER Anatomical pathology) will be related to the specimen, so not likely requiring left/right/bilateral/both.

Imaging findings may need left/right/bilateral. Although I suspect each finding should be recorded and described individually eg multiple lesions of different shape/size/location.

Lab and Imaging diagnosis will be similar to Diagnosis. However there may be multiple findings, so the we may need to look at creating an internal cluster ‘diagnosis group’ to handle the Left/right/bilateral qualifer per lab/imaging diagnosis (see orange box in mind map)

2020 06 04 Bilateral_Anatomical location.xmind (212.3 KB)


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If I understand you correctly, the essence of this is “it’s the diagnosis/procedure/request that’s bilateral, not the location”. This makes sense to me, and I support recording this on the level of the entry concept.

I think this is a good reason to specialise the Service request archetype for procedure requests as well.

That’s going to break one of the use-cases for the reusable Cluster - @bna - the DIPS requirement to be able to query for ‘left eye’ things, irrespective of the parent Entry.

Still think we are creating a very complex problem space where if we changed the anatomical archetype scope. I still have not heard the argument that we need the current scope to be so tight, other than as a theoretical construct.

What goes wrong if we loosen the scope to ‘stuff I might want to say that includes references to anatomical things’ which is basically the SNOMED scope’.

Genuinily do not understand the practical argument here, sorry :frowning:

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If you’re thinking of the Examination clusters based on, I don’t think that’s quite correct.

Those archetypes mainly differentiate using the “System or structure examined” element, where for example “Both eyes” is perfectly relevant to use. See for example the difference between Examination of both eyes ( and Examination of an eye (

For these archetypes, the “Body site” and “Structured body site” elements are mostly relevant only when examining larger organs such as the skin (

Hi Ian,

I think we both agree that the values of ‘left’/‘right’/‘bilateral’ are qualifiers, and this is aligned with SNOMED’s view of the world.

My proposal is based on the understanding that left/right within the context of CLUSTER.anatomical_location are only intended to be qualifiers of the Anatomical location that has been identified using the mandatory ‘Body site name’ (at0001). They aren’t intended to be qualifiers for the terms used to describe diagnoses, procedures, imaging requests etc.

If you want to record the side of the Diagnosis the qualifiers it makes sense for it to be recorded within the semantic context of Problem/Diagnosis archetype, and that is why I’ve suggested adding the qualifiers in that archetype. Same for Procedure, Imaging request etc. If you want to record where the diagnosis was found, eg multiple sites of psoriasis on the body, then this is the purpose of the Anatomical location archetype - one instance for each site.

It seems you are operating from a different assumption that ‘side’ can only be recorded in one archetype, but I am increasingly of the view that it is simply a qualifier that is used and defined wherever it is contextually relevant, including the use of value sets including addition of ‘bilateral’ or ‘left and right’ where it makes absolute clinical sense. More akin to our reuse of ‘Description’ and’Comment’ in many archetypes.



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When you say “bilateral [something]”, you’re not really supplementing the statement of the [something] with a location. The location/organ is implied in the name of the thing, for example “cataract” or “mastectomy”. The “bilateral” is a qualifier saying “it’s both of bilateral symmetrical organs specified in the name”. Or are there examples where “bilateral” is used without specifying a specific organ?