At Karolinska University Hospital we want to start working on modelling a radiology response for prostate cancer biopsy. For this, we are looking at the following archetypes:
In order to structure the imaging findings, our idea was to create a new Cluster-archetype for “Imaging examination of prostate” (rather than using “Imaging examination of a body structure”), similar to those created for other body structures, se attached picture.
I’d agree with a specialised archetype for prostate in this situation. You can add prostate specific findings for any modality to the specialisation and that would be useful to everyone.
These CLUSTERs are intentionally modality independent as many body structure-specific attributes might be found in more than one modality eg measurements of the prostate.
You can also see Imaging exam of an anomaly - https://ckm.openehr.org/ckm/archetypes/1013.1.5907 - intended for nesting in any of the imaging CLUSTERs for each/every body structure. It is not a specialisation as it is recording a lesion or other anomaly which isn’t strictly, ontologically, a ‘body structure’ yet it intentionally is designed with a similar pattern. This archetype is currently ‘in review’ although in reality, it has stalled because we can’t resolve how to represent a lesion or a tumour or a similar finding in a generic way. If you look at the history of the archetype, changes in archetype ID and feedback on each review round you can probably discern some of the approaches that have been tried but not ‘nailed’ the solution as yet. Any ideas welcome.
Thank you for your replies. @ian.mcnicoll we are in touch with @bna and his collegues and are currently scheduling a meeting hopefully for the end of May. Let me know if you want to join. @heather.leslie we’ll look at the archetype that you pointed out.
@heather.leslie I have been re-reading your answer and realized that I am not sure what you mean by “These CLUSTERs are intentionally modality independent as many body structure-specific attributes might be found in more than one modality eg measurements of the prostate.”? Do you mean the Specializations that have been developed for the “Imaging examination of a body structure”-cluster? Aren’t they modality-specific since they refer to “imaging examination”?
Yes, each imaging of a body structure CLUSTER archetype is intended for being reused across any imaging modality eg the same measurement may be determined by ultrasound or CT or MRI. There is not a separate one for each body structure and modality combination. The modality to which the findings apply is set in the Imaging OBSERVATION.
This is the current modelling pattern, and happy for feedback, especially if you have a use case where this does not work
I found this information under Use in Imaging examination of an anomaly: “This archetype is designed to be nested within the ‘Additional details’ SLOT in any of the CLUSTER.imaging_exam family of archetypes which will provide the context for the anomaly, but can also be used within other ENTRY or CLUSTER archetypes, where clinically appropriate.” So I suppose the Additional details SLOT in the prostate-specialization of Imaging examination of a body structure will be the correct spot to place this information.
Yes, you’re absolutley right. The included archetype ‘lesion’ mentioned in the SLOT has evolved into ‘anomaly’ as it goes thru review.
It has been hard to model a generic pattern for any/every unexpected anomaly and expect it to be able to be used in any bodysite. Interested to hear your feedback as you use it in your modelling.
I have yet some other questions when modelling radiology information.
Information about the MRI
We would need to capture information about whether the MRI was performed without or without dynamic contrast. We found Snomed CT codes for MRI with contrast and MRI without contrast and thought about binding those to the Modality-attribute.
However, we were wondering if we should capture information about contrast under modality, or if we should rather keep it to MRI only?
If information about contrast shouldn’t be captured under Modality, would it be possible to put that information in a cluster which could be added under the Structured technique/procedure-SLOT
Besides information about contrast, we would even need to capture information about the strength of the magnetic field (which is expressed as for instance 1,5 Tesla or 3 Tesla). Even that information could maybe be put in the same cluster which would be added under the Structured technique/procedure-SLOT?
Capturing dimensions of the prostate and lesion
We need to capture the dimensions of e.g. the prostate and lesion. We saw that the archetype contains a Dimensions-attribute which allows to enter length, width, height, depth and diameter.
For both prostate and lesion we are only interested in width, depth and height. In archetype designer, we couldn’t find where to set a restriction to those 3 parameters. Do you have any input here?
Thank you for your valid questions. As the family of Imaging archetypes are fairly new, they need to be “tested” in practical use cases in order to assure their usefulness and to identify possible flaws or deficits. The archetypes might need to be altered, expanded or new ones made, and the community relies on the implementers to ask questions as yours, and to get feedback. The following is my take on your questions, but isn’t necessarily the only truth
The archetype does not dictate into details on where to record MRI with contrast vs MRI without contrast. The Comment on the “Modality” element says: “Coding of the ‘Modality’ with a value set is recommended, such as the DICOM CID 29 Acquisition Modality value set. Equivalent to ImagingStudy.modality in FHIR and Modality (0008, 0060) in DICOM.” In the mentioned DICOM value set there is only “MRI”, while, as you show, SNOMED CT have codes for both procedures.
The “Study name” element can also be used to define whether the MRI is done with contrast or not.
In practical terms, it leaves it up to your requirements, to decide where to put that information. Please also see the “Use” section, where it is recommended to embed the ACTION.medication archetype in the same template, if you want to add information about the contrast used.
As of now, there are no CLUSTER specific to carry information about the strength of the magnetic field. If this is important to keep in a separate archetype, it might be proposed as a new CLUSTER, possibly along with other information not yet identified. A preliminary and local CLUSTER can be made if you are in a hurry. The “Comment” element can also be used.
I agree. This is where we test the theoretical model in the real world. In AU we needed to specify whether contrast is ordered, as a separate data element alongside the modality. You can see this in the latest version of the proposed specialisation - Imaging INSTRUCTION, currently in an incubator - https://ckm.openehr.org/ckm/archetypes/1013.1.7240. Perhaps we need to add the use of contrast as a separate data element to the Imaging_exam OBSERVATION, while mindful that the Imaging exam ‘Study name’ may refer to contrast use.
I suspect there may be more data elements we can identify to complement than the # of Teslas used - it may be worth developing a CLUSTER dedicated to recording the ‘dose’ and method used etc, and inserting it in the SLOT you suggest.
TBH I’d prefer a well named CLUSTER with only one data element for the Dose that can be submitted to CKM and grown by others in the community, rather than just a local one. I think the requirement is probably universal, but the scope and extent may take some more investigation.
Maybe we need an MRI study- or technique-specific one, and another for Ultrasound etc. I’m honestly not sure - this is where an investigation of patterns is required to inform the best approach, rather than just developing ad hoc archetypes without a strategy for coherence.
I don’t think we can go far wrong with CLUSTER.MRI_study_details or similar, even if it only contains that one dose-related data element for now, plus the usual ‘Description’ and ‘Comment’.
Generally agree, although I’m wondering if the dosage recording for MRIs are similar in intent as for electromagnetic radiation based examinations and therapy such as X-ray, CT or radiotherapy? Apart from the units used (tesla vs Gray?), could this be generalised? Alternatively, could the existing CLUSTER.dosage archetype be used to record the dosage component?
@David-Jobling is working on a template for joint/spinal injections that includes a need to record details of image-guidance, including use of contrast, so that might be an additional use-case. It is mostly about the procedure itself and use of an Imaging Observation archetype feels like overkill.
The Use section in OBS.imaging_exam_result guides the implementers in such cases:
“If an imaging examination is carried out as part of a more complex activity, such as a surgical operation carried out under imaging guidance, the imaging findings should be recorded using this archetype.
Structured details about the surgical procedure and medications or contrast administered should be recorded using the ACTION.procedure and/or ACTION.medication archetypes, respectively. In this situation, it is recommended that all related archetypes should be reported within the same template.”
