JIRA Link: https://projects.jira.snomed.org/browse/IHTSDO-1192

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Release used for analysis: July 2021

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Content Issue Summary 

a. Summary of issue 

Duplex ultrasound scans combine two modes of ultrasound imaging, Doppler and B-mode.  The B-mode transducer obtains an image of the vessel being studied.  The Doppler probe within the transducer evaluates the velocity and direction of flow in the vessel.

Duplex and Doppler ultrasound scans are currently modelled with the USING DEVICE attribute and value of 43770009 |Doppler device (physical object)| but with METHOD of  278292003 |Ultrasound imaging - action (qualifier value)| or 302204005 |Ultrasound - action (qualifier value)|.  It is not possible at the present time to sufficiently model the duplex procedures in order to make them distinct from Doppler scans.

b. Related content projects and requests 

A CRS request has been received from a member country wishing to submit new requests for duplex ultrasound scans and have asked how these should be modelled for submission.  The question was raised at the internal editors call with agreement that this issue could be resolved by updating the 278292003 |Ultrasound imaging - action (qualifier value)| to support the detailed subtypes, using the qualifier value hierarchy to model doppler and duplex scans rather than a device.

https://projects.jira.snomed.org/browse/GC-207 This relates to a CRS request that notes doppler does not always involve imaging.  22 concepts that were sound only were modeled with Ultrasound imaging - action (qualifier value).  This was changed to Ultrasound - action (qualifier value).  The intention now is to change this to the new concept representing method, Doppler ultrasound - action (qualifier).

Analysis of Issue

At the time of analysis there were six concepts representing duplex scans but a request is expected for further content.

• 312725000 |Duplex scan of lower limb veins (procedure)|

• 312727008 |Duplex scan veins of upper limb (procedure)|

• 312724001 |Duplex scan of lower limb arteries (procedure)|

• 312726004 |Duplex scan of upper limb arteries (procedure)|

• 86410006 |Imaging of carotid arteries by duplex scan with spectrum analysis (procedure)|

• 252819009 |B scan ultrasound - with Doppler studies (procedure)|

765172009 |Doppler ultrasound (procedure)| has 184 descendants which will all need re-modeling but this could be done as a bulk update based on an updated template.

Additional issues identified

• 18 concepts that contain the word Doppler but are not descendants of 765172009 |Doppler ultrasound (procedure)|.  This would be corrected by the suggested modeling below.

• 8306009 |Diagnostic Doppler ultrasonography (procedure)| is modelled with diagnostic intent, has 131 descendants and it is modelled with Procedure site direct of 59820001 |Blood vessel structure (body structure)| though there is no reference to blood vessels in any description.  The use case for 8306009 |Diagnostic Doppler ultrasonography (procedure)| is not clear and most references point to Doppler ultrasound imaging as mainly a diagnostic procedure.  There are a small number of Doppler guided interventional procedures.  8306009 |Diagnostic Doppler ultrasonography (procedure)| could be inactivated as ambiguous and possibly equivalent to - 765173004 |Doppler ultrasonography of blood vessel (procedure)| and a new concept Doppler ultrasonography (procedure).  Although Doppler ultrasonography is usually blood it can be used to generate images of the movement of tissues and other body fluids. Doppler ultrasonography is a section in the Editorial guide under Clinical Imaging Naming Conventions  https://snomed.atlassian.net/wiki/display/public/WIPEG/Ultrasonography but a generic procedure does not currently exist and could be created.  Additionally there is a template for Doppler ultrasonography of X which has the status of ready for implementation but is not yet in production https://snomed.atlassian.net/wiki/display/SCTEMPLATES/Doppler+ultrasonography+of+%5Bbody+structure%5D+-+Ready+for+implementation?src=contextnavpagetreemode  This template will need updating.

• Concept 252819009 |B scan ultrasound - with Doppler studies (procedure)| modeled with eye region structure but has no mention of the body structure in any descriptions.  It classifies as a subtype of 241452002 |Orbital B scan (procedure)| and 765172009 |Doppler ultrasound (procedure)|.  It should be inactivated and replaced with a new concept.

• 16 Doppler flow mapping concepts need review as descriptions are inconsistent - 431218003 |Ultrasound doppler flow mapping of vein of lower limb (procedure)|, 6291000087101 |Doppler ultrasonography flow mapping of vein of left lower limb (procedure)|  

• 431394000 |Ultrasound doppler flow mapping of vein of upper limb (procedure)| incorrectly classifies as a 312727008 |Duplex scan veins of upper limb (procedure)| - modeling improvements will correct this.

Solution

Addition of new concepts to 302204005 |Ultrasound - action (qualifier value)| hierarchy and remodelling of existing content in this hierarchy will enable duplex procedures to be sufficiently defined.  Hierarchy before and after:

Existing hierarchy

Open

Proposed hierarchy

Open

Construction 

1. Re-model 399064001 |2D mode ultrasound (qualifier value), which has subtype of 399009009 |B mode ultrasound (qualifier value), as a subtype of 278292003 |Ultrasound imaging - action (qualifier value)|

2. Create new concepts:

   1. Doppler ultrasound - action (qualifier value) as a subtype of 302204005 |Ultrasound - action (qualifier value)|

   2. Doppler ultrasound imaging – action (qualifier value) as a subtype of the new concept Doppler ultrasound – action (qualifier value)

   3. Doppler ultrasonography (procedure)

   4. Duplex ultrasonography (procedure)

3. Re-model 312236008 |Duplex ultrasound (qualifier value)| as a subtype of 399009009 |B mode ultrasound (qualifier value)| and Doppler ultrasound imaging – action (qualifier value)

4. Add existing Doppler subtypes to the new concept Doppler ultrasound imaging – action (qualifier value)

   1. 261197005 |Doppler color flow (qualifier value)|

   2. 261198000 |Doppler continuous wave (qualifier value)|

   3. 261199008 |Doppler pulsed (qualifier value)|

   4. 425704008 |Power doppler ultrasound (qualifier value)|

5. Model procedure concepts to be consistent with these methods removing USING DEVICE 43770009 |Doppler device (physical object)|

6. Inactivate:

   1. 252819009 |B scan ultrasound - with Doppler studies (procedure)| and replace with new concept Duplex ultrasonography of eye (procedure)

   2. 8306009 |Diagnostic Doppler ultrasonography (procedure)| as ambiguous and possibly equivalent to 765173004 |Doppler ultrasonography of blood vessel (procedure)| and new concept Doppler ultrasonography (procedure)

7. Update Doppler ultrasonography of [body structure] template

8. Modelling guidance for Editorial Guide to be provided.

Transition phase 

Glossary of Terms