Although multiple medical ontologies currently exist (e.g.,
RadLex,
SNOMED,
ICD-10),
we found it necessary to develop an integrated ontology for the ViSion structured reporting system to function optimally (2-3).
The ViSion ontology consists of a collection of anatomy,
pathology,
and secondary characteristic terms that are organized into hierarchies (i.e.,
tree structures) to define anatomical locations,
radiological observations and diagnoses for each anatomical location,
and secondary descriptors that provide more detail for each observation or diagnosis.
Observations and diagnoses in the ViSion system are created by pairing anatomy and pathology terms (e.g.,
Colon:Polyp).
Radiologists have many ways of saying the same thing (4).
Thus,
the ViSion ontology provides a means to manage synonyms and homonyms associated with preferred terms.
The anatomy terms are organized in a hierarchy that describes anatomical locations from head-to-toe and are divided into seven main body sections (Figure 2):
- Head
- Neck
- Chest
- Abdomen
- Pelvis
- Upper extremity
- Lower extremity
Fig. 2: ViSion's anatomical hierarchy lists locations among seven body sections.
Each body section contains a list of the major organs found in that section followed by “common organ systems” shared by all sections:
- Artery
- Vein
- Lymphatic
- Skeleton
- Muscle
- Soft tissues
Each organ is subdivided when appropriate. For example,
the colon is divided into the anus,
rectum,
sigmoid colon,
descending colon,
splenic flexure of colon,
transverse colon,
hepatic flexure of colon,
ascending colon,
ileocecal valve,
cecum,
and appendix.
Every anatomical term is paired to a hierarchy of pathology terms that define the radiological observations and diagnoses that are applicable to that anatomy (Figure 3).
The first level of each pathology tree is divided into the following categories:
- Normal
- Inflammation
- Neoplasm
- Trauma
- Systemic
- Function
- Observation
- Needs definition
Fig. 3: Example of the pathology hierarchy associated with the anatomy term "Colon." Each pathology tree is organized with first-level divisions of Normal, Inflammation, Neoplasm, Trauma, Systemic, Function, Observation, and Requires definition. The last entry allows a user to recommend a term for inclusion into the ViSion ontology.
The pathology terms that are contained in each category are specific to a particular anatomical location.
The last entry,
“Needs definition,” allows for users to recommend terms that are not contained in the ViSion ontology.
The combining of anatomy and pathology terms creates “observations” and “diagnoses.” Each observation/diagnosis can be described in further detail with “secondary characteristics.” For example,
the secondary characteristics associated with “Colon:Polyp” would include the following:
Shape:
- Pedunculated
- Sessile
- Mass
C-RADS:
- C-RADS 0
- C-RADS 1
- C-RADS 2
- C-RADS 3
- C-RADS 4
The ViSion ontology was constructed in English but the anatomy,
pathology,
and secondary characteristic terms have been translated to German,
Chinese,
Turkish,
French,
Arabic,
and Spanish (Figures 4-5).
Fig. 4: The ViSion report in Fig. 1 translated to Chinese.
Fig. 5: The ViSion report in Fig. 1 translated to Arabic.
The translations were performed initially using Google Translate,
but the output was reviewed and modified when necessary by radiologists who spoke these languages.
It is important to note that the ViSion system only translates the metadata used to tag images and not the entire narrative descriptions generated by radiologists.
Each of the radiological observations and diagnoses in the ViSion ontology has been crossed-referenced to other standardized medical ontologies (e.g.,
RadLex,
SNOMED,
LOINC,
ICD-9-CM,
and ICD-10-CM) when those items exist.
Finally,
each observation and diagnosis in the ViSion system has been prioritized on a 5-point scale to indicate a level of action that needs to be taken by a clinician with regard to a particular finding:
1. Incidental
- Requires no further action
2. Indeterminate
- Requires further evaluation with an additional imaging or other diagnostic procedures
3. Important
- Should be followed on subsequent imaging examinations
4. Urgent
- Requires attention as soon as possible
5. Life-Threatening
- Requires immediate action
In the ViSion reporting system,
these default priority settings can be modified as necessary by the radiologist.
When a report is signed that contains Urgent or Life-Threatening findings,
the ViSion system sends automatic notification of the critical results to the clinician by email and/or SMS messaging with return receipt verification.