Clinical cases on DxCases are organized according to two main parameters that help users navigate educational materials:
- Diagnostic confidence level reflects the degree of confirmation of the presented diagnosis.
- Clinical case complexity level reflects the interpretation challenges and diagnostic tasks associated with image analysis.
Ⅰ. Diagnostic Confidence Levels
What is diagnostic confidence?
Diagnostic verification is the degree to which a diagnosis is confirmed by additional supporting data.
In clinical practice, not all diagnoses have the same level of certainty. Sometimes a diagnosis is confirmed by histopathology or intraoperative findings. Sometimes it is based on the combination of clinical presentation, laboratory results, and findings from multiple imaging modalities. In other cases, it represents the most likely diagnostic assumption based on the findings of a single examination.
Therefore, clinical cases on this website use a diagnostic confidence level system.
Why are diagnostic confidence levels needed?
The confidence level helps the reader understand how reliably the diagnosis has been confirmed in a particular case.
This is important because imaging findings alone do not always represent definitive proof of a diagnosis. Imaging should be interpreted in the context of clinical presentation, laboratory data, disease progression, and, when available, surgical or pathological findings.
Level A — Definitively Verified
The diagnosis has the highest level of confirmation.
This level includes cases where the diagnosis has been confirmed by one of the most reliable methods:
- histopathological examination;
- intraoperative findings;
- endoscopic confirmation;
- microbiological confirmation, when essential for establishing the diagnosis;
- another highly reliable confirmatory method appropriate for the specific clinical situation.
Example:
A patient underwent ultrasound or CT examination, followed by confirmation of the diagnosis during surgery or through histological examination.
Level B — Highly Probable
The diagnosis is well supported, but definitive verification is unavailable.
This level includes cases where the diagnosis is supported by a combination of findings:
- clinical presentation is consistent with the diagnosis;
- imaging findings are characteristic;
- multiple imaging modalities demonstrate concordant findings, for example ultrasound + CT;
- laboratory data support the diagnosis;
- disease progression corresponds to the presumed diagnosis.
This represents a high level of diagnostic confidence but does not equal definitive histological or intraoperative confirmation.
Example:
The patient has typical clinical symptoms, characteristic ultrasound findings, and confirmatory CT features, but no surgery or pathological confirmation was performed.
Level C — Presumptive
The diagnosis is based on limited data and requires cautious interpretation.
This level includes cases where the diagnosis is established primarily based on a single imaging modality or indirect findings.
Such a diagnosis may be correct, but the degree of confirmation is lower compared with Levels A and B.
Example:
Ultrasound demonstrates findings most consistent with a particular disease, but there is no CT examination, surgery, pathology, or convincing clinical and laboratory confirmation.
How is this used in clinical cases?
Each clinical case may include a diagnostic confidence level:
- A — Definitively Verified
- B — Highly Probable
- C — Presumptive
The basis of verification may also be specified, for example:
- concordance between ultrasound and CT findings;
- intraoperative confirmation;
- histopathological confirmation;
- clinical and laboratory correlation.
Important Limitation
The diagnostic confidence level is not an assessment of image quality or physician performance.
It only reflects the type and degree of evidence supporting the diagnosis in the specific published case.
Even a typical imaging appearance may receive a Level B or C classification if definitive confirmation is unavailable. Conversely, an image of limited quality may still receive a Level A classification if the diagnosis was confirmed by pathology or intraoperative findings.
Ⅱ. Clinical Case Complexity Levels
Why difficulty levels are used
Difficulty levels help users navigate DxCases clinical cases and select educational materials according to their experience, learning goals, and diagnostic objectives.
They are not a strict scientific classification and do not reflect the “importance” of a case. Instead, they provide practical guidance regarding the educational complexity of the material.
Basic Level
Clinical cases with relatively typical imaging findings and straightforward diagnostic reasoning.
These cases are suitable for an initial introduction to a pathology, review of classic imaging features, and development of basic visual recognition patterns.
Typical features include:
- imaging findings are clearly expressed;
- the diagnostic pathway is relatively straightforward;
- the differential diagnosis is limited;
- the key finding is well demonstrated on imaging.
Intermediate Level
Clinical cases where imaging findings may be incomplete, variable, or require correlation with clinical data.
These cases help develop practical diagnostic reasoning and the ability to interpret ambiguous findings.
Typical features include:
- imaging findings are not fully expressed;
- clinical context plays an important role;
- differential diagnosis should be considered;
- subtle details of description and interpretation are important.
Advanced Level
Clinical cases involving rare pathology, unusual disease presentation, complex interpretation, or a high risk of diagnostic error.
These cases are intended for deeper analysis and development of an expert approach to clinical imaging.
Typical features include:
- the disease is uncommon;
- imaging findings are atypical;
- a broad differential diagnosis is required;
- pathophysiology, clinical context, and diagnostic confirmation are important.
Diagnostic Pitfall
Clinical cases where imaging findings may be misinterpreted as another condition or may lead to an incorrect diagnostic conclusion.
This is one of the most important sections of DxCases, as it helps not only recognize pathology but also avoid common diagnostic errors.
Typical features include:
- imaging findings mimic another pathology;
- a classic imaging sign has an unusual cause;
- a rare condition presents as a common disease;
- a common condition presents in an unusual way;
- incorrect interpretation may affect patient management.
Important Note
Difficulty levels are inherently subjective. The same case may be challenging for a trainee but straightforward for an experienced specialist.
Therefore, difficulty levels on DxCases are intended as an educational navigation tool and should not be interpreted as a formal assessment of a physician, diagnosis, or clinical significance of a case.