Reference ranges
Reference ranges provide context for CardiacNexus phenotypes, but they must match acquisition, analysis method, population, and normalization convention.
- Modality
- All modalities
- Pipeline step
- Interpretation
- Outputs
- Reference range notes by phenotype
- Maturity
- Draft interpretation page
Documentation rule
Each phenotype page should state whether a reference range is verified, method-dependent, literature context, not current output, or still needs verification. When a numeric value is shown, the table should name the source cohort and stratification variables.
No universal normal range
CMR reference values vary by age, sex, body size, ethnicity, scanner, acquisition protocol, and analysis method.
How CardiacNexus should present ranges
| Feature family | Preferred reference context | Evidence status to prefer |
|---|---|---|
| Ventricular volume and function | UK Biobank or CMR cohort ranges stratified by sex and age where possible | Verified source |
| Myocardial mass and wall thickness | Sex, age, and BSA-indexing convention | Verified source or method-dependent |
| Atrial volume and function | Sex, age, indexing convention, and atrial boundary definition | Verified source or method-dependent |
| Aortic structure and distensibility | Age, sex, blood pressure context, and analysis plane | Method-dependent |
| Native T1 and ECV | Scanner, field strength, mapping sequence, and acquisition protocol | Method-dependent; ECV is not current output unless implemented |
| Strain and torsion | Vendor/software/backend method and tracking protocol | Method-dependent or literature context |
Evidence status labels
| Status | Meaning | Display rule |
|---|---|---|
| Verified source | The value is traceable to a named CMR or UK Biobank source and matches the documented output concept. | Can be shown as a reference value with source and cohort. |
| Method-dependent | The value is valid only when acquisition, software, indexing, pressure, or smoothing conventions match. | Show the caveat next to the value. |
| Literature context | The value or association helps interpretation but is not a CardiacNexus-specific reference interval. | Do not call it a normal range. |
| Not current output | The phenotype is discussed in literature but is not emitted by the current pipeline. | Keep it out of feature summaries unless clearly labelled. |
| Needs verification | The value came from notes or LaTeX and has not yet been checked against the source paper. | Do not use for clinical-facing numeric claims. |
Use with caution
Reference intervals are not diagnostic thresholds. They are context for population comparison, and they should be interpreted alongside symptoms, clinical history, image quality, and the exact pipeline version used to generate the phenotype.
Source audit
- Draft interpretation layer checked against
docs/data/reference_range_sources.yml,docs/data/reference_sources.yml, and the promoted phenotype pages. docs/data/reference_sources.ymlexists and is the current bibliography/source registry used for this page; no duplicate source registry was created.- Numeric values should only be surfaced from
reference_range_sources.ymlafter row-level source-table adjudication. - Textbook context boundary: broad clinical textbook context is not surfaced here because page-specific CMR reference-range sources and the registry layer are the relevant evidence base for this page.
References
- Petersen SE, Aung N, Sanghvi MM, Zemrak F, Fung K, Paiva JM, Francis JM, Khanji MY, Lukaschuk E, Lee AM, Carapella V, Kim YJ, Leeson P, Piechnik SK, Neubauer S. Reference Ranges for Cardiac Structure and Function Using Cardiovascular Magnetic Resonance (CMR) in Caucasians from the UK Biobank Population Cohort. Journal of Cardiovascular Magnetic Resonance. 2017;19(1):18.
- Kawel-Boehm N, Hetzel SJ, Ambale-Venkatesh B, Captur G, Francois CJ, Jerosch-Herold M, Salerno M, Teague SD, Valsangiacomo-Buechel E, Van Der Geest RJ, Bluemke DA. Reference Ranges ("Normal Values") for Cardiovascular Magnetic Resonance (CMR) in Adults and Children: 2020 Update. Journal of Cardiovascular Magnetic Resonance. 2020;22(1):87.