Aortic structure
Feature summary
Global aortic centerline geometry
Whole-aorta diameter, length, tortuosity, curvature, and torsion from the aortic scout centerline.
Family: vascularAorticUnit family: mm, %, 1/mmSource: Scout/localizer imagingPrimary output group: Centerline geometryAortic aneurysm and dissection (I71)Coarctation of aorta (Q25.1)Disease badges are literature-context navigation only; not diagnoses, CardiacNexus classifiers, or validated phenotype-to-ICD associations.Ascending and descending arch geometry
Segment-level diameter, length, tortuosity, curvature, and torsion for upper-aortic arch components.
Family: vascularAorticUnit family: mm, %, 1/mmSource: Scout/localizer imagingPrimary output group: Arch geometryCongenital insufficiency of aortic valve (Q23.1)Disease badges are literature-context navigation only; not diagnoses, CardiacNexus classifiers, or validated phenotype-to-ICD associations.Arch width and height
Compact arch morphology descriptors derived from the upper-aortic centerline geometry.
Family: vascularAorticUnit family: mmSource: Scout/localizer imagingPrimary output group: Arch morphologyAortic aneurysm and dissection (I71)Disease badges are literature-context navigation only; not diagnoses, CardiacNexus classifiers, or validated phenotype-to-ICD associations.Descending and lower-aortic geometry
Descending-aortic and lower-aortic diameter, length, and shape descriptors.
Family: vascularAorticUnit family: mm, %, 1/mmSource: Scout/localizer imagingPrimary output group: Descending-aortic geometryAortic aneurysm and dissection (I71)Disease badges are literature-context navigation only; not diagnoses, CardiacNexus classifiers, or validated phenotype-to-ICD associations.
Aortic structure phenotypes describe 3D aortic size and geometry from the aortic scout/localizer segmentation. They are separate from cine aortic distensibility and phase-contrast flow phenotypes.
- Modality
- Aortic scout/localizer MRI
- UKB source
- Data Field 20207
- Pipeline step
- Aortic scout segmentation, mesh/centerline extraction, and geometric analysis
- Outputs
- aortic_structure.csv, visualization/aorta/*.png, aortic_mesh artifacts
- Maturity
- Source-audited phenotype page
Clinical question
Aortic structure outputs help quantify dilation, elongation, tortuosity, and arch-shape remodeling in cohort studies. Aneurysm, dissection, bicuspid-valve aortopathy, coarctation, and congenital aortic disease require clinical and guideline context beyond these geometry outputs.
Anatomical and physiological definition
The implementation derives a smoothed aortic mesh and centerline from aortic_scout.nii.gz and seg_aortic_scout.nii.gz. Diameter summarizes local luminal caliber. Length follows the centerline. Linear distance is the straight-line distance between segment endpoints. Tortuosity is excess centerline length over linear distance. Curvature is local bending, and torsion describes rotation of the osculating plane along the centerline [1].
Source acquisition and UKB field
The source acquisition is UK Biobank aortic scout/localizer imaging, Data Field 20207. This page should not be read as a 2D cine distensibility measurement page.
What exactly CardiacNexus measures
Global centerline geometry
CardiacNexus records global max/mean/min diameter, overall centerline length, overall linear distance, tortuosity, curvature, and torsion. The implementation scales VMTK-derived centimeter-like diameter/length values to millimeters and curvature/torsion to 1/mm.
Copyable formula
D_mm = 10 * D_sourceCopyable formula
L_mm = 10 * L_sourceThe code comment defines tortuosity as length divided by linear distance minus 1, with a straight segment approaching zero. The upstream df_raw field already stores that ratio-minus-one value, and CardiacNexus multiplies it by 100 for the output column.
Copyable formula
Tortuosity_percent = 100 * tortuosity_sourceCurvature and torsion are divided by 10 in the implementation to report 1/mm rather than the source geometry scale:
Copyable formula
curvature_1_per_mm = curvature_source / 10
Segment-level geometry
The upper aorta is split into ascending and descending arch components. A descending-aorta segment and lower-aorta segment are also derived from the centerline and acquisition planes. Segment definitions are implementation-specific and should be preserved in interpretation text.
| Segment family | Implementation route | Current output prefix | Interpretation boundary |
|---|---|---|---|
| Global centerline | single_image_inference global aorta geometry | Aortic Structure-Centerline:* | Whole extracted scout aorta, not a clinical segment threshold |
| Ascending arch | split_aorta_arch upper-aorta branch | Aortic Structure-Ascending Arch:* | Scout-derived ascending arch segment |
| Descending arch | split_aorta_arch upper-aorta branch | Aortic Structure-Descending Arch:* | Scout-derived descending arch segment |
| Descending aorta | extract_descending_aorta | Aortic Structure-Descending Aorta:* | Descending arch plus lower-aorta route in code comments |
| Arch | upper-aorta arch aggregate | Aortic Structure-Arch:* | Ascending plus descending arch aggregate |
| Lower aorta | extract_lower_upper_aorta lower segment | Aortic Structure-Lower Aorta:* | Segment between proximal and distal descending-aortic acquisition planes |
Arch width and height
Arch width and height are compact morphology descriptors derived from the arch geometry. They are useful for morphology comparison but are not standalone disease thresholds.
Output columns and units
CardiacNexus writes aortic structural features into aortic_structure.csv. The legacy spelling Maxium is preserved where it appears in current output labels.
| Display family | Exact output column | Unit | Status | Schema note |
|---|---|---|---|---|
| Global diameter | Aortic Structure-Centerline: Maxium Diameter [mm] | mm | current | Legacy spelling preserved |
| Global diameter | Aortic Structure-Centerline: Mean Diameter [mm] | mm | current | none |
| Global diameter | Aortic Structure-Centerline: Min Diameter [mm] | mm | current | none |
| Global length | Aortic Structure-Centerline: Length [mm] | mm | current | Centerline length |
| Global linear distance | Aortic Structure-Centerline: Linear Distance [mm] | mm | current | Straight-line endpoint distance |
| Global tortuosity | Aortic Structure-Centerline: Tortuosity Index [%] | % | current | Excess length ratio times 100 |
| Global curvature | Aortic Structure-Centerline: Curvature [1/mm] | 1/mm | current | Scaled from source geometry |
| Global torsion | Aortic Structure-Centerline: Torsion [1/mm] | 1/mm | current | Scaled from source geometry |
| Ascending arch diameter | Aortic Structure-Ascending Arch: Maxium Diameter [mm] | mm | current | Legacy spelling preserved |
| Ascending arch diameter | Aortic Structure-Ascending Arch: Mean Diameter [mm] | mm | current | none |
| Ascending arch diameter | Aortic Structure-Ascending Arch: Min Diameter [mm] | mm | current | none |
| Ascending arch length | Aortic Structure-Ascending Arch: Length [mm] | mm | current | Segment-level |
| Ascending arch linear distance | Aortic Structure-Ascending Arch: Linear Distance [mm] | mm | current | Straight-line endpoint distance |
| Ascending arch tortuosity | Aortic Structure-Ascending Arch: Tortuosity Index [%] | % | current | Excess length ratio times 100 |
| Ascending arch curvature | Aortic Structure-Ascending Arch: Curvature [1/mm] | 1/mm | current | Scaled from source geometry |
| Ascending arch torsion | Aortic Structure-Ascending Arch: Torsion [1/mm] | 1/mm | current | Scaled from source geometry |
| Descending arch diameter | Aortic Structure-Descending Arch: Maxium Diameter [mm] | mm | current | Legacy spelling preserved |
| Descending arch diameter | Aortic Structure-Descending Arch: Mean Diameter [mm] | mm | current | none |
| Descending arch diameter | Aortic Structure-Descending Arch: Min Diameter [mm] | mm | current | none |
| Descending arch length | Aortic Structure-Descending Arch: Length [mm] | mm | current | Segment-level |
| Descending arch linear distance | Aortic Structure-Descending Arch: Linear Distance [mm] | mm | current | Straight-line endpoint distance |
| Descending arch tortuosity | Aortic Structure-Descending Arch: Tortuosity Index [%] | % | current | Excess length ratio times 100 |
| Descending arch curvature | Aortic Structure-Descending Arch: Curvature [1/mm] | 1/mm | current | Scaled from source geometry |
| Descending arch torsion | Aortic Structure-Descending Arch: Torsion [1/mm] | 1/mm | current | Scaled from source geometry |
| Descending aorta diameter | Aortic Structure-Descending Aorta: Maximum Diameter [mm] | mm | current | Segment-level |
| Descending aorta diameter | Aortic Structure-Descending Aorta: Mean Diameter [mm] | mm | current | none |
| Descending aorta diameter | Aortic Structure-Descending Aorta: Min Diameter [mm] | mm | current | none |
| Descending aorta length | Aortic Structure-Descending Aorta: Length [mm] | mm | current | Segment-level |
| Descending aorta linear distance | Aortic Structure-Descending Aorta: Linear Distance [mm] | mm | current | Straight-line endpoint distance |
| Descending aorta tortuosity | Aortic Structure-Descending Aorta: Tortuosity Index [%] | % | current | Excess length ratio times 100 |
| Descending aorta curvature | Aortic Structure-Descending Aorta: Curvature [1/mm] | 1/mm | current | Scaled from source geometry |
| Descending aorta torsion | Aortic Structure-Descending Aorta: Torsion [1/mm] | 1/mm | current | Scaled from source geometry |
| Arch diameter | Aortic Structure-Arch: Maximum Diameter [mm] | mm | current | Upper-aorta arch aggregate |
| Arch diameter | Aortic Structure-Arch: Mean Diameter [mm] | mm | current | none |
| Arch diameter | Aortic Structure-Arch: Min Diameter [mm] | mm | current | none |
| Arch length | Aortic Structure-Arch: Length [mm] | mm | current | Upper-aorta arch aggregate |
| Arch width | Aortic Structure-Arch: Arch Width [mm] | mm | current | Arch morphology descriptor |
| Arch height | Aortic Structure-Arch: Arch Height [mm] | mm | current | Arch morphology descriptor |
| Arch tortuosity | Aortic Structure-Arch: Tortuosity Index [%] | % | current | Excess length ratio times 100 |
| Arch curvature | Aortic Structure-Arch: Curvature [1/mm] | 1/mm | current | Scaled from source geometry |
| Arch torsion | Aortic Structure-Arch: Torsion [1/mm] | 1/mm | current | Scaled from source geometry |
| Lower aorta diameter | Aortic Structure-Lower Aorta: Maximum Diameter [mm] | mm | current | Lower descending segment |
| Lower aorta diameter | Aortic Structure-Lower Aorta: Mean Diameter [mm] | mm | current | none |
| Lower aorta diameter | Aortic Structure-Lower Aorta: Min Diameter [mm] | mm | current | none |
| Lower aorta length | Aortic Structure-Lower Aorta: Length [mm] | mm | current | Segment-level |
| Lower aorta linear distance | Aortic Structure-Lower Aorta: Linear Distance [mm] | mm | current | Straight-line endpoint distance |
| Lower aorta tortuosity | Aortic Structure-Lower Aorta: Tortuosity Index [%] | % | current | Excess length ratio times 100 |
| Lower aorta curvature | Aortic Structure-Lower Aorta: Curvature [1/mm] | 1/mm | current | Scaled from source geometry |
| Lower aorta torsion | Aortic Structure-Lower Aorta: Torsion [1/mm] | 1/mm | current | Scaled from source geometry |
Output reconciliation
| Evidence layer | Status | Details |
|---|---|---|
| Implementation-emitted outputs | Verified source | eval_aortic_structure.py emits 49 aortic structure columns plus eid; all emitted aortic labels are listed above. |
output_column_inventory.yml | Reconciled | artifacts.aortic_structure.structural_columns contains the full current emitted set. |
phenotype_dictionary.yml | Reconciled | Aortic structure dictionary entries cover the full emitted set and point back to this page. |
| Page output table | Reconciled | The table above intentionally lists every current emitted aortic structure output label. |
Required upstream inputs
aortic_scout.nii.gzandseg_aortic_scout.nii.gz.- Aortic scout inference and mesh/centerline extraction through the aortic scout library.
- Successful VMTK/PyVista-based geometry route and output mesh directory.
Reference ranges with cohort and method context
| Feature | Source | Cohort | Reference value | Status | Note |
|---|---|---|---|---|---|
| Vascular geometry definitions | Piccinelli et al. vascular geometry framework [1] | vascular geometry methods | not a normal range | Definition source | Supports geometry terms, not CardiacNexus thresholds |
| Aortic arch geometry | Ou et al. age-related aortic arch geometry [2] | aortic arch geometry cohort | study-specific | Literature context | Segment definitions may differ from CardiacNexus scout segmentation |
| Aortic root CMR dimensions | Burman et al. CMR aortic-root measurement paper [3] | adult CMR reference context | plane- and line-specific normal values | Verified context source | Useful for aortic-root measurement conventions, not a direct scout-centerline normal range |
| Regional aortic size indexed to body size | Davis et al. CMR nomogram [4] | CMR regional aortic-size cohort | body-size-referenced nomogram | Verified context source | Regional aortic-size context; method does not directly match CardiacNexus 3D scout centerline outputs |
| Repaired coarctation aortic geometry | Minderhoud et al. aortic geometry outcome study [5] | repaired coarctation cohort with controls | disease-context geometry values | Literature context; source figure registered for draft | Supports centerline-geometry concepts and coarctation context, not CardiacNexus normal ranges |
| CardiacNexus scout centerline geometry | Current implementation source | UKB aortic scout/localizer pipeline | no published method-compatible normal range verified | Source-audited limitation | Numeric clinical thresholds are not copied into this page because they do not match the 3D scout centerline route. |
Source-located registry status: reference_range_sources.yml maps aortic-root dimensions to Burman 2008, regional aortic-size context to Davis 2014, aortic-arch geometry to age-related arch literature, and centerline geometry context to Minderhoud 2024. The current CardiacNexus scout/localizer route emits 3D centerline-derived geometry, so conventional 2D root or arch rows remain context unless the source locator and measurement plane match the current output.
Disease interpretation
Aortic dilation and altered arch geometry are relevant to aneurysm/dissection, bicuspid-valve aortopathy, coarctation, and other aortopathies [2] [4]. These badges are navigation aids only. Clinical thresholds depend on segment, body size, valve/genetic context, and guideline definitions.
QC caveats and maturity boundary
Incomplete scout coverage, segmentation leakage, centerline errors, or smoothing choices can change diameter, length, tortuosity, curvature, and torsion. Because this is a 3D scout/localizer route, values should not be mixed with cine aortic area or distensibility outputs without explicit modality context.
Implementation provenance
Current outputs are implemented in src/feature_extraction/Aortic_Scout_20207/eval_aortic_structure.py, with geometry helpers from libs/Aortic_Scout_20207/data_operations/phenotypes.py and the inference route under libs/Aortic_Scout_20207/train_operations.
| Feature family | Formula or computational route | Exact output columns | Source code file and function | Upstream dependencies | Conditional behavior | QC artifacts | Schema debt |
|---|---|---|---|---|---|---|---|
| Global centerline geometry | single_image_inference global centerline geometry; diameter/length multiplied by 10, tortuosity multiplied by 100, curvature/torsion divided by 10 | Aortic Structure-Centerline:* | eval_aortic_structure.py; single_image_inference | aortic_scout.nii.gz, seg_aortic_scout.nii.gz, aortic mesh output | Subject skipped if scout image or segmentation missing | visualization/aorta/aorta_structure.png, landmark screenshot | Maxium spelling preserved |
| Ascending and descending arch geometry | extract_lower_upper_aorta then split_aorta_arch; same scaling conventions | Aortic Structure-Ascending Arch:*, Aortic Structure-Descending Arch:* | eval_aortic_structure.py; split_aorta_arch | Successful mesh/centerline extraction | Same subject-level skip behavior | visualization/aorta/aorta_structure_arch.png | Maxium spelling preserved |
| Descending and lower-aorta geometry | extract_descending_aorta and lower-aorta segment between acquisition planes | Aortic Structure-Descending Aorta:*, Aortic Structure-Lower Aorta:* | eval_aortic_structure.py; extract_descending_aorta, extract_lower_upper_aorta | Successful centerline and analysis index | Same subject-level skip behavior | visualization/aorta/aorta_structure_descending.png, aorta_structure_lower_upper.png | Segment definitions are implementation-specific |
| Arch width and height | Arch aggregate fields from upstream geometry output, multiplied by 10 | Aortic Structure-Arch: Arch Width [mm], Aortic Structure-Arch: Arch Height [mm] | eval_aortic_structure.py; upstream df_raw arch fields | Successful arch split | Same subject-level skip behavior | visualization/aorta/aorta_structure_arch.png | Width/height are morphology descriptors, not thresholds |
Source audit
- Current output labels, scaling, segment names, and legacy spelling were checked against
eval_aortic_structure.py. - The full emitted output set was reconciled across the implementation, page output table,
docs/data/output_column_inventory.yml, anddocs/data/phenotype_dictionary.yml. docs/data/reference_sources.ymlis present and used as the curated reference-source registry for this page.- One aortic centerline geometry figure is displayed from a page-local public path and registered in
docs/data/figure_provenance.yml; permission and exact source-panel review remain pending for draft use.
Related pages
- Aortic stiffness and distensibility
- Scout/localizer imaging
- Aortic distensibility imaging
- Aortic disease and aortopathy
References
- Piccinelli M, Veneziani A, Steinman DA, Remuzzi A, Antiga L. A framework for geometric analysis of vascular structures: application to cerebral aneurysms. IEEE Transactions on Medical Imaging. 2009;28(8):1141-1155.
- Ou P, Celermajer DS, Raisky O, Jolivet O, Buyens F, Herment A, Sidi D, Bonnet D. Age-related changes in aortic arch geometry. Journal of the American College of Cardiology. 2011;58(12):1262-1270. doi:10.1016/j.jacc.2011.06.012.
- Burman ED, Keegan J, Kilner PJ. Aortic root measurement by cardiovascular magnetic resonance: specification of planes and lines of measurement and corresponding normal values. Circulation: Cardiovascular Imaging. 2008;1(2):104-113.
- Davis AE, Lewandowski AJ, Holloway CJ, Ntusi NAB, Banerjee R, Nethononda R, Pitcher A, Francis JM, Myerson SG, Leeson P, Donovan T, Neubauer S, Rider OJ. Observational study of regional aortic size referenced to body size: production of a cardiovascular magnetic resonance nomogram. Journal of Cardiovascular Magnetic Resonance. 2014;16:9. PMID:24447690; PMCID:PMC3899403.
- Minderhoud SCS, van Montfoort R, Meijs TA, Korteland S-A, Bruse JL, Kardys I, Wentzel JJ, Voskuil M, Hirsch A, Roos-Hesselink JW, van den Bosch AE. Aortic geometry and long-term outcome in patients with a repaired coarctation. Open Heart. 2024;11(1):e002642. PMID:38806222; PMCID:PMC11138275.