AAAResearch CalculatorResearch use only

Literature-bounded interpretation

AAA measurement context calculator

Compare entered imaging and plasma measurements with published human AAA study summaries. This tool describes measurement context—it does not estimate rupture risk.

Abdominal aortic aneurysm onlyNo clinical risk scorePatient-level research context

AAA-only scope

When to use

Use for

  • Adult abdominal aortic aneurysm research.
  • Hospital-reported maximum AAA diameter in mm.
  • Matched scan-day plasma D-dimer in mg/L FEU.
  • Source-bounded descriptive comparison with published cohorts.

Do not use for

  • Rupture or growth prediction, treatment, or surveillance decisions.
  • AAA screening or diagnosis.
  • Thoracic, intracranial, or other non-abdominal aneurysms.
  • Replacing 4D-CTA registration, motion qualification, or uncertainty QC.
1

Enter values

Patient measurements

Enter only values available from the hospital record. ILT and total-sac volumes are not treated as patient inputs.

Maximum AAA diameter
mm

Use the maximum outer-to-outer diameter reported from the patient’s clinical imaging record.

Selected automatically from AAA sizeAAA <55 mm published context

Typical ILT context: 57.2 mL, the published group median—not a patient-specific estimate from imaging.

Plasma D-dimer
mg/L FEU

Use the matched scan-day hospital laboratory value reported in mg/L FEU.

2

See context

Patient result

Hospital-reported AAA size50.0 mmautomatically uses the AAA <55 mm literature context50.0 mm → <55 mm
D-dimer2.16 mg/L FEU

Within this study group’s IQR

Published size-group median: 2.16 mg/L FEU
Typical ILT context≈ 57.2 mL

Published <55 mm group median

Context estimate only—not measured or predicted for this patient.

What this means

The entered hospital values select the published AAA <55 mm context. “Within IQR” means within that study’s middle 50%—not normal, safe, or low risk. The ILT number is the group median, not a patient measurement.

No clinical score is calculated.No rupture prediction, treatment threshold, or patient-care recommendation is produced.

P13 phase-resolved geometry

4D AAA wall–thrombus–lumen interaction

Press Play to move one integrated 3D model through CT0–CT5. The exterior wall, intraluminal thrombus, and lumen remain spatially coupled throughout the cycle.

De-identified P13CTA registration + segmentation
Cardiac phase 1 of 6CT0 · source-designated systolic configuration
Registration-derived wall motion from CT00.00 mm median0.00 mm 90th percentile

Drag to rotate · Scroll to zoom

Integrated 3D configurationLoading P13 phase geometry…

Motion source: CT0 was deformably registered to CT1–CT5 within the P13 aneurysm region; the resulting field moves all three paired surfaces together at 1× displacement. This display is not an uncertainty-qualified U50,A result.

Source: de-identified P13 4D-CTA and paired surface files from the supplied open 20-patient AAA dataset. The viewer retains the full labeled exterior-wall, ILT-interface, and lumen-interface triangle sets; phase offsets are computed in physical image coordinates.

Visual comparison

D-dimer against published study ranges

Horizontal bars show published IQRs, dots show medians, and the red dashed line shows the hospital D-dimer value.

Published IQRMedianPatient value
Plasma D-dimerMedian and interquartile range
036912<55 mm2.16Full cohort2.76>55 mm4.83Patient: 2.16mg/L FEU

Fan et al., 2020. The full cohort overlaps both size groups. Ranges are study-specific summaries, not clinical reference intervals.

Interpret carefully

Pearls & pitfalls

Pearls
  • AAA diameter automatically selects the matching published size context.
  • The D-dimer graph shows the hospital value beside published cohort summaries.
  • The displayed ILT value is a size-group median estimate, not a patient measurement.
Pitfalls
  • D-dimer is systemic and nonspecific; it cannot be assigned specifically to AAA thrombus.
  • Lower or higher wall motion alone does not establish flow, stiffness, wall strength, or rupture risk.
  • Published u99 and proposed U50,A are different motion endpoints and are not interchangeable.

Purpose

Why use this calculator?

1

Use hospital values

Enter only reported maximum AAA diameter and scan-day D-dimer.

2

See study context

Match size context automatically and compare D-dimer with published medians and IQRs.

3

Keep claims bounded

Separate descriptive measurement context from prediction, causation, and clinical decision-making.

Plain-language reference

Definitions

Relative ILT

Absolute ILT volume divided by total aneurysm-sac volume, multiplied by 100. It describes CTA-visible thrombus occupancy of the bounded sac.

Interquartile range (IQR)

The middle 50% of values reported in a study group. It is a descriptive study range, not a normal range or clinical threshold.

Plasma D-dimer

A systemic fibrin-turnover measurement. It is nonspecific and cannot be attributed only to AAA thrombus.

4D-CTA motion endpoint

Registration-derived wall displacement across ECG-gated CTA phases. U50,A must be qualified separately and does not measure stiffness, strength, flow, or rupture risk.

Research workflow

Research next steps

  1. 1

    Match the records

    Confirm the same patient, scan day, sample timing, and units.

  2. 2

    Check segmentation

    Review CTA boundaries and confirm total-sac volume is not smaller than ILT volume.

  3. 3

    Qualify motion separately

    Apply registration and uncertainty gates before interpreting U50,A.

  4. 4

    Analyze at patient level

    Report effect estimates, uncertainty, and null findings without converting associations into clinical risk.

Evidence and measurement notes

Published cohort context

Fan et al., Life Sciences (2020), n=181; D-dimer and CTA were assessed within fewer than 3 days.

View the Fan et al. study

Open 4D-CTA example data

A 2026 open dataset describes ECG-gated patient AAA volumes, wall and ILT surface models, and cardiac-phase frames.

View the open dataset paper

Research boundary

Patient is the statistical unit. Values support descriptive, uncertainty-qualified association testing—not a learned risk model.