Pediatric Coronary Artery Z-Scores (McCrindle 2007)
Historical McCrindle Boston model. Enter Haycock BSA and measured proximal LMCA, LAD, RCA diameters in cm. This does NOT diagnose or determine treatment for Kawasaki disease or another condition.
Results update as you type. Use Enter to move to the next field.Select the next field to continue.
Enter arterial diameters in cm. For example 2.5 mm = 0.25 cm. Leave unmeasured segments blank.
Results McCrindle 2007
Enter BSA and at least one measured segment.
Z = (measured diameter − predicted mean) / SD. Diameter, mean and SD display in mm; the original calculation remains in cm. Unmeasured segments have no Z-score.
LMCA Left main coronary artery
- Measured diameter
- Not entered
- Predicted mean
- —
- Standard deviation (SD)
- —
pLAD Proximal left anterior descending artery
- Measured diameter
- Not entered
- Predicted mean
- —
- Standard deviation (SD)
- —
pRCA Proximal right coronary artery
- Measured diameter
- Not entered
- Predicted mean
- —
- Standard deviation (SD)
- —
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Equations, population, method limitations and sources
Original model
Regression and SD are evaluated in centimetres from Haycock BSA in m². Convert mean/SD/measured values to millimetres only for display. Each segment is modeled separately; unmeasured values are not inferred.
Equations for BSA B
- LMCA: mean = 0.31747 × B^0.36008 − 0.02887; SD = 0.03040 + 0.01514 × B
- pLAD: mean = 0.26108 × B^0.37893 − 0.02852; SD = 0.01465 + 0.01996 × B
- pRCA: mean = 0.26117 × B^0.39992 − 0.02756; SD = 0.02407 + 0.01597 × B
Example (synthetic)
BSA 1 m², LMCA 0.28860 cm (2.886 mm): predicted mean 0.28860 cm, SD 0.04554 cm, Z = 0. Calculations use unrounded centimetre values.
Population and limitations
Original reference: Boston, 221 healthy subjects aged 0–18. The original cohort BSA range was not fully verified, so extrapolation is not approved. Distal artery segments, circumflex and variable LMCA anatomy are outside this formula. No Kawasaki disease classification or treatment decisions are implied.
Evidence
Coefficients verified 2026-11-10.