Get Pediatric PA Diameters & Z-Scores

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Calculates reference values and z-scores for pediatric pulmonary artery diameters based on a subject's weight, height, and a measured diameter. Diameters are measured perpendicular to the vessel on contrast-enhanced CMRA.

Provides z-scores and normal reference diameters for the pulmonary arteries in children based on body surface area (BSA).

The calculations are based on the reference paper: Knobel Z, Kellenberger CJ, Kaiser T, et al. Geometry and dimensions of the pulmonary artery bifurcation in children and adolescents: assessment in vivo by contrast-enhanced MR-angiography. Int J Cardiovasc Imaging. 2011;27:385–96.

Calculation Details:

1. Body Surface Area (BSA) is calculated from weight and height using the Mosteller formula: BSA = sqrt((wt_kg * ht_cm) / 3600)
2. Predicted Diameter (Mean) is calculated using the regression model: predicted = a + b * BSA^c (The coefficients a, b, c, and sd are looked up based on the parameter).
3. Z-Score is then calculated as: z-score = (measured - predicted) / SD
4. Limits (LL/UL) correspond to a z-score of -2 and +2.

Abbreviations:

• BSA: Body Surface Area
• SD: Standard Deviation of residuals
• RAO: Right Anterior Oblique view (paracoronal, parallel to right pulmonary artery)
• LAO: Left Anterior Oblique view (paracoronal, parallel to left pulmonary artery)