TABLE 2.

Definition of Parameters used to Quantify Dose Uncertainty (example of a child younger than the phantom, exposed to narrow fields)

Uncertainty parameters	Distribution type		Distribution parameters
Accuracy of peak skin dose	Uniform	[0.85, 1.15]	(minimum, maximum)
Lack of knowledge of X-ray generation parameters	Normal	[1, 0.1]	(mean, SD)
Bias correction for smaller subject cranium	Triangular	[1.0, 1.1, 1.15]	(minimum, mode, maximum)
Size of cranium: lack of information on subject	Normal	[1.0, 1.1]	(mean, SD)
Backscatter	Triangular	[0.88, 0.94, 1.0]	(minimum, mode, maximum)
Spatial resolution	Triangular	[0.80, 0.9, 1.0]	(minimum, mode, maximum)
Total uncertainty, UTot	Lognormal	[0.91, 1.21]	(geometric mean, geometric standard deviation)