Table 1.

Conversion table and methods from MR arbitrary units to Hounsfield Units for all defined tissue types used to generate a synthetic CT.

Tissue Type	MR Abitratry Units/HU Values Conversion Method	Hounsfield units (HU)
Bone	Inverse Linear	500 to 1100
Brain	Linear	35 to 75
Water (CSF, eyes)	Bulk Assignement	0
Soft tissues	Inverse Linear	−80 to −30
Air	Bulk Assignement	−1000

These values were slightly adapted from Yu et al. (15) and are in agreement with observed and published tissue density ranges.