TABLE 1.

Description of Different Approaches Used to Calculate R2* Values and Nomenclature for the Respective R2* Algorithms

Algorithm Name	Type of ROI	Type of Fitting	Curve-Fitting Model	Reference
R2*_PW_GA(3P)	Entire liver profile in the slice	Pixelwise approach	Offset model	[5]
R2*_Avg_GA(3P)	Entire liver profile in the slice	Averaged-signal approach	Offset model	[15]
R2*_Avg_GA(2P)	Entire liver profile in the slice	Averaged-signal approach	Truncation model	Not applicable
R2*_PW_ROI(3P)	Area of homogeneous liver tissue	Pixelwise approach	Offset model	[16]
R2*_Avg_ROI(3P)	Area of homogeneous liver tissue	Averaged-signal approach	Offset model	[18]
R2*_Avg_ROI(2P)	Area of homogeneous liver tissue	Averaged-signal approach	Truncation model	[17]

Note—Each approach is defined by three different aspects and two approaches differ for at least one of these aspects. PW = pixelwise, GA = global analysis, 3P = three parameter, Avg = average, 2P = two parameter.