Accuracy metrics: intercept (a), slope (b), average bias (c) and R2 (d) as a function of starting echo number for the cases in which n = 3, 4, 6, 10, and 13 were used for MRI-FF estimation. In each panel, each curve corresponds to a specific n, as indicated in the figure legend. Each point on a curve corresponds to a different m. For example, the first point on the interval curve MRI-FF(3,m) corresponds to MRI-FF(3,1), the MRI-FF calculation for echoes (1,2,3). The second point corresponds to MRI-FF(3,2): the MRI-FF calculation for echoes (2,3,4). The number of points in each curve depends on n: there are 14 possible estimates in the MRI-FF(3, m) curve, but only 4 possible estimates in the MRI-FF(13, m) curve.