Figure 7:

(a) ruCNR of bSSFP is displayed as a function of N and FA (Eq. (45)) with given TR (5 ms), T₁ (1000 ms) and T₂ (100 ms) values, for a condition of $\text{TR}<\overline{TR}$ (23.0 ms). An optimal N and FA pair (25, 180°) is found to maximize ruCNR (6.38, white star). Contours are shown for sacrificed ruCNR when η = 0.99, 0.95, 0.9. (b, c, d, e) The optimal N* and FA* (Eq. (47)), echo train duration N*·TR, and the maximal ruCNR_bSSFP (Eq. (48)) are plotted with respect to TR, with black circles indicating the values for TR = 5 ms, which match the white star in (a), and the solid black lines represent the original optimization results when η = 1. The red dashed lines, green dash-dot lines and blue dotted lines represent the corresponding optimization results (Eq. (50)) for optimal N*, FA*, echo train duration, and ruCNR* with varying TR, when η = 0.99, 0.95, 0.9, respectively. For TR = 5 ms and η = 0.99, 0.95, 0.90, (a) the maximal ruCNR* = η · 6.38 = 6.32, 6.06, 5.74 are achieved at N* = 31, 50, 71 and lower FA* = 128°, 85°, 65° (black stars), which match (b, c, d, e) the colored circles in the red dashed, green dash-dot and blue dotted lines.