Figure 2. Schematic representation of the SMS framework.

(A) Left: SMS3 with CAIPIRINHA encoding but without GC-LOLA. The application of CAIPIRINHA RF phase increments $\Delta {\varphi }_1=\frac{2\pi }{3}$ and $\Delta {\varphi }_3=-\frac{2\pi }{3}$ determines spatial shifts along the PE direction of apical and basal slices of FOV/3 and –FOV/3. When combining CAIPIRINHA encoding with bSSFP imaging, the bSSFP frequency response of apex and base is also shifted by ± a third of the total bandwidth with respect to the mid-slice (orange arrows). Right: schematic through-plane representation of the bSSFP frequency response for bands 1, 2, and 3 at positions z₁ z₂, and z₃ with CAIPIRINHA RF phase increments Δϕ ₁, Δϕ ₂, and Δϕ ₃. The shifts in the frequency response across slices are represented with an orange arrow. (B) GC-LOLA correction with SMS3. After the application of ΔM_LOLA and Δϕ_LOLA from Equations (1) and (2), all bands are aligned irrespective from their position along the z axis (orange arrow). bSSFP, balanced steady-state free precession; CAIPIRINHA, controlled aliasing in parallel imaging results in higher acceleration; GC-LOLA, gradient-controlled local Larmor adjustment; PE, phase encoding; SMS, simultaneous multi-slice