Figure 3.

Color‐coded ∆B ₀ maps for the proposed dynamic methods CEST‐GRE‐2TE (first row), CEST‐GRE‐1TE (second row), and NAV‐EPI‐2TE (third row) acquired at seven saturation frequency offsets around the water resonance (0 ppm) at ∆ω = [‐0.33 to 0.33] ppm (columns). NAV‐EPI‐2TE is the only dynamic method insensitive to the RF saturation pulses applied for CEST labeling. Methods CEST‐GRE‐1TE and CEST‐GRE‐2TE are consistent with these results distant to the water resonance, but suffer from corrupted maps for ∆ω < |0.33| ppm (i.e., close to water). CEST‐GRE‐1TE, chemical exchange saturation transfer‐gradient‐echo‐1TE; EPI, echo planar imaging; GRE, gradient‐echo; NAV‐EPI‐2TE, navigator‐echoplanar imaging‐2TE