Fig. 2. Effect of B₀ and B₁ variations on pH_enh and APTw signals.

The absolute error induced by B₀ and B₁ variations was determined for baseline conditions, while the normalized change was determined as a results of tissue acidosis. The baseline signal drift is less (more) sensitive to B₀ (B₁) for pH_enh (A–B). In the presence of B₀ and B₁ variations, changes of APTw and pH_enh signals due to tissue acidosis reduce, and the normalized change is smaller for pH_enh than APTw (C–D).