Figure 4a:

Graphs show representative records of MAX-freq and MAX-B₀-shim for (a) young control subject, (b) older control subject, (c) PD, and (d) MCI groups associated with motion records from Figure 2. Frequency changes show combined effect of head motion and frequency drifts partially introduced by spiral encoding of the 3D GABA-edited MR spectroscopic imaging. MAX-freq and MAX-B₀-shim are higher in subjects who performed more extensive movement (ie, older control subject, PD, and MCI groups). Larger left-to-right head rotation (on transverse plane) performed by subject with PD caused less B₀ field distortion in c than did rotation in other directions performed by subject with MCI in d.