Inherent Geometry Correction for Diffusion EPI Using the Reference Echoes as Navigators

Figure 3

3T T2W TSE (a) and fat-suppressed diffusion EPI images (phase shift direction P) from the manufacturer’s head phantom (25 cm diameter) and a bottle filled with oil. The setup has strong local field gradients, resulting in significant EPI distortions (b) that are corrected (c) by echo–by–echo phase subtraction using the nonphase–encoded navigator echoes.

(a)

(b)

(c)