1).

Schematic for the triple diffusion encoding (TDE) pulse sequence used in this study. The axial gradients are oriented in the x-direction while the radial gradients are oriented in the y- and z-directions. By design, the diffusion weighting in the axial direction is higher than for the radial directions, and the axial direction defines the diffusion encoding direction for the sequence. The amplitude of the axial gradient pulses is indicated by g_∥, and the amplitude of the radial gradient pulses is indicated by g_⊥. The diffusion time of each direction corresponds to the interval between the centers of the gradient pulses, and it is indicated by Δ_∥ for the axial direction and by Δ_⊥ for the radial directions. The gradient pulse durations correspond to the interval during which a gradient is at its maximum amplitude plus the rise time, and these are indicated by δ_∥ for the axial direction and by δ_⊥ for the radial directions. The b-matrix for the sequence is axially symmetric since the radial pulses have identical amplitudes and timings. Not shown in this schematic are the imaging gradients, which were implemented as a single shot EPI acquisition