Fig. 7.

Left image shows the water-filled phantom (diameter 2.9 cm) suspended in saline solution (NaCl ≈ 155 mM). Highlighted line in the center of phantom representative of length of line profiles on the right. Distance between the top of the profile and the middle of the step-like profile was used as an approximation of the FWHM of the true image PSF. Measurements for resolution estimation were taken from both sides of the tube (as shown left and right in the line profiles) and at a perpendicular angle to these over three slices (not shown)