Figure 2: A-D: ADC values of all phantoms. The inter-fiber spaces in (A/B) and (C/D) were respectively filled with the 0% and 20% solution. The phantom ADC values with different fiber permeabilities are shown separately. Each solid line connects values measured from three phantoms with different volume fractions of intra-fiber spaces. E-H: Representative ADC maps. For each subplot, the volume fractions of the intra-fiber spaces increase from left to right, and the PVP concentration of the intra-fiber spaces increase from top to bottom.

Figure 1: SEM images and phantom photographs. A: SEM images of the hollow PES fibers with small pore diameter (first row) and large pore diameter (second row). The images of the inner surfaces, outer surfaces, and cross sections are shown from left to right. B: Pore diameter distribution on the inner surface of two fibers. C: Photograph of the entire phantom. The red arrows point to the positions for the two openings of the inter-fiber spaces, and the blue arrows point to the positions of the intra-fiber spaces. D: Photograph of the potting layer.