From 2017 to 2018, 21 healthy women were enrolled, and scanned with resting-state functional magnetic resonance imaging under the empty bladder and strong desire to void, respectively. Brain connection matrix was established with Pearson's correlation analysis, and the differences in topologic properties between the two conditions were identified with paired t-test and Bonferroni correction. The small-world parameters, named clustering coefficient (C_p), characteristic path length (L_p), global efficiency (E_glob), local efficiency (E_loc) and nodal efficiency (E_nodal) were calculated.

There were two women dropped down because of head moving. For the other 19 women, the brain connection presented a small-world network property under the both conditions. Compared with the empty bladder, C_p, L_p, and E_loc decreased, and E_glob increased under the strong desire to void (P < 0.05); while E_nodal increased in left inferior frontal gyrus and superior frontal gyrus; right cingulate gyrus, middle occipital gyrus and middle temporal?gyrus; and bilateral gyrus rectus and inferior parietal lobes; and decreased in bilateral fusiform gyrus, calcarine fissure and surrounding, and lingual gyrus (P < 0.05).

Brain functional network presents a small-world network property under both empty bladder and a strong desire to void. The regulation of lower urinary tract function involves the coordination of multiple brain regions.