Fig. 2

Findings in patients with cesarean section (CS) on the left and in controls without CS on the right. By comparing the images, difficulties in LUS diagnosis and in finding valuable reference values for LUS thickness become clearer. Black point = amniotic fluid, black arrows = inner border of the LUS, white arrows = outer border of the LUS, asterisk = lower uterine front wall, black point = amniotic fluid. As demonstrated in comparison (a) versus (b), thinning of the LUS (thin arrows) and/or the lower uterine front wall (white arrow heads), as well as unclear definitions of LUS and bladder wall occurs in both scarred and unscarred uteri. In contrast, comparison of (c) versus (d) shows that a clear definition of a well-developed LUS from the urinary bladder wall is also commonly found after CS (white arrow heads). Comparison of (e) versus (f) shows that the MRI-signal of the LUS can be hypointense in women with and without previous CS. Even local thinning with an abrupt change of LUS diameter, which is assumed to be the most specific characteristic after CS (g), can probably related to myometrial contractions, occasionally also be observed in women without a uterine scar (f) and (h), (white arrow heads)