Figure 2

Measurement of puborectalis thickness and ADC. (a) Measurement of puborectal thickness where the puborectalis is at its widest (adjacent to the rectal wall at the point where the fibres attach to the pubis; the yellow lines indicate where the puborectal thickness measurements were obtained, right in the middle and at a third of the total length of each branch. (b) ROIs were placed at the slice where the puborectalis was widest. An ROI was first placed at the point of the thickest slice of the middle zone (M zone). Then, ROIs were placed at a third of the total length of the left and right branches, close to the M zone. (c) Another method for placing ROIs to increase the numbers of voxel is to add two ROIs on both sides of original ROI and average the values of the three ROI to get the final result.