Catphan ctp486 may have inverted top-bottom ROIs

[brjdenis]

Printing the ctp486 ROI coordinates gives:

for key, value in cbct.ctp486.rois.items():
     print(key, value.center)

-> Top Point(x=257.30, y=362.31, z=0.00)
-> Right Point(x=365.28, y=253.20, z=0.00)
-> Bottom Point(x=256.17, y=145.23, z=0.00)
-> Left Point(x=148.19, y=254.33, z=0.00)
-> Center Point(x=256.74, y=253.77, z=0.00)

The top has bigger y than the bottom point, but I think it should be vice-versa. Normally the images I am getting have the origin in the left top corner.