Prior hysterosalpingography (not included) showed two diverging uterine cavities, with large intercornual distance and wide angle of divergence, which was interpreted as bicornuate bicollis uterus.

However, 'angle of divergence' and 'intercornual distance' are losing relevance for infertility specialists. They need to clearly understand the external surface of uterus if its bifid or concave, which is usually termed a 'bicornuate uterus' and requires metroplasty.

In this case, external fundal surface is convex or at least can be termed 'flat' in some images, but definitely not bifid or concave. This MRI should be interpreted as a septate uterus, with a thin almost complete septum across uterine cavity, not reaching external os or vagina, with maintained fundal external surface. 

As we have to choose one of the two- I prefer to call it a 'septate uterus' and not a 'bicornuate uterus', which was agreed by infertility specialist, who treated by resection of uterine septum, with no enthusiasm for metroplasty in this case.