Figure 4b. HSG demonstration of septate versus bicornuate uteri. (a) Acute angle of divergence between uterine horns is most suggestive of a septate uterus (arrow). (b, c) Indeterminate angles of divergence may suggest either (b) septate uterus (arrow) or (c) bicornuate uterus (arrow). Final diagnoses were based on subsequent MR imaging results (not shown).