Figure 17. Unicornuate uterus with an obstructed functioning rudimentary horn (class 3). Coronal T2-weighted spin-echo image (4,000/120) shows a right unicornuate uterus (arrow). The obstructed functioning rudimentary horn appears as a blood-filled dumbbell-shaped mass. Its shape corresponds to the obstructed uterine horn (H) and its fallopian tube (T), a hematometrosalpinx. Both ovaries (Ov) are identified; each is related to its ipsilateral uterine horn.