Urogenital Imaging

Uterus, unicornuate

anomaly resulting from nondevelopment or incomplete development of one Mullers duct. The abnormal Mullerian duct is often associated with ipsilateral anomalies of the mesonephric system, and in those cases the ipsilateral kidney and ureter are usually absent. The ipsilateral ovary may or may not be absent. With incomplete development of one Mullerian duct, three separate subtypes of unicornuate anomaly are: a unicornuate uterus with a rudimentary horn that does not contain endometrium; a unicornuate uterus with a rudimentary horn which does contain endometrium but does not communicate with the main uterine cavity; and a unicornuate uterus which has a rudimentary horn which contains endometrium and does communicate with the main uterine cavity. A unicornuate uterus can support a normal pregnancy. About 40% of pregnancies will end in spontaneous abortion, 20% in live births. Unicornuate uterus may go undiagnosed until the patient is evaluated by a hysterosalpingography HSG or is subjected to a surgical procedure. At HSG, the uterine cavity is a "banana" shape, and curved to one side, instead of having a normal triangular shape (Fig.1). Only one tube opacifies.This appearance must be distinguished from an incompletely filled uterine cavity spasm of a Fallopian tube or uterine synechiae. At MRI, unicornuate uterus has a virtually diagnostic appearance due to the "banana"-shaped uterine cavity. Endometrial and myometrial width are normal. Ultrasonography is of limited accuracy in the diagnosis of unicornuate uterus.

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Fig.1

Hysterosalpingogram showing a rightsided unicornuate uterus.

Uterus, unicornuate, Fig.1