MRI appearance of cervical incompetence in a pregnant patient.

Ultrasonography is currently the principal imaging modality for diagnosing cervical incompetence during pregnancy. Various technical factors, both patient and technologist/transducer related, may limit its evaluation for cervical incompetence. MRI is not dependent on these technical considerations. MRI may demonstrate a higher degree of soft tissue contrast than ultrasonography for depicting uterine anatomy. MRI may, in some instances, be more accurate in depicting cervical incompetence in the gravid patient. We present the first case of cervical incompetence in a pregnant patient diagnosed by MRI, in which ultrasonography failed to provide conclusive evidence of extra-uterine herniation of the amniotic sac.