Fetal imaging of a rare case of dural sinus malformation: a case report

Abstract

Background: Dural sinus malformations (DSM) are rare congenital anomalies, accounting for less than 2% of all intracranial vascular malformations. Fetal MRI plays an important role in the confirmation of the diagnosis, prognostication, and planning of treatment strategies. Here, we present a rare case of dural sinus malformation without thrombosis, diagnosed by prenatal ultrasound and fetal MRI. In addition to this, fetal intracranial 3D gradient recalled echo Dixon-based MRA was done which, to the best of our knowledge, is a first. Case presentation: A 24-year-old multigravida with no known comorbidities underwent a routine second trimester anomaly scan in which an unusual posterior interhemispheric cyst was diagnosed. Further evaluation with fetal MRI revealed dilated posterior sinuses and torcula, normal internal jugular vein, and maintained flow voids with no mass effect. Fetal Dixon-based MRA and correlated Doppler revealed supply to the lesion by bilateral occipital arteries and posterior cerebral arteries. With these imaging features, a midline dural sinus malformation was diagnosed. Conclusion: Dural sinus malformations should be considered in the differential diagnosis of unusual posterior fossa cystic lesions detected on antenatal ultrasound coupled with a colour Doppler examination. Prompt fetal MRI is essential to establish the diagnosis, identify intracranial complications and decide the postnatal treatment strategy, thereby possibly improving the postnatal outcome.