Second-trimester diagnosis of intracranial vascular anomalies in a fetus with subdural hemorrhage

OBJECTIVES: Risk factors for intracranial hemorrhage occurring in prenatal life are imperfectly known. A case of prenatal diagnosis of subdural hemorrhage associated with multiple intracranial vascular aneurysms is described. METHODS: Sonography and magnetic resonance imaging of the fetal head were obtained at 21 weeks' gestation and compared with pathologic findings. RESULTS: Sonography showed a large transonic mass displacing the normal intracranial structures. Magnetic resonance imaging demonstrated the hemorrhagic origin of the mass and showed multiple vascular anomalies. Postmortem examination confirmed the compression of the cerebral hemisphere by a blood collection, probably because of bleeding from one of the multiple vascular aneurysms into the subdural space. CONCLUSION: Magnetic resonance imaging with the use of single-shot ultrafast sequences may be useful not only in the differential diagnosis of fetal intracranial hemorrhage but also in identifying vascular risk factors.