Prenatal Diagnosis of a Cavum Veli Interpositi

Abstract

The presence of an interhemispheric supratentorial fluid collection requires an attentive analysis for differentiation between interhemispheric supratentorial cystlike fluid collection lesions and pathologic cystic lesions. Interhemispheric supratentorial fluid lesions are a heterogeneous group of lesions with respect to their origin, natural history, association with other anomalies, and especially prognosis. They may represent physiologic median structures without clinical importance, such as an enlarged cavum vergae or cavum veli interpositi (CVI). 1 However, the differential diagnosis of midline cystic cerebral lesions includes an enlarged third ventricle, a vein of Galen malformation, an interhemispheric cyst associated with agenesis of the corpus callosum, a suprasellar arachnoid cyst, a porencephalic cyst, a glioependimal cyst, schizencephaly, a cystic neoplasm, and intracranial hemorrhage. The clinical spectrum and prognosis of these abnormalities are difficult to delineate because of the rarity of each entity and the different associations. The cystlike structures related to median structures are considered variants of physiologic structures, whereas the other structures include pathologic processes that may be associated with neurodevelopmental delays. We report a case of prenatal diagnosis of a CVI by 2-dimensional (2D) sonography, color Doppler imaging, 3-dimensional (3D) tomographic imaging, and 3D high-definition flow. The findings were confirmed by postnatal magnetic resonance imaging (MRI).