Brain Injury in Fetuses with Vein of Galen Malformation and Nongalenic Arteriovenous Fistulas: Static Snapshot or a Portent of More?

Abstract

BACKGROUND AND PURPOSE: Brain injury in fetuses with vein of Galen malformations and nongalenic AVFs is a rare complication whose appearance, course, and prognosis are poorly studied. We sought to characterize the MR imaging features and examine associations with postnatal outcome. MATERIALS AND METHODS:This was a retrospective analysis of fetal MRIs of subjects with vein of Galen malformation and nongalenic arteriovenous fistulas. Two pediatric neuroradiologists independently reviewed examinations to determine the presence of abnormalities on structural imaging (T1 volumetric interpolated breath-hold examination and T2-HASTE), DWI, and T2*-weighted images; discrepancies were adjudicated by a third reviewer. Radiologic progression of injury was determined by additional fetal or neonatal MRIs. A simple composite score evaluating poor neonatal clinical outcome as either intubation or death by postnatal day 2 was also queried. A body fetal imager evaluated the presence of systemic findings of right heart strain.RESULTS: Forty-nine fetal MR imaging examinations corresponding to 31 subjects (27 vein of Galen malformations and 4 nongalenic AVF cases) were analyzed. Injury was observed in 8 subjects (26%) with 14 fetal examinations; the mean gestational age at identification of injury was 32.2 (SD 4.9) weeks. Structural abnormalities were present in all subjects with injury; restricted diffusion, in 5/7 subjects with available data; and T2* abnormalities, in all subjects with available data (n ¼ 7). Radiologic progression was documented in all cases with follow-up imaging (n ¼ 7). All subjects with fetal brain injury had a poor neonatal clinical outcome. CONCLUSIONS:Brain injury in fetuses with vein of Galen malformation and nongalenic AVFs shows a combination of structural abnormalities, restricted diffusion, and blooming on T2* images. Injury appears to portend a poor prognosis, with relentless progression and a likely association with adverse neonatal outcomes.

Implications of serial magnetic resonance imaging in the management of a newborn with vein of Galen aneurysmal malformation and a review of the relevant literature

“…9 Fetal or neonatal MRI lesions among patients with VGAM are reported to be predominantly supratentorial in location and usually bilateral. 10 Presence of diffusion restriction is most commonly but not exclusively due to underlying ischemia, neuronal migration disorders are also included in the differential diagnosis. 11 Venous congestion and venous hypertension seem to be the main underlying pathogenesis for the development of cerebral ischemia in patients with VGAM.…”

Congenital Intracranial Vascular Malformations in Children : Radiological Overview

“…AVFs comprise approximately 4% of pediatric cerebral vascular malformations [ 15 ]. These lesions can be categorized into three entities : VGAM, pial AVF, and dural AVF within the context of dural sinus malformations (DSMs) [ 7 , 8 , 12 ].…”

“…The mural type corresponds to direct AV fistulas within the wall of MPV (Fig. 4) 1,8,20) . A two-dimensional real-time ultrasonography can identify an aneurysm as a hypoechoic midline mass posterior to the roof of the third ventricle.…”