Fetal intracranial hemorrhage and infarct: Main sonographic and MRI characteristics: A review article

Abstract

Early detection of fetal intracranial hemorrhage and infarct during pregnancy is crucial for preventing lethal and debilitating complications in neonatal life. Every radiologist must be aware of the imaging features of these conditions to refer patients to specialists. Sonographic and MRI features of fetal intracranial hemorrhage and infarct have been discussed in many previous articles. The aim of this article is to organize and categorize these findings into a practical guideline for improved application in diagnosing these diseases. The use of MRI sequences, such as DWI and multiplanar EPI should be developed for suspected prenatal infarct and intracranial hemorrhage and can serve as additional tools for early detection. In this review article, we first explain possible etiologic factors contributing to the development of fetal IVH and infarct. Then we discuss the different imaging features of these disorders on sonography and MRI separately, as well as their differential diagnosis. Finally, the mortality and morbidity associated with these two concerning fetal abnormalities will be addressed.

Keywords: IVH; Infarct; MRI; Sonography.

Fig. 1

Ultrasound findings in fetal IVH: a) large avascular, echogenic mass in a porencephalic cavity (large arrow) associated with ventriculomegaly and nodular echogenic ependyma (arrowhead); b) A 20 weeks fetus with unilateral IVH grade 1 (arrows) in parasagittal and coronal views.

Fig. 2

4 different fetuses with IVH grade 1–4 based on Paplie criteria in fetal MRI T2- weighted sequence. a) Unilateral IVH grade 1 in a 35 weeks fetus; b) Bilateral IVH grade 2 in a 20 weeks fetus with placental abruption; c) Bilateral IVH grade 3 with severe ventriculomegaly in a 27 weeks fetus; d) Unilateral IVH grade 4 in a 33 weeks fetus.

Fig. 3

A 25 weeks fetus with unilateral cerebellar atrophy with peripheral low T2 rim due to hemosiderin: Old hemorrhage.

Fig. 4

a monochorionic twin pregnancy, who underwent cord occlusion for one of the fetuses due to a twin reversed arterial perfusion (TRAP) sequence, was referred to our department at 24 h following the procedure for an ultrasound exam. The surviving twin developed bradycardia and hydrops after reduction. No anemia was found on Doppler imaging of MCA. However, increased echogenicity was detected in the watershed areas of bilateral frontoparietal and parieto-occipital lobes, which suggested an acute cerebral ischemic injury. The fetus expired almost six hours later;a) An edematous dead fetus with TRAP (wide arrow), an alive fetus (narrow arrow); b) mild ascites; c) bilateral mild pleural effusion; d) bradycardia and reversed diastolic flow in umbilical cord; e) reversed ductus venosus flow; f) increased echogenicity in frontoparietal and parietooccipital areas (arrows) due to acute brain infarction in watershed regions.

Fig. 5

A case of Vein of Galen Malformation (VGAM) with concurrent acute and chronic brain infarct. a,b,c) dilated prosencephalic vein or VGAM (asterisk), straight sinus and dilated tuft of vessels. Extensive encephalomalacia was found bilaterally more prominent in left side (small arrows). d-l) In 3 different axial levels, including T2-weighted images (d,f,g), T2 * -weighted (Hemo) sequence (e,h,k) and DWI sequence (f,I,l) you can see simultaneous acute (large arrows) and chronic (small arrows) fetal brain infarcts and cortical and intraparenchymal hemorrhage. Extension of acute infarct to genu of corpus callosum was present (narrow arrow in l). Foramen magnum stenosis as an accompanying abnormality (large arrows in b,c).