The MRI spectrum of congenital cytomegalovirus infection

Abstract

Human cytomegalovirus (CMV) is an ubiquitous pathogen, with a high worldwide seroprevalence. When acquired in the prenatal period, congenital CMV (cCMV) is a major cause of neurodevelopmental sequelae and hearing loss. cCMV remains an underdiagnosed condition, with no systematic screening implemented in pregnancy or in the postnatal period. Therefore, imaging takes a prominent role in prenatal diagnosis of cCMV. With the prospect of new viable therapies, accurate and timely diagnosis becomes paramount, as well as identification of fetuses at risk for neurodevelopmental sequelae. Fetal magnetic resonance imaging (MRI) provides a complementary method to ultrasound (US) in fetal brain and body imaging. Anterior temporal lobe lesions are the most specific finding, and MRI is superior to US in their detection. Other findings such as ventriculomegaly, cortical malformations and calcifications, as well as hepatosplenomegaly, liver signal changes and abnormal effusions are unspecific. However, when seen in combination these should raise the suspicion of fetal infection, highlighting the need for a full fetal assessment. Still, some fetuses deemed normal on prenatal imaging are symptomatic at birth or develop delayed cCMV-associated symptoms, leaving room for improvement of diagnostic tools. Advanced MR sequences may help in this field and in determining prognosis, but further studies are needed.

Prenatal cranial MR findings in fetuses with suspected CMV infection: Correlation with postnatal outcome and differential diagnostic considerations

“…3 Our work highlights the importance of ascertainment of cCMV infection by amniocentesis before ascribing abnormal imaging findings to cCMV infection because of the lack of specificity of most abnormal findings for cCMV. Although a recent review suggested that anterior temporal pole cysts were highly specific for CMV, 22 we observed this in a fetus with a mitochondrial disorder.…”

“…In one of the other three fetuses with germinolytic cysts, the cysts were located in the anterior temporal pole and associated with anterior temporal white matter signal hyperintensity in a case of confirmed cCMV and neurotypical short-term outcome and normal hearing. The anterior temporal pole predominance of T2 hyperintensity and germinolytic cysts is a characteristic, and some have suggested specific (Diogo et al 22 ) constellation of imaging abnormalities in cCMV on iuMR. However, the relationship of anterior temporal pole germinolytic cysts or anterior temporal pole T2 hyperintensity alone with adverse neurodevelopmental outcome remains controversial despite a recent review (Diogo et al 22 ) stating that 'white matter changes in the temporal lobe are associated with a higher chance of neurological sequelae', referring to the study by Cannie et al 18 Cannie et al 18 found that of 12 fetuses with cCMV who had anterior temporal pole germinolytic cysts on iuMR (classified as a grade 4 abnormality in this study), 7 of 12 had normal and 5 of 12 had delayed neurodevelopment compared with abnormal neurodevelopment being documented in 8% of all of the 121 fetuses with cCMV included in the entire study.…”

“…The anterior temporal pole predominance of T2 hyperintensity and germinolytic cysts is a characteristic, and some have suggested specific (Diogo et al 22 ) constellation of imaging abnormalities in cCMV on iuMR. However, the relationship of anterior temporal pole germinolytic cysts or anterior temporal pole T2 hyperintensity alone with adverse neurodevelopmental outcome remains controversial despite a recent review (Diogo et al 22 ) stating that ‘white matter changes in the temporal lobe are associated with a higher chance of neurological sequelae’, referring to the study by Cannie et al 18 …”

Detecting Fetal Central Nervous System Anomalies Using Magnetic Resonance Imaging and Ultrasound

“…The hypointense lesions on T2*-weighted gradient-echo must differ from calcification associated with fetal infections ( 21 ). However, intracranial calcifications associated with fetal infections are more common in the periventricular region and basal ganglia ( 27 ), and punctate calcifications may be difficult to detect on iuMRI ( 28 ). In addition to intracranial calcifications, fetal infections can present other abnormalities, such as intraventricular synechiae and extra-CNS symptoms, such as hepatomegaly, splenomegaly, and effusions (pericardial, pleural, and ascites) ( 27 ).…”

The use of MRI in fetal conditions amenable for antenatal management

“…Accurate diagnosis may be particularly challenging in the third trimester, in which involvement of the white matter can be the only feature. Herein, Diogo et al describe how MRI can confirm or exclude the diagnosis of CMV infection …”