Table 1.

List of possible magnetic resonance imaging (MRI) findings in fetuses with congenital cytomegalovirus (cCMV)

	Finding	MR characteristics	Notes
Brain	WM hyperintensities	T2‐hyperintense inhomogeneities of the WM Low SI on DWI Low SI on T1w‐/T2w FLAIR Use MRS?	Subjective Difficult to interpret particularly in the third trimester Temporal lobe worst prognosis.
	Ventriculomegaly	Increased lateral ventricle size (>10 mm), measured at the atria Mild: 10‐12 mm Moderate: 12‐15 mm Severe: >15 mm	May be uni‐ or bilateral Mild to moderate: low risk; severe: high risk of sequelae73
	Cysts/pseudocysts	Well defined lesions with SI similar to CSF on all sequences Most often periventricular	Inconsistent nomenclature temporal polar lesions highly predictive of CMV infection
	Ventriculitis	T1w and T2w hyperintensity of the ventricular rim. On T2WI not visible due to juxtaposition to CSF; T2w‐FLAIR useful if T1 is not informative	Rare finding. Most common lateral ventricles. Periventricular hyperechogenicity
	Intraventricular septations/adhesions	Tissue strands (T2w low SI) crossing the ventricles	Most common occipital horns
	Cortical malformations/polymicrogyria	Cortical infoldings located in abnormal positions; Thickened cortical ribbon Blurry gray/WM margins on T2WI/FLAIR	MRI superior to US
	Clefts (schizencephaly/porencephaly)	Schizencephaly: transmantle cleft, lined by T2 hypointense (=cortex) ribbon81 Porencephaly: cleft with no cortical lining. Margins may show high T2w/FLAIR hyperintensity	Lesions secondary to disruption. Final manifestation depends on time of insult.
	Calcifications	Low T2 and high T1 signal, often subtle Low T2*/EPI SI	Periventricular > deep gray nuclei > white matter
	Cerebellar hypoplasia/dysplasia	Small vermis and/or hemispheres Increased infra/retrocerebellar space (megacisterna magna >8 mm73) May have associated focal signal changes (ie hemorrhage, calcifications)	Rare fetal MRI Common postnatal imaging
	Hippocampal dysplasia	Dilated temporal horns Verticalization of the hippocampal± internal temporal lobe atrophy	Often not described in fetal MRI. Common postnatal imaging. (DeVries)
	Lenticullostriate vasculopathy	US diagnosis Low SI T2WI on basal ganglia Calcification (low EPI/T2* and high T1 SI) of basal ganglia	Late finding on MRI
Body	Hepato/Splenomegaly	Increased size of liver and/or spleen	Special attention should be payed to signal (easily missed on US)
	Liver	Low T1‐ and T2 SI may depict global liver involvement (fibrosis/insufficiency) May have high T2*/EPI SI	Intrahepatitic calcifications better identified on US
	Effusions (pericardial, pleural, ascitis)	Fluid collections in the pericardial, pleural or abdominal cavities. Identical signal to CSF/AF on all sequences.	Pulmonary hypoplasia may ensue secondary to pleural effusion or ascites105
	Skin edema	Increased thickness of skin + subcutaneous tissue High T2 SI, low T1 SI
	Hyperechogenic bowel	No findings on MRI Increase T1w meconium signal if blood ingestion	US change. MRI normal if no associated anomalies103
Other	Placenta	Placentomegaly placental thickness (>40 mm) Inhomogeneity on T1/T2 May have T2*/EPI
	Amniotic fluid	Oligo‐/Polyhydramnious High T1SI if intra‐amniotic hemorrhage	T2 low sensitivity to hemorrhage FLAIR may show false positive to hemorrhage (high SI) due to fetal movement

Abbreviations: AF, amniotic fluid; CSF, cerebral‐spinal fluid; IUGR, intrauterine growth restriction; SSFP, steady‐state free precession; WI, weighted images; WM, white matter.