CASE 1028 Published on 03.09.2001

Fetal MRI in Chiari II malformation

Section

Neuroradiology

Case Type

Clinical Cases

Authors

R.N.Sener, F.Tercan, S.Tamsel, O.Kitis, O.Yalman

Patient

20 years, female

Categories
No Area of Interest ; Imaging Technique MR
Clinical History
20-year-old pregnant woman. Intrauterine MRI
Imaging Findings
An obstetric ultrasound examination at the 24th week of gestation revealed enlarged lateral ventricles, and a small posterior fossa in association with lumbosacral meningocele. The woman was referred for intrauterine MRI. On MRI, the HASTE (half-Fourier single-shot turbo spin echo) was used to obtain images of the fetus in three imaging planes. Total acquisition time was 33 seconds (11 sec for each). Slice thickness was 4 mm.
Discussion
Fetal central nervous system, especially the brain, can be examined by newer fast imaging sequences including the HASTE sequence, providing high-quality images. In the current fetus lateral ventricles were dilated associated with prominent dilatation of the occipital horns (sometimes referred to as colpocephaly), and the posterior fossa was small. A lumbosacral meningocele was shown. These features were consistent with Chiari II malformation. The pregnancy was terminated, and the diagnosis was confirmed. Chiari II malformation is a severe and complex anomaly. Current hypotheses on pathogenesis of Chiari II malformation stress the role of myelomeninigocele and consequent CSF leaking on the origin of cerebellar squeezing, as in all the Chiari II patients there is meningomyelocele, usually in the lumbar spine (without meningomyelocele an alternative diagnosis such as rhombencephalosynapsis could be considered). It should be remembered that there is possibility of fetal surgery for meningomyelocele to prevent the formation of cerebellar herniation.
Differential Diagnosis List
Chiari II malformation
Final Diagnosis
Chiari II malformation
Case information
URL: https://www.eurorad.org/case/1028
DOI: 10.1594/EURORAD/CASE.1028
ISSN: 1563-4086