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Non-visualisation of cavum septi pellucidi: implication in prenatal diagnosis?

Hosseinzadeh K, Luo J, Borhani A, Hill L - Insights Imaging (2013)

Bottom Line: This manuscript reviews congenital anomalies and imaging findings associated with non-visualisation of the cavum septi pellucidi (CSP) found on prenatal sonogram.Isolated septal deficiency, a rare but controversial entity, is considered a variant of normal.Common pitfalls in the sonographic evaluation of CSP include columns of the fornix that mimic CSP, and prominent cavum vergae that can simulate non-visualisation of the CSP.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Presbyterian South Tower, University of Pittsburgh Medical Center, 200 Lothrop Street, Suite 3950, Pittsburgh, PA, 15213, USA, hosseinzadehk@upmc.edu.

ABSTRACT

Objective: This manuscript reviews congenital anomalies and imaging findings associated with non-visualisation of the cavum septi pellucidi (CSP) found on prenatal sonogram.

Background: Observation of a normal cavum septi pellucidi (CSP) is an important landmark in the second and third trimester prenatal ultrasound evaluation of the fetal brain, and its visualisation provides reassurance of normal central forebrain development. Non-visualisation of the CSP is a prenatal sonographic finding, which in most cases is associated with neuroanatomical anomalies that include agenesis of the corpus callosum, schizencephaly, septo-optic dysplasia, holoprosencephaly, chronic hydrocephalus and acquired fetal brain injury. Isolated septal deficiency, a rare but controversial entity, is considered a variant of normal. Common pitfalls in the sonographic evaluation of CSP include columns of the fornix that mimic CSP, and prominent cavum vergae that can simulate non-visualisation of the CSP. When non-visualisation of the CSP is suspected, magnetic resonance imaging (MRI) of the fetal brain can confirm and evaluate associated anomalies.

Conclusion: Visualisation of the CSP is an integral component of the prenatal ultrasound and its non-visualisation is associated with other malformations, diagnosis of which is aided by MRI.

Teaching points: • Cavum septi pellucidi (CSP) is an important landmark in the prenatal ultrasound evaluation of the fetal brain, and is a marker for normal central forebrain development. • Non-visualisation of the CSP is most commonly associated with other neuroanatomical abnormalities. • Examination of the fetal brain by MRI can confirm the sonographic findings and evaluate for associated anomalies.

No MeSH data available.


Related in: MedlinePlus

a, b, c Pseudo-absence of CSP: cavum vergae. a Coronal ultrasound through the frontal horns demonstrates non-visualisation of the CSP. The patient was referred for fetal MRI to assess for associated anomalies. b Coronal T2-weighted MRI demonstrates prominent CSP (asterisk) and lateral displacement of CSP leaflets mimicking absent CSP. c Axial T2-weighted MRI demonstrates extension of prominent CSP posterior to foramen of Monro consistent with cavum vergae
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Fig11: a, b, c Pseudo-absence of CSP: cavum vergae. a Coronal ultrasound through the frontal horns demonstrates non-visualisation of the CSP. The patient was referred for fetal MRI to assess for associated anomalies. b Coronal T2-weighted MRI demonstrates prominent CSP (asterisk) and lateral displacement of CSP leaflets mimicking absent CSP. c Axial T2-weighted MRI demonstrates extension of prominent CSP posterior to foramen of Monro consistent with cavum vergae

Mentions: A common pitfall is mistaking columns of the fornix for the CSP. Columns of the fornix are normal anatomic structures infero-posterior to and attaching to the CSP. It is composed of two bands, joined at the middle and separated at both ends. Although it is anatomically close to the CC and CSP, it is not related to them in embryonic development. Columns of the fornix can simulate the CSP because it is hypoechoic on ultrasound. It is important to distinguish this by identifying a centre line. Columns of the fornix show a linear reflection at their interface, therefore there are three echogenic lines on axial ultrasound view (Fig. 10). The CSP, on the other hand, appears as a fluid-filled space without a central line that is either triangular or rectangular in shape. Therefore, there are only two echogenic lines on axial ultrasound view [1]. Another pitfall occurs when a prominent CSP and cavum vergae displace CSP leaflets laterally. Normally the cavum vergae and CSP are contiguous in a mid-sagittal view. However, in some cases, displacement of the CSP leaflets laterally prohibits its identification sonographically, which can mimic non-visualisation of the CSP (Fig. 11).Fig. 10


Non-visualisation of cavum septi pellucidi: implication in prenatal diagnosis?

Hosseinzadeh K, Luo J, Borhani A, Hill L - Insights Imaging (2013)

a, b, c Pseudo-absence of CSP: cavum vergae. a Coronal ultrasound through the frontal horns demonstrates non-visualisation of the CSP. The patient was referred for fetal MRI to assess for associated anomalies. b Coronal T2-weighted MRI demonstrates prominent CSP (asterisk) and lateral displacement of CSP leaflets mimicking absent CSP. c Axial T2-weighted MRI demonstrates extension of prominent CSP posterior to foramen of Monro consistent with cavum vergae
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3675254&req=5

Fig11: a, b, c Pseudo-absence of CSP: cavum vergae. a Coronal ultrasound through the frontal horns demonstrates non-visualisation of the CSP. The patient was referred for fetal MRI to assess for associated anomalies. b Coronal T2-weighted MRI demonstrates prominent CSP (asterisk) and lateral displacement of CSP leaflets mimicking absent CSP. c Axial T2-weighted MRI demonstrates extension of prominent CSP posterior to foramen of Monro consistent with cavum vergae
Mentions: A common pitfall is mistaking columns of the fornix for the CSP. Columns of the fornix are normal anatomic structures infero-posterior to and attaching to the CSP. It is composed of two bands, joined at the middle and separated at both ends. Although it is anatomically close to the CC and CSP, it is not related to them in embryonic development. Columns of the fornix can simulate the CSP because it is hypoechoic on ultrasound. It is important to distinguish this by identifying a centre line. Columns of the fornix show a linear reflection at their interface, therefore there are three echogenic lines on axial ultrasound view (Fig. 10). The CSP, on the other hand, appears as a fluid-filled space without a central line that is either triangular or rectangular in shape. Therefore, there are only two echogenic lines on axial ultrasound view [1]. Another pitfall occurs when a prominent CSP and cavum vergae displace CSP leaflets laterally. Normally the cavum vergae and CSP are contiguous in a mid-sagittal view. However, in some cases, displacement of the CSP leaflets laterally prohibits its identification sonographically, which can mimic non-visualisation of the CSP (Fig. 11).Fig. 10

Bottom Line: This manuscript reviews congenital anomalies and imaging findings associated with non-visualisation of the cavum septi pellucidi (CSP) found on prenatal sonogram.Isolated septal deficiency, a rare but controversial entity, is considered a variant of normal.Common pitfalls in the sonographic evaluation of CSP include columns of the fornix that mimic CSP, and prominent cavum vergae that can simulate non-visualisation of the CSP.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Presbyterian South Tower, University of Pittsburgh Medical Center, 200 Lothrop Street, Suite 3950, Pittsburgh, PA, 15213, USA, hosseinzadehk@upmc.edu.

ABSTRACT

Objective: This manuscript reviews congenital anomalies and imaging findings associated with non-visualisation of the cavum septi pellucidi (CSP) found on prenatal sonogram.

Background: Observation of a normal cavum septi pellucidi (CSP) is an important landmark in the second and third trimester prenatal ultrasound evaluation of the fetal brain, and its visualisation provides reassurance of normal central forebrain development. Non-visualisation of the CSP is a prenatal sonographic finding, which in most cases is associated with neuroanatomical anomalies that include agenesis of the corpus callosum, schizencephaly, septo-optic dysplasia, holoprosencephaly, chronic hydrocephalus and acquired fetal brain injury. Isolated septal deficiency, a rare but controversial entity, is considered a variant of normal. Common pitfalls in the sonographic evaluation of CSP include columns of the fornix that mimic CSP, and prominent cavum vergae that can simulate non-visualisation of the CSP. When non-visualisation of the CSP is suspected, magnetic resonance imaging (MRI) of the fetal brain can confirm and evaluate associated anomalies.

Conclusion: Visualisation of the CSP is an integral component of the prenatal ultrasound and its non-visualisation is associated with other malformations, diagnosis of which is aided by MRI.

Teaching points: • Cavum septi pellucidi (CSP) is an important landmark in the prenatal ultrasound evaluation of the fetal brain, and is a marker for normal central forebrain development. • Non-visualisation of the CSP is most commonly associated with other neuroanatomical abnormalities. • Examination of the fetal brain by MRI can confirm the sonographic findings and evaluate for associated anomalies.

No MeSH data available.


Related in: MedlinePlus