Limits...
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

ACC. a, b Axial ultrasound and MRI at 33 and 35 weeks’ gestation respectively demonstrates non-visualisation of the CSP, parallel orientation of lateral ventricles (arrows), and colpocephaly (dotted arrow). c Coronal T2-weighted MRI through the frontal horns demonstrates absence of the CSP, ACC with steer horn configuration of the frontal ventricles (arrow)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3675254&req=5

Fig2: ACC. a, b Axial ultrasound and MRI at 33 and 35 weeks’ gestation respectively demonstrates non-visualisation of the CSP, parallel orientation of lateral ventricles (arrows), and colpocephaly (dotted arrow). c Coronal T2-weighted MRI through the frontal horns demonstrates absence of the CSP, ACC with steer horn configuration of the frontal ventricles (arrow)

Mentions: The CC is the largest bundle of white matter fibres connecting the two cerebral hemispheres and allows for intercommunication. The CC develops between 12 and 18 weeks of gestation from the lamina terminalis. Development of the CC is closely related to that of the CSP, both anatomically and embryologically [9]. Agenesis of the CC (ACC) is a common CNS anomaly with an incidence of 0.5–7 in 10,000 live births. The widely accepted theory for the embryogenesis of the CC suggests that the genu of the CC develop first, then the anterior body, posterior body, followed by the splenium. The exception to the orderly anterio-posterior callosal development is the rostrum, which forms last, typically by 20 weeks. Dysgenesis of the CC can be described as a partial agenesis of the CC or hypoplasia of the CC. In partial agenesis of the CC, the splenium and rostrum are usually absent and there may be hypoplasia of the remaining CC, and in callosal hypoplasia there is under-development of the entire CC [6, 11–13]. Prenatal imaging findings for ACC in addition to non-visualisation of the CSP include colpocephaly (enlargement of the trigone and occiptal horns of the lateral ventricle), high riding third ventricle, parallel orientation of the lateral ventricles, steer horn configuration of the frontal horns of lateral ventricles, convergence of median sulci towards the third ventricle, interhemispheric cyst, and abnormal course or absence of the pericallosal artery (Fig. 2). However, in dysgenesis of the CC, the CSP is typically present but may be shortened. The outcome of prenatally detected ACC is dependent on the presence or absence of associated anomalies. Patients with isolated ACC have the most favourable outcomes, with the majority experiencing relatively normal motor and cognitive development [14]. However, in a recent study by Fratelli et al. [15], 70 % of cases with agenesis or dysgenesis of the CC were associated with other fetal structural or chromosomal abnormalities, and 36 % of infants with isolated ACC had postnatal developmental delay. A full assessment therefore includes karyotyping and fetal MRI to search for more subtle features of genetic syndromes.Fig. 2


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

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

ACC. a, b Axial ultrasound and MRI at 33 and 35 weeks’ gestation respectively demonstrates non-visualisation of the CSP, parallel orientation of lateral ventricles (arrows), and colpocephaly (dotted arrow). c Coronal T2-weighted MRI through the frontal horns demonstrates absence of the CSP, ACC with steer horn configuration of the frontal ventricles (arrow)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig2: ACC. a, b Axial ultrasound and MRI at 33 and 35 weeks’ gestation respectively demonstrates non-visualisation of the CSP, parallel orientation of lateral ventricles (arrows), and colpocephaly (dotted arrow). c Coronal T2-weighted MRI through the frontal horns demonstrates absence of the CSP, ACC with steer horn configuration of the frontal ventricles (arrow)
Mentions: The CC is the largest bundle of white matter fibres connecting the two cerebral hemispheres and allows for intercommunication. The CC develops between 12 and 18 weeks of gestation from the lamina terminalis. Development of the CC is closely related to that of the CSP, both anatomically and embryologically [9]. Agenesis of the CC (ACC) is a common CNS anomaly with an incidence of 0.5–7 in 10,000 live births. The widely accepted theory for the embryogenesis of the CC suggests that the genu of the CC develop first, then the anterior body, posterior body, followed by the splenium. The exception to the orderly anterio-posterior callosal development is the rostrum, which forms last, typically by 20 weeks. Dysgenesis of the CC can be described as a partial agenesis of the CC or hypoplasia of the CC. In partial agenesis of the CC, the splenium and rostrum are usually absent and there may be hypoplasia of the remaining CC, and in callosal hypoplasia there is under-development of the entire CC [6, 11–13]. Prenatal imaging findings for ACC in addition to non-visualisation of the CSP include colpocephaly (enlargement of the trigone and occiptal horns of the lateral ventricle), high riding third ventricle, parallel orientation of the lateral ventricles, steer horn configuration of the frontal horns of lateral ventricles, convergence of median sulci towards the third ventricle, interhemispheric cyst, and abnormal course or absence of the pericallosal artery (Fig. 2). However, in dysgenesis of the CC, the CSP is typically present but may be shortened. The outcome of prenatally detected ACC is dependent on the presence or absence of associated anomalies. Patients with isolated ACC have the most favourable outcomes, with the majority experiencing relatively normal motor and cognitive development [14]. However, in a recent study by Fratelli et al. [15], 70 % of cases with agenesis or dysgenesis of the CC were associated with other fetal structural or chromosomal abnormalities, and 36 % of infants with isolated ACC had postnatal developmental delay. A full assessment therefore includes karyotyping and fetal MRI to search for more subtle features of genetic syndromes.Fig. 2

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