Fetal brain tumors: Prenatal diagnosis by ultrasound and magnetic resonance imaging.

Congenital central nervous system tumors diagnosed during pregnancy are rare, and often have a poor prognosis. The most frequent type is the teratoma. Use of ultrasound and magnetic resonance image allows the suspicion of brain tumors during pregnancy. However, the definitive diagnosis is only confirmed after birth by histology. The purpose of this mini-review article is to describe the general clinical aspects of intracranial tumors and describe the main fetal brain tumors.

Reference ranges for fetal brain fissure development on 3-dimensional sonography in the multiplanar mode.

OBJECTIVES: To determine reference ranges for measurements of fetal cerebral fissures by 3-dimensional (3D) sonography in the multiplanar mode and to evaluate the reliability and concordance of these measurements. METHODS: A cross-sectional study was conducted on 393 women with normal pregnancies at 22 weeks to 33 weeks 6 days. The distances between the internal bone plate of the fetal calvaria and the sylvian, parieto-occipital, hippocampal, and calcarine fissures were assessed. To obtain the distances for the first 3 fissures, a 3D sweep was made in the axial plane, at the level of the lateral ventricles. To obtain the distance for the calcarine fissure, a coronal sweep was used, at the level of the occipital lobes. To evaluate the correlation between the fissures and gestational age, polynomial regression was performed with adjustments using the coefficient of determination (R(2)). Reliability was determined with intraclass correlation coefficients and concordance with concordance limits. RESULTS: The mean distances ± SD to the sylvian, parieto-occipital, hippocampal, and calcarine fissures were 10.42 ± 2.28, 22.38 ± 3.23, 24.88 ± 4.67, and 21.19 ± 2.73 mm, respectively. These distances correlated with gestational age such that the best fit with the linear equation produced R(2) values of 0.582, 0.627, 0.860, and 0.458 for the sylvian, parieto-occipital, hippocampal, and calcarine fissures. Reliability analyses showed intraobserver and interobserver intraclass correlation coefficients of 0.90 to 0.95 and 0.85 to 0.97. The concordance limits were-1.33 to 1.30 and -2.38 to 2.28 mm for the intraobserver evaluation and -1.60 to 2.57 and -3.51 to 2.73 mm for the interobserver evaluation. CONCLUSIONS: Cerebral fissures can be measured by 3D sonography at 22 to 33 weeks of pregnancy with acceptable reliability and concordance. Reference ranges for this gestational period have thus been described.

Comparison between 2D ultrasonography and magnetic resonance imaging for assessing brain and spine parameters in fetuses with spina bifida.

PURPOSE: To compare two-dimensional ultrasonography (2DUS) and magnetic resonance imaging (MRI) for assessing brain and spine parameters in fetuses with spina bifida. METHODS: A cross-sectional study was conducted on 15 fetuses with spina bifida (one with encephalocele, four with rachischisis and 10 with myelomeningocele). The size of the atrium of the lateral ventricle, percentage shortening of the cerebellum, degree of compromising of the first vertebra and total number of vertebras affected by herniation were assessed. The MRI examination was performed not more than 7 days after the 2DUS. To compare and correlate the parameters from the two techniques, the paired Student's t test and intraclass correlation coefficient (ICC) were used. To assess the correlations of atrium measurements from 2DUS and MRI with other parameters, Pearson's correlation coefficient (r) was used. RESULTS: No significant difference was observed in any of the means of the parameters assessed using the two techniques (p > 0.05). Both 2DUS and MRI seemed to present satisfactory reliability in measurements on the size of the atrium of the lateral ventricle and the first vertebra affected (ICC = 0.88 and 0.75, respectively). Measurements on the atrium of the lateral ventricle from 2DUS correlated better with the other parameters than did measurements from MRI. CONCLUSIONS: In fetuses with spina bifida, 2DUS and MRI present similar results, but measurements on the atrium of the lateral ventricle from 2DUS correlated better with the other parameters.

Prenatal diagnosis of bilateral anophthalmia by 3D "reverse face" view ultrasound and magnetic resonance imaging.

OBJECTIVE: Primary anophthalmia is a rare congenital malformation that affects 0.6/10,000 liveborn infants. It is usually associated with central nervous system malformations, aneuploidies, cytomegalovirus infection and mental retardation and it can also be part of genetic conditions such as Fraser, Goltz, Goldenhar, Waardenburg and Lenz syndromes. Neonatal prognosis depends on whether anophthalmia is an isolated malformation, or it is associated with other defects or part of a syndrome. CASE REPORT: A healthy 43-year-old woman, G4 P3 with three previous healthy children, was referred to our clinic for a routine obstetric ultrasound at 28 weeks' gestation. The fetal eye globes and lenses could not be seen on two-dimensional (2D) ultrasound, which led to the diagnosis of bilateral congenital anophthalmia. No other fetal malformations were detected. At 30 weeks' gestation, a three-dimensional (3D) ultrasound was performed using the rendering mode and "reverse face" view. Using this technique, the absence of both eye globes could be clearly seen through a "slit". 3D-ultrasound allowed the parents to better understand their child's problem and possible postnatal implications. Fetal magnetic resonance imaging (MRI) was also performed, to study the fetal cortex in more detail. This exam revealed right cerebral hemisphere sulci and gyri hypoplasia. At 41 1/7 weeks, she went into spontaneous labor and delivered vaginally a 3525 g male infant with Apgar scores of 9 and 10. Postnatal exams confirmed bilateral congenital anophthalmia. CONCLUSION: This is the first case report in the literature of prenatal diagnosis of bilateral anophthalmia using 3D "reverse face" view ultrasound and MRI.

[Fetal brain fissures development a three-dimensional ultrasonography study]. / Desenvolvimento das fissuras cerebrais fetais: avaliação com ultrassonografia tridimensional.

PURPOSE: to assess the distance of the fetal cerebral fissures from the inner edge of the skull by three-dimensional ultrasonography (3DUS). METHODS: this cross-sectional study included 80 women with normal pregnancies between 21st and 34th weeks. The distances between the Sylvian, parieto-occiptal, hippocampus and calcarine fissures and the internal surface of the fetal skull were measured. For the evaluation of the distance of the first three fissures, an axial three-dimensional scan was obtained (at the level of the lateral ventricles). To obtain the calcarine fissure measurement, a coronal scan was used (at the level of the occipital lobes). First degree regressions were performed to assess the correlation between fissure measurements and gestational age, using the determination coefficient (R²) for adjustment. The 5th, 50th and 95th percentiles were calculated for each fissure measurement. Pearson's correlation coefficient (r) was used to assess the correlation between fissure measurements and the biparietal diameter (BPD) and head circumference (HC). RESULTS: all fissure measurements were linearly correlated with gestational age (Sylvian: R²=0.5; parieto-occiptal: R²= 0.7; hippocampus: R²= 0.3 and calcarine: R²= 0.3). Mean fissure measurement ranged from 7.0 to 14.0 mm, 15.9 to 28.7 mm, 15.4 to 25.4 mm and 15.7 to 24.8 mm for the Sylvian, parieto-occiptal, hippocampus and calcarine fissures, respectively. The Sylvian and parieto-occiptal fissure measurements had the highest correlations with the BPD (r=0.8 and 0.7, respectively) and HC (r=0.7 and 0.8, respectively). CONCLUSION: the distance from the fetal cerebral fissures to the inner edge of the skull measured by 3DUS was positively correlated with gestational age.

Desenvolvimento das fissuras cerebrais fetais: avaliação com ultrassonografia tridimensional / Fetal brain fissures development a three-dimensional ultrasonography study

OBJETIVO: avaliar a distância das fissuras cerebrais fetais à borda interna da calota craniana por meio da ultrassonografia tridimensional (US3D). MÉTODOS: realizou-se um estudo de corte transversal em 80 gestantes normais entre a 21ª e 34ª semanas de gestação. Avaliou-se a distância entre a tábua óssea interna da calota craniana fetal e as fissuras de Sylvius, parieto-occipital, hipocampo e calcarina. Para a obtenção desta distância para as três primeiras fissuras, realizou-se uma varredura tridimensional através do plano axial (nível dos ventrículos laterais). Para a obtenção da distância da fissura calcarina utilizou-se uma varredura coronal (nível dos lobos occiptais). Para avaliar a correlação entre as fissuras e a idade gestacional foram realizadas regressões de primeiro grau, sendo os ajustes calculados pelo coeficiente de determinação (R²). Foram determinados percentis 5, 50 e 95 para cada fissura. Avaliou-se ainda a correlação entre a distância destas fissuras com os diâmetros biparietal (DBP) e circunferência craniana (CC) utilizando o coeficiente de correlação de Pearson (r). RESULTADOS: todas as medidas das fissuras apresentaram correlação linear com a idade gestacional (Sylvius: R²=0,5; parieto-occipital: R²=0,7; hipocampo: R²=0,3 e calcarina: R²=0,3). A média da distância das fissuras variou de 7,0 a 14,0 mm, 15,9 a 28,7 mm, 15,4 a 25,4 mm e 15,7 a 24,8 mm para as fissuras de Sylvius, parieto-occipital, hipocampo e calcarina, respectivamente. As fissuras de Sylvius e parieto-occipital apresentaram as maiores correlações com o DBP (r=0,8 e 0,7, respectivamente) e a CC (r=0,7 e 0,8, respectivamente). CONCLUSÕES: a distância das fissuras cerebrais fetais à borda interna da calota craniana por meio da US3D apresentou correlação positiva com a idade gestacional.

PURPOSE: to assess the distance of the fetal cerebral fissures from the inner edge of the skull by three-dimensional ultrasonography (3DUS). METHODS: this cross-sectional study included 80 women with normal pregnancies between 21st and 34th weeks. The distances between the Sylvian, parieto-occiptal, hippocampus and calcarine fissures and the internal surface of the fetal skull were measured. For the evaluation of the distance of the first three fissures, an axial three-dimensional scan was obtained (at the level of the lateral ventricles). To obtain the calcarine fissure measurement, a coronal scan was used (at the level of the occipital lobes). First degree regressions were performed to assess the correlation between fissure measurements and gestational age, using the determination coefficient (R²) for adjustment. The 5th, 50th and 95th percentiles were calculated for each fissure measurement. Pearson's correlation coefficient (r) was used to assess the correlation between fissure measurements and the biparietal diameter (BPD) and head circumference (HC). RESULTS: all fissure measurements were linearly correlated with gestational age (Sylvian: R²=0.5; parieto-occiptal: R²= 0.7; hippocampus: R²= 0.3 and calcarine: R²= 0.3). Mean fissure measurement ranged from 7.0 to 14.0 mm, 15.9 to 28.7 mm, 15.4 to 25.4 mm and 15.7 to 24.8 mm for the Sylvian, parieto-occiptal, hippocampus and calcarine fissures, respectively. The Sylvian and parieto-occiptal fissure measurements had the highest correlations with the BPD (r=0.8 and 0.7, respectively) and HC (r=0.7 and 0.8, respectively). CONCLUSION: the distance from the fetal cerebral fissures to the inner edge of the skull measured by 3DUS was positively correlated with gestational age.

Development of fetal brain sulci and gyri: assessment through two and three-dimensional ultrasound and magnetic resonance imaging.

BACKGROUND: Cerebral malformations may lead to permanent postnatal sequels. The antenatal detection of anomalous or absent fetal sulci and gyri may indicate abnormal brain development and future neurological and psychomotor problems in that infant. The prenatal diagnosis of these conditions allows genetic counseling, psychological support of the parents and optimization of obstetric management. Diagnosis is usually based on two-dimensional obstetric ultrasound (2DUS) and eventually fetal magnetic resonance imaging (MRI), to confirm findings. Fetal three-dimensional ultrasound (3DUS) using the rendering mode has been recently introduced but has not yet been extensively tested in clinical practice. CONTEXT: This study reviewed and compared three imaging modalities, 2DUS, 3DUS, and MRI, in the analysis of the development of the main sulci and gyri of central nervous system of normal fetuses between 20 and 32 weeks' gestation.

Morphological evaluation of lateral ventricles of fetuses with ventriculomegaly by three-dimensional ultrasonography and magnetic resonance imaging: correlation with etiology.

PURPOSE: To evaluate morphology of lateral ventricles of ventriculomegaly/hydrocephaly fetuses using 3D-sonography by virtual organ computer-aided analysis (VOCAL) technique and magnetic resonance imaging (MRI) and verify morphologic patterns related to etiology. METHODS: Seventeen fetuses presenting with ventricular enlargement (atria > 10 mm) were evaluated. 3D datasets were acquired from a coronal reference plane and post-processed by the rotational imaging using VOCAL 30°. MRI study was analyzed in the three plans in all sequences. Morphologic aspects such as global shape, anterior, posterior and inferior horn characteristics, wall irregularities and deformities were analyzed and related to etiology factor. RESULTS: Twenty-nine percent of the cases were secondary to Arnold-Chiari syndrome and presented with global dilation of the three-horns. Cases related to aqueduct stenosis presented with ependymal rupture and wall irregularities in advanced cases. Corpus callosum agenesis cases presented with small ventricular volumes, thin shape, normal or slightly enlarged anterior and inferior horns with dilation restricted to posterior horn. Cases related to trisomy 18 and cytomegalovirus presented irregular ventricular walls associated with anomalous ventricular shapes, suggesting parenchymal destruction. CONCLUSION: Ventricular morphology evaluation gives important information on etiology of ventricular enlargement, supporting prognosis prediction and decision making process of the affected fetuses and their families.

Fetal lung volume in fetuses with urinary tract malformations: comparison by 2D-, 3D-sonography and magnetic resonance imaging.

OBJECTIVE: To evaluate the concordance between two-dimensional ultrasonography (2DUS), three-dimensional ultrasonography (3DUS) and magnetic resonance imaging (MRI) in the assessment of lung volume in fetuses with urinary tract malformations (UTM). METHODS: This was a cross-sectional study involving 12 pregnancies between 19 and 34 weeks, with various fetal UTM. Pulmonary volume was obtained by 2DUS using the following equation: total lung volume = [right lung antero-posterior diameter (X) x transverse diameter (Y) x cranial-caudal diameter x 0.152 + left lung (X1) x (Y1) x (Z1) x 0.167]. Pulmonary volume by 3DUS was obtained using the virtual organ computer-aided analysis (VOCAL) method with a 30 degrees (VOL30), 18 degrees (VOL18) and 12 degrees (VOL12) rotation. A fast sequence of transverse lung section was also obtained by MRI. The intraclass correlation coefficient was used to evaluate the correlation between the three methods. The paired student t-test was used to compare the means. RESULTS: There was a strong correlation between the three methods, and the highest correlations were between MRI and VOL18 for the right (ICC = 0.913) and left (ICC = 0.947) lungs. A strong correlation was also found between the lung volumes obtained through MRI and VOL12 as well as VOL18 (p = 0.544 and 0.286, respectively). However, for the left lung there was only a correlation between MRI and VOL12 (p = 0.49). CONCLUSIONS: There is a good concordance between 3DUS (VOL12) and MRI in the evaluation of lung volume in fetuses with UTM.