Ultrasound and magnetic resonance imaging features of fetal intracranial cystic lesions: A pictorial essay.

This pictorial essay focuses on ultrasound (US) and magnetic resonance imaging (MRI) features of fetal intracranial cysts. Intracranial cysts are common findings in prenatal imaging, and if great attention is paid to their size, location, and imaging features, they can be diagnosed accurately. They are usually detected by fetal ultrasound exams. However, when ultrasound data on cystic lesion characteristics is insufficient, MRI and fetal neurosonogram are the best options for detecting other associated anomalies. The prognosis is highly dependent on their location and whether they are associated with other fetal anomalies.

Fetal corpus callosum abnormalities: Ultrasound and magnetic resonance imaging role.

The corpus callosum (CC) is the major interhemispheric commissure and its abnormalities include agenesis, hypoplasia, and hyperplasia. The CC anomalies are typically related to other central nervous system (CNS) or extra-CNS malformations. The antenatal diagnosis of complete CC agenesis is easy after mid-trimester by ultrasound (US) even in the axial plane. The non-visualization of cavum septum pellucidum and colpocephaly are critical signs in the axial view. More subtle findings (i.e., hypoplasia and partial agenesis) might also be recognized antenatally. In this review, the focus was given on the prenatal diagnosis of CC abnormalities in US and magnetic resonance imaging.

A Spectrum of Ultrasound and MR Imaging of Fetal Gastrointestinal Abnormalities: Part 2 Anorectal Malformation, Liver, and Abdominal Wall Anomalies.

Ultrasound (US) and magnetic resonance imaging (MRI) are two modalities for diagnosing fetal gastrointestinal (GI) anomalies. Ultrasound (US) is the modality of choice. MRI can be used as a complementary method. Despite its expanding utilization in central nervous system (CNS) fetal malformation, MRI has not yet been established for evaluation of fetal GI abnormalities. Therefore, more attention should be paid to the clinical implications of MRI investigations following screening by US.

A Spectrum of Ultrasound and MR Imaging of Fetal Gastrointestinal Abnormalities: Part 1 Esophagus to Colon.

Ultrasound (US) and magnetic resonance imaging (MRI) are two modalities for diagnosing fetal gastrointestinal (GI) anomalies. Ultrasound (US) is the modality of choice. MRI can be used as a complementary method. Despite its expanding utilization in central nervous system (CNS) fetal malformation, MRI has not yet been established for evaluation of fetal GI abnormalities. Therefore, more attention should be paid to the clinical implications of MRI investigations following screening by US.

Cavum velum interpositum cysts in normal and anomalous fetuses in second trimester of pregnancy: Comparison of its size and prevalence.

OBJECTIVE: Cavum veli interpositi (CVI) is a potential space below the splenium of corpus callosum and sometimes presents as a cyst. MATERIALS AND METHODS: In this prospective cross-sectional study, 360 fetuses with normal second trimester scan and 152 s trimester fetuses with structural abnormalities were included. RESULTS: The CVI cysts were more common in fetuses with brain anomaly compared to normal fetuses and fetuses with extra-central nervous system (CNS) anomalies (23% vs 18.3% and 18% respectively; p value < 0.01). The mean size of cysts in normal fetuses, fetuses with extra-CNS anomalies and fetuses with brain abnormalities was 4.6 mm, 5.8 mm and 9.2 mm respectively. There was a significant difference between cysts size in normal fetuses and fetuses with brain anomalies (p value < 0.01) and the cut-point was 7.1 mm. CONCLUSION: The prevalence of CVI cysts is more in fetuses with brain anomaly. Fetuses with a cyst size >7.1 mm need a more detailed brain examination.

A case of prenatally detected left isomerism and hemiazygos continuation of inferior vena cava.

Heterotaxy syndromes are defined as the disorders that involve abnormal arrangement of viscera. We present a case of prenatally diagnosed left isomerism in a 30-year-old primigravida woman referred to our hospital for complex cardiac abnormality. Sonographic findings included heart block, unbalanced atrioventricular septal defect, interruption of the inferior vena cava with hemiazygos continuation, double superior vena cava, a right-sided stomach, and biliary atresia. The hemiazygos vein drained into the right atrium by the persistent left superior vena cava. This type of inferior vena cava interruption and continuation is rarely reported in prenatally detected cases of left isomerism. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:430-433, 2017.

Correlation of nuchal translucency and thyroxine at 11-13 weeks of gestation.

OBJECTIVE: Nuchal translucency (NT) thickness is one of the major screening markers during the first trimester that could be influenced by several factors. Here, we investigated the association between NT thickness and thyroid related hormones. METHODS: NT thickness was measured with transabdominal ultrasound in 643 pregnant women between 11 and 13 weeks of gestation. Maternal thyroxine (T4), free thyroxine (fT4) and thyroid-stimulating hormone (TSH) were evaluated. Bivariate correlations were assessed and thyroid profile was subcategorized with regard to the calculated reference ranges. RESULTS: An inverse relation was found between serum levels of maternal T4 with NT thickness (r = -0.128, p = 0.001) and CRL (r = -0.168, p < 0.001). TSH and hCG were also found to be correlated (Spearman's correlation coefficient = -0.092, p = 0.019). Prevalence of maternal hypothyroidism and subclinical hypothyroidism were 1.1% and 3.7%, respectively. CONCLUSION: Thyroid function tests are found to independently influence NT measurements in the first trimester. Assessment of hormones such as thyroxine could optimize the interpretation of screening tests for pathological conditions during pregnancy.

Normal ranges for fetal femur and humerus diaphysis length during the second trimester in an Iranian population.

OBJECTIVES: Shortening of the fetal long bones is a sonographic soft marker for screening of Down syndrome in the second trimester that can be influenced by ethnicity. The purpose of this study was to provide normal reference ranges for femur and humerus diaphysis length during the second trimester of pregnancy in an Iranian population. METHODS: This cross-sectional study was performed on 3011 singleton fetuses at 15 to 28 weeks' menstrual age. The relationship between menstrual age and both femur and humerus diaphysis length was determined, and percentile values for each menstrual week were provided. RESULTS: The median femur diaphysis length ranged from 18.05 mm at 15 menstrual weeks to 52.20 mm at 28 menstrual weeks, and the mean humerus diaphysis length ranged from 17.65 mm at 15 menstrual weeks to 48.10 mm at 28 menstrual weeks. There was a linear relationship between menstrual age and both femur diaphysis length (R² = 0.957) and humerus diaphysis length (R² = 0.941). CONCLUSIONS: We have provided normal reference ranges for femur and humerus diaphysis length during the second trimester of pregnancy in an Iranian population.

Normal ranges of fetal nasal bone length during the second trimester in an Iranian population.

OBJECTIVE: To provide a normal reference range for nasal bone length (NBL) during the second trimester of pregnancy in an Iranian population. METHODS: This cross-sectional study was performed on 3201 fetuses at 15 to 28 weeks of gestational age (GA). Both singleton and twin fetuses were evaluated. The relationship between NBL and GA was determined and percentile values for each gestational week were provided. RESULTS: NBL measurement was obtained in 98% of singleton and 96% of twin fetuses. There was a linear relationship between GA and NBL both in singleton (R(2) = 0.62) and in twin (R(2) = 0.74) fetuses. There was no significant difference between twins regarding NBL (p = 0.18). CONCLUSION: We have provided the normal reference range for NBL during the second trimester in an Iranian population. NBL in singleton and twin fetuses is similar and there is no significant difference between twins regarding NBL.