Measurement of the Area and Circumference of the Leg: Preliminary Results of a New Method for Estimating Leg Muscle Trophism in Fetuses With Open Lumbosacral Spina Bifida.

OBJECTIVE: To standardize a new technique to evaluate the fetal leg muscle trophism by measuring the area and circumference, and comparing this technique between normal and fetuses with open lumbosacral spina bifida (SB). METHODS: Observational cross-sectional study was carried out on pregnant women with 26 weeks who were divided into two groups: Group I-fetuses with diagnosis of open lumbosacral SB; Group II-normal fetuses (control). In fetuses with SB, subjective evaluation of the lower limbs was performed (muscle echogenicity and leg movements). To estimate the leg muscle trophism, the measurement of the area and circumference of the leg were standardized, and the reproducibility of this method was performed. RESULTS: Thirty-one fetuses with open lumbosacral SB and 51 normal fetuses were evaluated. The measurements of the area and circumference of the leg proved to be highly reproducible (intraclass correlation coefficient-ICC > 0.95). The leg area and circumference measurements were statistically lower in the SB group than in the control group (p < .001). When subjective ultrasound assessment demonstrated hypotrophy of the lower limbs, the measurements of the area and circumference of the leg were statistically lower when compared to normal fetuses (p < .001). Fetuses with open SB with abnormal lower limb movements had lower measurements of the area and circumference of the leg than fetuses with normal movements (p < .001). CONCLUSION: A new technique for estimating fetal leg muscle trophism was standardized, which proved to be highly reproducible and was able to show the difference between normal and fetuses with SB.

The occipitum-dens line: the purpose of a new ultrasonographic landmark in the evaluation of the relationship between the foetal posterior fossa structures and foramen magnum.

PURPOSE: The aims of this study were to describe a new ultrasonographic technique to assess the normal level of the cerebellum and the brainstem in the posterior fossa in normal foetuses and to compare in pathologic cases. METHODS: We propose a new line cross between the dens cervical and the inferior portion of occipitum (occipitum-dens line-ODL). In a cross-sectional study, a single observer with experience in foetal neurosonography evaluated 54 foetuses (40 normal and 14 with open neural tube defect) between 20 and 28 weeks of gestation. The reference points for the ODL are principally the lower portion of the occipital bone (occipitum) and odontoid process of the second cervical vertebra (dens). The line was considered the level zero (near level of foramen magnum). Structures above it had a positive measurement and below it had a negative measurement. RESULTS: Moreover, in most foetuses with open neural tube defect (93 %), the end portion of cerebellum was below the ODL associated with different degrees of ventriculomegaly. CONCLUSION: The proposed innovation aims to bring to the ultrasound the most likely anatomical parameters of evaluation in normal foetuses and in foetuses with spinal dysraphism.

Assessment of cerebral circulation in normal fetuses by three-dimensional power Doppler ultrasonography.

OBJECTIVE: To assess the three-dimensional power Doppler ultrasonography (3D power Doppler) vascular indices in the middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA) territories. METHODS: A cross-sectional study was carried out on 111 normal pregnancies between 26 and 34 weeks. The MCA, ACA and PCA territories closest to the transducer were scanned and volumes were calculated by using the VOCAL (Virtual Organ Computer-aided Analysis) program. The 3D power Doppler indices--vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) were calculated. Scatter graphs, Pearson correlation coefficients (r) and linear regression models were used. RESULTS: Only the FI-MCA (r=0.38 and p<0.001), VFI-MCA (r=0.23 and p=0.016) and FI-PCA (r=0.191 and p=0.040) had a low correlation with gestational age. The other 3D power Doppler indices VI-MCA (r=0.153 and p=0.150), VI-ACA (r=0.105 and p=0.271), FI-ACA (r=0.154 and p=0.106), VFI-ACA (r=0.134 and p=0.161), VI-PCA (r=0.105 and p=0.270) and VFI-PCA (r=0.126 and p=0.180) showed no statistically significant correlation with gestational. CONCLUSION: It was observed a low correlation between gestational age and the FI-MCA, VFI-MCA and FI-PCA.

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.