Ultrasonographic assessment of mediastinal shift angle (MSA) in isolated left congenital diaphragmatic hernia for the prediction of postnatal survival.

Objectives: To quantify mediastinal shift in isolated congenital diaphragmatic hernia (CDH), by the introduction of a new ultrasonographic (US) marker, defined as mediastinal shift angle (MSA) and to evaluate its ability in predicting postnatal survival at discharge.Methods: Twenty-four consecutive fetuses from singleton pregnancies with isolated left-sided CDH were included in the study group and then subdivided into group A (16 survivors) and group B (8 nonsurvivors). The study group was matched with a control group of 95 fetuses from singleton pregnancies free from structural and/or chromosomal anomalies. On the same US stored images commonly used for lung-to-head ratio (LHR) measurement, a landmark line was drawn from a point on the posterior face of the vertebral body, splitting it into two equal parts, to the mid-posterior surface of the sternum. Another landmark line was then traced from the same point of the vertebral body to touch tangentially the lateral wall of the right atrium. The angle between these two lines was used to quantify mediastinal shift and called "mediastinal shift angle" (MSA).Results: Median MSA was significantly different between group A (34.3° range 29.3-45.9°) and group B (42.7° range 34.1-58.9°) (p < .001) and between study group as a whole and the control group (19° range 13.8-25.9°) (p < .001). Statistical analysis confirmed an inverse correlation between MSA values and survival (p = .004). The best cutoff value for MSA was 43.7°, which demonstrated the highest discriminatory power (sensitivity 63%; specificity 93.75%).Conclusions: In fetuses with isolated CDH, the mediastinal shift may be quantified using mediastinal shift angle (MSA) and this US marker, similarly to the widely accepted and used US prenatal prognostic indicators (LHR and O/E LHR), seems to reliably predict survival.

Determination of fetal lung maturity using magnetic resonance imaging signal intensity measurements.

PURPOSE: The objective of this study was to determine if magnetic resonance signal intensity measurements can be used to predict gestational age and hence fetal lung maturity. METHODS: This institutional review board-approved study was a retrospective review of 394 fetal magnetic resonance imaging cases from a single institution for the years 2001 to 2011. For each case, T1- and T2-weighted sequences were selected for data collection. A single reviewer obtained 10 regions of interest (when possible) from each scan (fetal lung, fetal liver, fetal muscle, fetal spleen, and maternal urine, for both T1- and T2-weighted sequences). The medical record was searched for relevant information including best estimate of gestational age, Apgar scores, karyotype, and fetal diagnosis. A variety of organ-to-organ ratios and direct organ signal intensity measurements were assessed for correlation with gestational age. RESULTS: Three hundred thirty-five cases met inclusion criteria with gestational ages ranging from 17 to 39 weeks (mean, 28.6 weeks). A significant relationship between magnetic resonance signal intensity ratios and gestational age was demonstrated on the T2 lung-to-liver, T2 lung-to-spleen, T2 lung-to-muscle, T1 lung-to-liver, and T1 lung-to-spleen ratios (P < 0.05). T2 lung-to-liver and T2 lung-to-muscle demonstrated the strongest relationship with gestational age (best correlation r = 0.483, P < 0.001). T1 lung-to-liver and T1 lung-to-spleen demonstrated inverse relationships with gestational age (r = -0.174 [P = 0.03] and r = -0.236 [P = 0.02], respectively). CONCLUSIONS: A significant correlation between multiple signal intensity ratios and gestational age is demonstrated. However, the large variances preclude a clinically useful relationship.

Morphometric growth relationships of the immature human mandible and tongue.

The masticatory apparatus is a highly adaptive musculoskeletal complex comprising several relatively independent structural components, which assist in functions including feeding and breathing. We hypothesized that the tongue is elemental in the maintenance of normal ontogeny of the mandible and in its post-natal growth and development, and tested this using a morphometric approach. We assessed tongue and mandibular measurements in 174 (97 male) human cadavers. Landmark lingual and mandibular data were gathered individuals aged between 20 gestational weeks and 3 yr postnatal. In this analysis, geometric morphometrics assisted in visualizing the morphometrical growth changes in the mandible and tongue. A linear correlation in conjunction with principal component analysis further visualized the growth relationship between these structures. We found that the growth of the tongue and mandible were intrinsically linked in size and shape between 20 gestational weeks and 24 months postnatal. However, the mandible continued to change in shape and size into the 3rd yr of life, whereas the tongue only increased in size over this same period of time. These findings provide valuable insights into the allometric growth relationship between these structures, potentially assisting the clinician in predicting the behaviour of these structures in the assessment of malocclusions.

Magnetic resonance imaging evaluation of fetal maxillary sinuses.

BACKGROUND AND OBJECTIVE: The growth of maxillary sinus is closely connected to the development of facial structures. However, its definition and reference standards on fetal magnetic resonance imaging (MRI) have not been analyzed so far. In this study, the objectives were to define and evaluate the fetal maxillary sinus (fMS) formation with MRI. METHODS: We reviewed T2-weighted coronal MRI images of 75 fetuses. The MRI features, time of appearance, and boundaries of fMS were defined. Craniocaudal and transverse diameters of both maxillary sinuses and bone biparietal diameters were measured and statistically evaluated. RESULTS: In 150 fMS site analysis, 91 fMSs were identified. The fMSs were visualized as a hyperintense structures on T2-weighted image above the tooth bud. It first appeared at the 22nd gestational week, and in 4% (3/75) of fetuses, there was unilateral development. Mean craniocaudal length was 2.84 mm (1.1-4.8 mm), and mean transverse diameter was 2.67 mm (1.5-4.2 mm). CONCLUSIONS: Magnetic resonance imaging features of fMS that should be sought for the assessment of craniofacial anatomy are identified in this study. Fetal maxillary sinuses can be observed as hyperintense structures on T2-weighted MRI images starting from 22 weeks of gestation. The growth of fMS follows a predictable course throughout gestation; however, the dimensions are larger than the previously reported ex vivo series.

A landmark-free framework for the detection and description of shape differences in embryos.

This paper introduces a new method to quantify and characterize shape changes during early facial development without the use of landmarks. Landmarks are traditionally used in morphometric analysis, but very few can be identified reliably across all stages of embryonic development. This method uses deformable registration to produce a dense vector field describing the point correspondences between two images. Low and mid-level features are extracted from the deformable vector field to find regions of organized differences that are biologically relevant. These methods are shown to detect regions of difference when evaluated on chick embryo images warped with small magnitude deformations in regions critical to midfacial development.

Prenatal assessment of the antero-posterior jaw relationship in human fetuses: from anatomical to ultrasound cephalometric analysis.

OBJECTIVES: We wished to develop an ultrasound cephalometric analysis, particularly of the antero-posterior jaw relationship, to increase the accuracy of prenatal diagnosis of retrognathism during the routine midterm test. METHODS: Anatomical cephalometric analysis was performed in 18 formalin-fixed human fetuses (between 16 and 39 gestational weeks), and ultrasound cephalometry was prospectively carried out in 52 pregnant women (21 to 25 gestational weeks). The same landmarks were used in the anatomical and ultrasound median sagittal planes for comparison. Four cephalometric angles were measured relative to the anterior cranial base: alveolar projection of the maxilla and the mandible, chin projection, and facial angle. The antero-posterior jaw discrepancy was calculated. RESULTS: The projection of the maxilla was similar in the two cephalometric analyses (IC [-3.39, 0.23]), whereas the values of the projection of the mandible were lower in the ultrasound sample. The slope of the regression line of the antero-posterior jaw discrepancy on fetuses' age did not show significant differences (IC [-0.05, 1.54]) between anatomical and ultrasound cephalometry, although a difference of 3.23° ± 0.78° (IC [1.69, 4.77]) was observed. Despite this variability, the projections of mandible and chin were well determined by the projection of the maxilla both in the anatomical and ultrasound sample. CONCLUSIONS: Cephalometric analysis by prenatal sonography can be performed to study the antero-posterior jaw relationship. We think that this procedure could be useful to improve prenatal diagnosis of retrognathism in high-risk pregnancies. Further studies should address the reproducibility and accuracy of such analysis.