Metopic suture in fetuses with holoprosencephaly at 11 + 0 to 13 + 6 weeks of gestation

Typical changes of ethmocephaly and holoprosencephaly in a fetus at 14 weeks of gestation

Background

This case report is to show the details of the face of a very rare ethmocephaly at 14 weeks of gestation.

Case presentation

After the regular transabdominal two-dimensional (2D) scan for nuchal translucency we could describe the following malformations: holoprosencephaly, proboscis and an abnormal face, omphalocele containing bowel, hyperechoic kidneys and megacystis. In addition, we acquired transvaginal three-dimensional (3D) ultrasound volume blocks of the fetal head, scanned with different insonation angles and stored them for later analysis. Using the multiplanar mode the volume blocks taken from the front show all details of the face: proboscis, hypotelorism, microphthalmia, cleft palate, accelerated development of the frontal bones and premature closure of the metopic suture. The volume blocks taken through the squamosal suture show all details of the fossa posterior and brain: fused thalami surrounded by the typical monoventricle, normal brain stem, elongation of anterior membranous area. Render mode shows a precise 3D image of the face. To better demonstrate the changes of the fetal face a post-mortem photo of the fetal face is included.

Conclusion

This case report can demonstarte the typical changes of ethmocephaly in the first trimester using transvaginal 3D scan.

Cleft lip and palate results from Hedgehog signaling antagonism in the mouse: Phenotypic characterization and clinical implications

BACKGROUND

The Hedgehog (Hh) pathway provides inductive signals critical for developmental patterning of the brain and face. In humans and in animal models interference with this pathway yields birth defects, among the most well-studied of which fall within the holoprosencephaly (HPE) spectrum.

METHODS

Timed-pregnant C57Bl/6J mice were treated with the natural Hh signaling antagonist cyclopamine by subcutaneous infusion from gestational day (GD) 8.25 to 9.5, or with a potent cyclopamine analog, AZ75, administered by oral gavage at GD 8.5. Subsequent embryonic morphogenesis and fetal central nervous system (CNS) phenotype were respectively investigated by scanning electron microscopy and high resolution magnetic resonance imaging (MRI).

RESULTS

In utero Hh signaling antagonist exposure induced a spectrum of craniofacial and brain malformations. Cyclopamine exposure caused lateral cleft lip and palate (CLP) defects attributable to embryonic deficiency of midline and lower medial nasal prominence tissue. The CLP phenotype was accompanied by olfactory bulb hypoplasia and anterior pituitary aplasia, but otherwise grossly normal brain morphology. AZ75 exposure caused alobar and semilobar HPE with associated median facial deficiencies. An intermediate phenotype of median CLP was produced infrequently by both drug administration regimens.

CONCLUSIONS

The results of this study suggest that interference with Hh signaling should be considered in the CLP differential and highlight the occurrence of CNS defects that are expected to be present in a cohort of patients having CLP. This work also illustrates the utility of fetal MRI-based analyses and establishes a novel mouse model for teratogen-induced CLP.

Three-dimensional ultrasound imaging

This review is about the development of three-dimensional (3D) ultrasonic medical imaging, how it works, and where its future lies. It assumes knowledge of two-dimensional (2D) ultrasound, which is covered elsewhere in this issue. The three main ways in which 3D ultrasound may be acquired are described: the mechanically swept 3D probe, the 2D transducer array that can acquire intrinsically 3D data, and the freehand 3D ultrasound. This provides an appreciation of the constraints implicit in each of these approaches together with their strengths and weaknesses. Then some of the techniques that are used for processing the 3D data and the way this can lead to information of clinical value are discussed. A table is provided to show the range of clinical applications reported in the literature. Finally, the discussion relating to the technology and its clinical applications to explain why 3D ultrasound has been relatively slow to be adopted in routine clinics is drawn together and the issues that will govern its development in the future explored.

Three-dimensional ultrasound in prenatal diagnosis

PURPOSE OF REVIEW

Several technological advances have greatly improved three-dimensional sonography, which have improved acquisition and display capabilities. This review describes these technical changes as well as current applications of 3D sonography in prenatal diagnosis.

RECENT FINDINGS

Recently published papers have emphasized the potential of getting a precise 'any plane of choice' from a three-dimensional volume, as a new way of scanning, based on the off-line analysis of a volume dataset. Surface mode has been used to demonstrate malformations and genetic diseases. The maximum rendering mode, which highlights bones, has great potential for imaging the nasal bones and the frontal bones with the metopic suture. Organ volume can be measured, but the utility of this in clinical practice remains to be determined. Three-dimensional ultrasound needs to be standardized.

SUMMARY

Three-dimensional ultrasonography is the most rapidly developing technique in fetal imaging. New features will permit the transition from the era of 'sonography in two-dimensional planes' to 'volume ultrasound'.

Frontomaxillary facial angle in fetuses with trisomy 13 at 11 + 0 to 13 + 6 weeks

OBJECTIVE

To investigate the frontomaxillary facial (FMF) angle in fetuses with trisomy 13 at 11 + 0 to 13 + 6 weeks of gestation.

METHODS

A three-dimensional (3D) volume of the fetal head was obtained before karyotyping at 11 + 0 to 13 + 6 weeks of gestation in 23 fetuses with trisomy 13. The FMF angle, defined as the angle between the upper surface of the maxilla and the frontal bone in a midsagittal view of the fetal face, was measured and compared to the angle in 500 chromosomally normal fetuses.

RESULTS

In 10 of 12 (83.3%) fetuses with trisomy 13 and holoprosencephaly, the FMF angle was above the 95(th) centile of the normal range. In the 11 fetuses with no holoprosencephaly, the FMF angle was not significantly different from normal. There was no significant difference in the FMF angle between the trisomy 13 fetuses with and without facial cleft.

CONCLUSIONS

In fetuses with trisomy 13, the FMF angle at 11 + 0 to 13 + 6 weeks of gestation is increased only in cases with associated holoprosencephaly.

How useful is 3D and 4D ultrasound in perinatal medicine?

AIM

The purpose of this paper is to review and analyze the published literature on the use of three-dimensional (3DUS) and four-dimensional (4DUS) ultrasound in perinatal medicine.

METHODS

We systematically searched Medline through PubMED (January 2000-January 2006), including EMBASE/Excerpta Medica database as well as the Cochrane Database of Systematic Reviews. The search terms used to identify clinical application of 3DUS and 4DUS studies in perinatal medicine were technical development, special features, and recommendation for fetal imaging, research on 3DUS or 4DUS, and the usage of invasive 3DUS or 4DUS procedures. The reference bibliographies of relevant books were also manually searched for supplementary citations. Inclusion criteria were as follows: (1) studies related to the use of 3DUS or 4DUS in perinatal medicine; (2) full text were available in English; (3) publication format of original scientific articles, case reports, editorials or literature reviews and chapters in the books.

RESULTS

Five hundred and seventy-five articles were identified, and among those, 438 were relevant to this review.

CONCLUSIONS

3DUS and 4DUS provided additional information for the diagnosis of facial anomalies, evaluation of neural tube defects, and skeletal malformations. Additional research is needed to determine the clinical utility of 3DUS and 4DUS for the diagnosis of congenital heart disease, central nervous system (CNS) anomalies and detection of fetal neurodevelopmental impairment assessed by abnormal behavior in high-risk fetuses.

Intérêt de l’échographie 3D-4D en échographie fœtale et gynécologique : principes et indications

Three-dimensional ultrasound has become an essential tool for visualization of fetal structures in the past few years. The recent improvements in transducers and signal processing provide new information, particularly in obstetrics and gynecology sonography. The present paper will present the most recent advances in volume acquisition and presentation modes followed by results of fetal organ visualization in normal and abnormal cases as well as applications in gynecology.