Role of TUI in First Trimester Evaluation of Palate

Abstract

The purpose of the study is to report on the application of tomographic ultrasound imaging (TUI) in prenatal sonographic study of fetal palate in 11–14 week scan. TUI is a technology that allows the examiner to obtain a volume data set that allows the display of numerous 2D slices from a given volume on any of the three orthogonal planes. It allows automatic slicing of the volume datasets displaying multiple parallel images. The fetal palate was examined with TUI in thirteen abnormal volumes and in ninety-four normal volumes. The appearance of maxillary line in sagittal sections and the base of the retronasal triangle in coronal sections serve as key landmarks in evaluating palatine clefts. The intact palatal line in sagittal sections was observed in all the ninety-four normal volumes. The midline anatomy of the palate has been described in the study emphasising that the vomer can mimic palate in midsagittal section in secondary palatine clefts. The parasagittal sections truly reflects the presence or absence of the palate without the confounding factor of the vomer bone which was demonstrated in the abnormal volumes with TUI. The potential advantage of TUI in evaluating palate is that it allows the display of both midsagittal and parasagittal sections simultaneously. The different types of cleft have a constant reproducible pattern in TUI imaging which can be used to diagnose palatine clefts including isolated cleft of palate. Prospective studies are needed to confirm these promising results.

First Trimester Ultrasound Evaluation of the Cleft Palate: Midsagittal, Axial or Coronal View-Which View is Best?

“…In a large first-trimester screening study, including more than 45,000 ultrasound examinations, the detection rate was only about 5% [9]. Several approaches have been reported in the literature that are designed to improve this low detection rate [4][5][6][7][8]. In 2010, Sepulveda et al proposed the use of the retronasal triangle view for the detection of a cleft palate and micrognathia.…”

“…Campbell also observed that the axial views of the secondary palate provide more clarity as the secondary palate is larger in the lateral than in the anteroposterior dimension which favours its examination in the axial plane [30]. The possible use of volume imaging should always be considered in the first trimester whenever there is a suspicion of a cleft on routine conventional sonography [6,7,31].…”

“…The anatomical landmarks in sagittal, coronal and in axial view were retrospectively evaluated in 17 cases of palatine clefts. Only the diagnosed cases with known postnatal outcomes from our earlier case series were included in this study [6,7]. Informed consent was obtained in all cases.…”

“…In the first trimester, detection of cleft lip and palate can be achieved with high-resolution sonography, but it requires obtaining optimal views of the fetal face and a high index of suspicion. The optimal views currently published in literature would be the mid-sagittal view to evaluate the maxillary gap sign proposed by Chaoui et al and the retronasal triangle (RNT) in coronal view proposed by Sepulveda et al [4,5] We have recommended the utilisation of all three planes namely the sagittal, axial and coronal planes in screening for palatine clefts in our earlier study and the utility of three-dimensional (3D) ultrasound in confirming the diagnosis of clefts [6,7]. The purpose of this study is to highlight the utility of the transverse axial view in first trimester evaluation of the fetal palate.…”