MR Imaging of the Fetal Face: Comprehensive Review

Standardised and structured reporting in fetal magnetic resonance imaging: recommendations from the Fetal Task Force of the European Society of Paediatric Radiology

Over the last decades, magnetic resonance imaging (MRI) has emerged as a valuable adjunct to prenatal ultrasound for evaluating fetal malformations. Several radiological societies advocate for standardised and structured reporting practices to enhance the uniformity of imaging language. Compared to narrative formats, standardised and structured reports offer enhanced content quality, minimise reader variability, have the potential to save reporting time, and streamline the communication between specialists by employing a shared lexicon. Structured reporting holds promise for mitigating medico-legal liability, while also facilitating rigorous scientific data analyses and the development of standardised databases. While structured reporting templates for fetal MRI are already in use in some centres, specific recommendations and/or guidelines from international societies are scarce in the literature. The purpose of this paper is to propose a standardised and structured reporting template for fetal MRI to assist radiologists, particularly those with less experience, in delivering systematic reports. Additionally, the paper aims to offer an overview of the anatomical structures that necessitate reporting and the prevalent normative values for fetal biometrics found in current literature.

Fetal Head and Neck Imaging

Prenatal MRI plays an essential role in the evaluation of the head and neck. This article overviews technical considerations and both isolated and syndromic anomalies of the fetal calvarium, globes and orbits, ears, maxilla, mandible, and neck.

Diagnostic Potential of Complementation of MRI to Prenatal Ultrasound for Detecting Orofacial Clefts in High-Risk Fetuses: A Network Meta-Analysis

OBJECTIVE

To compare the complementation of magnetic resonance imaging (MRI) to prenatal ultrasound (US) with prenatal US alone in detecting orofacial clefts in high-risk fetuses.

DESIGN

A network meta-analysis.

SETTING

Literature retrieval in PubMed, EMBASE, and Cochrane library, and meta-analysis based on STATA 14.0.

PATIENTS

Fetuses were at high-risk for orofacial clefts.

INTERVENTIONS

Prenatal US and the complementation of MRI to prenatal US.

MAIN OUTCOME MEASURES

The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic odds ratio (DOR), and area under the curve (AUC).

RESULTS

Thirteen studies involving 776 patients were included. Direct meta-analysis showed that the complementation of MRI to prenatal US did not differ from prenatal US in detecting orofacial clefts if the type of orofacial clefts was not distinguished. Subgroup analysis showed that the specificity of prenatal US for the detection of isolated cleft palate (CP) was lower than that of the complementation of MRI to prenatal US. Furthermore, network meta-analysis consistently suggested a comparable diagnostic value between prenatal US and the complementation of MRI to prenatal US. Moreover, subgroup analysis showed that the specificity of prenatal US was significantly lower than that of complementation of MRI to prenatal US for the detection of isolated CP.

CONCLUSIONS

MRI is more accurate than ultrasound in detecting cleft palate. Therefore, MRI should be offered if there is a fetus with a possible or ultrasound diagnosis of cleft palate, especially if the evaluation of cleft palate is deemed unsatisfactory after careful evaluation of the images.

Craniofacial phenotyping with fetal MRI: a feasibility study of 3D visualisation, segmentation, surface-rendered and physical models

This study explores the potential of 3D Slice-to-Volume Registration (SVR) motion-corrected fetal MRI for craniofacial assessment, traditionally used only for fetal brain analysis. In addition, we present the first description of an automated pipeline based on 3D Attention UNet trained for 3D fetal MRI craniofacial segmentation, followed by surface refinement. Results of 3D printing of selected models are also presented.Qualitative analysis of multiplanar volumes, based on the SVR output and surface segmentations outputs, were assessed with computer and printed models, using standardised protocols that we developed for evaluating image quality and visibility of diagnostic craniofacial features. A test set of 25, postnatally confirmed, Trisomy 21 fetal cases (24-36 weeks gestational age), revealed that 3D reconstructed T2 SVR images provided 66-100% visibility of relevant craniofacial and head structures in the SVR output, and 20-100% and 60-90% anatomical visibility was seen for the baseline and refined 3D computer surface model outputs respectively. Furthermore, 12 of 25 cases, 48%, of refined surface models demonstrated good or excellent overall quality with a further 9 cases, 36%, demonstrating moderate quality to include facial, scalp and external ears. Additional 3D printing of 12 physical real-size models (20-36 weeks gestational age) revealed good/excellent overall quality in all cases and distinguishable features between healthy control cases and cases with confirmed anomalies, with only minor manual adjustments required before 3D printing.Despite varying image quality and data heterogeneity, 3D T2w SVR reconstructions and models provided sufficient resolution for the subjective characterisation of subtle craniofacial features. We also contributed a publicly accessible online 3D T2w MRI atlas of the fetal head, validated for accurate representation of normal fetal anatomy.Future research will focus on quantitative analysis, optimizing the pipeline, and exploring diagnostic, counselling, and educational applications in fetal craniofacial assessment.

Identification of novel homozygous variants in FOXE3 and AP4M1 underlying congenital syndromic anophthalmia and microphthalmia

BACKGROUND

Anophthalmia and microphthalmia are severe developmental ocular disorders that affect the size of the ocular globe and can be unilateral or bilateral. The disease is found in syndromic as well as non-syndromic forms. It is genetically caused by chromosomal aberrations, copy number variations and single gene mutations, along with non-genetic factors such as viral infections, deficiency of vitamin A and an exposure to alcohol or drugs during pregnancy. To date, more than 30 genes having different modes of inheritance patterns are identified as causing anophthalmia and microphthalmia.

METHODS

In the present study, a clinical and genetic analysis was performed of six patients with anophthalmia and microphthalmia and/or additional phenotypes of intellectual disability, developmental delay and cerebral palsy from a large consanguineous Pakistani family. Whole exome sequencing followed by data analysis for variants prioritization and validation through Sanger sequencing was performed to identify the disease causing variant(s). American College of Medical Genetics and Genomics (ACMG) guidelines were applied to classify clinical interpretation of the prioritized variants.

RESULTS

Clinical investigations revealed that the affected individuals are afflicted with anophthalmia. Three of the patients showed additional phenotype of intellectual disability, developmental delays and other neurological symptoms. Whole exome sequencing of the DNA samples of the affected members in the family identified a novel homozygous stop gain mutation (NM_012186: c.106G>T: p.Glu36*) in Forkhead Box E3 (FOXE3) gene shared by all affected individuals. Moreover, patients segregating additional phenotypes of spastic paraplegia, intellectual disability, hearing loss and microcephaly showed an additional homozygous sequence variant (NM_004722: c.953G>A: p.Arg318Gln) in AP4M1. Sanger sequencing validated the correct segregation of the identified variants in the affected family. ACMG guidelines predicted the variants to be pathogenic.

CONCLUSIONS

We have investigated first case of syndromic anophthalmia caused by variants in the FOXE3 and AP4M1. The present findings are helpful for understanding pathological role of the mutations of the genes in syndromic forms of anophthalmia. Furthermore, the study signifies searching for the identification of second variant in families with patients exhibiting variable phenotypes. In addition, the findings will help clinical geneticists, genetic counselors and the affected family with respect to prenatal testing, family planning and genetic counseling.

The role of MRI in the prenatal diagnosis and classification of fetal microtia

OBJECTIVE

To investigate the role of MRI in the diagnosis and classification of fetal microtia.

METHODS

Ninety-five fetuses with suspected microtia based on ultrasound and MRI performed within 1 week were enrolled in this study. The diagnosis based on MRI was compared with postnatal diagnosis. Among the microtia cases suspected on the basis of MRI, mild and severe cases were further classified. In addition, external auditory canal (EAC) atresia was evaluated by MRI in 29 fetuses with a gestational age > 28 weeks, and the accuracy of MRI in the diagnosis and classification of microtia was determined.

RESULTS

Of 95 fetuses, 83 were considered to have microtia on the basis of MRI, 81 were confirmed to have microtia, and 14 were found to be normal according to postnatal diagnosis. Among 190 external ears in 95 fetuses, 40 ears were suspected to have mild microtia, and 52 ears were suspected to have severe microtia on the basis of MRI. According to the postnatal diagnosis, mild and severe microtia were confirmed in 43 and 49 ears, respectively. Among the 29 fetuses with a gestational age > 28 weeks, 23 ears were suspected to have EAC atresia according to MRI and 21 ears were ultimately confirmed to have EAC atresia. The accuracy of MRI in diagnosing microtia and EAC atresia was 93.68% and 93.10%, respectively.

CONCLUSION

MRI shows good performance in diagnosing fetal microtia and has the potential to evaluate its severity on the basis of classification and EAC status.

CLINICAL RELEVANCE STATEMENT

This study was aimed at investigating the role of MRI in the diagnosis and classification of fetal microtia. MRI shows good performance and can help evaluate microtia severity and EAC atresia, thus allowing for better clinical management.

KEY POINTS

• MRI is a useful adjunct to prenatal ultrasound. • MRI has a higher accuracy rate than ultrasound in diagnosing fetal microtia. • The accurate classification of fetal microtia and the diagnosis of external auditory canal atresia through MRI may help guide clinical management.

Understanding the distinction between cleft lip and cleft palate: a critical step for successful prenatal detection

PURPOSE OF REVIEW

Orofacial clefts (OCs) are among the most common congenital anomalies, however, prenatal detection of cleft palate without cleft lip (CP) remains low. CP is associated with a higher risk of associated structural anomalies, recurrence risk and genetic aberrations. There is opportunity to optimize prenatal diagnosis, counseling and diagnostic genetic testing for OCs.

RECENT FINDINGS

Improving prenatal diagnosis of CP requires understanding that embryologically, the secondary palate develops from the 6th to the 10th week and fuses with the primary palate by the 12th week. Multiple first, second and third trimester 2D ultrasonographic markers for OCs have been described including the maxillary gap, frontal space, maxilla-nasion-mandible angle, retronasal triangle, palatino-maxillary diameter, equal sign, nonvisualization or gap in the soft to hard palate interface and loss of the superimposed line. We discuss the technique, evidence and limitations of each.

SUMMARY

Prenatal detection of OC can be optimized by employing 2D sonographic markers. Prenatal detection of CP may be improved by recognizing its high association with retrognathia/micrognathia.

Indications for magnetic resonance imaging of the fetal body (extra-central nervous system): recommendations from the European Society of Paediatric Radiology Fetal Task Force

The indications for fetal body MRI are amplifying because of the expanding possibilities of fetal and perinatal therapy. However, huge heterogeneity regarding the indications for fetal body MRI is seen among different European countries that is mostly related to local use of US, but also to local fetal MRI expertise and legislation on pregnancy termination. The purpose of this article is to summarize the precise indications for fetal MRI, excluding the central nervous system. MRI indications arise from the sonographic findings, based on the operator's experience and the various practices in the countries and institutions represented on the European Society of Paediatric Radiology Fetal Task Force. We also highlight the strengths and weaknesses of fetal US and MRI of the fetal body.

Comparison of prenatal ultrasound with MRI in the evaluation and prediction of fetal orofacial clefts

BACKGROUND

Orofacial clefts (OFCs) are common craniofacial abnormalities. This study aimed to compare the diagnostic and predictive values of prenatal ultrasonography (US) and magnetic resonance imaging (MRI).

METHODS

We reviewed the newborn physical examinations or fetal autopsy data with OFCs. Between January 2013 and December 2018, the diagnoses resulting from prenatal US and MRI examination were compared retrospectively with the postpartum diagnoses. The diagnostic prediction of prenatal imaging was then determined.

RESULTS

334 infants were identified with OFCs by either newborn physical exam or stillborn autopsy. For detection of OFCs by US, the total accuracy (ACC), true positive rate (TPR), true negative rate (TNR), positive predictive value (PPV), and negative predictive value (NPV) were 99.9% (111,178/110,286), 81.9% (230/281), 99.9% (109,948/110,005), 80.1% (230/287), and 99.9% (109,948/109,999), respectively. For MRI, the ACC, TPR, TNR, PPV, and NPV were 99.8% (4,125/4,132), 89.8% (44/49), 99.9% (4,081/4,083), 95.7% (44/46), and 99.9% (4,081/4,086), respectively. When we compared the predictive values between prenatal US and MRI, there were significant differences in the PPV of OFCs (P < 0.05), NPV of OFCs (P < 0.05), TPR of CLO (P < 0.001), PPV of CLP (P < 0.05), and TPR of CPO (P < 0.05).

CONCLUSION

Our results suggest that prenatal US could be effective for diagnosing and ruling out fetal OFCs. Diagnostic confidence is significantly improved when fetal MRI is used to assess fetal OFCs as an adjunct to US examination.

A rare case of anophthalmia without any family history and antenatal risk factors

Anophthalmia is a rare genetic disorder. It is defined as the absence of one or both eyes in a patient. It can be unilateral or bilateral. Based on the absence of anatomical structures, it is divided into primary, secondary, and degenerative anophthalmia. It occurs in an infant with a diabetic mother or any exposure to teratogens. Most of the patients have a positive family history of anophthalmia or related genetic disorder. Its diagnosis is crucial as there is a similar condition called micro ophthalmia. Sometimes it is difficult to differentiate between severe microphthalmia and anophthalmia. We present a case of a 5-day-old infant diagnosed with bilateral anophthalmia. In the majority of the cases of bilateral anophthalmia the patients usually have a positive family history of antenatal exposure to teratogenic substances. But in our case, no family history or antenatal teratogenic exposure was noted.

Contribution of computed tomography and magnetic resonance imaging in the analysis of fetal craniofacial malformations

A wide range of craniofacial malformations can be diagnosed in utero using ultrasonography. However, even with highly experienced sonographers and diagnostic physicians and optimal conditions of examination, some anatomical structures cannot be properly analyzed by this technique. The aim of this pictorial essay is to show the additional value of fetal magnetic resonance imaging and computed tomography in this setting and to illustrate the role of these modalities in facial clefts; craniosynostosis; ear, eye and nose abnormalities; otomandibular dysplasias; and facial cephaloceles.

Discussion on Ultrasound Diagnosis of Prenatal Cleft Lip: How does Its Accuracy Affects the Family? Prenatal Counseling for Clefts: The University of Illinois at Chicago, Craniofacial Center's Protocols and Experience

ABSTRACT

Prenatal diagnosis of cleft lip and palate as well as other craniofacial differences is now possible with a significant level of accuracy due to sonographic and other evaluations. Thus, prospective parents have the opportunity to be informed ahead of time about these conditions making them better prepared to deal with their child after birth. The role of the plastic surgeon and other craniofacial team members in prenatal consultations is becoming increasingly important and well accepted. Therefore, any additional publication reviewing the topic from different angles and specifically from the parents' perspective is a welcome addition to our understanding of the parents' points of view and enables the team to most effectively assist them as they cope with the new diagnosis.This review describes details about our Craniofacial Center's efforts over 24 years. Our focus has always been on providing support through face-to-face multidisciplinary consultations with prospective parents as well as offering education to the public and referring sources, such as obstetricians and sonographers through direct communications, newsletters, and our website for timely referrals. As an additional service, the authors have organized a group of volunteer parents of children who are patients of the Center to share their short long-term experiences.

Congenital bony nasal cavity stenosis: A review of current trends in diagnosis and treatment

Congenital bony nasal cavity stenosis is caused by alterations of the normal embryological development of the nasal cavity. Depending on the site of the obstruction, the most important types of stenosis are: choanal atresia and stenosis, congenital nasal pyriform aperture stenosis, congenital midnasal stenosis, arhinia and nasal septum deviation. Although they are uncommon, they could be potentially life-threatening conditions that require early diagnosis and proper treatment. In case of neonatal nasal obstruction, appropriate differential diagnosis with other causes, such as rhinitis and sinonasal masses, are performed by nasal endoscopy and radiological exams. Treatment strategy consisting of medical nasal therapies and endoscopic or open nasal surgery should be tailored according to the types and the degree of the stenosis. When indicated, endoscopic endonasal approach is considered the most effective technique in neonates warranting minimal surgical invasiveness and maximum effect. In order to promote the management of these rare yet clinically relevant neonatal nasal breath disorders, we review the current trends in diagnosis and treatment of congenital bony nasal cavity stenosis.

How to read a fetal magnetic resonance image 101

Accurate antenatal diagnosis is essential for planning appropriate pregnancy management and improving perinatal outcomes. The provision of information vital for prognostication is a crucial component of prenatal imaging, and this can be enhanced by the use of fetal MRI. Image acquisition, interpretation and reporting of a fetal MR study can be daunting to the individual who has encountered few or none of these examinations. This article provides the radiology trainee with a general approach to interpreting a fetal MRI. The authors review the added value of prenatal MRI in the overall assessment of fetal wellbeing, discuss MRI protocols and techniques, and review the normal appearance of maternal and fetal anatomy. The paper concludes with a sample template for structured reporting, to serve as a checklist and guideline for reporting radiologists.

Spotlight on the pediatric eye: a pictorial review of orbital anatomy and congenital orbital pathologies

Orbital lesions in the pediatric population vary from adults in terms of their presentation, unique pathology, and imaging characteristics. The prompt and accurate diagnosis of these lesions is imperative to prevent serious consequences in terms of visual impairment and disfigurement. Along with dedicated ophthalmologic examination, imaging is instrumental in characterizing these lesions, both for accurate diagnosis and subsequent management. In our pictorial essay, we provide a basic review of orbital embryology, anatomy, and congenital orbital pathologies, with emphasis on radiological findings.

Diagnostic accuracy of fetal MRI to detect cleft palate: a meta-analysis

This systematic review aims to determine the diagnostic accuracy of fetal MRI for detecting cleft palate in fetuses at risk for orofacial clefts. Pubmed, Embase, and CINAHL were searched systematically. A diagnostic study was included if it performed MRI (index test) and postnatal examination (reference test) in fetuses at risk for orofacial clefts. Methodological quality was assessed using the QUADAS-2. A meta-analysis was performed with a random-effects model, calculating the pooled sensitivity, specificity, and area under the curve. The search resulted in eight studies (334 fetuses) to be included: four prospective and four retrospective studies. The applicability concern was low. There was, however, a risk of selection and information bias. All studies showed that MRI well predicted the chance of cleft palate. The sensitivity results were homogeneous, but heterogeneity was assumed regarding the specificity estimate (Cochrane's Q test: p = 0.00). The pooled sensitivity was 0.97 (95% CI 0.93-0.99); the pooled specificity was 0.94 (0.89-0.97). The area under the curve was 0.98 (95% CI 0.98-0.99).Conclusion: This meta-analysis shows that MRI has an excellent sensitivity and good to excellent specificity for diagnosing cleft palate in fetuses at risk for orofacial clefts. Future research should assess applicability for clinical care.What is Known:• Using ultrasound for prenatal detection of cleft palate leads to misdiagnosis frequently.• MRI could potentially improve the prenatal detection rate of cleft palate.What is New:• Eight studies describe the diagnostic accuracy of MRI for detecting cleft palate.• Combined results show excellent sensitivity and good to excellent specificity.

Craniofacial malformations and their association with brain development: the importance of a multidisciplinary approach for treatment

The craniofacial complex develops mainly in the first trimester of pregnancy, but its final shaping and the development of the teeth extend into the second and third trimesters. It is intimately connected with the development of the brain because of the crucial role the cranial neural crest cells play and the fact that many signals which control craniofacial development originate in the brain and vice versa. As a result, malformations of one organ may affect the development of the other. Similarly, there are developmental connections between the craniofacial complex and the teeth. Craniofacial anomalies are either isolated, resulting from abnormal development of the first two embryonic pharyngeal arches, or part of multiple malformation syndromes affecting many other organs. They may stem from gene mutations, chromosomal aberrations or from environmental causes induced by teratogens. The craniofacial morphologic changes are generally cosmetic, but they often interfere with important functions such as chewing, swallowing and respiration. In addition, they may cause hearing or visual impairment. In this review we discussed only a small number of craniofacial malformations and barely touched upon related anomalies of dentition. Following a brief description of the craniofacial development, we discussed oral clefts, craniofacial microsomia, teratogens that may interfere with craniofacial development resulting in different malformations, the genetically determined craniosynostoses syndromes and few other relatively common syndromes that, in addition to the craniofacial complex, also affect other organs. The understanding of these malformations is important in dentistry as dentists play an integral role in their diagnosis and multidisciplinary treatment.