Imaging in craniosynostosis: when and what?

Intraoperative Ultrasound in Endoscopic Sagittal Suture Synostosis to Optimize Incision Planning and Avoid Misdiagnosis

Endoscopy-assisted craniectomy with lateral osteotomies and postoperative helmet molding therapy is a widely used approach in managing sagittal suture craniosynostosis. Generally, the incisions are placed just posterior to the anterior fontanel and just anterior to the posterior fontanel and lambdoid sutures, and accurate incision placement optimizes the safe separation of the superior sagittal sinus. The authors present their 10 year experience with an ultrasound-assisted approach to identify the lambdoid sutures and precisely place the skin incisions. The authors included all patients in care at their institution between 2010 and 2023 who operated for sagittal suture craniosynostosis with endoscopy-assisted craniectomy with lateral osteotomies and postoperative helmet molding therapy. A retrospective review of clinical parameters, surgical data, as well as outcomes, and imaging studies was performed. One hundred patients were operated during the observation period. The mean age was 3.9 ± 3.5 (range: 2.7-6.4) months. Intraoperative ultrasound was documented in 61% of cases (n = 61). In 100% of cases, the incisions were placed behind the anterior and in front of the posterior fontanel, as planned with ultrasound. In 2 additional cases, intraoperative sonography identified a patent sagittal suture in the operating room. A histopathological review showed suture ossification in 100% of operated cases with available reports. Using this technique of ultrasound-guided identification of the lambdoid suture/posterior fontanel, as well as coronal suture/anterior fontanel, may aid in the adequate placement of skin incisions. Patent sutures can be identified in clinically misdiagnosed patients. This study reaffirms the overall utility of ultrasound in pediatric operative neurosurgery.

Black Bone MRI vs. CT in temporal bone assessment in craniosynostosis: a radiation-free alternative

BACKGROUND AND PURPOSE

Craniosynostoses are rare congenital craniofacial malformations, variably affected by hearing loss, often requiring repeated CT examinations to assess skull or temporal bone (TB) abnormalities. In order to avoid radiation exposure in these young patients, efforts are made to assess the skull abnormalities on MR bone imaging sequences, such as Black Bone (BB). Our aim is to compare BB, a radiation-free imaging technique, with CT for the assessment of the TB.

MATERIALS AND METHODS

48 patients who underwent both BB and CT (2016-2021) in Sophia Children's Hospital, Erasmus MC, Rotterdam, were retrospectively investigated. BB and CT (the diagnostic gold standard for imaging the temporal bone) were evaluated blindly and independently by 3 observers; visibility and abnormalities of TB structures and cranial nerves were scored; abnormal findings were confirmed by a senior pediatric neuroradiologist. The statistical analysis was performed using Gwet's AC1 agreement and modified versions of the Wilcoxon signed-rank test and sign test with a Bonferroni-Holm correction (p < 0.05).

RESULTS

CT was rated higher than BB in structure visibility (global p = 0.0002), but was rated similar to BB when assessing TB anatomy and pathology (global p = 0.58). The visibility ratings showed better interobserver agreement values on CT than BB. In the normal/abnormal ratings, both BB (0.75-1) and CT (0.88-1) showed high interobserver agreement values.

CONCLUSION

Our preliminary results suggest that BB is a promising tool for screening TB pathology in patients with craniosynostosis who require MR imaging.

Evaluation of ultra-low-dose CT with tin filter for craniosynostosis

INTRODUCTION

CT has replaced skull radiography as the gold standard for assessment of craniosynostosis in children. To minimise the risks of ionising radiation in this radiosensitive population, low-dose CT protocols are increasingly being adopted. This study evaluates the effectiveness of an ultra-low-dose CT protocol with a tin filter in reducing radiation exposure whilst maintaining diagnostic quality for craniosynostosis, and its utility in the evaluation of other findings not appreciable on skull radiography.

METHODS

Twenty-seven patients who underwent ultra-low-dose CT for craniosynostosis were compared with an age-matched control group who received standard-dose CT for indications other than craniosynostosis. Differences in radiation dosimetry and quantitative image quality parameters were analysed using independent two-tailed t-tests. Radiologist reports were also examined for the frequency of other incidental radiological findings.

RESULTS

Mean effective dose for the 27 ultra-low-dose CT scans was 0.14 mSv, a 92% reduction compared with the control group. Image quality, measured by contrast-to-noise ratio, was significantly lower in the ultra-low-dose scans compared with the standard-dose scans; however, all scans were diagnostic for detecting or excluding craniosynostosis. Hydrocephalus was able to be ruled out in all 27 ultra-low-dose scans.

CONCLUSION

Ultra-low-dose CT with a tin filter allows for the diagnosis of craniosynostosis with a 92% dose reduction compared with the standard CT protocol. Despite lower image quality with the ultra-low-dose protocol when compared to standard CT, all 27 scans were adequate for craniosynostosis diagnosis. Additionally, it allowed for the assessment of other relevant findings not appreciable with skull radiography, highlighting its advantages as the new clinical standard for craniosynostosis assessment.

Neuroimaging in Nonsyndromic Craniosynostosis: Key Concepts to Unlock Innovation

Craniosynostoses (CRS) are caused by the premature fusion of one or more cranial sutures, with isolated nonsyndromic CRS accounting for most of the clinical manifestations. Such premature suture fusion impacts both skull and brain morphology and involves regions far beyond the immediate area of fusion. The combined use of different neuroimaging tools allows for an accurate depiction of the most prominent clinical-radiological features in nonsyndromic CRS but can also contribute to a deeper investigation of more subtle alterations in the underlying nervous tissue organization that may impact normal brain development. This review paper aims to provide a comprehensive framework for a better understanding of the present and future potential applications of neuroimaging techniques for evaluating nonsyndromic CRS, highlighting strategies for optimizing their use in clinical practice and offering an overview of the most relevant technological advancements in terms of diagnostic performance, radiation exposure, and cost-effectiveness.

Machine learning applications in craniosynostosis diagnosis and treatment prediction: a systematic review

Craniosynostosis refers to the premature fusion of one or more of the fibrous cranial sutures connecting the bones of the skull. Machine learning (ML) is an emerging technology and its application to craniosynostosis detection and management is underexplored. This systematic review aims to evaluate the application of ML techniques in the diagnosis, severity assessment, and predictive modeling of craniosynostosis. A comprehensive search was conducted on the PubMed and Google Scholar databases using predefined keywords related to craniosynostosis and ML. Inclusion criteria encompassed peer-reviewed studies in English that investigated ML algorithms in craniosynostosis diagnosis, severity assessment, or treatment outcome prediction. Three independent reviewers screened the search results, performed full-text assessments, and extracted data from selected studies using a standardized form. Thirteen studies met the inclusion criteria and were included in the review. Of the thirteen papers examined on the application of ML to the identification and treatment of craniosynostosis, two papers were dedicated to sagittal craniosynostosis, five papers utilized several different types of craniosynostosis in the training and testing of their ML models, and six papers were dedicated to metopic craniosynostosis. ML models demonstrated high accuracy in identifying different types of craniosynostosis and objectively quantifying severity using innovative metrics such as metopic severity score and cranial morphology deviation. The findings highlight the significant strides made in utilizing ML techniques for craniosynostosis diagnosis, severity assessment, and predictive modeling. Predictive modeling of treatment outcomes following surgical interventions showed promising results, aiding in personalized treatment strategies. Despite methodological diversities among studies, the collective evidence underscores ML's transformative potential in revolutionizing craniosynostosis management.

3D printing in pediatric neurosurgery: experimental study of a novel approach using biodegradable materials

PURPOSE

3D printing technologies have become an integral part of modern life, and the most routinely used materials in reconstructive surgery in children are biodegradable materials. The combination of these two technologies opens up new possibilities for the application of innovative methods in neurosurgery and a patient-centered approach in medical care. The aim of the study was to determine whether a physician without specialized programming and printing skills could independently create materials in a clinical setting for the treatment of patients.

METHODS

We conducted a preclinical study on 15 male Balb-C mice. Cylindrical materials made of polylactic acid (PLA) plastic were 3D printed. Sterilization of the obtained material was performed using a cold plasma sterilizer with hydrogen peroxide vapor and its plasma. The sterile material was implanted subcutaneously into the mice for 30 days, followed by histological examination. Using open-source software for modeling and printing, plates and screws made of PLA plastic were manufactured. The produced components were tested in the biomedical laboratory of the institute.

RESULTS

The histological material showed that no inflammatory changes were observed at the implantation site during the entire observation period. The cellular composition is mainly represented by macrophages and fibroblasts. There was a gradual resolution of the material and its replacement by native tissues. Research conducted to assess the effectiveness of material sterilization in a cold plasma sterilizer demonstrated its high bactericidal efficiency.

CONCLUSION

The method we developed for obtaining biodegradable plates and fixation elements on a 3D printer is easy to use and has demonstrated safety in a preclinical study on an animal model.

Atypical sagittal suture craniosynostosis: pathological considerations for early closure of the anterior part of the sagittal suture

Sagittal suture synostosis is one of the most common craniosynostoses and is often diagnosed by characteristic narrow and long skull shape, scaphocephaly. However, some patients with sagittal suture synostosis do not present with typical scaphocephaly, making early diagnosis difficult. In this study, five cases of characteristic skull deformity showing a narrowing of the cranium posterior to the coronal suture on computed tomography (CT) are presented. The three older children presented with papilledema and intellectual disability and a closed sagittal suture on CT. The two infant cases were diagnosed with the characteristic cranial deformities with aggravation of the deformity over time, but sagittal suture closure was not evident on CT. All patients underwent cranial remodeling surgery. In the two infant cases, the histopathological findings showed that the anterior part of the sagittal suture was firmly fused with fibrous tissue without bony fusion. These findings suggested that narrowing of the cranium posterior to the coronal suture might be due to functional fusion of the anterior portion of the sagittal suture prior to bony fusion. In an infant presenting with such a deformity that shows aggravation of the deformity over time, surgical treatment should be considered.

Facial skeleton dysmorphology in syndromic craniosynostosis: differences between FGFR2 and no-FGFR2-related syndromes and relationship with skull base and facial sutural patterns

PURPOSE

To assess the role of FGFR2 mutations and sutural synostotic patterns on facial skeleton dysmorphology in children with syndromic craniosynostosis.

METHODS

Preoperative high-resolution CT images in 39 infants with syndromic craniosynostosis were evaluated. Patients were divided into infants with and without FGFR2 mutations; each group was split according to synostotic involvement of minor sutures/synchondroses: isolated or combined involvement of middle (MCF) and posterior cranial fossae (PCF). Quantitative analysis of the midface and mandible measures was performed. Each subgroup was compared with a group of age-matched healthy subjects.

RESULTS

Twenty-four patients with FGFR2 related syndromes were clustered in 3 subgroups: MCF + PCF (8 patients, 5.4 ± 1.75 months), MCF (8 patients, 3.62 ± 1.68 months), and PCF (8 patients, 2.75 ± 0.46 months). Fifteen no-FGFR2 patients were clustered in 2 subgroups: MCF + PCF (7 patients, 9.42 ± 0.78 months) and PCF (8 patients, 7.37 ± 2.92 months). Both FGFR2 and no-FGFR2 groups with involvement of minor sutures coursing in MCF showed more facial sutural synostoses. Children with minor suture/synchondrosis synostosis of MCF (MCF-PCF and MCF subgroups) showed altered position of glenoid fossa and mandibular inclination ([Formula: see text]), but children in the FGFR2 group had also reduced midfacial depth and maxillary length ([Formula: see text]). Children with minor suture/synchondrosis synostosis of PCF (PCF subgroups) had reduced posterior mandibular height, but those children in the FGFR2 group also showed reduced intergonion distance ([Formula: see text]).

CONCLUSIONS

In children with syndromic craniosynostosis, both skull base and facial suture synostosis affect facial dysmorphology/hypoplasia. FGFR2 mutations may worsen facial hypoplasia both acting on bone development and causing an earlier premature closure of facial sutures.

Can Craniosynostosis be Diagnosed on Physical Examination? A Retrospective Review

Craniosynostosis is a developmental craniofacial defect in which one or more sutures of the skull fuse together prematurely. Uncorrected craniosynostosis may have serious complications including elevated intracranial pressure, developmental delay, and blindness. Proper diagnosis of craniosynostosis requires a physical examination of the head with assessment for symmetry and palpation of sutures for prominence. Often, if craniosynostosis is suspected, computed tomography (CT) imaging will be obtained. Recent literature has posited that this is unnecessary. This study aims to address whether physical examination alone is sufficient for the diagnosis and treatment planning of single suture craniosynostosis. Between 2015 and 2022, the Divisions of Pediatric Neurosurgery and Pediatric Plastic Surgery at UTHealth Houston evaluated 140 children under 36 months of age with suspected craniosynostosis by physical examination and subsequently ordered CT imaging for preoperative planning. Twenty-three patients received a clinical diagnosis of multi-sutural or syndromic craniosynostosis that was confirmed by CT. One hundred seventeen patients were diagnosed with single suture craniosynostosis on clinical examination and follow-up CT confirmed suture fusion in 109 (93.2%) patients and identified intracranial anomalies in 7 (6.0%) patients. These patients underwent surgical correction. Eight (6.8%) patients showed no evidence of craniosynostosis on CT imaging. Treatment for patients without fused sutures included molding helmets and observation alone. This evidence suggests that physical examination alone may be inadequate to accurately diagnose single suture synostosis, and surgery without preoperative CT evaluation could lead to unindicated procedures.

Surface Cranial Ultrasound: The Natural Heir to X-Ray for the Screening of Skull Deformities in Infants

PURPOSE

Volumetric tomography (3D-CT) is currently considered the gold standard for the diagnosis of craniosynostosis, but its use as the first-line examination for cranial deformities is a topic of debate, because of skull X-ray radiation and low sensitivity and specificity. Cranial ultrasound is an emerging noninvasive radiation-free alternative, but its diagnostic accuracy still needs confirmation.

MATERIALS AND METHODS

The present prospective study included 350 infants with skull deformities, who underwent cranial ultrasound as the first-line examination, followed by 3D-CT if the echography results was positive or unclear. If the results were negative, infants underwent physical treatment and follow-up. To evaluate ultrasound reliability, we focused on cases that underwent both the index test and the gold standard and performed a double-blind comparison of the echography and 3D-CT results.

RESULTS

Ultrasound documented patent sutures in 293 infants and 9 had inconclusive results. The 293 ultrasound-negative infants were followed clinically: all improved, except 28 that underwent 3D-CT. In all of these cases, 3D-CT confirmed the ultrasonography results (no false negatives). 48 infants showed premature suture closure and underwent 3D-CT: 47 were confirmed (true positive), 1 was false positive. The sensitivity was 100%, the specificity was 99.7%, the positive and negative predictive values were 97.9% and 100%, respectively, the accuracy was 99.7%, and the diagnostic test evaluation was conclusive.

CONCLUSION

The study documented the high sensitivity and specificity of echography for the diagnosis of craniosynostosis in a referral center, with better results being achieved before 6 months of age. Major limitations are the loss of diagnostic significance as the child grows and the learning curve needed. The advantages are avoidance of radiation and chance to evaluate the brain at the same time.

Commensal Microbiota Effects on Craniofacial Skeletal Growth and Morphology

Microbes colonize anatomical sites in health to form commensal microbial communities (e.g., commensal gut microbiota, commensal skin microbiota, commensal oral microbiota). Commensal microbiota has indirect effects on host growth and maturation through interactions with the host immune system. The commensal microbiota was recently introduced as a novel regulator of skeletal growth and morphology at noncraniofacial sites. Further, we and others have shown that commensal gut microbes, such as segmented filamentous bacteria (SFB), contribute to noncraniofacial skeletal growth and maturation. However, commensal microbiota effects on craniofacial skeletal growth and morphology are unclear. To determine the commensal microbiota's role in craniofacial skeletal growth and morphology, we performed craniometric and bone mineral density analyses on skulls from 9-week-old female C57BL/6T germ-free (GF) mice (no microbes), excluded-flora (EF) specific-pathogen-free mice (commensal microbiota), and murine-pathogen-free (MPF) specific-pathogen-free mice (commensal microbiota with SFB). Investigations comparing EF and GF mice revealed that commensal microbiota impacted the size and shape of the craniofacial skeleton. EF versus GF mice exhibited an elongated gross skull length. Cranial bone length analyses normalized to skull length showed that EF versus GF mice had enhanced frontal bone length and reduced cranial base length. The shortened cranial base in EF mice was attributed to decreased presphenoid, basisphenoid, and basioccipital bone lengths. Investigations comparing MPF mice and EF mice demonstrated that commensal gut microbes played a role in craniofacial skeletal morphology. Cranial bone length analyses normalized to skull length showed that MPF versus EF mice had reduced frontal bone length and increased cranial base length. The elongated cranial base in MPF mice was due to enhanced presphenoid bone length. This work, which introduces the commensal microbiota as a contributor to craniofacial skeletal growth, underscores that noninvasive interventions in the gut microbiome could potentially be employed to modify craniofacial skeletal morphology. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Postoperative computed tomography imaging of pediatric patients with craniosynostosis: radiation dose and image quality comparison between multi-slice computed tomography and O-arm cone-beam computed tomography

BACKGROUND

When postoperative multi-slice computed tomography (MSCT) imaging of patients with craniosynostosis is used, it is usually performed a few days after surgery in a radiology department. This requires additional anesthesia for the patient. Recently, intraoperative mobile cone-beam CT (CBCT) devices have gained popularity for orthopedic and neurosurgical procedures, which allows postoperative CT imaging in the operating room.

OBJECTIVE

This single-center retrospective study compared radiation dose and image quality of postoperative imaging performed using conventional MSCT scanners and O-arm CBCT.

MATERIALS AND METHODS

A total of 104 pediatric syndromic and non-syndromic patients who were operated on because of single- or multiple-suture craniosynostosis were included in this study. The mean volumetric CT dose index (CTDIvol) and dose-length product (DLP) values of optimized craniosynostosis CT examinations (58 MSCT and 46 CBCT) were compared. Two surgeons evaluated the subjective image quality.

RESULTS

CBCT resulted in significantly lower CTDIvol (up to 14%) and DLP (up to 33%) compared to MSCT. Multi-slice CT image quality was considered superior to CBCT scans. However, all scans were considered to be of sufficient quality for diagnosis.

CONCLUSION

The O-arm device allowed for an immediate postoperative CBCT examination in the operating theater using the same anesthesia induction. Radiation exposure was lower in CBCT compared to MSCT scans, thus further encouraging the use of O-arms. Cone-beam CT imaging with an O-arm is a feasible method for postoperative craniosynostosis imaging, yielding less anesthesia to patients, lower health costs and the possibility to immediately evaluate results of the surgical operation.

Time course of sutural width during the physiological growth from birth to adulthood: CT quantitative and qualitative evaluations of sutural arches

PURPOSE

We performed a retrospective qualitative and quantitative evaluation of the sutural changes during the physiological growth to define the age-related ossification stages of major and minor skull sutures or synchondroses.

METHODS

A total of 390 healthy subjects, examined for cranio-facial trauma and whose CT scans turned out to be normal, were clustered into homogenous age-matched groups ranged from birth to 90 years. High-resolution CT was used to assess the degree of sutural closure according to a 3-grade scoring system, the sutural pattern, the width, and the density of the gap calculated as the average of two or three ROIs along each suture/synchondrosis.

RESULTS

The identification of a definite pattern depended on the suture's type, the closure degree, and the width of the gap (p < 0.001). The interdigitation process was more intricate for most of vault sutures than the skull base sutures/synchondroses. Closing grades 1, 2, and 3 were associated to an identifiable sutural pattern and the cutoff value of 1.45 mm of the gap width allowed to detect an identifiable sutural pattern with the best combination of sensitivity (97%) and specificity (98%). Age and sutural closing degree were inversely related to gap width while positively related to the gap density (p < 0.001).

CONCLUSION

The sutural ossification is an age-related process, distinctive for each suture, and synchondrosis; it occurs neither according to a predefined order along sutural arches nor following a sequential distribution in the cranial fossae, and some sutures continued their growth process during lifetime.

Moderne Behandlung von Kraniosynostosen

Hintergrund

Bei 13–48 % aller Lebendgeborenen treten Auffälligkeiten der Schädelform auf. Meistens ist ein lagerungsbedingter Plagiozephalus ursächlich. Bei vorzeitigem Verschluss von Schädelnähten resultieren pathognomische Deformitäten durch das kompensatorische Wachstum der umgebenden Schädelknochen. Es muss zwischen Einzelnahtsynostosen und Kraniosynostosen im Rahmen syndromaler Erkrankungen unterschieden werden.

Ziel

Diese Arbeit soll einen Überblick über Diagnostik, konservative und chirurgische Therapie von Kraniosynostosen geben.

Methoden

Narratives Review.

Ergebnis

Bei Verdacht auf eine Kraniosynostose erfolgt zunächst die klinische Beurteilung und Einschätzung durch erfahrene Untersucher. Die pathognomische Schädelform ergibt die Arbeitsdiagnose. Bestätigt wird diese durch Verfahren wie 3D-Stereofotografie und Sonographie. In komplexen Fällen können CT oder MRT notwendig sein.

Die Indikation für eine Therapie ergibt sich aus ästhetischen Gesichtspunkten und der Vorbeugung psychosozialer Folgen. Bei syndromalen Formen besteht diese insbesondere zur Vermeidung möglicher Folgen eines erhöhten Hirndrucks.

Besteht die Indikation zur Operation muss zwischen endoskopischer und offener Technik unterschieden werden. Unterschiede bestehen hier hinsichtlich Invasivität und möglichem Korrekturausmaß. Im Anschluss an die operative Behandlung schließt sich häufig eine Helmtherapie an, um das bestmögliche Ergebnis zu erreichen. Die anschließende Follow-up-Periode erstreckt sich mindestens bis zum 12. Lebensjahr. Insgesamt sollte die Behandlung im Team mit Neurochirurgen, Mund‑, Kiefer‑, Gesichtschirurgen, Kinderärzten, Augenärzten und Humangenetikern stattfinden.

[Difficulties in differential diagnosis of sagittal synostosis (scaphocephaly)]

Craniosynostosis is characterized by congenital absence or premature closure of skull sutures. The most common form of craniosynostosis is synostosis of sagittal suture followed by scaphocephaly. There are some head deformities similar to scaphocephaly such as positional and constitutional dolichocephaly, etc. These patients have no sagittal suture synostosis. However, there are difficulties in differential diagnosis between these deformities and scaphocephaly.

OBJECTIVE

To develop differential diagnostic criteria between dolichocephalic head deformities and true scaphocephaly following sagittal synostosis.

MATERIAL AND METHODS

The study included 33 patients with dolichocephaly (25 (75.8%) boys and 8 (24.2%) girls) between December 2013 and August 2022. The inclusion criterion was available CT or ultrasound data confirming or excluding sagittal synostosis. Age of patients was 8.62±7.71 (1.77-36) months. We analyzed anamnestic, clinical and radiological data. Radiological data was compared with diagnostic findings in 20 patients with scaphocephaly. Both groups were comparable in age, gender and cranial index.

RESULTS

We present clinical and radiological signs, as well as algorithm for differential diagnosis between scaphocephaly and dolichocephaly.

CONCLUSION

There are objective difficulties in differential diagnosis between scaphocephaly following sagittal synostosis and dolichocephalic head deformities. In most cases, we cannot establish the cause of congenital forms of dolichocephaly. The most likely causes may be pre- and postnatal compressive and positional effects. Ultrasound of skull sutures is preferable for differential diagnosis between these abnormalities. Correction of dolichocephaly can be carried out according to aesthetic indications with individual cranial orthoses.

A case-control study on the driving factors of childhood brain volume loss: What pediatricians must explore

BACKGROUND

The brain volume loss also known as brain atrophy is increasingly observed among children in the course of performing neuroimaging using CT scan and MRI brains. While severe forms of brain volume loss are frequently associated with neurocognitive changes due to effects on thought processing speed, reasoning and memory of children that eventually alter their general personality, most clinicians embark themselves in managing the neurological manifestations of brain atrophy in childhood and less is known regarding the offending factors responsible for developing pre-senile brain atrophy. It was therefore the goal of this study to explore the factors that drive the occurrence of childhood brain volume under the guidance of brain CT scan quantitative evaluation.

METHODS

This study was a case-control study involving 168 subjects with brain atrophy who were compared with 168 age and gender matched control subjects with normal brains on CT scan under the age of 18 years. All the children with brain CT scan were subjected to an intense review of their birth and medical history including laboratory investigation reports.

RESULTS

Results showed significant and influential risk factors for brain atrophy in varying trends among children including age between 14-17(OR = 1.1), male gender (OR = 1.9), birth outside facility (OR = 0.99), immaturity (OR = 1.04), malnutrition (OR = 0.97), head trauma (OR = 1.02), maternal alcoholism (OR = 1.0), antiepileptic drugs & convulsive disorders (OR = 1.0), radiation injury (OR = 1.06), space occupying lesions and ICP (OR = 1.01) and birth injury/asphyxia (OR = 1.02).

CONCLUSIONS

Pathological reduction of brain volume in childhood exhibits a steady trend with the increase in pediatric age, with space occupying lesions & intracranial pressure being the most profound causes of brain atrophy.

Update in Management of Craniosynostosis

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the craniofacial dysmorphology of craniosynostosis, and the variation of each type. 2. Identify the functional concerns and learn the rationale behind timing of operative intervention. 3. Approach each dysmorphology critically and identify the operative intervention needed to improve form and function 4. Understand and address the specific issues related to syndromic craniosynostosis and be able to delineate management plan.

SUMMARY

Craniosynostosis is a condition in which premature fusion of one or more cranial sutures lead to abnormal head shape and growth restriction of the brain. Nonsyndromic craniosynostosis occurs in isolation, and usually involves a single suture, whereas syndromic craniosynostosis may involve multiple sutures and is associated with extracraniofacial findings. Although surgical management can be similar, the treatment plan must take into consideration issues specific to the syndromes. This article aims to provide a concise overview of the authors' current understanding regarding the presentation, treatment principle, surgical option, and debates in craniosynostosis.

Application of Deep Learning Techniques for Automated Diagnosis of Non-Syndromic Craniosynostosis Using Skull X-Ray

ABSTRACT

Non-syndromic craniosynostosis (NSCS) is a disease, in which a single cranial bone suture is prematurely fused. The early intervention of the disease is associated with a favorable outcome at a later age, so appropriate screening of NSCS is essential for its clinical management. The present study aims to develop a classification and detection system of NSCS using skull X-ray images and a convolutional neural network (CNN) deep learning framework. A total of 56 NSCS cases (scaphocephaly [n = 17], trigonocephaly [n = 28], anterior plagiocephaly [n = 8], and posterior plagiocephaly [n = 3]) and 25 healthy control infants were included in the study. All the cases underwent skull X-rays and computed tomography scan for diagnosis in our institution. The lateral views obtained from the patients were retrospectively examined using a CNN framework. Our CNN model classified the 4 NSCS types and control with high accuracy (100%). All the cases were correctly classified. The proposed CNN model may offer a safe and high-sensitivity screening of NSCS and facilitate early diagnosis of the disease and better neurocognitive outcome for patients.

Gnas Loss Causes Chondrocyte Fate Conversion in Cranial Suture Formation

Calvaria development is distinct from limb formation. Craniosynostosis is a skull deformity characterized by premature cranial suture fusion due to the loss of the GNAS gene and, consequently, its encoded protein Gαs. This birth defect requires surgery, with potential lethal consequences. So far, hardly any early-stage nonsurgical interventions for GNAS loss-related craniosynostosis are available. Here, we investigated the role of the Gnas gene in mice in guarding the distinctiveness of intramembranous ossification and how loss of Gnas triggered endochondral-like ossification within the cranial sutures. Single-cell RNA sequencing (scRNA-seq) of normal neonatal mice cranial suture chondrocytes showed a Hedgehog (Hh) inactivation pattern, which was associated with Gαs signaling activation. Loss of Gnas evoked chondrocyte-to-osteoblast fate conversion and resulted in cartilage heterotopic ossification (HO) within cranial sutures and fontanels of the mouse model, leading to a skull deformity resembling craniosynostosis in patients with loss of GNAS. Activation of ectopic Hh signaling within cranial chondrocytes stimulated the conversion of cell identity through a hypertrophy-like stage, which shared features of endochondral ossification in vivo. Reduction of Gli transcription activity by crossing with a loss-of-function Gli2 allele or injecting GLI1/2 antagonist hindered the progression of cartilage HO in neonatal stage mice. Our study uncovered the role of Gαs in maintaining cranial chondrocyte identity during neonatal calvaria development in mice and how reduction of Hh signaling could be a nonsurgical intervention to reduce skull deformity in craniosynostosis due to loss of GNAS.

Examining the Role of Early Diagnostic Imaging for Craniosynostosis in the Era of Endoscopic Suturectomy: A Single Institution Experience

ABSTRACT

Endoscopic suturectomy is a minimally invasive surgical treatment for single-suture craniosynostosis in children between 1 and 4 months of age. This study sought to characterize the role played by diagnostic imaging in facilitating early surgical management with endoscopic suturectomy. The authors also characterized the overall diagnostic utility of imaging in patients assessed for abnormal head shape at their institution, regardless of surgical status. A retrospective cohort of children diagnosed with single-suture synostosis undergoing either primary endoscopic suturectomy or open calvarial reconstruction at the authors' institution from 1998 to 2018 was first reviewed. Of 132 surgical patients, 53 underwent endoscopic suturectomy and 79 underwent open repair. There was no difference in the proportion of endoscopic and open surgery patients imaged preoperatively before (24.5% versus 35.4%; P = 0.24) or after (28.3% versus 25.3%; P = 0.84) craniofacial assessment. Stratifying by historical epoch (1998-2010 versus 2011-2018), there was also no difference found between preoperative imaging rates (63.6% versus 56.4%; P = 0.35). In another cohort of 175 patients assessed for abnormal head shape, 26.9% were imaged to rule out craniosynostosis. Positive diagnostic imaging rates were recorded for suspected unicoronal (100%), metopic (87.5%), lambdoidal (75.0%), sagittal (63.5%), multi-suture (50%), and bicoronal (0%) synostosis. The authors conclude that the use of diagnostic imaging at their institution has not increased despite higher utilization of endoscopic suturectomy and need for expedient identification of surgical candidates. However, their results suggest that imaging may play a greater diagnostic role for suspected bicoronal, sagittal, and multi-sutural synostosis among sutural subtypes of synostosis.

Epidemiology of Hospital Admissions for Craniosynostosis in Australia: A Population-Based Study

To describe trends, age, and sex-specific patterns of population hospital admissions with a diagnosis of craniosynostosis (CS) in Australia.

Population data for hospital separations (in-patient) from public and private hospitals (July 1996-June 2018) were obtained from the publicly available Australian Institute of Health and Welfare (AIHW) National Hospital Morbidity Database.

The outcome variables were hospital separation rates (HSR) (number of hospital separations divided by the estimated resident population [ERP] per year) and average length of stay (aLOS) (patient days divided by the number of hospital separations) with a diagnosis of CS. Trends in HSR and aLOS adjusted for age, sex, and type of CS were investigated by negative binomial regression presented as annual percent change (APC).

In 8057 admissions identified, we observed no significant change in the annual trend for HSR for the 22-year period. However, a marginal annual decrease of 1.6% (95% CI: -0.7, -2.4) in the aLOS was identified for the same time period. HSR were higher for males, infants, and single suture synostosis. aLOS was 3.8 days (95% CI: 3.8, 3.9) per visit, longer for syndromic conditions.

There was a minor reduction in the average length of hospital stay for CS over the 22-year period potentially indicative of improved care. Population-level information on hospitalisations for rare craniofacial conditions can inform research, clinical, and surgical practice.

Novel Screening and Monitoring Techniques for Deformational Plagiocephaly: A Systematic Review

This article summarizes the current state of diagnostic modalities for infant craniofacial deformities and highlights capable diagnostic tools available currently to pediatricians.

Management of Lambdoid Craniosynostosis: A Comprehensive and Systematic Review

BACKGROUND

Craniosynostosis is a condition characterized by the premature fusion of 2 or more skull bones. Craniosynostosis of the lambdoid suture is one of the rarest forms, accounting for 1-4% of all craniosynostoses. Documented cases are separated into simple (single suture), complex (bilateral), and associated with adjacent synostoses ("Mercedes Benz" Pattern) or syndromes (i.e., Crouzon, Sathre-Chotzen, Antley-Bixler). This condition can manifest phenotypic deformities and neurological sequelae that can lead to impaired cognitive function if improperly treated or left undiagnosed. Preferred surgical techniques have varied over time but all maintain the common goals of establishing proper head shape and preventing of complications that could contribute to aforementioned sequelae.

SUMMARY

This comprehensive review highlights demographic distributions, embryological development, pathogenesis, clinical presentation, neurological sequelae, radiologic findings, surgical techniques, surgical outcomes, and postoperative considerations of patients with lambdoid craniosynostosis presentation. In addition, a systematic review was conducted to explore the operative management of lambdoid craniosynostosis using PubMed, Embase, and Scopus databases, with 38 articles included after screening. Key Messages: Due to a low volume of published cases, diagnosis and treatment can vary. Large overlap in presentation can occur in patients that display lambdoid craniosynostosis and posterior plagiocephaly, furthering the need for comprehensive analysis. Possessing the knowledge and tools to properly assess patients with lambdoid craniosynostosis will allow for more precise care and improved outcomes.

Multisuture and syndromic craniosynostoses: Simplifying the complex

Most complex craniosynostoses are managed the same way as syndromic craniosynostoses (SCs), as these patients often experience similar problems regarding cognition and increased intracranial pressure (ICP). The evaluation and treatment plan for craniosynostoses is complex, and this, additionally, is complicated by the age at presentation. In this article, the authors review the complexity of SCs in the presentation and management. An algorithm is necessary for such multifaceted and multidimensional pathology as craniosynostoses. In most algorithms, posterior calvarial distraction is a consistent early option for complex craniosynostoses presenting early with raised ICP. Addressing the airway early is critical when significant airway issues are there. All other surgical interventions are tailored on the basis of presentation and age.

Postnatal diagnosis of single-suture craniosynostosis with cranial ultrasound: a systematic review

INTRODUCTION

The optimal protocol for diagnostic workup of craniosynostosis and the role of specific imaging modalities remain controversial. Skull X-rays and 3-dimensional head CTs are options when physical exam is equivocal but involve ionizing radiation. Ultrasound has emerged as an alternative modality for visualization of cranial sutures, but its use is not widespread.

METHODS

The authors performed a systematic review of the literature on the use of ultrasound for the diagnosis of craniosynostosis.

RESULTS

A total of 12 studies involving 1062 patients were included. Overall, 300 patients (28.2%) were diagnosed with craniosynostosis. A total of 369 (34.7%) patients had their diagnosis (craniosynostosis vs. patent sutures) confirmed with another imaging modality in addition to ultrasound. Among studies, the specificity of ultrasound ranged from 86 to 100%, and the sensitivity from 71 to 100%.

CONCLUSIONS

Ultrasonography of cranial sutures is a feasible and accurate tool for the diagnosis of single-suture craniosynostosis when physical exam findings are insufficient. Although technical aspects of ultrasonography and its interpretation have an associated learning curve, ultrasound can achieve high sensitivity and specificity among patients with suspected craniosynostosis.

Facial Suture Pathology in Syndromic Craniosynostosis: Human and Animal Studies

BACKGROUND

Facial deformities in syndromic craniosynostosis are not only functionally, psychosocially, and aesthetically impairing but also notoriously challenging to reconstruct. Whether facial suture synostosis plays a significant role in the pathogenesis of these deformities is inadequately studied in human patients.

METHODS

The MEDLINE database was queried using a methodologically generated search term inventory. Article inclusion was adjudicated by 2 authors after independent review. Articles provided insight into facial suture involvement in either syndromic craniosynostosis patients or animal models of disease.

RESULTS

Comprehensive review yielded 19 relevant articles meeting inclusion criteria. Mid-20th century craniofacial biologists characterized how patent facial sutures are essential for normal postnatal facial development. They also posited that premature ossification disrupts growth vectors, causing significant dysmorphologies. Recently, facial suture synostosis was found to cause midfacial deformities independent of cranial base pathology in mouse models of syndromic craniosynostosis. Few recent studies have begun exploring facial suture involvement in patients, and although they have paved the way for future research, they bear significant limitations.

CONCLUSIONS

The hypothesis that facial suture synostosis acts in conjunction with cranial base pathology to produce the prominent, multifocal facial deformities in syndromic craniosynostosis may fundamentally alter surgical management and warrants further investigation. Methodically evaluating the literature, this review synthesizes all basic science and human clinical research thus far on the role of facial sutures in syndromic craniosynostosis and elucidates important topics for future research. We ultimately identify the need for rigorous imaging studies that longitudinally evaluate facial osteology across patients with various craniosynostosis syndromes.

Computed Tomography in Patients With Craniosynostosis: A Survey to Ascertain Practice Patterns Among Craniofacial Surgeons

BACKGROUND

In patients with craniosynostosis, imaging remains up to the discretion of the plastic surgeon or neurosurgeon. To inform best practice guidelines, we sought to obtain data surrounding the frequency at which craniofacial surgeons order computed tomography (CT), as well as indications. We hypothesized that we would identify considerable variation in both imaging and associated indications.

METHODS

We surveyed members of the American Society of Maxillofacial Surgeons and the American Society of Craniofacial Surgeons to measure the frequency of preoperative and postoperative head CTs, as well as indications. Initial items were piloted with 2 craniofacial surgeons and 1 neurosurgeon, using interviews to ensure content validity. χ2 Tests were used to measure associations between operative volume, years in practice, and imaging.

RESULTS

Eighty-five craniofacial surgeons responded (13.8% response rate), with the majority (63.5%) having performed a craniosynostosis operation in the last month. Only 9.4% of surgeons never order preoperative CTs. Of those who do, the most common indications included diagnosis confirmation (31.2%) and preoperative planning (27.3%). About 25% of surgeons always obtain postoperative head CTs, usually to evaluate surgical outcomes (46.7%). Only 13.3% of respondents order 2 or more postoperative scans. Higher operative volume was associated with a lower likelihood of ordering preoperative head CTs (P = 0.008).

CONCLUSIONS

The majority of surgeons obtain preoperative head CTs, whereas only 25% obtain CTs postoperatively, often to evaluate outcomes. Because outcomes may be evaluated clinically, this is a poor use of resources and exposes children to radiation. Consensus guidelines are needed to create best practices and limit unnecessary studies.

Computed tomography associated radiation exposure in children with craniosynostosis

BACKGROUND

The role of computed tomography (CT) for diagnosis and surgical planning for craniosynostosis (CS) is well-established. The aim of this study was to quantify the cumulative medical radiation exposure from CT in patients with CS at a tertiary care children's hospital.

METHODS

Medical records of patients who presented at < 2 years of age and underwent surgical intervention for CS were examined for demographic information. Effective radiation dose (ERD) in mSv was calculated for each head CT. Descriptive statistics and ANOVA were performed. Mean ± SD is reported; p < 0.05 was considered significant.

RESULTS

Two hundred seventy-two patients met inclusion criteria: 241 nonsyndromic and 31 with syndromic diagnoses. For nonsyndromic patients, mean age at first head CT was 6.0 ± 4.9 months, mean number of CT scans obtained was 2.1 ± 1.1, and the mean total combined ERD was 9.1 ± 4.8 mSv. CT scans obtained at < 6 months of age had a significantly greater ERD than those obtained at > 6 months, 5.3 ± 1.9 versus 4.3 ± 1.4 mSv, respectively (p = 0.001).

CONCLUSIONS

Patients with nonsyndromic CS undergo 2 CT scans on average related to their diagnosis, with a mean total ERD of 9.1 mSv; this is equivalent to 1.5 years of the average annual background radiation dose a person living in the USA will encounter from environmental radiation, medical exposures, and consumer products. A CT obtained at < 6 months is associated with a higher ERD; thus, we recommend delaying imaging from the initial presentation to the time of pre-operative planning when possible.

Neuroimaging for the Primary Care Provider: A Review of Modalities, Indications, and Pitfalls

When evaluating a child with a potential neurologic or neurodevelopmental disorder, identifying indications for imaging and the correct imaging modality to order can be challenging. This article provides an overview of computed tomography, MRI, ultrasonography, and radiography with an emphasis on indications for use, pitfalls to be avoided, and recent advances. A discussion of the appropriate use of ionizing radiation, intravenous contrast, and sedation is also provided.

Cranial Suture Evaluation on Routine Pediatric MRI

PURPOSE

The efficacy of magnetic resonance imaging (MRI) for evaluating sutures has not been well studied. CT with 3-dimensional reformats is currently the preferred modality for imaging the major cranial sutures. The role of MRI is primarily is for evaluating the brain for any concurrent malformations. Our objective was to evaluate the reliability of MRI when compared to CT for evaluation of cranial sutures.

METHODS

A list of 500 consecutive patients who underwent an MRI as well as a CT study was obtained. Studies were done between January 2011 and December 2016. The inclusion criteria required the 2 studies to be performed within 3 months of each other. All MRI studies were reviewed by a pediatric neuroradiologist to determine whether the sagittal, coronal, and lambdoid sutures were patent, fused or could not be assessed with confidence. In cases where a confident determination could not be made, the studies were reviewed with another pediatric neuro-radiologist and a decision made in concurrence. The CT scans were then evaluated in a similar fashion, after the MRI review was completed. The CT and MRI results were then compared to determine the accuracy of the MRI in assessing the sutures.

RESULTS

Mean age of the studied children was 8.54 years. Seventy-two percent of the sagittal sutures were seen. When seen the sagittal suture was correctly identified in 98% of cases as either fused or patent. The lambdoid suture was seen in 94.3% of studies and was correctly designated as patent or fused in 99.6% of that subset of cases. The coronal suture was seen in 66.3% of the cases and when seen was always (100%) correctly designated. The probability of agreement between MRI and CT increased with age. The probability of sutures which were not seen decreased with age. The false negative and positives remained low for all ages.

CONCLUSIONS

MRI is a viable tool for detection of cranial sutures. The 3-dimensional T1 Weighted sequence was particularly useful in suture evaluation. Although the visibility of sutures is inferior to that on a CT scan, if detected, the accuracy scan is fairly accurate in establishing fusion vs patency. It should be a part of routine surveillance on every pediatric neuro MRI study given the neurocognitive implications of incidental sutural synostosis.