How ultrasonography can contribute to diagnosis of craniosynostosis

Imaging approach to pediatric calvarial bulges

Palpable calvarial lesions in children may require multi-modality imaging for adequate characterization due to non-specific clinical features. Causative lesions range from benign incidental lesions to highly aggressive pathologies. While tissue sampling may be required for some lesions, others have a typical imaging appearance, and an informed imaging approach facilitates diagnosis. This review illustrates imaging findings of common and clinically important focal pediatric calvarial bulges to aid the radiologist in narrowing the differential diagnosis and directing appropriate referral. We focus on birth-related lesions, congenital abnormalities, and modeling disturbances (i.e., those that produce a change in calvarial contour early in development), normal variants, and neoplastic lesions with their mimics.

Predictive Value of Sonographic Parameters on the Effects of Cranial Molding Helmet Therapy in Infants with Positional Plagiocephaly

Positional plagiocephaly is a deformational cranial flattening frequently treated in pediatric neurosurgical practice. Positional maneuvers and orthotic helmet therapy are preferred therapeutic options for moderate-to-severe forms. Treatment response seems to be age-dependent. Nevertheless, predictive data are vague, and cost-efficiency might be a limiting factor for treatment. The purpose of this study was to investigate the early predictive value of sonographic parameters on the efficacy of orthotic helmet therapy through the assessment of changes in skull shape and correlation of the parameters with caliper cephalometry values and with age. A consecutive cohort of 49 patients < 10 months of age, undergoing orthotic helmet therapy for positional plagiocephaly, was recruited prospectively. The authors routinely assessed the patency of the lambdoid sutures by ultrasound and the following additional skull parameters were measured: suture width, adjacent full bone thickness, adjacent cortical bone thickness and occipital angle. Caliper cephalometric values, as well as demographic and clinical data were collected. Retrospective data analysis showed an inverse relation between both cortical and full skull bone thickness and early treatment efficacy, defined by a reduction in the occipital angle. The improvement of sonographic parameters correlated with the development of cranial caliper cephalometry values. In conclusion, the sonographic assessment of skull bone thickness is a safe and cost-effective tool to predict the early efficacy of orthotic helmet therapy in positional plagiocephaly and might, therefore, help the clinician to foresee the potential evolution of the deformity.

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.

[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.

Quantitative ultrasonographic diagnostics for midface and mandible fractures

The aim of this study was to examine whether ultrasonography and three-dimensional radiological procedures produce significantly different measurement results with respect to fracture dislocation. This was a retrospective study of patients who were admitted to the department for oral and maxillofacial surgery of the Medical Highschool Hannover with facial skull fracture and underwent high-resolution computed tomography and ultrasonography imaging during a period from 1 January 2019 to 31 August 2019. A 10 mHz transducer was used for fracture imaging, and the largest dislocation of each fracture was measured. A paired t-test for dependent samples was used for statistical evaluation of the measured differences, and the p-value was set at 0.05. A total of 16 patients with 29 fractures were included. The fractures were characterized as follows: zygomatic arch (n = 7), lateroorbital region (n = 4), maxilla/zygomatic bone (n = 15), mandible (n = 2), and frontal sinus (n = 1). Regardless of the fracture location, we found no statistical difference in fracture measurements between the ultrasonography and the computed tomography (p = 0.17 (fractures of the zygomatic arch) to p = 0.85 (all fractures)). The study findings suggest that ultrasonography not only allows basic detection but also a quantification of the dislocation in facial skull fractures. The ultrasonography results are not significantly different from those of the computed tomography. In everyday clinical practice, ultrasonography of facial fractures can be considered an adequate imaging procedure. If used correctly, additional radiation exposure to the patient can be avoided, thus representing a diagnostic alternative to computed tomography.

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.

Preoperative imaging patterns and intracranial findings in single-suture craniosynostosis: a study from the Synostosis Research Group

OBJECTIVE

The diagnosis of single-suture craniosynostosis can be made by physical examination, but the use of confirmatory imaging is common practice. The authors sought to investigate preoperative imaging use and to describe intracranial findings in children with single-suture synostosis from a large, prospective multicenter cohort.

METHODS

In this study from the Synostosis Research Group, the study population included children with clinically diagnosed single-suture synostosis between March 1, 2017, and October 31, 2020, at 5 institutions. The primary analysis correlated the clinical diagnosis and imaging diagnosis; secondary outcomes included intracranial findings by pathological suture type.

RESULTS

A total of 403 children (67% male) were identified with single-suture synostosis. Sagittal (n = 267), metopic (n = 77), coronal (n = 52), and lambdoid (n = 7) synostoses were reported; the most common presentation was abnormal head shape (97%), followed by a palpable or visible ridge (37%). Preoperative cranial imaging was performed in 90% of children; findings on 97% of these imaging studies matched the initial clinical diagnosis. Thirty-one additional fused sutures were identified in 18 children (5%) that differed from the clinical diagnosis. The most commonly used imaging modality by far was CT (n = 360), followed by radiography (n = 9) and MRI (n = 7). Most preoperative imaging was ordered as part of a protocolized pathway (67%); some images were obtained as a result of a nondiagnostic clinical examination (5.2%). Of the 360 patients who had CT imaging, 150 underwent total cranial vault surgery and 210 underwent strip craniectomy. The imaging findings influenced the surgical treatment 0.95% of the time. Among the 24% of children with additional (nonsynostosis) abnormal findings on CT, only 3.5% required further monitoring.

CONCLUSIONS

The authors found that a clinical diagnosis of single-suture craniosynostosis and the findings on CT were the same with rare exceptions. CT imaging very rarely altered the surgical treatment of children with single-suture synostosis.

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.

Sutures ultrasound: useful diagnostic screening for posterior plagiocephaly

PURPOSE

Posterior plagiocephaly (PP) is a common clinical condition in pediatric age. There are two main causes of PP: postural plagiocephaly and craniosynostosis. Early diagnosis is important, as it prevents neurological complications and emergencies. Diagnosis in the past was often made late and with imaging tests that subjected the infant to a high radiation load. Suture ultrasound does not use ionizing radiation; it is easy to perform, allows an early diagnosis, and directs toward the execution of the cranial 3D-CT scan, neurosurgical consultation, and possible intervention. The aim of the study is to describe the high sensitivity and specificity of suture ultrasound for the differential diagnosis between plagiocephaly and craniosynostosis.

METHODS

We reported our prospective experience and compared it with the data in the literature through a systematic review. The systematic review was conducted on electronic medical databases (PubMed, Embase, Cochrane Library, Scopus, and Web of Science) evaluating the published literature up to November 2020. According to Preferred Reporting Items for Systematic Reviews and Meta-ANALYSES (PRISMA statement), we identified 2 eligible studies. Additionally, according to AMSTAR 2, all included reviews have been critically rated as high quality. A total of 120 infants with abnormal skull shape were examined in NICU. All underwent clinical and ultrasound examination.

RESULTS

Of the total, 105 (87.5%) had plagiocephaly and 15 dolichocephaly/scaphocephaly (12.5%). None of these had associated other types of malformations and/or neurological disorders. The synostotic suture was identified ultrasonographically in 1 infant and subsequently confirmed by 3D CT scan (100%).

CONCLUSION

Cranial sutures ultrasonography can be considered in infants a selective, excellent screening method for the evaluation of skull shape deformities as first technique before the 3D CT scan exam and subsequent neurosurgical evaluation. Cranial suture ultrasonography should be considered part of clinical practice especially for pediatricians.