High-frequency ultrasound confirmation of positional plagiocephaly

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.

[Cranial suture ultrasound for reducing radiation exposure in diagnosis of craniosynostosis in young children]

Currently, there are no standards for examining patients with suspected craniosynostosis. CT of the brain with 3D skull reconstruction is a common approach to diagnose craniosynostosis in many hospitals. This technique in pediatric patients is associated with a high dose of ionizing radiation and prompts searching for other diagnostic methods.

OBJECTIVE

To generalize an experience of cranial suture ultrasound and compare diagnostic capabilities of various ultrasound devices.

MATERIAL AND METHODS

We retrospectively analyzed data of cranial suture ultrasound in 49 patients under the age of 14 months with a suspected craniosynostosis. All patients underwent expert-class ultrasound. Of these, 10 patients underwent middle-class ultrasound. Age of these patients ranged from 2 to 10 months.

RESULTS

According to ultrasound data, we have found 48 synostotic sutures in 42 patients. There were 2 inaccurate results among these 48 sutures. In both cases, expert-class ultrasound confirmed partial closure of cranial sutures while 3D CT revealed their complete closure. Sensitivity and specificity of technique were 95.8% and 100%, respectively. Both expert- and middle-class ultrasound revealed synostotic sutures in 10 children under 1 year old.

CONCLUSION

Our data have shown that ultrasound of cranial sutures may be a first-line imaging technique. This method has high sensitivity and specificity in pediatric patients. Moreover, middle-class ultrasound devices may be used for diagnosis.

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.

The Evolution of the Role of Imaging in the Diagnosis of Craniosynostosis: A Narrative Review

Craniosynostosis, the premature closure of cranial sutures, is one of the principal causes of pediatric skull deformities. It can cause aesthetic, neurological, acoustic, ophthalmological complications up to real emergencies. Craniosynostosis are primarily diagnosed with accurate physical examination, skull measurement and observation of the deformity, but the radiological support currently plays an increasingly important role in confirming a more precise diagnosis and better planning for therapeutic interventions. The clinician must know how to diagnose in the earliest and least invasive way for the child. In the past, technological limitations reduced the choices; today, however, there are plenty of choices and it is necessary to use the various types of available imaging correctly. In the future, imaging techniques will probably rewrite the common classifications we use today. We provide an updated review of the role of imaging in this condition, through the ages, to outline the correct choice for the clinician for an early and non-invasive diagnosis.

Cranial Suture Measurement by 2-point Method in Ultrasound Screening of Craniosynostosis

Background:

Diagnostic imaging for craniosynostosis currently relies entirely on radiation images, but it has been estimated that a risk of cancer from diagnostic x-rays may exist. Use of ultrasound imaging has been reported, but very little has been written on normal findings of the cranial suture. Also, ultrasound diagnostic methods have not been established. To obtain images for the diagnosis of abnormal sutures in craniosynostosis, we investigated the normal ultrasonographic appearance of the suture. To establish screening methods for craniosynostosis, we prepared a 2-point method for simple evaluation and confirmed its usefulness.

Methods:

Ultrasonography was performed in infants with normal head, deformational plagiocephaly, and craniosynostosis. We focused on the measurement indices and decided on the order for making our observations. Furthermore, we developed an evaluation method (2-point method) and recorded our finding in a useful table.

Results:

We could clearly judge whether the cranial suture was patent or closed and were able to measure the suture width. Even for 2-year-old children, the width of the sutures at the points measured exceeded the echocardiographic resolution. By using the 2-point evaluation method, all the sutures could be inspected in about 2 minutes. Sensitivity was 100% and specificity was 95.1%.

Conclusions:

Our present studies showed that normal or abnormal suture can be clearly distinguished by ultrasound. By evaluating the fixed points instead of the whole line, it was possible to shorten the inspection time. Ultrasound screening by applying the 2-point method is very useful.

Positional Skull Deformities

BACKGROUND

Especially in the first 6 months of life, skull deformities manifesting as a uni- or bilateral flattening of the occiput often give rise to questions of differential diagnosis and potential treatment. In this review, the authors summarize the current understanding of risk factors for this condition, and the current state of the relevant diagnostic assessment and options for treatment.

METHODS

The recommendations given in this selective review of the literature are based on current studies and on existing guidelines on the prevention of sudden infant death, the recommendations of the German Society for Pediatric Neurology (Deutsche Gesellschaft für Neuropädiatrie), and the American guidelines on the treatment of positional plagiocephaly in infancy.

RESULTS

Pre-, peri-, and postnatal risk factors can contribute to the development of positional skull deformities. These deformities can be diagnosed and classified on the basis of their clinical features, supplemented in unclear cases by ultrasonography of the cranial sutures. The putative relationship between positional skull deformities and developmental delay is currently debated. The main preventive and therapeutic measure is parent education to foster correct positioning habits (turning of the infant to the less favored side; prone positioning on occasion when awake) and beneficial stimulation of the infant (to promote lying on the less favored side). If the range of motion of the head is limited, physiotherapy is an effective additional measure. In severe or refractory cases, a skull orthosis (splint) may be useful.

CONCLUSION

The parents of children with positional skull deformities should be comprehensively informed about the necessary preventive and therapeutic measures. Treatment should be initiated early and provided in graded fashion, according to the degree of severity of the problem. Parental concern about the deformity should not be allowed to lead to a rejection of the reasonable recommendation for a supine sleeping position.

Genetic advances in craniosynostosis

Craniosynostosis, the premature ossification of one or more skull sutures, is a clinically and genetically heterogeneous congenital anomaly affecting approximately one in 2,500 live births. In most cases, it occurs as an isolated congenital anomaly, that is, nonsyndromic craniosynostosis (NCS), the genetic, and environmental causes of which remain largely unknown. Recent data suggest that, at least some of the midline NCS cases may be explained by two loci inheritance. In approximately 25-30% of patients, craniosynostosis presents as a feature of a genetic syndrome due to chromosomal defects or mutations in genes within interconnected signaling pathways. The aim of this review is to provide a detailed and comprehensive update on the genetic and environmental factors associated with NCS, integrating the scientific findings achieved during the last decade. Focus on the neurodevelopmental, imaging, and treatment aspects of NCS is also provided.

A new ultrasound method for assessment of head shape change in infants with plagiocephaly

Objective

To compare a new ultrasound measurement method with calliper cephalometry in infants with deformational plagiocephaly (DP) and to assess the differences of two methods according to the severity of DP.

Methods

Fifty-two infants with DP were divided into two groups according to the degree of cranial vault asymmetry (CVA); group 1 included 42 infants with CVA over 10 mm, and group 2 included 10 infants with CVA under 10 mm. Cranial vault asymmetry index (CVAI) and occipital angle ratio (OAR) were measured by using calliper and ultrasound measurements, respectively. The occipital angle was defined as the angle between the lines projected along the lambdoid sutures of the skull.

Results

The occipital angles of the affected sides were significantly greater than those of unaffected sides in both groups. The CVAI and OAR were significantly greater in group 1 than in group 2 (CVAI, 9.3%±2.3% vs. 4.6%±1.5%; OAR, 1.05±0.4 vs. 1.01±0.0; p<0.05). The OAR was positively correlated with the CVAI in all infants (r=0.789) and in group 1 (r=0.784; p<0.05).

Conclusion

Our study revealed that OAR using the new ultrasound measurement was positively correlated with the CVAI in infants with DP. Therefore, the occipital angle measurement using ultrasound combined with cephalometry could provide better understanding about the characteristics of the overall cranial bone and lambdoid suture complex in infants with DP.

Craniosynostosis: imaging review and primer on computed tomography

Craniosynostosis is encountered in the pediatric population in isolated or syndromic forms. The resulting deformity depends on the number and type of sutures involved and, in multi-sutural synostosis, the order of suture fusion. Primary craniosynostosis needs to be differentiated from the secondary variety and positional or deformational mimics. Syndromic craniosynostoses are associated with other craniofacial deformities. Evaluation with 3-D CT plays an important role in accurate diagnosis and management; however, implementation of appropriate CT techniques is essential to limit the radiation burden in these children. In this article, the authors briefly review the classification, embryopathogenesis and epidemiology and describe in detail the radiologic appearance and differential diagnoses of craniosynostosis.