Normal and abnormal development of the fetal anterior fontanelle: a three-dimensional ultrasound study

3D Ultrasonic Brain Imaging with Deep Learning Based on Fully Convolutional Networks

Compared to magnetic resonance imaging (MRI) and X-ray computed tomography (CT), ultrasound imaging is safer, faster, and more widely applicable. However, the use of conventional ultrasound in transcranial brain imaging for adults is predominantly hindered by the high acoustic impedance contrast between the skull and soft tissue. This study introduces a 3D AI algorithm, Brain Imaging Full Convolution Network (BIFCN), combining waveform modeling and deep learning for precise brain ultrasound reconstruction. We constructed a network comprising one input layer, four convolution layers, and one pooling layer to train our algorithm. In the simulation experiment, the Pearson correlation coefficient between the reconstructed and true images was exceptionally high. In the laboratory, the results showed a slightly lower but still impressive coincidence degree for 3D reconstruction, with pure water serving as the initial model and no prior information required. The 3D network can be trained in 8 h, and 10 samples can be reconstructed in just 12.67 s. The proposed 3D BIFCN algorithm provides a highly accurate and efficient solution for mapping wavefield frequency domain data to 3D brain models, enabling fast and precise brain tissue imaging. Moreover, the frequency shift phenomenon of blood may become a hallmark of BIFCN learning, offering valuable quantitative information for whole-brain blood imaging.

Anterior Fontanel Size Among Term Newborns: A Systematic Review and Meta-Analysis

Background: Anterior fontanel is an integral element of an infant craniofacial system. There are six fontanels in the newborn skull, namely anterior, posterior, two mastoid, and two sphenoid fontanels. The anterior fontanel is the largest, prominent, and most important for clinical evaluation. Sex, race, genetics, gestational age, and region are the principal factors that influence anterior fontanel size. There exist inconclusive findings on the size of anterior fontanel in newborns. Therefore, this systematic review and meta-analysis aimed to determine the pooled mean size of anterior fontanel among term newborns and to identify the pooled mean difference of anterior fontanel size between males and females.

Methods: PubMed/Medline, Google Scholar, Science Direct, JBI Library, embase, and Cochrane Library databases were systematically searched. All essential data were extracted using a standardized data extraction format. The heterogeneity across studies was assessed using the Cochrane Q test statistic, I² test statistic, and p-values. A fixed-effect model and random effect model were used to estimate the pooled mean size of anterior fontanel and the pooled mean difference between male newborns and female newborns, respectively. To deal with heterogeneity, sub-group analysis, meta-regression analysis, and sensitivity analysis were considered. JBI quality appraisal checklist was used to evaluate the quality of studies.

Results: In this meta-analysis, 8, 661 newborns were involved in twenty-six studies. Among studies, 13 conducted in Asia, 7 in Africa, 5 in America, and 1 in Europe. The pooled mean size of anterior fontanel was 2.58 cm (95% CI: 2.31, 2.85 cm). The pooled mean size of anterior fontanel for Asia, Africa, America, and Europe region was 2.49, 3.15, 2.35, and 2.01 cm, respectively. A statistically significant mean difference was detected between male and female newborns (D + L pooled MD = 0.15 cm, 95% CI: 0.02, 0.29 cm).

Conclusion: The pooled estimate of this review does provide the mean value of the anterior fontanel size in the newborns. There was a statistically significant mean fontanel size difference between male and female newborns. Therefore, male newborns had a significantly larger mean size than female newborns.

Determining Anterior Fontanel Size and Associated Factors Among Term Neonates on the First Day of Life Born at Jimma University Medical Center (JUMC), Southwest Ethiopia: A Linear Regression Model

BACKGROUND

Knowledge of the normal variation in AF size may be helpful to cue early diagnosis of congenital hypothyroidism, hyperthyroidism, cardiac disease, meningitis, degree of dehydration or provide a clue to disorders of neural and skeletal development. However, the data is scarce. Therefore, this study was aimed to determine AF size and associated factors among term neonates on the first day of life born in Jimma University Medical Center (JUMC), Southwest Ethiopia.

METHODOLOGY

An institution-based cross-sectional study design was used to consecutively sample term and health newborns. Descriptive statistics, one-way ANOVA, independent samples t-test and correlation were implemented. Finally, multiple Linear regressions were used to see the association of the dependent and independent variables at 95% confidence interval. The significance level was declared at <0.05 p-value.

RESULTS

The mean AF size of the study population was 3.018 cm with standard deviation (±SD) of 0.909 cm (range 0.4-5.50cm). A multiple linear regression analysis revealed that neonatal birth weight (B=0.001, 95% CI: 0.000-0.001, p=0.000), crown heel length (B=0.048, 95% CI, 0.018-0.078, p=0.002), labor duration (B= -0.028, p=0.001, 95% CI: -0.45; -0.012), and gender of the neonates (B=-0.275, 95% CI: -.441; -.109, p=0.001) were statistically significantly associated with AF size. In a multiple linear regression analysis AF size was explained by independent variables by 54.3%.

CONCLUSIONS

AF size of the study population was 3.018 cm with a standard deviation (±SD) of 0.909 cm. Birth weight, crown heel length, duration of labor, and gender of the neonate were significantly associated with AF size.

Temporal mapping of the closure of the anterior fontanelle and contiguous sutures using computed tomography, in silico models of modern infants

The aim of this study is to quantify and statistically model the age-related decline in the fibrous connective tissue interface of the anterior fontanelle in modern Australian infants, using three-dimensional, semi-automated computed-assisted design protocols. Non-linear regression with variance models, using power functions, combined with quantile regression of the 5th and 95th population percentiles, were utilised to assess absolute anterior fontanelle surface area (AFSA) as a function of age, using multi-slice cranial computed tomography scans obtained from 256 infants aged < 30 months (males: n = 126, females: n = 109) from Brisbane children's hospitals. Normalised AFSA (NFSA), standardised for variation in cephalic size, followed a progressive decline from birth, the greatest velocity change occurring between the 3-6 and 6-9 month cohorts. Growth of the neurocranium is the most significant within the first 8 months postpartum, with a mean increase of 19.03 mm in maximum cranial length and 10.04 mm in breadth. Directionality of fontanelle closure, quantified using spline curves refutes fundamental assumptions that the anterior fontanelle is consistent with a quadrilateral, and contiguous sutures exhibit constant velocity of closure. The present study provides normative values for fontanelle size and diameters as well as new predictive non-linear models for age substantiation, screening of developmental abnormalities and indicators of suspected child maltreatment in modern infants aged birth to 30 months.

Anterior fontanelle size among term neonates on the first day of life born at University of Gondar Hospital, Northwest Ethiopia

Background

Anterior fontanelle is the largest, prominent and most important fontanelle, which is used for clinical evaluation. It is mainly characterized by its size and shape variation and is possibly influenced by gender, race and genetics. Understanding the variation of anterior fontanelle is used for recognition of different medical disorders and abnormal skeletal morphogenesis.

Objective

To determine the mean size of anterior fontanelle among term neonates on the first day of life born at University of Gondar Hospital, Gondar Town, Northwest Ethiopia, 2018.

Methods

Descriptive cross sectional study design was undertaken in 384 term and apparently healthy neonates, using standard methods. Descriptive analysis, student t-test, one way ANOVA and Pearson correlation coefficient were implemented.

Results

In this study, the mean size of anterior fontanelle in term neonates was 3.00 ± 0.62 cm (range 1.70–5.50 cm). The mean size of anterior fontanelle was 3.10 ± 0.66 cm for males, and 2.88 ± 0.57 cm for females. There was statistically significant difference in anterior fontanelle size in neonates of different genders (p<0.001), mode of delivery (p<0.001) and duration of labour (p = 0.006). However, the size of anterior fontanelle was not significantly affected by the birth order, onset of labour and socio-demographic variables of the mother except occupation of the mother (p = 0.01). There was a significant positive correlation between the mean size of anterior fontanelle with birth weight (r = 0.11; p = 0.04) and head circumference (r = 0.17; p = 0.001).

Conclusions

At term, male neonates had significantly larger anterior fontanelle than female neonates and anterior fontanelle size has a direct relationship with birth weight and head circumference.

Size of the anterior fontanelle: three-dimensional measurement of a key trait in human evolution

The anterior fontanelle (AF) is an integral element of the developing human infant craniofacial system. Consideration of the AF is crucial for assessing craniofacial growth, as altered development of this feature may indicate abnormal growth. Moreover, prolonged patency of the AF may represent a derived hominin feature. The AF is regarded as essential for fetal head molding during birth in humans, with deformation of the head during birth often necessary for successful delivery. However, the function of a patent AF among fossil hominins is unclear. Because the AF represents an important structure in both a clinical and evolutionary context, techniques for estimating the size of the AF must be accurate and reproducible. Therefore, we have developed a novel method for assessing surface area of the AF with the goal of creating a more accurate measure of this feature. In this study, we test the accuracy and repeatability of a novel three-dimensional (3D) method for assessing the size of the AF in human infants and compare the results obtained for surface area of the AF using the conventional and 3D methods.

3D ultrasound system to investigate intraventricular hemorrhage in preterm neonates

Intraventricular hemorrhage (IVH) is a common disorder among preterm neonates that is routinely diagnosed and monitored by 2D cranial ultrasound (US). The cerebral ventricles of patients with IVH often have a period of ventricular dilation (ventriculomegaly). This initial increase in ventricle size can either spontaneously resolve, which often shows clinically as a period of stabilization in ventricle size and eventual decline back towards a more normal size, or progressive ventricular dilation that does not stabilize and which may require interventional therapy to reduce symptoms relating to increased intracranial pressure. To improve the characterization of ventricle dilation, we developed a 3D US imaging system that can be used with a conventional clinical US scanner to image the ventricular system of preterm neonates at risk of ventriculomegaly. A motorized transducer housing was designed specifically for hand-held use inside an incubator using a transducer commonly used for cranial 2D US scans. This system was validated using geometric phantoms, US/MRI compatible ventricle volume phantoms, and patient images to determine 3D reconstruction accuracy and inter- and intra-observer volume estimation variability. 3D US geometric reconstruction was found to be accurate with an error of <0.2%. Measured volumes of a US/MRI compatible ventricle-like phantom were within 5% of gold standard water displacement measurements. Intra-class correlation for the three observers was 0.97, showing very high agreement between observers. The coefficient of variation was between 1.8-6.3% for repeated segmentations of the same patient. The minimum detectable difference was calculated to be 0.63 cm(3) for a single observer. Results from ANOVA for three observers segmenting three patients of IVH grade II did not show any significant differences (p > 0.05) for the measured ventricle volumes between observers. This 3D US system can reliably produce 3D US images of the neonatal ventricular system. There is the potential to use this system to monitor the progression of ventriculomegaly over time in patients with IVH.

Three-dimensional printing (3DP) of neonatal head phantom for ultrasound: thermocouple embedding and simulation of bone

A neonatal head phantom, comprising of an ellipsoidal geometry and including a circular aperture for simulating the fontanel was designed and fabricated, in order to allow an objective assessment of thermal rise in tissues during trans-cranial ultrasonic scanning of pre-term neonates. The precise position of a series of thermocouples was determined on the basis of finite-element analysis, which identified crucial target points for the thermal monitoring within the phantom geometry. Three-Dimensional Printing (3DP) was employed for the manufacture of the skull phantom, which was subsequently filled with dedicated brain-mimic material. A novel 3DP material combination was found to be able to mimic the acoustic properties of neonatal skull bone. Similarly, variations of a standard recipe for tissue mimic were examined, until one was found to mimic the brain of an infant. A specific strategy was successfully pursued to embed a thermocouple within the 3DP skull phantom during the manufacturing process. An in-process machine vision system was used to assess the correct position of the deposited thermocouple inside the fabricated skull phantom. An external silicone-made skin-like covering completed the phantom and was manufactured through a Direct Rapid Tooling (DRT) technique.

Surface area measurement using rendered three-dimensional ultrasound imaging: an in-vitro phantom study

OBJECTIVE

Cranial sutures and fontanelles can be reliably demonstrated using three-dimensional (3D) ultrasound with rendering. Our objective was to assess the repeatability and validity of fontanelle surface area measurement on rendered 3D images.

METHODS

This was an in-vitro phantom validation study. Four holes, representing fontanelles, were cut on a flat vinyl tile. The phantom was scanned in a test-tank by two sonographers, at four different depths and using two different 3D sweep directions. The surface areas were measured on scan images and also directly from the phantom for comparison. Coefficients of variation (CVs), intraclass correlation coefficients (ICCs) and Bland-Altman plots were used for repeatability analysis. Validity was expressed as the percentage difference of the measured area from the true surface area.

RESULTS

Validity of measurement was satisfactory with a mean percentage difference of - 5.9% (median = - 3.5%). The 95% limits of agreement were - 23.9 to 12.1%, suggesting that random error is introduced during image generation and measurement. Repeatability of caliper placement on the same image was higher (intraobserver CV = 1.6%, ICC = 0.999) than for measurement of a newly generated scan image (intraobserver CV = 5.5%, ICC = 0.992). Reduced accuracy was noted for the smallest shape tested.

CONCLUSION

Surface area measurements on rendered 3D ultrasound images are accurate and reproducible in vitro.