Three-dimensional digital capture of head size in neonates - a method evaluation

The three-dimensional course of cranial development of very preterm infants during the first year of life

BACKGROUND

Cranial measurements are crucial for evaluating preterm general development because they are a surrogate tool for evaluating brain growth. Usually, they are based on tape-measured head circumference; however, a three-dimensional (3D) approach expands the diagnostic spectrum to the evaluation of cranial volume and shape.

AIMS

Very preterm (vPT) infants face multiple risks and obstacles in their early development. In this study, we analyze the risk for cranial anomalies of vPT compared with term-born (TB) infants during the first year of life.

STUDY DESIGN AND SUBJECTS

In this single-centre prospective cohort study, 23 vPT and 24 TB healthy infants were assessed. At term equivalent age (TEA) of vPT and time of birth of TB, and 1, 3, 6 and 12 months of postmenstrual age, respectively, a 3D head scan was performed and cephalometrically evaluated regarding cranial growth (head circumference, cranial volume) and shape.

RESULTS

Head circumference and cranial volume showed a similar course in vPT and TB. Cranial shape differed significantly between vPT and TB. At TEA, vPT showed longer and narrower heads (dolichocephaly), a difference that disappeared around the 6th month of life. Presence of plagiocephaly was initially similar in vPT and TB, with an increasing difference between both groups with a peak at six months when 34.8 % of the vPT versus none of the TB showed a moderate to severe plagiocephaly (p = 0.004). In vPT, cranial volume significantly correlated with cranial shape, whereas dolichocephaly at TEA had no influence on the further course of plagiocephaly.

CONCLUSION

Cranial development of vPT follows a different course than of TB in terms of cranial shape anomalies, while cranial growth remains unaffected. German Clinical Trials Register number: DRKS00022558.

Therapeutic Effectiveness of a Novel Cranial Remolding Helmet (baby band2) for Positional Plagiocephaly: A Multicenter Clinical Observational Study

This multicenter study evaluated the efficacy and safety of a novel cranial remolding helmet (baby band2), which is completely custom-made based on the shape of an infant's cranium. The study included 224 full-term infants from moderate to very severe positional plagiocephaly in Japan. Cranial geometry was assessed before and after helmet therapy using a three-dimensional scanner, and changes in the cranial vault asymmetry index (CVAI) were analyzed. The CVAI improved significantly in all patients, with the most significant improvement observed in the most severely affected group [very severe group: -9.1, severe group: -6.6, moderate group: -4.4 (mean values), p < 0.001]. The group that started therapy before the age of 7 months showed greater improvement compared to those who started therapy at the age of 7 months or older; however, both groups demonstrated significant improvement (<7 months group: -6.6, ≥7 months group: -4.4 (mean values), p < 0.001). No significant differences were observed in therapy efficacy between the centers (p = 0.402) and sex (p = 0.131). During the study period, helmet therapy did not lead to head circumference stunting, and the incidence of redness with baby band2 was five patients (2.2%). This study demonstrated that baby band2 is effective and safe for the therapy of positional plagiocephaly.

Incidence of Nonsynostotic Plagiocephaly and Developmental Disorders

Importance

This is the first population-based study quantifying the incidence of nonsynostotic positional plagiocephaly and/or brachycephaly (PPB) in infancy and its association with developmental disorders.

Objective

To report the incidence of PPB before age 1 year, the incidence of craniosynostosis, and the percentage of children with PPB diagnosed with a developmental disorder by age 7 years.

Design, Setting, and Participants

This was a retrospective, population-based cohort study of children in the Rochester Epidemiology Project (REP) born in Olmsted County, Minnesota, from January 1, 2008, through December 31, 2012, with follow-up through age 7 years. Data were analyzed from March 2021 to April 2024.

Exposure

Physical examination detecting cranial deformity.

Main Outcomes and Measures

The primary outcome was the incidence of PPB. Secondary outcomes were the incidence of craniosynostosis and the percentage of children with PPB diagnosed with a developmental disorder by age 7 years.

Results

Of 9909 infants (5084 [51.3%] male; 9205 [92.9%] born at term and 704 [7.1%] born preterm) included in the study, 575 had PPB, for a PPB incidence of 5.8% (95% CI, 5.3%-6.3%). The incidence of PPB was 5.3% (95% CI, 4.8%-5.8%) in term infants vs 11.8% (95% CI, 9.4%-14.6%) in preterm infants. The incidence of craniosynostosis was 0.16% (95% CI, 0.09%-0.26%). A developmental disorder was known or suspected in 4.2% (95% CI, 2.7%-6.2%) of infants at the time of PPB diagnosis; among 402 infants with PPB and follow-up through age 7 years, 30 (7.5%; 95% CI, 5.0%-10.7%) had a confirmed developmental disorder by 7 years of age. The prevalence of autism spectrum disorder (ASD) in children with a history of PPB who were followed up to age 7 years was 2.2% (9 of 402 children).

Conclusions and Relevance

This study found that only a small percentage of the infants had positional head deformity significant enough to be documented and/or referred for subspecialty evaluation, and only a small subset of these children went on to have a developmental disorder in childhood. This information is helpful for counseling families about their child's developmental risk at time of PPB diagnosis.

Efficacy of Cranial Orthosis for Plagiocephaly Based on 2D and 3D Evaluation

Background  With the advent of cranial orthoses as therapeutic medical devices for the treatment of severe positional head deformities in Japan, an increasing number of patients are being treated with them. However, assessing the effectiveness of a treatment is often difficult due to the use of different metrics. This study aimed to evaluate the effectiveness of cranial orthoses for deformational plagiocephaly using two- (2D) and three-dimensional (3D) evaluation metrics. Methods  We conducted a retrospective study of infant patients with deformational plagiocephaly who underwent cranial orthosis treatment. We evaluated the severity of deformational plagiocephaly using cranial asymmetry (CA) and the cranial vault asymmetry index (CVAI) as 2D metrics, and anterior and posterior symmetry ratios as 3D metrics. The patients were divided into 24 subgroups based on the initial severity of each outcome and their age at the start of treatment. We analyzed the changes in outcomes and correlations within improvements across the age and severity categories. Results  Overall, 1,038 infants were included in this study. The mean CA, CVAI, and anterior and posterior symmetry ratios improved significantly after cranial orthosis treatment. The improvement in each score was greater in patients with more severe initial deformities and in those who underwent treatment at a younger age. Conclusion  Cranial orthosis treatment was effective in correcting deformational plagiocephaly in infants, as demonstrated by improvements in both 2D and 3D metrics. Patients with more severe initial deformities and those who underwent treatment at a younger age showed greater improvement.

Changes in Cranial Shape and Developmental Quotient at 6 Months of Age in Preterm Infants

The purpose of this study was to investigate changes in cranial shape among preterm neonates aged 1-6 months and the relationship between developmental quotient (DQ) and cranial shape at 6 months of age. Preterm infants who were hospitalized in our hospital were prospectively followed for 6 months. The cephalic index (CI) and cranial vault asymmetry index (CVAI) were evaluated at 1 (T1), 3 (T2), and 6 months (T3) of age and compared with those of the full-term infants. The relationship between CI or CVAI and DQ at T3 was analyzed using the Enjoji Scale of Infant Analytical Development. A total of 26 participants born at 34.7 ± 1.9 weeks of gestation were included. The CI increased with age (T1: 77.2%, T2: 82.9%, T3: 85.4%, p < 0.01). The prevalence of dolichocephaly at T3 did not significantly differ from that in full-term infants (15.4% vs. 4.5%, p = 0.08). CVAI did not significantly differ between preterm and full-term infants. The DQ showed no significant correlation with either the CI or CVAI (correlation coefficients: 0.23 for CI, -0.01; CVAI). Dolichocephaly improved over time in preterm infants and no relationship between cranial shape and development was observed in preterm infants at 6 months of age.

Cranial Shape Measurements Obtained Using a Caliper and Elastic Bands Are Useful for Brachycephaly and Deformational Plagiocephaly Screening

We assessed a method for screening the cranial shape of 1-month-old infants using a simple measuring instrument instead of a three-dimensional scanner. The Mimos craniometer was used to measure cranial length, cranial width, and two diagonal lengths to calculate the cranial index (CI) and cranial asymmetry (CA). We defined a CI > 90% as brachycephaly and CA > 5 mm as deformational plagiocephaly (DP). Intra- and inter-examiner accuracy analyses were performed on a dummy doll and 1-month-old infants. The measurements of healthy 1-month-old infants were compared with previously reported three-dimensional scanner measurements. Intra- and inter-rater measurements showed good accuracy; diagnostic accuracy comparisons of brachycephaly and DP using a three-dimensional scanner showed kappa values of 1.0 and 0.8, respectively. Comparisons were made among 113 infants matched for day-age at the date of measurement; there were no significant differences in the CI (85.0% vs. 85.2%, p = 0.98) and CA (5.9 mm vs. 6.0 mm, p = 0.48) between the scanner and caliper measurements, nor in the prevalence of brachycephaly (12.4% vs. 17.7%, p = 0.35) or DP (58.4% vs. 56.6%, p = 0.89). This simple measurement method using calipers and bands was useful in screening for brachycephaly and DP in 1-month-old infants.

Cranial shapes of Japanese preterm infants at one month of age using a three-dimensional scanner

BACKGROUND

Recently, cranial shape measurements of preterm infants have been performed using handheld three-dimensional (3D) scanners and can now be objectively quantified.

AIMS

To measure the cranial shapes of Japanese preterm infants at one month of age using a 3D scanner, compare these values with those of healthy term infants, and examine the risk factors for dolichocephaly.

STUDY DESIGN

A multicenter, retrospective cohort study.

SUBJECTS

Preterm infants born at <37 weeks of gestation and staying in the neonatal intensive care unit or visiting an outpatient clinic for a one-month checkup between April 2020 and March 2022.

OUTCOME MEASURES

A 3D scanner was used to quantify cranial shape. Comparison was made with full-term, one-month-old infants.

RESULTS

Ninety-four preterm infants (42 boys) and 165 full-term infants were enrolled. Preterm infants had a significantly lower cephalic index (77.9% and 85.0%, p < 0.01) and a higher incidence of dolichocephaly (54.3% and 13.3%, p < 0.01) compared to term infants. No significant difference in incidence of deformational plagiocephaly was found between the groups (41.5% vs. 47.3%, p = 0.44). The risk of dolichocephaly was significantly higher for female sex (odds ratio [OR], 3.32; 95% confidence interval, 1.30-8.50), cesarean section (OR, 4.07; 95% confidence interval, 1.23-13.5), and use of mechanical ventilation (OR, 4.66; 95% confidence interval, 1.09-20.0).

CONCLUSIONS

Japanese preterm infants at the first month of life had longer heads than full-term infants; the risk factors identified were female sex, cesarean section, and use of mechanical ventilation.

Evaluating Cranial Growth in Japanese Infants Using a Three-dimensional Scanner: Relationship between Growth-related Parameters and Deformational Plagiocephaly

In this study, we aimed to evaluate the longitudinal changes in the cranial shape of healthy Japanese infants using a three-dimensional scanner and construct a normal values database for the growth process. Preterm infants (gestational age < 37 weeks), infants with neonatal asphyxia (5-minute Apgar score of <7), and patients who started helmet therapy for deformational plagiocephaly were excluded from this study. The first scan was performed at approximately 1 month of age, followed by two scans conducted at 3 and 6 months of age. The parameters considered were as follows: cranial length, width, height, circumference, volume, cranial vault asymmetry index, and cephalic index. A cranial vault asymmetry index >5% was defined as deformational plagiocephaly. Changes in each parameter were examined using repeated-measures analysis of variance classified by sex and deformational plagiocephaly status. The rate of increase in each parameter was also examined. In total, 88 infants (45 boys and 43 girls) were included in this study. All growth-related parameters were noted to increase linearly with time. Sex differences were observed in all parameters except cranial length. Deformational plagiocephaly was found to have no effect on growth-related parameters. Cranial volume increased by 60% from 1 to 6 months of age. The growth almost uniformly influenced the rate of increase in volume in each coordinate axis direction. Overall, the mean trends in three-dimensional parameters in infants up to 6 months of age were obtained using a three-dimensional scanner. These trends could be used as a guide by medical professionals involved in cranioplasty.

Anthropometric Landmarking for Diagnosis of Cranial Deformities: Validation of an Automatic Approach and Comparison with Intra- and Interobserver Variability

Shape analysis of infant's heads is crucial to diagnose cranial deformities and evaluate head growth. Currently available 3D imaging systems can be used to create 3D head models, promoting the clinical practice for head evaluation. However, manual analysis of 3D shapes is difficult and operator-dependent, causing inaccuracies in the analysis. This study aims to validate an automatic landmark detection method for head shape analysis. The detection results were compared with manual analysis in three levels: (1) distance error of landmarks; (2) accuracy of standard cranial measurements, namely cephalic ratio (CR), cranial vault asymmetry index (CVAI), and overall symmetry ratio (OSR); and (3) accuracy of the final diagnosis of cranial deformities. For each level, the intra- and interobserver variability was also studied by comparing manual landmark settings. High landmark detection accuracy was achieved by the method in 166 head models. A very strong agreement with manual analysis for the cranial measurements was also obtained, with intraclass correlation coefficients of 0.997, 0.961, and 0.771 for the CR, CVAI, and OSR. 91% agreement with manual analysis was achieved in the diagnosis of cranial deformities. Considering its high accuracy and reliability in different evaluation levels, the method showed to be feasible for use in clinical practice for head shape analysis.

Stereophotogrammetry can feasibly assess 'physiological' longitudinal three-dimensional head development of very preterm infants from birth to term

Head development is a surrogate for brain development in infants and is related to neurocognitive outcome. There is only limited knowledge on early extra-uterine head shape and size assessment in very preterm infants. Here, 26 very preterm infants with a mean gestational age of 29.1 ± 2.2 weeks and a mean birth weight of 1273.8 ± 427.7 g underwent serial stereophotogrammetric 3D head imaging in weekly intervals from birth to term-equivalent age. The main outcome was the longitudinal assessment of the 'physiological' preterm head development with cephalometric size (head circumference, cranial volume) and shape parameters (cranial index, cranial vault asymmetry index) according to chronological and postmenstrual age (PMA). Potential clinical risk factors for the development of an abnormal low cranial index (dolichocephaly) were analysed. In serial measurements of 26 infants, the estimated head volume (95% confidence interval) increased from 244 (226-263) cm3 at 28 weeks PMA to 705 (688-721) cm3 at 40 weeks PMA. Moderate or severe dolichocephaly occurred in 21/26 infants (80.8%). Cranial index decreased over time (72.4%; 70.7-74 95% confidence interval). Brachycephaly and plagiocephaly were uncommon. No risk factors for severe dolichocephaly were identified. Our study shows that early detection of head shape and size anomalies utilizing 3D stereophotogrammetry is feasible and safe even in very preterm infants < 1500 g and/or < 32 weeks. 3D stereophotogrammetry could be used for timely identification of infants at risk for head shape anomalies. No specific risk factors for head shape anomalies were identified, especially not mode and duration of respiratory support.

Three-Dimensional versus Two-Dimensional Evaluations of Cranial Asymmetry in Deformational Plagiocephaly Using a Three-Dimensional Scanner

This study aimed to assess the measurement precision of a three-dimensional (3D) scanner that detects the geometric shape as surface data and to investigate the differences between two-dimensional (2D) and 3D evaluations in infants with deformational plagiocephaly. Using the 3D scanner that can perform both 2D and 3D evaluations, we calculated cranial asymmetry (CA) for the 2D evaluation, and the anterior symmetry ratio (ASR) and posterior symmetry ratio (PSR) for the 3D evaluation. Intra- and inter-examiner precision analyses revealed that the coefficients of the variation measurements were extremely low (<1%) for all variables, except CA (5%). In 530 infants, the coincidence rate of CA severity by the 2D evaluation and the 3D evaluation was 83.4%. A disagreement on severity was found between 2D and 3D evaluations in 88 infants (16.6%): 68 infants (12.8%) were assessed as severe by 2D evaluation and mild by the 3D evaluation, while 20 infants (3.8%) were evaluated as mild by 2D and severe by 3D evaluation. Overall, the 2D evaluation identified more infants as severe than the 3D evaluation. The 3D evaluation proved more precise than the 2D evaluation. We found that approximately one in six infants differed in severity between 2D and 3D evaluations.

Body size measuring techniques enabling stress-free growth monitoring of extreme preterm infants inside incubators: A systematic review

Introduction

Growth monitoring of preterm infants is essential for assessing the nutritional effects on their growth. The current growth monitoring techniques are too stressful, however, for the smallest preterm infants. We performed a systematic review to summarize studies on stress-free techniques for measuring the body size of preterm infants inside incubators other than the traditional calliper and tape measure-based instruments.

Methods

We searched four online literature databases: Embase, Medline, Web of Science Core Collection, and Cochrane, using search terms related to patients (neonates, infants, children) and body size measuring techniques. By means of expert judgement we assessed the techniques’ suitability for stress-free body size measurement of an infant lying in an incubator. As a criterion for suitability, we used an imaginary ideal technique.

Results

Twenty-six studies were included in this review. In 24 studies, the technique for body size measurement was related to 3D technology, and the majority of these studies acknowledged clinical superiority of 3D over 2D data. Two 3D techniques were assessed as suitable for stress-free measurement of preterm infants inside incubators. The first technique used a commercially available 3D handheld scanner which needed 3D postprocessing to derive measurement data. The second technique used a self-developed stereoscopic vision system.

Conclusions

3D volumetric parameters have higher clinical value for growth monitoring than 2D. In addition, contactless 3D measurements enable stress-free growth monitoring of even the smallest preterm infants. However, the time-consuming 3D postprocessing challenges the usability of 3D techniques. Regrettably, none of the identified suitable 3D techniques met all our requirements of an ideal all-in-one body size measuring technique for extreme preterm infants. Handheld 3D scanning might have the best properties for developing this ideal technique.

Cranial Shape in Infants Aged One Month Can Predict the Severity of Deformational Plagiocephaly at the Age of Six Months

In this study, we aimed to monitor changes in cranial shape using three-dimensional (3D) scanning to determine whether the severity of deformational plagiocephaly (DP) at the age of 6 months could be predicted at the age of 1 month. The cranial shape was measured at the ages of 1, 3, and 6 months (T1, T2, and T3, respectively) in 92 infants. We excluded those who received helmet treatment before T3. The cranial vault asymmetry index (CVAI) using 3D scanning was evaluated in all infants. DP was defined as a CVAI > 5.0% with mild (CVAI ≤ 6.25%) or moderate/severe severity (CVAI > 6.25%). The CVAI cut-off value at T1 for severe DP at T3 was determined using receiver operating characteristic (ROC) curves. At T1, T2, and T3, the respective CVAI median values were 5.0%, 5.8%, and 4.7% and the DP incidence was 50.0%, 56.8%, and 43.2%, respectively. The DP severity temporarily worsened from T1 to T2 but then improved at T3. Among the infants, 73.9% had a similar DP severity at T1 and T3 (p = 1.0). A ROC curve analysis revealed a CVAI cut-off value of 7.8% at T1 predicted severe DP. It was concluded that later DP severity could be predicted using 3D scanning at T1 with properly defined cut-off values.

Reference Values for Cranial Morphology Based on Three-dimensional Scan Analysis in 1-month-old Healthy Infants in Japan

Currently, molded helmet therapy is used to treat infants with deformational plagiocephaly. However, the indices of normal cranial shape remain unclear, and thus, the prevalence of deformational plagiocephaly is unknown, particularly in Japan. We investigated the reference values for cranial morphological characteristics in 1-month-old Japanese infants using a three-dimensional scanner, to determine the prevalence of deformational plagiocephaly. One hundred fifty-three healthy infants who visited three hospitals (from April 2020 to March 2021) were enrolled. Cranial shape was measured using a three-dimensional scanner and was analyzed using image analysis software. Outcome measures were cranial volume, length, width, length-width ratio, circumference, asymmetry, and vault asymmetry index; cephalic index; and anterior, posterior, and overall symmetry ratios. The cranial vault asymmetry index >3.5% or ≥10% were diagnosed as deformational or severe deformational plagiocephaly, respectively. The mean age at measurement was 35.7 days. The mean cranial volume was 559 mL; cranial length, 129 mm; cranial width, 110 mm; length-width ratio, 118%; cephalic index, 85.2%; cranial circumference, 377 mm, cranial asymmetry, 6.4 mm; cranial vault asymmetry index, 5.0%; and anterior, posterior, and overall asymmetry ratios, 93.1%, 91.3%, and 96.4%, respectively. The prevalence of deformational and severe deformational plagiocephaly was 64.7% and 6.6%, respectively. Sex-based differences were observed for cranial volume and width. The results obtained in this study can be considered standard values that can facilitate the differentiation of abnormal infant cranial morphological characteristics for Japanese medical practitioners.

Charts and LMS Tables of Transfontanellar and Transvertical Ear-to-Ear Distances for Gestational Age

INTRODUCTION

To date cranial development has only been described by analyzing occipitofrontal circumference (OFC). More precise methods of determining head measurements have not been widely adopted. The use of additional measurements has the potential to better account for the three-dimensional structure of the head. Our aim was to put forward centile curves of such measurements for gestational age along with a compound head volume index.

METHODS

We created generalized additive models for location, scale, and shape of two ear-to-ear distances (EED), transfontanellar (fEED) and transvertical (vEED), from birth anthropometric data. Same was done for OFC, crown-heel length, and birth weight to allow for comparison of our models with growth charts by Voigt et al. and Fenton and Kim.

RESULTS

Growth charts and tables of LMS parameters for fEED and vEED were derived from 6,610 patients admitted to our NICU and 625 healthy term newborns. With increasing gestational age EEDs increase about half as fast compared to OFC in absolute terms, their relative growths are fairly similar.

DISCUSSION

Differences to the charts by Fenton and Kim are minute. Tape measurements, such as fEED or vEED can be added to routine anthropometry at little extra costs. These charts may be helpful for following and evaluating head sizes and growth of preterm and term infants in three dimensions.

A comparative study between traditional head measurement and structured light three-dimensional scanning when measuring infant head shape

BACKGROUND

This study aimed to evaluate the correlation and consistency between traditional head measurement and structured light three-dimensional (3D) scanning parameters when measuring infant skull shape.

METHODS

A total of 76 infants aged 3 months to 2.5 years old were included in the study. Head circumference (HC) was measured with a tape measure. The transverse, anteroposterior, and oblique diameters were measured using a spreading caliper, and the cranial vault asymmetry index (CVAI) and a cranial index (CI) of symmetry were calculated; 76 cases were measured successfully. The above indexes were measured using a structured light 3D scanning system (71 cases were measured with success). Thus, in the end, the valid data of 71 cases were analyzed, and the measurements of the two approaches were compared.

RESULTS

The 95% confidence interval of traditional head measurement and structured light 3D scanning was between 0.633 and 0.988. Pearson's correlation coefficient indicated a high correlation between the two methods (r=0.793-0.980). The correlation coefficients of the transverse diameter, anteroposterior diameter, and HC, and the CI of symmetry were higher than 0.9. The lowest correlation coefficient for the CVAI was 0.793. The P values of the above measurement data were all <0.001, which indicated that they were closely related. A Bland-Altman plot indicated reasonable consistency between the two methods.

CONCLUSIONS

Both traditional head measurement and structured light 3D scanning are suitable for the measurement of infant head shape. However, while traditional head measurement using a spreading caliper is economical and simple, making it suitable for general screening at a basic level, structured light 3D scanning can deliver additional parameters, which is useful for infants with an abnormal head shape. The latter is also convenient for designing a customized helmet for skull correction when needed.

Stereophotogrammetric head shape assessment in neonates is feasible and can identify distinct differences between term-born and very preterm infants at term equivalent age

The development of head shape and volume may reflect neurodevelopmental outcome and therefore is of paramount importance in neonatal care. Here, we compare head morphology in 25 very preterm infants with a birth weight of below 1500 g and / or a gestational age (GA) before 32 completed weeks to 25 term infants with a GA of 37–42 weeks at term equivalent age (TEA) and identify possible risk factors for non-synostotic head shape deformities. For three-dimensional head assessments, a portable stereophotogrammetric device was used. The most common and distinct head shape deformity in preterm infants was dolichocephaly. Severity of dolichocephaly correlated with GA and body weight at TEA but not with other factors such as neonatal morbidity, sex or total duration of respiratory support. Head circumference (HC) and cranial volume (CV) were not significantly different between the preterm and term infant group. Digitally measured HC and the CV significantly correlated even in infants with head shape deformities. Our study shows that stereophotogrammetric head assessment is feasible in all preterm and term infants and provides valuable information on volumetry and comprehensive head shape characteristics. In a small sample of preterm infants, body weight at TEA was identified as a specific risk factor for the development of dolichocephaly.

Reference Charts for Neonatal Cranial Volume Based on 3D Laser Scanning to Monitor Head Growth

Background: Postnatal brain growth is an important predictor of neurodevelopmental outcome in preterm infants. A new reliable proxy for brain volume is cranial volume, which can be measured routinely by 3-D laser scanning. The aim of this study was to develop reference charts for normal cranial volume in newborn infants at different gestational ages starting from late preterm for both sexes. Methods: Cross-sectional cohort study in a German university hospital, including singleton, clinically stable, neonates born after 34 weeks of gestation. Cranial volume was measured in the first week of life by a validated 3-D laser scanner. Cranial volume data was modeled to calculate percentile values by gestational age and birth weight and to develop cranial volume reference charts for girls and boys separately. Results: Of the 1,703 included infants, 846 (50%) were female. Birth weights ranged from 1,370 to 4,830 grams (median 3,370). Median cranial volume ranged from 320 [interquartile range (IQR) 294-347] ml at 34 weeks to 469 [IQR 442-496] ml at 42 weeks and was higher in boys than in girls. Conclusions: This study presents the first reference charts of cranial volume which can be used in clinical practice to monitor brain growth between 34 and 42 weeks gestation in infants.

Reliability of optical devices for three-dimensional facial anatomy description: a systematic review and meta-analysis

The use of three-dimensional (3D) optical instruments to measure soft tissue facial characteristics is increasing, but systematic assessments of their reliability, practical use in research and clinics, outcome measurements, and advantages and limitations are not fully established. Therefore, a review of the current literature was performed on the reliability of facial anthropometric measurements obtained by 3D optical facial reproductions as compared to conventional anthropometry or other optical devices. The systematic literature search was conducted in electronic databases following the PRISMA guidelines (PROSPERO registration: CRD42018085473). Overall, 815 studies were identified, with 27 final papers included. Two meta-analyses were conducted. Tested devices included conventional cameras, laser scanning, stereophotogrammetry, and structured light. Studies measured living people or inanimate objects. Overall, the optical devices were considered reliable for the measurement of linear distances. Some caution is needed for surface assessments. All instruments are suitable for the analysis of inanimate objects, but fast scan devices should be preferred for living subjects to avoid motion artefacts in the orbital and nasolabial areas. Prior facial landmarking is suggested to improve measurement accuracy. Practical needs and economic means should direct the choice of the most appropriate instrument. Considering the increasing interest in surface-to-surface measurements, fast scan devices should be preferred, and dedicated protocols devised.

Three-dimensional head shape acquisition in preterm infants - Translating an orthodontic imaging procedure into neonatal care

BACKGROUND

Head shape and head volume of preterm infants give important information on short- and long-term development. Three-dimensional (3D) assessment of a preterm infant's head would therefore provide more information than currently used two-dimensional methods.

AIMS

To evaluate a contactless 3D imaging system to assess head shape and volume in preterm infants.

METHODS

A protocol for 3D imaging and reconstruction of an infant's head with a portable stereophotogrammetric camera system was developed. It was validated on a manikin by comparison to an established stationary stereophotogrammetric device. Feasibility for clinical routine and 3D data analysis were assessed in six preterm infants.

RESULTS

Ten 3D reconstructions from a manikin were done with ten images each taken from different angles. The accuracy of the 3D reconstruction was measured at the overlapping areas between two images. Comparing the portable to the stationary system, a high concordance was found for the 3D manikin head-reconstructions (mean difference 0.21 ± 0.03 mm). In preterm infants, digital evaluation of the head was proven to be feasible for head circumference (HC), cranial index and asymmetry indices. There was good concordance between manual and digital measurement of the HC (95% CI -0.85 to 0.38 mm).

CONCLUSIONS

The portable camera system allowed fast and contactless 3D image capture of a preterm infant's head without any risk or interference with neonatal care. Together with a new software, this technique would allow more precise evaluation of head growth even in very preterm infants and thereby may improve their care and long-term outcome.

Non-invasive estimation of brain-volume in infants

BACKGROUND

Neurological development is determined by brain growth. Methods to measure total brain volume (TBV) in clinical settings are limited. MR-imaging represents the gold-standard.

AIMS

The present study tests the hypotheses that in infants without any brain pathology, TBV - as determined by MRI - can be accurately estimated by cranial volume (CrV), measured by 3D-laser scanning. In case of good correlation of CrV with TBV it was further tested, whether CrV can be also estimated by (I) head circumference (HC) or (II) by other technology than laser scanning.

STUDY DESIGN & SUBJECTS

To test the hypothesis, that TBV can be reliably estimated by CrV-measurement, data from routine MRI and 3D-laser-scanner measurements were analyzed in infants if no major structural brain anomaly was found in MR-imaging. To test whether CrV can be predicted by HC-measurements during infancy, data from routine follow-up visits were used from preterms born in a two year period. Preterms are invited for a routine follow-up visit (which includes laser scanning of the head) at an age of 3 months and, for further follow-ups at 6, 9 or 12 months. To compare accuracy of CrV measurement by other techniques, a puppet head was measured, using different 3D-measurement principles: (i) Structured light projection system, (ii) The non-invasive laser-shape-digitizer, and (iii) Structure-from-motion (SFM) technique.

OUTCOME MEASURES

TBV was compared with CrV using a Passing-Bablok-Regression. To determine how well HC predicts CrV, the coefficient of determinant (R²) was calculated for each age group.

RESULTS

CrV and TBV of 25 infants (median age 19 month, body weight of 11 kg) showed a median bias of -86.7 mm³ with a slightly smaller TBV (median of 1034.1 mm³, IQR 875.9 … 1179.8 mm³) than CrV (median 1092.2, IQR 950.5 … 1258.4 mm³). CrV was poorly estimated by HC, with R² between 0.79 and 0.87 at 3 and 9 month of age respectively. For the non-invasive laser-shape-digitizer and the SFM-technique the accuracy was good (radial coordinate differences ±0.3 vs. ±0.5 mm).

CONCLUSION

The present study provides convincing evidence that CrV can be used to estimate TBV in routine care, whereas HC is a poor predictor of individual CrV.

Measuring for nonsynostotic head deformities in preterm infants during NICU management: A pilot study

BACKGROUND

Research has focused on the presence of nonsynostotic head deformities (NHD: plagiocephaly, dolichocephaly, brachycephaly) in preterm infants at discharge and within the first year after discharge. However, there is limited data on NHD in preterm neonates during neonatal intensive care unit (NICU) stay.

AIM

To acquire quantitative data on head shapes among preterm neonates during NICU hospital stay.

STUDY DESIGN

Investigators performed weekly head measurements on 68 premature infants starting within two weeks of birth or when medically stable until discharge. Infants recruited for the study were born at <34 weeks gestational age.

OUTCOME MEASURES

Cranial index (CI) and cranial vault asymmetry index (CVAI) were calculated from Ballert cranial caliper measurements during the infants stay (27 to 40 weeks postmenstrual age) in the NICU/Special Care Nursery (SCN) setting. Inter-rater retest reliability was determined for CI and CVAI.

RESULTS

Throughout the measurement period, CI consistently demonstrated dolichocephaly (CI < 0.76), and CVAI fluctuated above and below the range indicating plagiocephaly (CVAI ≥ 3.5%). Good to acceptable levels of test-retest reliability was demonstrated; prevalence of dolichocephaly and plagiocephaly at discharge was 82% and 36%, respectively; and mean head dimension measurement time for different combinations of bed types and support systems ranged from 1.1 to 1.9 min.

CONCLUSIONS

Following the progression of CI and CVAI during the NICU stay using the cranial caliper method is reliable, and a substantial presence of NHD was reported.

A collaborative, mixed-methods evaluation of a low-cost, handheld 3D imaging system for child anthropometry

3D imaging for body measurements is regularly used for design of garments and ergonomic products. The development of low‐cost 3D scanners provided an opportunity to extend the use of 3D imaging to the health sector. We developed and tested the AutoAnthro System, the first mobile, low‐cost, full‐body, 3D imaging system designed specifically for child anthropometry. This study evaluated the efficiency, invasiveness, and user experience of the AutoAnthro System. We used a mixed‐methods, collaborative approach that included a quantitative time‐motion study and qualitative interviews of anthropometrists. For cooperative children, anthropometrists considered the use of 3D imaging an easy, “streamlined experience,” but with uncooperative children, anthropometrists reported that capturing a good quality scan was out of their control. The mean time to complete a full set of scans was 68 s (standard deviation [SD] 29), compared with 135 s (SD 22) for a set of manual measurements (stature, head circumference, and arm circumference). We observed that crying was more common during manual measurement, and anthropometrist interviews confirmed that 3D imaging was less stressful for children than manual measurement. In a previous publication, we showed the potential of 3D imaging to produce reliable and accurate measurements. In this study, we found that anthropometrists were not ready to abandon manual equipment for 3D scanners because of difficulty in measuring uncooperative children. Revising the AutoAnthro System to address anthropometrists' concerns on capturing good quality scans of uncooperative children should help to facilitate widespread use of 3D imaging for child anthropometry.

Measurements agreement between low-cost and high-level handheld 3D scanners to scan the knee for designing a 3D printed knee brace

Use of additive manufacturing is growing rapidly in the orthotics field. This technology allows orthotics to be designed directly on digital scans of limbs. However, little information is available about scanners and 3D scans. The aim of this study is to look at the agreement between manual measurements, high-level and low-cost handheld 3D scanners. We took two manual measurements and three 3D scans with each scanner from 14 lower limbs. The lower limbs were divided into 17 sections of 30mm each from 180mm above the mid-patella to 300mm below. Time to record and to process the three 3D scans for scanners methods were compared with Student t-test while Bland-Altman plots were used to study agreement between circumferences of each section from the three methods. The record time was 97s shorter with high-level scanner than with the low-cost (p = .02) while the process time was nine times quicker with the low-cost scanner (p < .01). An overestimation of 2.5mm was found in high-level scanner compared to manual measurement, but with a better repeatability between measurements. The low-cost scanner tended to overestimate the circumferences from 0.1% to 1.5%, overestimation being greater for smaller circumferences. In conclusion, 3D scanners provide more information about the shape of the lower limb, but the reliability depends on the 3D scanner and the size of the scanned segment. Low-cost scanners could be useful for clinicians because of the simple and fast process, but attention should be focused on accuracy, which depends on the scanned body segment.

Neuropädiatrische Differenzialdiagnostik der Mikrozephalie im Kindesalter

Eine Mikrozephalie betrifft 2–3 % der Bevölkerung und geht oftmals mit einer Intelligenzminderung einher. Die zugrunde liegende Reduktion des Gehirnvolumens kann sowohl durch exogene Faktoren als auch durch genetische Ursachen bedingt sein. Problematisch sind sowohl die uneinheitliche Klassifikation als auch die große Heterogenität der hinter dem klinischen Zeichen Mikrozephalie stehenden Erkrankungen. Im vorliegenden Artikel stellen wir unseren Vorschlag für die diagnostische Herangehensweise an ein Kind mit Mikrozephalie aus neuropädiatrischer Sicht vor.

Individual course of cranial symmetry and proportion in preterm infants up to 6 months of corrected age

INTRODUCTION

A significant proportion of preterm infants have dolichocephaly and/or deformational plagiocephaly (DP) at term equivalent age. However, quantitative data on the clinical course after discharge is limited in these infants.

AIMS

To quantify the individual course of cranial symmetry and proportion in infants born <32 gestational weeks up to six months of corrected age (CA) and to investigate, whether measurements at discharge predict subsequent cranial deformations.

METHODS

A total of 56 infants were examined at discharge, three and six months of CA. Cranial proportion and symmetry were quantified using a 3D laser scan method. Classification and prevalence data were obtained using age related reference values. Predictive value of DP at discharge regarding subsequent deformation was evaluated.

RESULTS

Cranial Vault Asymmetry Index was 3.9% at discharge, 4.5% at three months and 3.7% at six months of CA. Prevalence of DP was 34% at discharge, 46% at three months and 27% at six months. Cranial Index was 71.4% at discharge and constantly increased over the examination period. Prevalence of dolichocephaly was high at discharge (77%) and subsequently decreased. While severe DP at discharge was predictive for a persistent deformation (PPV 0.78), 46% of infants without DP at discharge developed DP by six months of CA.

DISCUSSION

Despite a high prevalence at discharge, the decreased prevalence of DP and dolichocephaly at six months of CA suggests an optimistic course. However, changes in head shape are hardly predictable for the individual infant. Thus, an accurate quantification should be part of neonatal follow-up programs.

Prevalence of head deformities in preterm infants at term equivalent age

INTRODUCTION

Due to a rising number of head deformities in healthy newborns, there has been an increasing interest in nonsynostotic head deformities in children over recent years. Although preterm infants are more likely to have anomalous head shapes than term newborns, there is limited data available on early prevalence of head deformities in preterm infants.

AIMS

The purposes of the present study were to acquire quantitative data on head shape of preterm infants at Term Equivalent Age (TEA), to determine the prevalence of symmetrical and asymmetrical head deformities and to identify possible risk factors.

METHODS

In a cross-sectional study design, Cranial Vault Asymmetry Index (CVAI) and Cranial Index (CI) calculated from routine head-scans with a non-invasive laser shape digitizer were recorded and categorized in type and severity of deformation for three different groups of gestational age. Perinatal and postnatal patient data was tested for possible associations.

RESULTS

Scans of 195 infants were included in the study. CVAI at TEA was higher in very preterm (4.1%) compared to term and late preterm infants. Prevalence of deformational plagiocephaly was 38% in very preterm infants. CI was lower in very (71.4%) and late (77.2%) preterm infants compared to term infants (80.0%). Compared to term babies (11%), a large number of very (73%) and late (28%) preterm infants exhibited dolichocephaly at TEA.

DISCUSSION

Prevalence of symmetrical and asymmetrical head deformities in preterm infants is high at TEA. Interventions are required to prevent head deformities in preterm infants during the initial hospital stay.