Can 3-dimensional cranial ultrasound be used to successfully reconstruct a 2-dimensional image without compromising on image quality in a neonatal population?

BACKGROUND: Cranial ultrasound is frequently performed in neonatal intensive care units and acquiring 2-dimensional (D) images requires significant training. Three-D ultrasound images can be acquired semi-automatically. OBJECTIVE: This proof-of-concept study aimed to demonstrate that 3-D study image quality compares well with 2-D. If this is successful, 3-D images could be acquired in remote areas and read remotely by experts. MATERIALS AND METHODS: This was a prospective study of 20 neonates, who underwent both routine 2-D and 3-D cranial ultrasounds. Images were reconstructed into standard views extracted from the 3-D volume and evaluated by three radiologists blinded to the acquisition method. The radiologists assessed for the presence of anatomical landmarks and overall image quality. RESULTS: More anatomical structures were identified in the 3-D studies (P<0.01). There was a trend that 3-D ultrasound demonstrated better image quality in the coronal plane, and 2-D in the sagittal plane, only reaching statistical significance for two coronal views and two sagittal views. CONCLUSION: Overall, this study has demonstrated that 3-D cranial ultrasound performs similarly to 2-D and could be implemented into neonatal practice.

[Abdominal and cranial ultrasound screenings in our Neonatal Intensive Care Unit]. / Hasi és agyi ultrahang-szurovizsgálatok Neonatális Intenzív Centrumunkban.

INTRODUCTION: Previously, all admitted neonates to our tertiary Neonatal Unit, University of Szeged, had a cranial and abdominal ultrasound performed as part of their care. OBJECTIVE: To analyze the findings and to evaluate the effectiveness of the universal ultrasound screening. METHOD: Results of cranial and abdominal ultrasound imaging performed in our Unit between 1st January 2014 and 31st December 2015 were analyzed retrospectively. Abnormalities found during the screening scans were studied further and assessed until discharge and during the first 2 years. All imagings were performed by a radiologist. RESULTS: During the examined 2 years, 579 neonates were admitted (gestational age mean 34.2 weeks [23-41, SD ± 4.04]), abdominal ultrasound was performed in 562 (97%) and cranial ultrasound in 560 (97%) babies, on the 3.6th day of life at an average (0-18, SD ± 2.24). Of all abdominal ultrasound scans, 87% (n = 488) was carried out as screening, and the found abnormalities in 140 (29%) of the cases: renal pelvic dilatation (n = 67 [47.9%]), free abdominal fluid (n = 17 [12.1%]), echogenic kidneys (n = 13 [9.3%]), congenital abnormalities of the kidney and urinary tract (n = 9 [6.4%]), abnormalities of the liver, bile system, adrenal gland [n = 14 [10%]). The screening identified 4 (0.8%) neonates with renal abnormilaties requiring surgical correction. In regards of renal abnormalities, we observed male (p = 0.18) and left sided (p = 0.54) predominance. Screening cranial ultrasound was performed in 65% (n = 362) of all neonates, discovering 51 (14%) anomalies: plexus chorioideus cyst (n = 21 [41%]), plexus chorioideus hemorrhage (n = 9 [17.6%]), mild ventricular asymmetry (n = 8 [15.7%]), subependymal hemorrhage (n = 5 [9.8%]), abnormalities of the periventricular area (n = 4 [7.8%]), colpocephaly, hydrocephalus externus, echogenic meninx and thalamic nodule [n = 1-1 (1.9-1.9%)]. CONCLUSION: Abdominal ultrasound screening discovered renal abnormalities and umbilical line complications as clinically relevant findings. However, a small number of renal abnormalities identified by screening required surgical intervention. Further studies are needed to identify possible risk groups to develop more efficient screening strategy to decrease the number of screened babies for 1 relevant finding (number to screen). Cranial ultrasound screening did not identify any abnormalities that needed intervention. We can not recommend universal cranial ultrasound screening based on our results. Orv Hetil. 2023; 164(31): 1222-1230.

Cranial US in Infants Exposed to Zika Virus: The NATZIG Cohort.

Background Studies addressing neuroimaging findings as primary outcomes of congenital Zika virus infection are variable regarding inclusion criteria and confirmatory laboratory testing. Purpose To investigate cranial US signs of prenatal Zika virus exposure and to describe frequencies of cranial US findings in infants exposed to Zika virus compared to those in control infants. Materials and Methods In this single-center prospective cohort study, participants were enrolled during the December 2015-July 2016 outbreak of Zika virus infection in southeast Brazil (Natural History of Zika Virus Infection in Gestation cohort). Eligibility criteria were available cranial US and laboratory findings of maternal Zika virus infection during pregnancy confirmed with RNA polymerase chain reaction testing (ie, Zika virus-exposed infants). The control group was derived from the Zika in Infants and Pregnancy cohort and consisted of infants born to asymptomatic pregnant women who tested negative for Zika virus infection during pregnancy. Two radiologists who were blinded to the maternal Zika virus infection status independently reviewed cranial US scans from both groups and categorized them as normal findings, Zika virus-like pattern, or mild findings. Associations between cranial US findings and prenatal Zika virus exposure were assessed with univariable analysis. Results Two hundred twenty Zika virus-exposed infants (mean age, 53.3 days ± 71.1 [standard deviation]; 113 boys) and born to 219 mothers infected with Zika virus were included in this study and compared with 170 control infants (mean age, 45.6 days ± 45.8; 102 boys). Eleven of the 220 Zika virus-exposed infants (5%), but no control infants, had a Zika virus-like pattern at cranial US. No difference in frequency of mild findings was observed between the groups (50 of 220 infants [23%] vs 44 of 170 infants [26%], respectively; P = .35). The mild finding of lenticulostriate vasculopathy, however, was nine times more frequent in Zika virus-exposed infants (12 of 220 infants, 6%) than in control infants (one of 170 infants, 1%) (P = .01). Conclusion Lenticulostriate vasculopathy was more common after prenatal exposure to Zika virus, even in infants with normal head size, despite otherwise overall similar frequency of mild cranial US findings in Zika virus-exposed infants and in control infants. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Benson in this issue.

Ultrasound Technologies for Imaging and Modulating Neural Activity.

Visualizing and perturbing neural activity on a brain-wide scale in model animals and humans is a major goal of neuroscience technology development. Established electrical and optical techniques typically break down at this scale due to inherent physical limitations. In contrast, ultrasound readily permeates the brain, and in some cases the skull, and interacts with tissue with a fundamental resolution on the order of 100 µm and 1 ms. This basic ability has motivated major efforts to harness ultrasound as a modality for large-scale brain imaging and modulation. These efforts have resulted in already-useful neuroscience tools, including high-resolution hemodynamic functional imaging, focused ultrasound neuromodulation, and local drug delivery. Furthermore, recent breakthroughs promise to connect ultrasound to neurons at the genetic level for biomolecular imaging and sonogenetic control. In this article, we review the state of the art and ongoing developments in ultrasonic neurotechnology, building from fundamental principles to current utility, open questions, and future potential.

The early pattern of human corpus callosum development: A transvaginal 3D neurosonographic study.

OBJECTIVE: To provide an in-vivo description of early corpus callosum (CC) development. METHODS: We reviewed 3D US volumes acquired transvaginally (TVUS) through the anterior fontanelle, between 14 to 17 weeks. The following landmarks were recognized: tela-choroidea (TC), foramina of Moro, early CC and the evolving cavum septi pellucidi. The following measurements were taken: total, anterior and posterior sections, and height of the CC (referenced to the anterior TC border). All measurements were correlated to both the gestational age and the transverse cerebellar diameter (TCD). RESULTS: Eighty nine volumes were included in the study (mean 15.1 weeks ± 0.84, TCD range, 13.1-18.4 mm) with high inter and intra observer correlation of the measurements. We found high correlation between CC length and height, and TCD. The anterior segment of the CC appear earlier than the posterior one, and growth continues bi-directionally. Initially, the posterior elongation is significantly larger than the anterior one. Association of all CC measurements with TCD remained significant when co-varying for maternal age and fetal sex. CONCLUSIONS: imaging the fetal CC is feasible from 14 weeks by TVUS, by following the suggested insonation approach. The early CC develops bi-directionally, and the posterior elongation is more significant than the anterior one.

Cranial ultrasound findings in preterm germinal matrix haemorrhage, sequelae and outcome.

Germinal matrix-intraventricular haemorrhage (GMH-IVH), periventricular haemorrhagic infarction (PHI) and its complication, post-haemorrhagic ventricular dilatation (PHVD), are still common neonatal morbidities in preterm infants that are highly associated with adverse neurodevelopmental outcome. Typical cranial ultrasound (CUS) findings of GMH-IVH, PHI and PHVD, their anatomical substrates and underlying mechanisms are discussed in this paper. Furthermore, we propose a detailed descriptive classification of GMH-IVH and PHI that may improve quality of CUS reporting and prediction of outcome in infants suffering from GMH-IVH/PHI.

The development and validation of a cerebral ultrasound scoring system for infants with hypoxic-ischaemic encephalopathy.

BACKGROUND: Hypoxic-ischaemic encephalopathy (HIE) is an important cause of morbidity and mortality in neonates. When the gold standard MRI is not feasible, cerebral ultrasound (CUS) might offer an alternative. In this study, the association between a novel CUS scoring system and neurodevelopmental outcome in neonates with HIE was assessed. METHODS: (Near-)term infants with HIE and therapeutic hypothermia, a CUS on day 1 and day 3-7 after birth and available outcome data were retrospectively included in cohort I. CUS findings on day 1 and day 3-7 were related to adverse outcome in univariate and the CUS of day 3-7 also in multivariable logistic regression analyses. The resistance index, the sum of deep grey matter and of white matter involvement were included in multivariable logistic regression analyses. A comparable cohort from another hospital was used for validation (cohort II). RESULTS: Eighty-three infants were included in cohort I and 35 in cohort II. The final CUS scoring system contained the sum of white matter (OR = 2.6, 95% CI 1.5-4.7) and deep grey matter involvement (OR = 2.7, 95% CI 1.7-4.4). The CUS scoring system performed well in cohort I (AUC = 0.90) and II (AUC = 0.89). CONCLUSION: This validated CUS scoring system is associated with neurodevelopmental outcome in neonates with HIE.

Preterm white matter injury: ultrasound diagnosis and classification.

White matter injury (WMI) is the most frequent form of preterm brain injury. Cranial ultrasound (CUS) remains the preferred modality for initial and sequential neuroimaging in preterm infants, and is reliable for the diagnosis of cystic periventricular leukomalacia. Although magnetic resonance imaging is superior to CUS in detecting the diffuse and more subtle forms of WMI that prevail in very premature infants surviving nowadays, recent improvement in the quality of neonatal CUS imaging has broadened the spectrum of preterm white matter abnormalities that can be detected with this technique. We propose a structured CUS assessment of WMI of prematurity that seeks to account for both cystic and non-cystic changes, as well as signs of white matter loss and impaired brain growth and maturation, at or near term equivalent age. This novel assessment system aims to improve disease description in both routine clinical practice and clinical research. Whether this systematic assessment will improve prediction of outcome in preterm infants with WMI still needs to be evaluated in prospective studies.

Ultrasound of acquired posterior fossa abnormalities in the newborn.

Neonatal brain sonography is part of routine clinical practice in neonatal intensive care units, but ultrasound imaging of the posterior fossa has gained increasing attention since the burden of perinatal acquired posterior fossa abnormalities and their impact on motor and cognitive neurodevelopmental outcome have been recognized. Although magnetic resonance imaging (MRI) is often superior, posterior fossa abnormalities can be suspected or detected by optimized cranial ultrasound (CUS) scans, which allow an early and bed-side diagnosis and monitoring through sequential scans over a long period of time. Different ultrasound appearances and injury patterns of posterior fossa abnormalities are described according to gestational age at birth and characteristics of the pathogenetic insult. The aim of this review article is to describe options to improve posterior fossa sequential CUS image quality, including the use of supplemental acoustic windows, to show standard views and normal ultrasound anatomy of the posterior fossa, and to describe the ultrasound characteristics of acquired posterior fossa lesions in preterm and term infants with effect on long-term outcome. The limitations and pitfalls of CUS and the role of MRI are discussed.

State-of-the-art neonatal cerebral ultrasound: technique and reporting.

In the past three decades, cerebral ultrasound (CUS) has become a trusted technique to study the neonatal brain. It is a relatively cheap, non-invasive, bedside neuroimaging method available in nearly every hospital. Traditionally, CUS was used to detect major abnormalities, such as intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, and (cystic) periventricular leukomalacia (cPVL). The use of different acoustic windows, such as the mastoid and posterior fontanel, and ongoing technological developments, allows for recognizing other lesion patterns (e.g., cerebellar hemorrhage, perforator stroke, developmental venous anomaly). The CUS technique is still being improved with the use of higher transducer frequencies (7.5-18 MHz), 3D applications, advances in vascular imaging (e.g. ultrafast plane wave imaging), and improved B-mode image processing. Nevertheless, the helpfulness of CUS still highly depends on observer skills, knowledge, and experience. In this special article, we discuss how to perform a dedicated state-of-the-art neonatal CUS, and we provide suggestions for structured reporting and quality assessment.

When classical music relaxes the brain: An experimental study using Ultrasound Brain Tissue Pulsatility Imaging.

INTRODUCTION: Recent evidence suggests that biomechanical parameters of the brain, such as Brain Tissue Pulsatility (BTP), could be involved in emotional reactivity. However, no study has investigated the impact of an emotional task on BTP. We used the ultrasound method of Tissue Pulsatility Imaging (TPI) to assess changes in BTP to exciting and relaxing classical music, in a musical perception task, as a validated paradigm to assess emotional reactivity. METHODS: 25 healthy volunteers were exposed via earphones to four 5-minute musical excerpts (two exciting and two relaxing musical excerpts) presented in a randomized order and intersected by 5 silence periods. Measures of BTP, Heart Rate (HR) and Skin Conductance (SC) were collected during the entire task. RESULTS: The BTP significantly decreased with relaxing music compared to silence, and especially with the excerpt 'Entrance of the Shades' by Minkus. The HR and SC, but not Heart Rate Variability, were also decreased with relaxing music. We found no significant effect of exciting music. DISCUSSION: We report, for the first time, that classical relaxing music decreases the amplitude of the brain pulsatile movements related to cerebral blood flow and mechanical properties of the brain parenchyma, which provides further evidence of the involvement of BTP in emotional reactivity. In addition, we validate the use of TPI as a non-invasive, portable and low cost tool for studies in psychophysiology, with the potential to be implemented as a biomarker in musicotherapy trials notably.

Pediatric encephalic ultrasonography: the essentials.

Nowadays, cranial ultrasonography (US) of the newborn represents the first imaging method in brain damage study and its possible outcomes. This exam is performed using the natural fontanelles, especially the anterior one. It is fast, non-invasive and does not produce any side effect. Ultrasonographic examination is usually performed in cases of prematurity, especially in children with birth weight less than 1500 g, because important informations about the possible presence of pathologies such as cerebral hemorrhage and hypoxic-ischemic encephalopathy are given. This approach can be useful also in the study of pre- and post-natal infections, for example, type II Herpes Simplex virus or Cytomegalovirus infections, or pointing out vascular malformations such as vein of Galen aneurysm. Although less important than methods such as computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of trauma and tumors, ultrasound can provide useful informations or be used in first instance in the suspicion of a brain mass.

The most useful cranial ultrasound predictor of neurodevelopmental outcome at 2 years for preterm infants.

AIM: To determine the most important cranial ultrasound predictors of abnormality associated with neurodevelopmental outcome at 2 years of age in preterm infants. MATERIALS AND METHODS: A total of 343 preterm infants born between 2005 and 2010 and cared for in KK Women's and Children's Hospital, a tertiary paediatric hospital, with birth weight ≤1,250 g were assessed in this retrospective study. Serial cranial ultrasound examinations were examined for intraventricular haemorrhage and cystic periventricular leukomalacia. Ventricular-brain ratio on term equivalent cranial ultrasound was measured. Neurodevelopmental outcome was assessed by the performance on Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III) at 2 years corrected age. Mental delay was defined as having a combined Bayley-III score (the average of cognitive and language scores) <80. RESULTS: The mean cognitive, language, and motor scores on Bayley-III in this cohort were 93±15, 83±18, and 92±15, respectively. Twenty-six percent of the preterm infants had mental delay and 4% had cerebral palsy. Ventricular-brain ratio >0.35 was the most significant factor associated with mental delay (odds ratio 5.28, 95% CI: 1.49-18.71, p=0.01). Other significant risk factors for mental delay were male gender, postnatal steroids, and necrotising enterocolitis, whereas maternal tertiary education was a protective factor against adverse outcome. CONCLUSION: Ventricular-brain ratio >0.35 on term-equivalent cranial ultrasound in preterm infants is the strongest predictor for mental delay on Bayley score at 2 years of age.

Simulation-Based Structured Education Supports Focused Neonatal Cranial Ultrasound Training.

OBJECTIVES: Brain injury in preterm neonates may cause clinical deterioration and requires timeous bedside diagnosis. Teaching cranial ultrasound (US) skills using fragile preterm neonates is challenging. The purpose of this study was to test the effectiveness and feasibility of using task-trainer computer-based simulators and US-suitable cranial phantoms in combination with teaching sessions in teaching novices to perform focused cranial US evaluations for identifying substantial intraventricular hemorrhage. METHODS: This was a prospective interventional educational study targeting participants with no prior skills in neonatal cranial US. Participants attended a 2-day training workshop, with didactic and hands-on interactive sessions using computer-based and 3-dimensional printed phantom simulators. Participants then performed a cranial US scan on a healthy neonate to assess the diagnostic quality of the images acquired. Individual precourse and postcourse knowledge tests were compared. To test recall, participants also submitted US images acquired on neonates within 3 and 6 months of attending the course. RESULTS: Forty-five participants completed the training modules. Mean knowledge scores increased significantly (in brain anatomy, brain physiology, intracranial disorders, and US physics domains). Thirty-eight cranial US scans were acquired during the course, 22 within 3 months after completion, and 34 within 6 months after completion. Thirty-two (84%) of the initial 38 case images, 17 (77%) of 22 images submitted within 3 months, and 32 (94%) of 34 images submitted within 6 months after course completion were of diagnostic quality. CONCLUSIONS: A structured training module with didactic and hand-on training sessions using simulators and phantoms is feasible and supports training of clinicians to perform focused cranial US examinations.

Feasibility of Ultrafast Doppler technique for cranial ultrasound in neonates.

AIMS: The aim of this study was to compare the performances of Ultrafast Doppler ultrasound (US) with classic Doppler US, for cranial ultrasound in neonates. MATERIALS AND METHODS: We measured the peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) of the anterior cerebral artery (ACA), middle cerebral artery (MCA) and posterior cerebral artery (PCA) in neonates using both conventional and Ultrafast Doppler US and acquisition times were compared. Distal ACA branches were assessed with Ultrafast Doppler US. RESULTS: A total of 138 neonates were included. The PSV and EDV of the cranial arteries were comparable between the two Doppler methods (PSV, 64.6-85.5 cm/s vs. 63.4-84.1 cm/s, p=0.100-0.510; EDV, 19.1-26.5 cm/s vs. 17.8-24.2 cm/s, p=0.100-0.981). The RIs of the ACA and PCA were not significantly different (0.69-0.73 vs 0.68-0.74, p=0.174-0.810). Ultrafast Doppler US required shorter acquisition times than conventional Doppler US (6.7 s vs. 11.0 s, p=0.003). The PSV and EDV of the distal ACA were higher than the proximal ACA (20.1-63.3 cm/s vs. 9.4-36.7, p<0.001) although the RI was similar (0.69 vs. 0.68, p=0.251). CONCLUSIONS: Ultrafast Doppler US provides comparable values to conventional Doppler US with shorter acquisition times. This novel imaging technique provides quantitative information and is suitable for distal cranial artery evaluation.

Early Prediction of Periventricular Leukomalacia Using Quantitative Texture Analysis of Serial Cranial Ultrasound Scans in Very Preterm Infants.

We compared texture parameters of serial cranial ultrasound (cUS) images of periventricular leukomalacia (PVL) and normal periventricular echogenicity (PVE) in very preterm infants and evaluated the early predictive values of texture analysis (TA) for PVL. Ten individuals with PVL and 10 control individuals with PVE assessed with an initial cUS within 1 wk of birth and follow-up cUS at 2-3 and 4-6 wk of life were included. TA was performed on the region of interest of PVE at the parieto-occipital area on serial cUS. Opposite changes in variance were obtained between the first two cUS sessions in both groups (p = 0.017 in PVL and p = 0.005 in PVE). The variance-to-mean ratio (VMR) between the second and first cUS sessions differed (p = 0.016) and reliably stratified the groups (area under the receiver operating characteristic curve: 0.820, 95% confidence interval: 0.587-1.000, sensitivity: 100%, specificity: 60%). TA of serial cUS helps to predict PVL within 3 wk of life.