Intravenous administration of ultrasound contrast to critically ill pediatric patients

BACKGROUND

The off-label use of contrast-enhanced ultrasound has been increasingly used for pediatric patients.

OBJECTIVE

The purpose of this retrospective study is to report any observed clinical changes associated with the intravenous (IV) administration of ultrasound contrast to critically ill neonates, infants, children, and adolescents.

MATERIALS AND METHODS

All critically ill patients who had 1 or more contrast-enhanced ultrasound scans while being closely monitored in the neonatal, pediatric, or pediatric cardiac intensive care units were identified. Subjective and objective data concerning cardiopulmonary, neurological, and hemodynamic monitoring were extracted from the patient's electronic medical records. Vital signs and laboratory values before, during, and after administration of ultrasound contrast were obtained. Statistical analyses were performed using JMP Pro, version 15. Results were accepted as statistically significant for P-value<0.05.

RESULTS

Forty-seven contrast-enhanced ultrasound scans were performed on 38 critically ill patients, 2 days to 17 years old, 19 of which were female (50%), and 19 had history of prematurity (50%). At the time of the contrast-enhanced ultrasound scans, 15 patients had cardiac shunts or a patent ductus arteriosus, 25 had respiratory failure requiring invasive mechanical oxygenation and ventilation, 19 were hemodynamically unstable requiring continual vasoactive infusions, and 8 were receiving inhaled nitric oxide. In all cases, no significant respiratory, neurologic, cardiac, perfusion, or vital sign changes associated with IV ultrasound contrast were identified.

CONCLUSION

This study did not retrospectively identify any adverse clinical effects associated with the IV administration of ultrasound contrast to critically ill neonates, infants, children, and adolescents.

Improving sub-pixel accuracy in ultrasound localization microscopy using supervised and self-supervised deep learning

With a spatial resolution of tens of microns, ultrasound localization microscopy (ULM) reconstructs microvascular structures and measures intravascular flows by tracking microbubbles (1-5 μm) in contrast enhanced ultrasound (CEUS) images. Since the size of CEUS bubble traces, e.g. 0.5-1 mm for ultrasound with a wavelength λ = 280 μm, is typically two orders of magnitude larger than the bubble diameter, accurately localizing microbubbles in noisy CEUS data is vital to the fidelity of the ULM results. In this paper, we introduce a residual learning based supervised super-resolution blind deconvolution network (SupBD-net), and a new loss function for a self-supervised blind deconvolution network (SelfBD-net), for detecting bubble centers at a spatial resolution finer than λ/10. Our ultimate purpose is to improve the ability to distinguish closely located microvessels and the accuracy of the velocity profile measurements in macrovessels. Using realistic synthetic data, the performance of these methods is calibrated and compared against several recently introduced deep learning and blind deconvolution techniques. For bubble detection, errors in bubble center location increase with the trace size, noise level, and bubble concentration. For all cases, SupBD-net yields the least error, keeping it below 0.1 λ. For unknown bubble trace morphology, where all the supervised learning methods fail, SelfBD-net can still maintain an error of less than 0.15 λ. SupBD-net also outperforms the other methods in separating closely located bubbles and parallel microvessels. In macrovessels, SupBD-net maintains the least errors in the vessel radius and velocity profile after introducing a procedure that corrects for terminated tracks caused by overlapping traces. Application of these methods is demonstrated by mapping the cerebral microvasculature of a neonatal pig, where neighboring microvessels separated by 0.15 λ can be readily distinguished by SupBD-net and SelfBD-net, but not by the other techniques. Hence, the newly proposed residual learning based methods improve the spatial resolution and accuracy of ULM in micro- and macro-vessels.

The Acceptance and Use of Digital Technologies for Self-Reporting Medication Safety Events After Care Transitions to Home in Patients With Cancer: Survey Study

BACKGROUND

Actively engaging patients with cancer and their families in monitoring and reporting medication safety events during care transitions is indispensable for achieving optimal patient safety outcomes. However, existing patient self-reporting systems often cannot address patients' various experiences and concerns regarding medication safety over time. In addition, these systems are usually not designed for patients' just-in-time reporting. There is a significant knowledge gap in understanding the nature, scope, and causes of medication safety events after patients' transition back home because of a lack of patient engagement in self-monitoring and reporting of safety events. The challenges for patients with cancer in adopting digital technologies and engaging in self-reporting medication safety events during transitions of care have not been fully understood.

OBJECTIVE

We aim to assess oncology patients' perceptions of medication and communication safety during care transitions and their willingness to use digital technologies for self-reporting medication safety events and to identify factors associated with their technology acceptance.

METHODS

A cross-sectional survey study was conducted with adult patients with breast, prostate, lung, or colorectal cancer (N=204) who had experienced care transitions from hospitals or clinics to home in the past 1 year. Surveys were conducted via phone, the internet, or email between December 2021 and August 2022. Participants' perceptions of medication and communication safety and perceived usefulness, ease of use, attitude toward use, and intention to use a technology system to report their medication safety events from home were assessed as outcomes. Potential personal, clinical, and psychosocial factors were analyzed for their associations with participants' technology acceptance through bivariate correlation analyses and multiple logistic regressions.

RESULTS

Participants reported strong perceptions of medication and communication safety, positively correlated with medication self-management ability and patient activation. Although most participants perceived a medication safety self-reporting system as useful (158/204, 77.5%) and easy to use (157/204, 77%), had a positive attitude toward use (162/204, 79.4%), and were willing to use such a system (129/204, 63.2%), their technology acceptance was associated with their activation levels (odds ratio [OR] 1.83, 95% CI 1.12-2.98), their perceptions of communication safety (OR 1.64, 95% CI 1.08-2.47), and whether they could receive feedback after self-reporting (OR 3.27, 95% CI 1.37-7.78).

CONCLUSIONS

In general, oncology patients were willing to use digital technologies to report their medication events after care transitions back home because of their high concerns regarding medication safety. As informed and activated patients are more likely to have the knowledge and capability to initiate and engage in self-reporting, developing a patient-centered reporting system to empower patients and their families and facilitate safety health communications will help oncology patients in addressing their medication safety concerns, meeting their care needs, and holding promise to improve the quality of cancer care.

Sonothrombolysis: State-of-the-Art and Potential Applications in Children

In recent years, advances in ultrasound therapeutics have been implemented into treatment algorithms for the adult population; however, the use of therapeutic ultrasound in the pediatric population still needs to be further elucidated. In order to better characterize the utilization and practicality of sonothrombolysis in the juvenile population, the authors conducted a literature review of current pediatric research in therapeutic ultrasound. The PubMed database was used to search for all clinical and preclinical studies detailing the use and applications of sonothrombolysis, with a focus on the pediatric population. As illustrated by various review articles, case studies, and original research, sonothrombolysis demonstrates efficacy and safety in clot dissolution in vitro and in animal studies, particularly when combined with microbubbles, with potential applications in conditions such as deep venous thrombosis, peripheral vascular disease, ischemic stroke, myocardial infarction, and pulmonary embolism. Although there is limited literature on the use of therapeutic ultrasound in children, mainly due to the lower prevalence of thrombotic events, sonothrombolysis shows potential as a noninvasive thrombolytic treatment. However, more pediatric sonothrombolysis research needs to be conducted to quantify the safety and ethical considerations specific to this vulnerable population.

Cerebral Microvascular Imaging in Infants: Scan Technique and Potential Clinical Applications

ABSTRACT

Brain ultrasound in infants, although widely utilized, provides limited functional insights into the brain. Although color and power Doppler ultrasounds have allowed quantitative assessment of cerebral macrovascular flow dynamics, there is no standardized tool integrated into the current neurosonography protocol that allows cerebral microvascular flow assessment. The evaluation of anatomic and functional changes in cerebral microvessels is important, as microvascular alterations have been shown to precede macrovascular and tissue injury in a variety of neurologic diseases of infancy. In this regard, the cerebral microvascular imaging technique is a commercially available, advanced Doppler technique in which slow flow of cerebral microvessels can be detected via a static noise suppression algorithm. This article therefore shares the basic scan technique and clinical examples of the integrated use of microvascular imaging in neurosonography for infants, setting the stage for future clinical integration of the technique.

Personalization in digital health interventions for older adults with cancer: A scoping review

INTRODUCTION

Digital health interventions (DHIs) are promising to support older adults with cancer in managing their conditions and improving their health outcomes. However, there is a lack of overall understanding of various DHIs for the aging population with cancer. Specifically, it is unclear how personalization components are included in those DHIs to promote engagement in the interventions among older adults with cancer. This study aimed to provide a comprehensive overview of existing DHIs for older adults with cancer and identify the intervention components, especially personalized features, and effectiveness of these DHIs for improving self-management and psychosocial health.

MATERIALS AND METHODS

A scoping review was conducted following Joanna Briggs Institute guidelines, focusing on older adults diagnosed with cancer who participated in DHIs to improve self-management and psychosocial health. Studies using an experimental design and published from 2000 to January 2023 were retrieved from four databases: PubMed, Embase, CINAHL, and Scopus. After primary data extraction of study characteristics, participants, interventions, and outcomes, DHIs were categorized according to personalized features.

RESULTS

Out of 9,750 articles, 20 were eligible for this scoping review. The main personalized features of DHIs were categorized into four domains: goal setting, adjusting the plan, data-driven approaches, and motivating behavioral changes. Self-management outcomes were focused on physical activity, diet, and symptom management. Quality of life, depression, and anxiety were addressed as psychosocial health-related outcomes. Although no consistent results were reported on the effectiveness, DHIs with a combination of multiple personalized features, more than three domains, were likely to be more effective in improving self-management outcomes.

DISCUSSION

This review enhances the understanding of personalized DHIs for older adults with cancer by identifying intervention components, personalized features, and effectiveness on self-management and psychosocial health. Several gaps were identified, including the absence of targeted studies exclusively focusing on older adults, a relative scarcity of personalized features for improving patient engagement, a lack of understanding of the mechanism of effective personalized features, and the necessity for more experimental studies. Addressing these gaps can contribute to improving health outcomes and the quality of care for older adults with cancer by providing the direction for developing effective DHIs.

The effect of nurse-led digital health interventions on blood pressure control for people with hypertension: A systematic review and meta-analysis

PURPOSE

Nurse-led digital health interventions (DHIs) for people with chronic disease are increasing. However, the effect of nurse-led DHIs on blood pressure control and hypertension self-management remains unclear. This study aimed to identify the characteristics of nurse-led DHIs for people with hypertension and compared the effect size of nurse-led DHIs with that of usual care to establish evidence for the development of effective nursing interventions using technologies.

DESIGN

Systematic review and meta-analysis.

METHODS

This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews of Intervention (PRISMA) guidelines and registered the protocol in PROSPERO. Studies published from 2000 to August 5, 2021, were searched using the international databases: PubMed; Embase; Cochrane Central Register of Controlled Trials; Web of Science; CINAHL; Korean databases: RISS, KISS, KMBASE; and NDSL. Risk of bias 2.0 was used for evaluating the quality of studies. The primary outcome was blood pressure control. The secondary outcomes were self-management, medication adherence, and diet adherence. Publication bias was assessed using the funnel plot and Egger's regression tests.

FINDINGS

The systematic review included 26 studies. A meta-analysis of 21 studies was conducted to calculate the effect size and identify heterogeneity among the included studies. In our meta-analysis, we observed that nurse-led DHIs reduced systolic blood pressure by 6.49 mmHg (95% confidence interval [CI]: -8.52 to -4.46, I2  = 75.4%, p < 0.05) and diastolic blood pressure by 3.30 mmHg (95% CI: -4.58 to -2.01, I2  = 70.3%, p < 0.05) when compared with usual care. Concerning secondary outcomes, the effect size on self-management, medication adherence, and diet adherence was 0.98 (95% CI: 0.58 to 1.37, I2  = 63.2%, p < 0.05), 1.05 (95% CI: 0.41 to 1.69, I2  = 92.5%, p < 0.05), and 0.80 (95% CI: 0.17 to 1.42, I2  = 80.5%, p < 0.05), respectively.

CONCLUSION

Nurse-led DHIs were more effective in reducing blood pressure and enhancing self-management than usual care among people with hypertension. Therefore, as new technologies are being rapidly developed and applied in healthcare systems, further studies and policy support are needed to utilize the latest digital innovations with nursing interventions.

CLINICAL RELEVANCE

This study could be used to identify that nurse-led interventions may take advantage of real-time communication by employing digital technologies for improving blood control and self-management behaviors such as medication adherence and diet adherence. Using nurse-led DHIs allows nurses to provide patient-centered interventions such as reflecting on patients' needs and shared decision-making without space constraints and limited treatment time.

A Template for Translational Bioinformatics: Facilitating Multimodal Data Analyses in Preclinical Models of Neurological Injury

Background

Pediatric neurological injury and disease is a critical public health issue due to increasing rates of survival from primary injuries (e.g., cardiac arrest, traumatic brain injury) and a lack of monitoring technologies and therapeutics for the treatment of secondary neurological injury. Translational, preclinical research facilitates the development of solutions to address this growing issue but is hindered by a lack of available data frameworks and standards for the management, processing, and analysis of multimodal data sets.

Methods

Here, we present a generalizable data framework that was implemented for large animal research at the Children's Hospital of Philadelphia to address this technological gap. The presented framework culminates in an interactive dashboard for exploratory analysis and filtered data set download.

Results

Compared with existing clinical and preclinical data management solutions, the presented framework accommodates heterogeneous data types (single measure, repeated measures, time series, and imaging), integrates data sets across various experimental models, and facilitates dynamic visualization of integrated data sets. We present a use case of this framework for predictive model development for intra-arrest prediction of cardiopulmonary resuscitation outcome.

Conclusions

The described preclinical data framework may serve as a template to aid in data management efforts in other translational research labs that generate heterogeneous data sets and require a dynamic platform that can easily evolve alongside their research.

Advanced Neuromonitoring Modalities on the Horizon: Detection and Management of Acute Brain Injury in Children

Timely detection and monitoring of acute brain injury in children is essential to mitigate causes of injury and prevent secondary insults. Increasing survival in critically ill children has emphasized the importance of neuroprotective management strategies for long-term quality of life. In emergent and critical care settings, traditional neuroimaging modalities, such as computed tomography and magnetic resonance imaging (MRI), remain frontline diagnostic techniques to detect acute brain injury. Although detection of structural and anatomical abnormalities remains crucial, advanced MRI sequences assessing functional alterations in cerebral physiology provide unique diagnostic utility. Head ultrasound has emerged as a portable neuroimaging modality for point-of-care diagnosis via assessments of anatomical and perfusion abnormalities. Application of electroencephalography and near-infrared spectroscopy provides the opportunity for real-time detection and goal-directed management of neurological abnormalities at the bedside. In this review, we describe recent technological advancements in these neurodiagnostic modalities and elaborate on their current and potential utility in the detection and management of acute brain injury.

Cerebral Blood Flow of the Neonatal Brain after Hypoxic-Ischemic Injury

OBJECTIVE

Hypoxic-ischemic encephalopathy (HIE) in infants can have long-term adverse neurodevelopmental effects and markedly reduce quality of life. Both the initial hypoperfusion and the subsequent rapid reperfusion can cause deleterious effects in brain tissue. Cerebral blood flow (CBF) assessment in newborns with HIE can help detect abnormalities in brain perfusion to guide therapy and prognosticate patient outcomes.

STUDY DESIGN

The review will provide an overview of the pathophysiological implications of CBF derangements in neonatal HIE, current and emerging techniques for CBF quantification, and the potential to utilize CBF as a physiologic target in managing neonates with acute HIE.

CONCLUSION

The alterations of CBF in infants during hypoxia-ischemia have been studied by using different neuroimaging techniques, including nitrous oxide and xenon clearance, transcranial Doppler ultrasonography, contrast-enhanced ultrasound, arterial spin labeling MRI, 18F-FDG positron emission tomography, near-infrared spectroscopy (NIRS), functional NIRS, and diffuse correlation spectroscopy. Consensus is lacking regarding the clinical significance of CBF estimations detected by these different modalities. Heterogeneity in the imaging modality used, regional versus global estimations of CBF, time for the scan, and variables impacting brain perfusion and cohort clinical characteristics should be considered when translating the findings described in the literature to routine practice and implementation of therapeutic interventions.

KEY POINTS

· Hypoxic-ischemic injury in infants can result in adverse long-term neurologic sequelae.. · Cerebral blood flow is a useful biomarker in neonatal hypoxic-ischemic injury.. · Imaging modality, variables affecting cerebral blood flow, and patient characteristics affect cerebral blood flow assessment..

Brain Targeted Xenon Protects Cerebral Vasculature After Traumatic Brain Injury

Cerebrovascular dysfunction following traumatic brain injury (TBI) is a well characterized phenomenon. Given the therapeutic potential of xenon, we aimed to study its effects after localized delivery to the brain using microbubbles. We designed xenon containing microbubbles stabilized by dibehenoylphosphatidylcholine (DBPC) and polyethylene glycol (PEG) attached to saturated phospholipid (DPSE-PEG5000). Using a pig model of TBI, these microbubbles were intravenously injected, and ultrasound was used release xenon at the level of the carotid artery. Control group received perfluorobutane containing microbubbles. Diffusion tensor imaging (DTI) showed higher fractional anisotropy for pigs receiving xenon microbubbles compared to control group at 1 day after injury. Radial diffusivity analysis showed that this effect was mainly due acute edema. Pigs were sacrificed at 5 days, and the brain tissues of xenon treated animals showed reduction of perivascular inflammation and blood-brain barrier disruption. Endothelial cell culture experiment showed that glutamate reduces tight junction protein zona occludens-1 (ZO-1), but treatment with xenon microbubbles attenuates this effect. Xenon treatment protects cerebrovasculature and astroglial reactivity after TBI. Furthermore, these data support the future use of localized delivery of various therapeutic agents for brain injury using microbubbles in order to limit systemic side effects and reduce costs. .

A concise guide to transtemporal contrast-enhanced ultrasound in children

Brain contrast-enhanced ultrasound offers insights into the brain beyond the anatomic information offered by conventional grayscale ultrasound. In infants, the open fontanelles serve as acoustic windows. In children, whose fontanelles are closed, the temporal bone serves as the ideal acoustic window due to its relatively smaller thickness than the other skull bones. Diagnosis of common neurologic diseases such as stroke, hemorrhage, and hydrocephalus has been performed using the technique. Transtemporal ultrasound and contrast-enhanced ultrasound, however, are rarely used in children due to the prevalent notion that the limited acoustic penetrance degrades diagnostic quality. This review seeks to provide guidelines for the use of transtemporal brain contrast-enhanced ultrasound in children.

Transtemporal brain contrast-enhanced ultrasound in children: preliminary experience in patients without neurological disorders

AIM

To evaluate the use of transtemporal brain contrast-enhanced ultrasound (CEUS) to assess cerebral blood perfusion in a cohort of children without neurological disorders.

METHODS

We included pediatric patients who were undergoing a clinically-indicated CEUS study. Brain scans were performed with a Siemens Sequoia scanner and a 4V1 transducer, that was placed on the left transtemporal bone. Brain scans were performed simultaneously with the images of the clinically-indicated organ of interest. Qualitative and quantitative analysis was performed to evaluate the hemispherical blood flow at the level of the midbrain during the wash-in and wash-out phases of the time-intensity curve. Clinical charts were reviewed to evaluate post-CEUS adverse events.

RESULTS

Five patients were evaluated (mean age 5.8 ± 5.1 years). Qualitatively, more avid enhancement in the midbrain than the cortex was observed. Structures depicted ranged between the centrum semiovale at the level of the lateral ventricles and the midbrain. A quantitative analysis conducted on four patients demonstrated less avid perfusion on the contralateral (i.e. right) side, with a mean left/right ratio ranging between 1.51 and 4.07. In general, there was a steep positive wash-in slope starting at approximately 10 s after contrast injection, reaching a peak intensity around 15-26 s on the left side, and 17-29 s on the right side. No adverse events were reported.

CONCLUSION

Transtemporal brain CEUS is feasible and safe in the pediatric population and allows qualitative and quantitative assessment of cerebral perfusion.

Ultrasound-Estimated Bladder Weight Correlates With Videourodynamic Studies in Neurogenic Bladder Dysfunction

PURPOSE

This retrospective study was designed to evaluate which lower urinary tract ultrasound parameter(s) could predict the results of invasive urodynamic testing which are the current reference standard in the evaluation of bladder dysfunction in children with spina bifida.

MATERIALS AND METHODS

Fifty eight children with spina bifida undergoing video urodynamic evaluation and a renal bladder ultrasound as their standard of care were evaluated. Quantitative and qualitative ultrasound parameters were then correlated with the videourodynamic study results which served as the reference standard.

RESULTS

For bladders with ending storage pressures above 15 cm H₂ O, there were increases in these ultrasound measured parameters: 1) bladder mass (P = .00019), 2) bladder/body mass ratio (P = .0059), and 3) wall thickness (P = .01). We defined the storage cost as the final storage pressure divided by the percentage of expected bladder capacity attained. These data were analyzed to compute receiver operating curves with assuming end storage pressures cutoff points of 15, 20, 30, and 40 cm H₂ O. The optimal area under the curve was found for a bladder weight of 65 g and a pressure cutoff of 30 cm H₂ O with a sensitivity of 75% with a specificity of 84%.

CONCLUSION

Bladder weight is independent of luminal volume, can be normalized to body weight, and may serve as a clinically valuable tool for noninvasive screening to define a subset of patients with neurogenic bladder with a higher likelihood of having abnormal videourodynamic results.

Utility of Cerebral Microvascular Imaging in Infants Undergoing ECMO

PURPOSE

Infants who require extracorporeal membrane oxygenation (ECMO) therapy have an increased risk of neurological complications and mortality. Microvascular imaging (MVI) is an advanced Doppler technique that allows high-resolution visualization of microvasculature in the brain. We describe the feasibility and utility of MVI for the evaluation of cerebral microvascular perfusion in patients undergoing ECMO.

METHODS

We retrospectively analyzed brain MVI scans of neonates undergoing ECMO. Two pediatric radiologists qualitatively assessed MVI scans to determine the presence or absence of tortuosity, symmetry, heterogeneity, engorgement, and hypoperfusion of the basal ganglia-thalamus (BGT) region, as well as the presence or absence of white matter vascular engorgement and increased peri-gyral flow in the cortex. We tested the association between the presence of the aforementioned brain MVI features and clinical outcomes.

RESULTS

We included 30 patients, 14 of which were male (46.7%). The time of ECMO duration was 11.8 ± 6.9 days. The most prevalent microvascular finding in BGT was lenticulostriate vessel tortuosity (26/30, 86.7%), and the most common microvascular finding in the cortex was increased peri-gyral flow (10/24, 41.7%). Cortical white matter vascular engorgement was significantly associated with the presence of any poor outcome as defined by death, seizure, and/or cerebrovascular events on magnetic resonance imaging (p = 0.03).

CONCLUSION

MVI is a feasible modality to evaluate cerebral perfusion in infants undergoing ECMO. Additionally, evidence of white matter vascular engorgement after ECMO cannulation could serve as a predictor of poor outcomes in this population.

Quantitative Evaluation of Brain Echogenicity in Hypoxic-Ischemic Encephalopathy in Term Neonates Compared with Controls

Purpose Neurosonography evaluation of neonatal hypoxic-ischemic encephalopathy (HIE) is mainly qualitative. We aimed to quantitatively compare the echogenicity of several brain regions in patients with HIE to healthy controls.

Materials and Methods 20 term neonates with clinical/MRI evidence of HIE and 20 term healthy neonates were evaluated. Seven brain regions were assessed [frontal, parietal, occipital, and perirolandic white matter (WM), caudate nucleus head, lentiform nucleus, and thalamus]. The echogenicity of the calvarial bones (bone) and the choroid plexus (CP) was used for ratio calculation. Differences in the ratios were determined between neonates with HIE and controls.

Results Ratios were significantly higher for HIE neonates in each region (p<0.05). The differences were greatest for the perirolandic WM, with CP and bone ratios being 0.23 and 0.22 greater, respectively, for the HIE compared to the healthy neonates (p<0.001). The perirolandic WM had a high AUC, at 0.980 for both the CP and bone ratios. The intra-observer reliability for all ratios was high, with the caudate to bone ratio being the lowest at 0.832 and the anterior WM to CP ratio being the highest at 0.992.

Conclusion When coupled with internal controls, quantitative neurosonography represents a potential tool to identify early neonatal HIE changes. Larger cohort studies could reveal whether a quantitative approach can discern between degrees of severity of HIE. Future neurosonography protocols should be tailored to evaluate the perirolandic region, which requires posterior coronal scanning.

Contrast-Enhanced Ultrasound of Brain Perfusion in Cardiopulmonary Resuscitation

ABSTRACT

To evaluate the feasibility and potential utility of contrast-enhanced ultrasound for real-time imaging of whole-brain perfusion during cardiopulmonary resuscitation (CPR), cardiac arrest was induced in 8- to 7-week-old 10-kg piglets ( Sus scrofa domesticus ). Contrast-enhanced ultrasound was performed through a parietal cranial window in the coronal plane visualizing the thalami during hemodynamic-directed CPR. Whole-brain mean and maximum pixel intensities in each slice during resuscitation were calculated. Piglets were monitored for 24 hours postarrest. Seven piglets achieved return of spontaneous circulation and 6 survived to 24 hours. Of the 6 surviving piglets, 2 piglets demonstrated greater intra-CPR brain enhancement at maximum 73.2% and 42.1% and mean 36.7% and 31.9% enhancement above background, respectively, compared with maximum 5.8%, 22.9%, 6.0%, and 26.6% and mean 5.1%, 8.9%, 2.9%, and 6.6% above background, respectively, in the other 4. Intra-CPR average mean arterial pressures were similar between all 6 surviving piglets. One piglet achieved return of spontaneous circulation but expired 10 minutes later with enhancement maximum 45.2% and mean 18.9% enhancement above background. The final piglet did not achieve return of spontaneous circulation and exhibited minimal enhancement at maximum 2.8% and mean 0.9% enhancement above background. Contrast-enhanced ultrasound can detect brain perfusion during CPR, identifying a spectrum of cerebral blood flow responses in the brain despite similar systemic hemodynamics. This novel application can form the basis for future large animal model studies and eventually human clinical studies to further explore the neurologic implications of cerebral blood flow responses during resuscitation and stimulate novel strategies for optimizing brain perfusion restoration.

Contrast-enhanced ultrasound of adrenal hemorrhage: a helpful problem solving tool

AIMS

A focal lesion in the region of the adrenal gland in a newborn often requires further assessment. Ultrasound (US) is the initial imaging method of choice in young children as it does not use radiation or require sedation and it has excellent spatial resolution. In this case series, we present contrast-enhanced ultrasound (CEUS) as a problem-solving tool in the evaluation of neonatal adrenal lesions.

MATERIAL AND METHODS

The imaging and medical records of five patients with adrenal lesions were retrospectively reviewed. All patients underwent US as an initial examination and all had US follow-up. Additionally, two patients had MRI examinations. CEUS was performed in all patients as a follow up examination. The enhancement characteristics of the adrenal masses on CEUS were analyzed with the use of VueBox software. In addition, qualitative analysis of the cine loops for the presence of vascularization within the lesions was performed by consensus between two radiologists.

RESULTS

The presence of an adrenal hematoma was correctly detected and characterized by CEUS in all five cases using VueBox perfusion analysis. Adrenal hematomas had no internal perfusion and flat time intensity curves.

CONCLUSION

The quantitative and qualitative CEUS assessment of the mass can distinguish hemorrhage from a malignant lesion. Based on our findings, CEUS could serve as an alternative diagnostic tool to magnetic resonance imaging in the diagnosis of slowly resolving NAH lesions.

High-resolution neurosonographic examination of the lenticulostriate vessels in neonates with hypoxic-ischemic encephalopathy

OBJECTIVE

To assess the feasibility of visualizing lenticulostriate vessels (LV) using a linear high-resolution ultrasound probe and characterize LV morphology to determine whether morphological alterations in LV are present in neonatal hypoxic-ischemic encephalopathy (HIE) as compared to the unaffected infants.

METHODS

We characterized LV by their echogenicity, width, length, tortuosity, and numbers of visualized stems/branches in neurosonographic examinations of 80 neonates. Our population included 45 unaffected (non-HIE) and 35 with clinical and/or imaging diagnosis of HIE. Of the neonates with clinical diagnosis of HIE, 16 had positive MRI findings for HIE (HIE+MRI) and 19 had negative MRI findings (HIE-MRI). Annotations were performed twice with shuffled data sets at a 1-month interval and intrarater reliability was assessed. Focused comparison was conducted between non-HIE, HIE+MRI and HIE-MRI neonates whose images were acquired with a high frequency linear transducer.

RESULTS

Studies acquired with the two most frequently utilized transducers significantly differed in number of branches (p = 0.002), vessel thickness (p = 0.007) and echogenicity (p = 0.009). Studies acquired with the two transducers also significantly differed in acquisition frequency (p < 0.001), thermal indices (p < 0.001) and use of harmonic imaging (p < 0.001). Groupwise comparison of vessels imaged with the most frequently utilized transducer found significantly fewer branches in HIE + MRI compared to HIE-MRI negative and non-HIE patients (p = 0.005).

CONCLUSION

LV can be visualized in the absence of pathology using modern high-resolution neurosonography. Visualization of LV branches varies between HIE + MRI, HIE-MRI neonates and controls.

ADVANCES IN KNOWLEDGE

High-resolution neurosonography is a feasible technique to assess LV morphology in healthy neonates and neonates with HIE.

Intracranial Pressure and Cerebral Hemodynamic Monitoring After Cardiac Arrest in Pediatric Pigs Using Contrast Ultrasound-Derived Parameters

OBJECTIVES

We explore the correlation of contrast-enhanced ultrasound (CEUS) parameters to intracranial pressure (ICP) in a porcine experimental model of pediatric cardiac arrest.

METHODS

Eleven pediatric pigs underwent electrically induced cardiac arrest followed by cardiopulmonary resuscitation. ICP was measured using intracranial bolt monitor and CEUS was monitored through a cranial window. Various CEUS parameters were monitored at baseline, immediately post return of spontaneous circulation (ROSC), 1 hour-post ROSC, and 3 hours post-ROSC.

RESULTS

There was significant ICP correlation with wash-out slope assessed by CEUS time intensity curve analysis at immediate post-ROSC. At 3 hours post-ROSC there was also significant negative correlation between ICP and peak enhancement which may be due to the evolution of anoxic injury.

CONCLUSION

The use of CEUS in assessing disruption of cerebral hemodynamics and ICP post cardiac arrest will need future validation and comparison to other imaging modalities. The correlation between CEUS parameters and ICP may be due to the alterations in cerebral autoregulation that result from anoxic brain injury.

OP0154 COMORBIDITY CLUSTERS IN ANKYLOSING SPONDYLITIS AND THEIR ASSOCIATION WITH DISEASE ACTIVITY AND FUNCTIONAL IMPAIRMENT: DATA FROM THE PSOAS COHORT

Background

Comorbidities in ankylosing spondylitis (AS) occur more frequently than in the general population and are associated with higher morbidity and mortality. Some comorbidities may occur together, making one more likely in the presence of another, and different combinations of comorbidities may have differential considerations for AS management and outcomes.

Objectives

To examine the association of baseline comorbidities with disease activity and functional status in AS.

Methods

We used baseline data from the Prospective Study Of Ankylosing Spondylitis (PSOAS) cohort, a multicenter, prospective cohort from five centers (4 in the US, 1 in Australia). AS patients ≥ 18 years fulfilling mNY criteria for AS (2002-20) were included. Patient-reported AS comorbidities (N=28) and extra-musculoskeletal manifestations (EMMs, N=2) within 3 years of enrollment (prespecified on the baseline case-report form) and only those occurring in ≥1% were included. Undocumented comorbidities were assumed to be absent if missing in <15% of patients, and those missing in >50% of patients were excluded. Comorbidity clusters were identified using K-median clustering. The optimal number of clusters was determined using scree plot of the sum of squared errors and “elbow” on the graph line. Baseline characteristics of the clusters were compared, and associations of with disease activity and functional status measures (primary outcomes: ASDAS-CRP and BASFI) were examined using linear regression adjusted for age and sex.

Results

There were 1,270 AS patients included with a mean age of 44.6 ±14.3 years, 74.4% males, and 81.2% whites. Mean AS symptom duration was 20.6±5.6 years, 81.6% HLA-B27 positive, and CRP elevated in 27.5% of patients at baseline. Depression was the most prevalent comorbidity (31.4%) followed by hypertension (26.1%); uveitis was the most common EMM (30.4%). The five clusters identified included depression (27%), no comorbidities (22%), hypertension (21%), uveitis (20%), and asthma/low bone mass (10%) (Figure 1). The cluster with no comorbidities was significantly younger, with lower symptom duration (p<0.001). Females had higher odds of being in the depression (OR=2.00, 95% CI 1.38- 2.90) and uveitis (OR=2.09, 95% CI 1.41-3.11) clusters compared to the cluster with no comorbidities. The number of comorbidities and clusters with depression and hypertension were significantly associated with worse disease activity and functional status (Table 1).

Table 1.

Age and sex adjusted associations between comorbidity clusters, compared to cluster 3, and baseline disease activity/ functional status measures in ankylosing spondylitis based on Linear regression models.

Cluster 1 (depression)Cluster 3 (hypertension)Cluster 4 (uveitis)Cluster 5 (asthma, low bone mass)OutcomesCoef (95% CI)Coef (95% CI)Coef (95% CI)Coef (95% CI)ASDAS-CRP0.98 (0.78-1.18)0.43 (0.18-0.68)0.04 (-0.19-0.27)0.16 (-0.12-0.44)BASFI (0-10)1.92 (1.51-2.34)1.00 (0.53-1.48)-0.03 (-0.49-0.42)0.64 (0.076-1.20)Enthesitis count1.17 (0.73-1.61)0.73 (0.19-1.26)0.18 (-0.32-0.68)0.48 (-0.13-1.08)Swollen joint count (0-44)0.27 (-0.08-0.62)0.43 (-0.01-0.86)0.31 (-0.09-0.71)-0.95 (-0.58-0.39)Tender joint count (0-46)1.24 (0.59-1.88)0.44 (-0.34-1.23)0.56 (-0.18-1.29)0.34 (-0.55-1.23)BASDAI (0-10)2.30 (1.88-2.71)0.88 (0.36-1.40)0.30 (-0.17-0.78)0.61 (0.03-1.19)Patient Global (0-10)2.25 (1.82-2.68)0.76 (0.21-1.30)-0.22 (-0.71-0.27)0.29 (-0.31-0.89)Patient Pain (0-10)2.45 (1.95-2.94)1.00 (0.37-1.62)0.19 (-0.38-0.75)0.16 (-0.54-0.85)Spinal pain (0-10)2.40 (1.89-2.91)1.05 (0.41-1.70)0.43 (-0.16-1.01)0.76 (0.04-1.47)Figure 1.

Comorbidity clusters in PSOAS cohort at baseline

Conclusion

Distinct comorbidity clusters were identified in AS patients in the PSOAS cohort. In addition to the number of comorbidities, the type of comorbidity seems to be important. Depression and hypertension clusters seem to be associated with worse disease activity and function.

Disclosure of Interests

Paras Karmacharya: None declared, Cynthia S. Crowson: None declared, Dilli Poudel: None declared, John M Davis III Consultant of: Dr. Davis has received consulting fees and/or honoraria from AbbVie and Sanofi-Genzyme (less than $10,000 each), Grant/research support from: Dr. Davis has received research support from Pfizer., Alexis Ogdie Consultant of: Dr. Ogdie has served as a consultant for AbbVie, Amgen, BMS, Celgene, Corrona, Gilead, Janssen, Lilly, Novartis, Pfizer, and UCB (less than 10,000 each), Grant/research support from: Dr. Ogdie has received grants from Novartis and Pfizer to Penn and from Amgen to Forward (grants more than 10,000)., Jean Liew Grant/research support from: Dr. Liew received grant/research support from Pfizer (> $10,000), Michael Ward: None declared, Mariko Ishimori: None declared, Michael Weisman Consultant of: Dr. Weisman received consulting fees for Novartis, UCB, Gilead, and GSK (< $10,000)., Matthew Brown: None declared, Mohammad Rahbar: None declared, Mark Hwang: None declared, John D Reveille Consultant of: JDR received consulting fees for UCB (< $10,000), Grant/research support from: Dr. Reveille received research support from Lilly and Janssen unrelated to this work., Lianne S. Gensler Consultant of: Dr. Gensler has received consulting fees for AbbVie, Eli Lilly, GSK, Gilead, Pfizer (< $10,000)., Grant/research support from: Dr. Gensler received grant/research support from UCB and Novartis (> $10,000).

Current understanding and future potential applications of cerebral microvascular imaging in infants

Microvascular imaging is an advanced Doppler ultrasound technique that detects slow flow in microvessels by suppressing clutter signal and motion-related artifacts. The technique has been applied in several conditions to assess organ perfusion and lesion characteristics. In this pictorial review, we aim to describe current knowledge of the technique, particularly its diagnostic utility in the infant brain, and expand on the unexplored but promising clinical applications of microvascular imaging in the brain with case illustrations.

Cerebrospinal Fluid Flow Detection in Post-hemorrhagic Hydrocephalus With Novel Microvascular Imaging Modality

Cerebrospinal fluid flow dynamics serve as an important biomarker to guide medical and/or surgical intervention of hydrocephalus in infants. Imaging of cerebrospinal fluid flow can be assessed with magnetic resonance imaging, but routine evaluation is limited by practical challenges. We show for the first time that cerebrospinal fluid flow can be depicted using brain ultrasound by implementing highly sensitive ultrasound-based microvascular imaging technology (B-flow). This novel application could potentially expand the use of this technology beyond its current application in depiction of vascular flow pathologies in newborns.

Ultrasound imaging of preterm brain injury: fundamentals and updates

Neurosonography has become an essential tool for diagnosis and serial monitoring of preterm brain injury. Preterm infants are at significantly higher risk of hypoxic-ischemic injury, intraventricular hemorrhage, periventricular leukomalacia and post-hemorrhagic hydrocephalus. Neonatologists have become increasingly dependent on neurosonography to initiate medical and surgical interventions because it can be used at the bedside. While brain MRI is regarded as the gold standard for detecting preterm brain injury, neurosonography offers distinct advantages such as its cost-effectiveness, diagnostic utility and convenience. Neurosonographic signatures associated with poor long-term outcomes shape decisions regarding supportive care, medical or behavioral interventions, and family members' expectations. Within the last decade substantial progress has been made in neurosonography techniques, prompting an updated review of the topic. In addition to the up-to-date summary of neurosonography, this review discusses the potential roles of emerging neurosonography techniques that offer new functional insights into the brain, such as superb microvessel imaging, elastography, three-dimensional ventricular volume assessment, and contrast-enhanced US.

The role of ultrasound in necrotizing enterocolitis

Ultrasound has proved to be a useful modality for enhancing the diagnostic accuracy of necrotizing enterocolitis and associated complications. The standard imaging algorithm for evaluating necrotizing enterocolitis includes radiographs and clinical symptoms, the combination of which constitutes the Bell criteria. Major limitations of using the Bell criteria for diagnosing and clinically managing necrotizing enterocolitis include low diagnostic accuracy of radiographs and nonspecific symptomatology of preterm infants. In this regard, US can offer additional insights into bowel health by helping to characterize bowel motility, echogenicity, thickness, pneumatosis and perfusion. Extramural findings such as portal venous gas, nature and extent of ascites, and pneumoperitoneum can also be assessed. Recently, contrast-enhanced US was explored in a case series of preterm bowel disease and its diagnostic utility warrants further investigation. This article reviews the US features of necrotizing enterocolitis and highlights the role of US as a complement to radiographs, as well as the emerging use of contrast-enhanced US in necrotizing enterocolitis.

Brain contrast-enhanced ultrasound and elastography in infants

Advanced ultrasound techniques, including brain contrast-enhanced ultrasonography and elastography, are increasingly being explored to better understand infant brain health. While conventional brain ultrasonography provides a convenient, noninvasive means of assessing major intracranial pathologies, its value in revealing functional and physiologic insights into the brain lags behind advanced imaging techniques such as magnetic resonance imaging. In this regard, contrast-enhanced ultrasonography provides highly precise functional information on macrovascular and microvascular perfusion, while brain elastography offers information on brain stiffness that may be associated with relevant physiological factors of diagnostic, therapeutic, and/or prognostic utility. This review details the technical background, current understanding and utility, and future directions of these two emerging advanced ultrasound techniques for neonatal brain applications.

Cerebral microcirculation mapped by echo particle tracking velocimetry quantifies the intracranial pressure and detects ischemia

Affecting 1.1‰ of infants, hydrocephalus involves abnormal accumulation of cerebrospinal fluid, resulting in elevated intracranial pressure (ICP). It is the leading cause for brain surgery in newborns, often causing long-term neurologic disabilities or even death. Since conventional invasive ICP monitoring is risky, early neurosurgical interventions could benefit from noninvasive techniques. Here we use clinical contrast-enhanced ultrasound (CEUS) imaging and intravascular microbubble tracking algorithms to map the cerebral blood flow in hydrocephalic pediatric porcine models. Regional microvascular perfusions are quantified by the cerebral microcirculation (CMC) parameter, which accounts for the concentration of micro-vessels and flow velocity in them. Combining CMC with hemodynamic parameters yields functional relationships between cortical micro-perfusion and ICP, with correlation coefficients exceeding 0.85. For cerebral ischemia cases, the nondimensionalized cortical micro-perfusion decreases by an order of magnitude when ICP exceeds 50% of the MAP. These findings suggest that CEUS-based CMC measurement is a plausible noninvasive method for assessing the ICP and detecting ischemia.

Can Ultrasound-Guided Xenon Delivery Provide Neuroprotection in Traumatic Brain Injury?

Traumatic brain injury (TBI) is associated with high mortality and morbidity in children and adults. Unfortunately, there is no effective management for TBI in the acute setting. Rodent studies have shown that xenon, a well-known anesthetic gas, can be neuroprotective when administered post-TBI. Gas inhalation therapy, however, the approach typically used for administering xenon, is expensive, inconvenient, and fraught with systemic side effects. Therapeutic delivery to the brain is minimal, with much of the inhaled gas cleared by the lungs. To bridge major gaps in clinical care and enhance cerebral delivery of xenon, this study introduces a novel xenon delivery technique, utilizing microbubbles, in which a high impulse ultrasound signal is used for targeted cerebral release of xenon. Briefly, an ultrasound pulse is applied along the carotid artery at the level of the neck on intravenous injection of xenon microbubbles (XeMBs) resulting in release of xenon from microbubbles into the brain. This delivery technique employs a hand-held, portable ultrasound system that could be adopted in resource-limited environments. Using a high-fidelity porcine model, this study demonstrates the neuroprotective efficacy of xenon microbubbles in TBI for the first time.

Advanced Ultrasound Techniques for Neuroimaging in Pediatric Critical Care: A Review

Because of its portability, safety profile, and accessibility, ultrasound has been integral in pediatric neuroimaging. While conventional B-mode and Doppler ultrasound provide anatomic and limited flow information, new and developing advanced ultrasound techniques are facilitating real-time visualization of brain perfusion, microvascular flow, and changes in tissue stiffness in the brain. These techniques, which include contrast-enhanced ultrasound, microvascular imaging, and elastography, are providing new insights into and new methods of evaluating pathologies affecting children requiring critical care, including hypoxic–ischemic encephalopathy, stroke, and hydrocephalus. This review introduces advanced neurosonography techniques and their clinical applications in pediatric neurocritical care.

Emerging contrast-enhanced ultrasound applications in children

Ultrasound contrast agent (UCA) use in radiology is expanding beyond traditional applications such as evaluation of liver lesions, vesicoureteral reflux and echocardiography. Among emerging techniques, 3-D and 4-D contrast-enhanced ultrasound (CEUS) imaging have demonstrated potential in enhancing the accuracy of voiding urosonography and are ready for wider clinical adoption. US contrast-based lymphatic imaging has been implemented for guiding needle placement in MR lymphangiography in children. In adults, intraoperative CEUS imaging has improved diagnosis and assisted surgical management in tumor resection, and its translation to pediatric brain tumor surgery is imminent. Because of growing interest in precision medicine, targeted US molecular imaging is a topic of active preclinical research and early stage clinical translation. Finally, an exciting new development in the application of UCA is in the field of localized drug delivery and release, with a particular emphasis on treating aggressive brain tumors. Under the appropriate acoustic settings, UCA can reversibly open the blood-brain barrier, allowing drug delivery into the brain. The aim of this article is to review the emerging CEUS applications and provide evidence regarding the feasibility of these applications for clinical implementation.

Translational research in pediatric contrast-enhanced ultrasound

The role of contrast-enhanced ultrasound (CEUS) imaging is being widely explored by various groups for its use in the pediatric population. Clinical implementation of new diagnostic or therapeutic techniques requires extensive and meticulous preclinical testing and evaluation. The impact of CEUS will be determined in part by the extent to which studies are oriented specifically toward a pediatric population. Rather than simply applying principles and techniques used in the adult population, these studies are expected to advance and augment preexisting knowledge with pediatric-specific information. To further develop this imaging modality for use in children, pediatric-focused preclinical research is essential. In this paper we describe the development and implementation of the pediatric-specific preclinical animal and phantom models that are being used to evaluate CEUS with the goal of clinical translation to children.

Pediatric contrast-enhanced ultrasound: optimization of techniques and dosing

When performing contrast-enhanced ultrasound (CEUS), ultrasound (US) scanner settings, examination technique, and contrast agent dose and administration must be optimized to ensure that high-quality, diagnostic and reproducible images are acquired for qualitative and quantitative interpretations. When carrying out CEUS in children, examination settings should be tailored to their body size and specific indications, similar to B-mode US. This review article details the basic background knowledge that is needed to perform CEUS optimally in children, including considerations related to US scanner settings and US contrast agent dose selection and administration techniques.

Contrast-enhanced ultrasound: a comprehensive review of safety in children

Contrast-enhanced ultrasound (CEUS) has been increasingly used in pediatric radiology practice worldwide. For nearly two decades, CEUS applications have been performed with the off-label use of gas-containing second-generation ultrasound contrast agents (UCAs). Since 2016, the United States Food and Drug Administration (FDA) has approved the UCA Lumason for three pediatric indications: the evaluation of focal liver lesions and echocardiography via intravenous administration and the assessment of vesicoureteral reflux via intravesical application (contrast-enhanced voiding urosonography, ceVUS). Prior to the FDA approval of Lumason, numerous studies with the use of second-generation UCAs had been conducted in adults and children. Comprehensive protocols for clinical safety evaluations have demonstrated the highly favorable safety profile of UCA for intravenous, intravesical and other intracavitary uses. The safety data on CEUS continue to accumulate as this imaging modality is increasingly utilized in clinical settings worldwide. As of August 2021, 57 pediatric-only original research studies encompassing a total of 4,518 children with 4,906 intravenous CEUS examinations had been published. As in adults, there were a few adverse events; the majority of these were non-serious, although very rarely serious anaphylactic reactions were reported. In the published pediatric-only intravenous CEUS studies included in our analysis, the overall incidence rate of serious adverse events was 0.22% (10/4,518) of children and 0.20% (10/4,906) of all CEUS examinations. Non-serious adverse events from the intravenous CEUS were observed in 1.20% (54/4,518) of children and 1.10% (54/4,906) of CEUS examinations. During the same time period, 31 studies with the intravesical use of UCA were conducted in 12,362 children. A few non-serious adverse events were encountered (0.31%; 38/12,362), but these were most likely attributable to the bladder catheterization rather than the UCA. Other developing clinical applications of UCA in children, including intracavitary and intralymphatic, are ongoing. To date, no serious adverse events have been reported with these applications. This article reviews the existing pediatric CEUS literature and provides an overview of safety-related information reported from UCA uses in children.

Contrast-enhanced ultrasound of the pediatric brain

Brain contrast-enhanced ultrasound (CEUS) is an emerging application that can complement gray-scale US and yield additional insights into cerebral flow dynamics. CEUS uses intravenous injection of ultrasound contrast agents (UCAs) to highlight tissue perfusion and thus more clearly delineate cerebral pathologies including stroke, hypoxic-ischemic injury and focal lesions such as tumors and vascular malformations. It can be applied not only in infants with open fontanelles but also in older children and adults via a transtemporal window or surgically created acoustic window. Advancements in CEUS technology and post-processing methods for quantitative analysis of UCA kinetics further elucidate cerebral microcirculation. In this review article we discuss the CEUS examination protocol for brain imaging in children, current clinical applications and future directions for research and clinical uses of brain CEUS.

Inhalational Gases for Neuroprotection in Traumatic Brain Injury

Despite multiple prior pharmacological trials in traumatic brain injury (TBI), the search for an effective, safe, and practical treatment of these patients remains ongoing. Given the ease of delivery and rapid absorption into the systemic circulation, inhalational gases that have neuroprotective properties will be an invaluable resource in the clinical management of TBI patients. In this review, we perform a systematic review of both pre-clinical and clinical reports describing inhalational gas therapy in the setting of TBI. Hyperbaric oxygen, which has been investigated for many years, and some of the newest developments are reviewed. Also, promising new therapies such as hydrogen gas, hydrogen sulfide gas, and nitric oxide are discussed. Moreover, novel therapies such as xenon and argon gases and delivery methods using microbubbles are explored.

Optimization of Mechanical Indices for Clinical Contrast-Enhanced Ultrasound

The quality of contrast-enhanced ultrasound (CEUS) imaging performed with high-frequency convex and linear transducers is often suboptimal. A common solution to improving the microbubble signal is by increasing the volume of the ultrasound contrast agent being administered. An alternative technique to improve the signal from the contrast agent is to adjust the mechanical index (MI). This study aimed to compare the manufacturer's default MI to an optimal MI (as determined by the best contrast-to-tissue ratio) for improving the CEUS image quality using linear and convex transducers. This study found that in most cases, the default CEUS MI setting by the manufacturer is often suboptimal, and increasing the MI is necessary to improve the contrast-to-tissue ratio and image quality. The MI can be modified by the clinician during the study to improve the quality of the clinical CEUS examination.

Gray-scale ultrasound findings of hypoxic-ischemic injury in term infants

Brain ultrasound has become a critical tool for bedside screening and monitoring of hypoxic-ischemic injury in infants. Transfontanellar ultrasound in infants allows delineation of anatomical structures of the brain and posterior fossa. The technique's low cost, lack of ionizing radiation and repeatability make it a popular alternative to magnetic resonance imaging. The published literature on interpreting hypoxic-ischemic injury on brain ultrasound is wide and varied, yet diagnostic challenges remain when detecting subtle or diffuse changes. This pictorial essay summarizes and illustrates the spectrum of sonographic findings of hypoxic-ischemic injuries in term infants.

POS0904 FACTORS ASSOCIATED WITH SWITCHING FROM ONE ANTI-TNF AGENT TO ANOTHER ANTI-TNF, OR IL17 AGENT IN PATIENT WITH ANKYLOSING SPONDYLITIS

Background:

A recent study examining Commercial Claims Insurance database found that many patients with ankylosing spondylitis (AS) do not remain on their initial TNF inhibitor two years after initiation, particularly women and those taking opioids.

Objectives:

To examine factors associated with switching from one TNF inhibitor (i)agent to either another TNFi, IL-17i or JAKi over time (at <2years and >2 years) in a longitudinal cohort of AS patients.

Methods:

Patients enrolled in the Prospective Study of Outcomes in AS (PSOAS), an observational longitudinal study of predictors of AS severity operative since 2002-2020 including over 1250 patients meeting modified New York criteria. Data collected included age, gender, ethnicity, HLA-B27 status, disease activity (BASDAI or ASDAS), erythocyte sedimentation rate (ESR), C-reactive protein (CRP), disease severity,(functional (BASFI) or radiographic (mSASSS)), comorbidities, smoking, exercise, disease duration, depression (either by self report or by the Center for Epidemiologic Studies Depression Scale (CES-D) and other medication usage (NSAIDs, including the NSAID index, nonbiologic DMARDs, opioids, anti-depressants, anxiolytics and hypnotics). Logistic regression models were built to identify clinical and sociodemographic characterstics associated with medication switching to another TNFi, IL-17i, or other biologic therapy (another TNFi, Il-17i, or JAKi) within 2 years and after 2 years of initiation).

Results:

Of those patients in PSOAS who had at least two years of follow-up, 496 were prescribed anti-TNF, 34 anti-IL-17 and 3 anti-JAK agents. According to the multinomial logistic regression analysis, patients who switched from their original TNFito another TNFi, IL-17i or JAKi within two years after initiating their original TNFi were more likely to be older, have higher baseline subjective disease activity (BASDAI), less radiographic severity by MSASSS, exercise > 120 minutes/week and less likely to be currently smoking. Patients who switched after two years were less likely be depressed, had shorter disease duration, had greater subjective disease activity, were more likely to be exercising > 120 minutes/week, and had more comorbidities.

Conclusion:

Different factors were encountered in AS patients who switched from their initial TNFi to another TNFi, IL-17i or JAKi within 2 years versus after 2 years of treatment.

Table 1.

Factors Associated With Switching From One TNFi To A Second TNFi or IL-17i or JAKi Before or After Two Years Based On Multinomial Logistic Regression Model (N=496 Patients)

VariableSwitched within 2 years vs. not switchedp-value*Switched after 2 years vs. not switchedp-value*Gender (Male vs. Female)0.99(0.637, 1.549)0.980.95 (0.528, 1.719)0.87HLA-B27_(+ vs. -)0.99 (0.639, 1.523)0.950.66 (0.365, 1.192)0.17Depression (CESD≥ 16 or self-report)(Yes vs. No)0.99 (0.676, 1.445)0.950.35 (0.182, 0.672)0.002Disease duration at baseline (≥20 vs. <20 years)0.72 (0.485, 1.062)0.100.27 (0.146, 0.491)<0.001Age at baseline (≥40 vs. <40) (years)2.00 (1.291, 3.101)0.0021.23 (0.693, 2.193)0.48CRP (≥0.8 vs. <0.8)1.94 (1.230, 3.056)0.0040.90 (0.454, 1.789)0.77BASFI (≥40 vs. <40)1.34 0.852, 2.118)0.200.87 (0.450, 1.688)0.68BASDAI (≥4 vs. <4)1.73 (1.064, 2.797)0.032.31 (1.202, 4.427)0.01NSAID index (≥50 vs. <50)1.32 (0.822, 2.128)0.250.83 (0.437, 1.586)0.58NSAIDs used (Yes vs. No)0.84 (0.534, 1.309)0.430.85 (0.479, 1.510)0.58Exercise (≥120 vs. <120) (minutes/week)1.95 (1.396, 2.731)<0.0011.66(1.057, 2.613)0.03ASDAS (≥3 vs. <3)0.78 (0.454, 1.356)0.391.07 (0.478, 2.399)0.87Number of comorbidities (≥2 vs. <2)1.40 (0.997, 1.951)0.051.63 (1.029, 2.575)0.04mSASSS (≥4, vs. <4)0.63 (0.421, 0.957)0.030.81(0.474, 1.392)0.03Current smoker (Yes vs No)0.69 (0.385, 1.225)<0.0010.79 (0.297, 2.076)0.20

*p-values calculated based on multinomial logistic regression model when switching is defined as being prescribed a second TNFi or taking IL-17i or JAKi before or after 2 years from first TNFi initiation

Disclosure of Interests:

Mark Hwang Consultant of: UCB, Novartis, Michael Weisman Consultant of: Novartis, GSK, UCB, Lilly, Lianne S. Gensler Consultant of: AbbVie, GlaxoSmithKline, Eli Lilly, Novartis, Pfizer, UCB Pharma, Amirali Tahanan: None declared, Mariko Ishimori: None declared, Theresa Hunter Employee of: Eli Lilly, Rebecca Bolce Employee of: Eli Lilly, Jeffrey Lisse Employee of: Eli Lilly, Mohammad Rahbar: None declared, Minyang Shan Employee of: Eli Lilly, John D Reveille Consultant of: UCB, Grant/research support from: Eli Lilly

Possible additional MRI markers for critical brain swelling with increased intracranial pressure in children?

A retrospective study was performed evaluating the volume and T2/T1 signal intensity of orbital fat in five children diagnosed with severe global brain swelling and confirmed cessation of cerebral perfusion. Imaging showed a volume increase (five of five) and a heterogeneous T2-hypointensity of orbital fat (four of five). This preliminary study suggests that swelling and T2-hypointensity of orbital fat may be a marker of global brain swelling and/or increased intracranial pressure.

The Wash-Out of Contrast-Enhanced Ultrasound for Evaluation of Hypoxic Ischemic Injury in Neonates and Infants: Preliminary Findings

ABSTRACT

We evaluated the use of quantitative contrast-enhanced ultrasound (CEUS) to study wash-out behavior of ultrasound contrast agents in the pediatric brain in cases of hypoxic ischemic injury (HII). Six neonates and young infants were imaged using CEUS for suspected HII in the Neonatal Intensive Care Unit/Pediatric Intensive Care Unit. After receiving a bolus of ultrasound contrast agent Lumason (Bracco Diagnostics Inc.), analysis was performed in the whole brain, cortex, cortical/subcortical gray and white matter and central gray nuclei to quantify wash-out metrics and ratios. On magnetic resonance imaging clinical imaging findings, 3 children were classified as unaffected and 3 with classical imaging findings consistent with HII. A lower wash-out rate was found in the case of HII compared with the unaffected cases. Here, we present initial work exploring the wash-out behavior for differentiation between unaffected and HII in the brain. These preliminary findings are indicative of altered hemodynamics in HII and are promising for the potential use of CEUS to quantitatively differentiate between the unaffected and HII brain. Little is known about the CEUS wash-out dynamics, especially in the setting of the pediatric brain injury. Our preliminary findings are encouraging and warrant further investigation into the mechanisms behind delayed clearance of the ultrasound contrast agent in the setting of HII.

Sex-related differences in arterial spin-labelled perfusion of metabolically active brain structures in neonatal hypoxic-ischaemic encephalopathy

AIM

To investigate the sex-related differences in arterial spin-labelled (ASL) perfusion of metabolically active brain structures in neonatal hypoxic-ischaemic encephalopathy (HIE).

MATERIALS AND METHODS

Seventy-three term neonates were identified for a retrospective case-control study following an institutional review board (IRB) approved protocol. The cerebral pulsed arterial spin labelling values were compared by permutation test to identify metabolically active brain structures with significant perfusion changes between 10 male controls and eight female controls, and between 31 HIE males and 24 HIE females.

RESULTS

In the perfusion comparison between HIE male and female neonates, significantly lower perfusion was found in the thalamus in males (p=0.02). The other brain clusters, including basal ganglia, hippocampus cluster, cingulate gyrus cluster, brainstem cluster, sensorimotor cortex cluster, and cerebellum and peduncle cluster, demonstrated no significant differences between HIE males and females. In the perfusion comparison between male and female controls, there were no significant perfusion changes in those brain clusters.

CONCLUSION

Brain perfusion in neonatal HIE differs between males and females in the thalamus, a metabolically active region within neonates, with males demonstrating lower perfusion. This difference in perfusion may reflect sex-related disparities in response to and recovery from hypoxic-ischaemic events.

Radiologic-pathologic evidence of brain injury: hypoperfusion in the Papez circuit results in poor neurodevelopmental outcomes in neonatal hypoxic ischemic encephalopathy

PURPOSE

To provide radiologic-pathologic correlation of brain injury in the Papez circuit in hypoxic-ischemic encephalopathy (HIE) neonates and correlate radiologic findings with long-term neurodevelopmental outcomes.

METHODS

Twenty full-term HIE neonates were evaluated. Cerebral blood flow (CBF) values, obtained through pulsed arterial spin labeling (ASL) perfusion-weighted MRI, were compared by permutation test to identify brain regions with statistically significant perfusion changes between 14 HIE neonates without evidence of developmental delay by Bayley-III (mean age 8.2 ± 7.2 days) and 6 HIE neonates with evidence of developmental delay (mean age 13.1 ± 8.0 days). Four histopathologic studies on specimens were taken from post-mortem brains of another group of infants (mean age 10 ± 6.8 days) with HIE. The infants were not the same ones who had MRIs.

RESULTS

Significantly decreased perfusion in Papez circuit was found in HIE neonates with developmental delay compared with HIE neonates without delay. Decreased ASL perfusion values were seen in Papez circuit structures of the fornix (p = 0.002), entorhinal cortex (p = 0.048), amygdala (p = 0.036), hippocampus (p = 0.033), and thalamus (p = 0.036). In autopsy specimens of neonates with HIE, anoxic (eosinophilic) neurons, reactive astrocytes, and white matter rarefaction were observed in these regions, providing pathology correlation to the imaging findings of HIE.

CONCLUSION

The Papez circuit is susceptible to hypoxic-ischemic injury in neonates as demonstrated by perfusion-weighted imaging and histopathology. This sheds new light onto a possible non-familial mechanism of neuropsychiatric disease evolution initiated in the infant period and raises the potential for early identification of at-risk children.

Brain Contrast-Enhanced Ultrasound Evaluation of a Pediatric Swine Model

ABSTRACT

Brain injury remains a leading cause of morbidity and mortality in children. We evaluated the feasibility of using a pediatric swine model to develop contrast-enhanced ultrasound (CEUS)-based measures of brain perfusion for clinical application in various types of brain injury monitoring. Six-week-old, 10-kg swine (N = 10) were anesthetized, and an acoustic window was created in the right frontal cranium to provide visualization of an oblique coronal plane and bilateral thalami. Ultrasound contrast agent was administered via a femoral venous catheter as a weight-based (0.03 mL/kg) bolus. After localization of the imaging plane, CEUS cine clips were acquired for 90 seconds. Bolus injection of contrast agent provided global visualization of cerebral perfusion and highlighted microvasculature in the brain. Preliminary evaluation of bolus kinetics in piglets showed a central gray nuclei-to-cortex ratio similar to human infants with a steep wash-in that crossed and remained above the 1.0 threshold for most of the enhancement period. We demonstrated the similarity in brain perfusion between piglets and human infants, specifically central gray nuclei-to-cortex ratio, showing preliminary feasibility of its use as a pediatric model of brain perfusion. Contrast-enhanced ultrasound can be performed at the bedside as a minimally invasive procedure, and quantitative CEUS may provide critical information regarding changes in brain perfusion as a result of injury or as a response to therapy.

Contrast-enhanced US in Pediatric Patients: Overview of Bowel Applications

Contrast material-enhanced US is a technique that is approved by the U.S. Food and Drug Administration for the characterization of liver lesions and intravesicular applications in children; however, contrast-enhanced US has several other pediatric applications in clinical practice. The most common application is for patients with inflammatory bowel disease (IBD). Contrast-enhanced US can be used to diagnose IBD, distinguish regions of active or chronic inflammation of the bowel wall, and evaluate associated complications such as abscesses, fistulas, and strictures. Dynamic contrast material evaluation provides qualitative and quantitative information about mural and mesenteric blood flow, which is essential in the determination of disease activity in these patients. It also has the potential to provide a means of monitoring the response to therapy beyond endoscopy or MR enterography. In addition to its use for IBD, contrast-enhanced US can be used to assess for bowel perfusion when problem solving in patients with necrotizing enterocolitis, neonatal bowel infarction, or intussusception. It is a useful imaging technique to fortify diagnoses that may otherwise be indeterminate, such as appendicitis, epiploic appendagitis, intraluminal bowel masses, and complex cysts. Finally, innovative applications such as shear-wave elastography have the potential to provide information about the stiffness of the bowel wall. Online supplemental material is available for this article. ©RSNA, 2020 See discussion on this article by Watson and Humphries.

AB1358-HPR DIAGNOSIS OF AXIAL SPONDYLOARTHRITIS: A PRIMARY UNMET EDUCATIONAL NEED FOR RHEUMATOLOGISTS

Background:

Diagnosis of axial spondyloarthritis (axSpA) is challenging because of absent physical findings in early disease and the limited diagnostic performance of laboratory markers. Considerable reliance is placed on imaging of the sacroiliac joints (SIJ) but specialty training is primarily focused on interpretation of plain radiographic abnormalities.

Objectives:

We aimed to identify what might be the primary unmet educational needs of rheumatologists completing fellowship training by using clinical and imaging data from an inception cohort of patients presenting with undiagnosed back pain. We hypothesized that concordance would increase after imaging is reviewed after the clinical data.

Methods:

The diagnosis of axSpA was compared between local rheumatologists, axSpA experts and pF using clinical and imaging data from the multicenter Screening for Axial Spondyloarthritis in Psoriasis, Iritis, and Colitis (SASPIC) Study. In this inception cohort, patients ≤45 years of age with ≥3 months back pain undergo diagnostic evaluation by a local SASPIC rheumatologist, including imaging of the SIJ, who then records a global evaluation of presence/absence of axial SpA. This is done at 3 consecutive stages: 1.After the clinical evaluation. 2.After the results of labs (HLA B27, CRP) and radiography. 3.After review of the local MRI. In this exercise, 20 cases were selected from the SASPIC cohort and the rheumatologist global evaluations were removed from the eCRFs. Four experts in axSpA reviewed the clinical and imaging data in each eCRF and provided their global evaluations for stages 1, 2, and 3 of these 20 cases. Subsequently, 4 pF rheumatologists conducted the same exercise blinded to the assessments of the local rheumatologist and experts in axSpA. Concordance (% agreement) between the assessors was analyzed.

Results:

Diagnosis of axSpA by the local SASPIC rheumatologist was made in 90%, 65%, and 75% of cases after stages 1, 2, and 3, respectively. Majority diagnosis of axSpA by experts was made in 84.2% (16/19), 57.9% (11/19), and 63.2% (12/19), after stages 1,2, and 3, respectively. Majority diagnosis of axSpA by pF rheumatologists was made in 94.4% (17/18), 100% (16/16), and 93.8% (15/16). Concordance among experts and between experts and local SASPIC rheumatologists increased after review of imaging data. For pf-rheumatologists concordance with experts increased after review of imaging for 2 assessors and decreased for the other 2 assessors. For the latter, the primary reason for decrease in concordance with experts was false positive diagnosis of axSpA in 35% and 30% of the cases after review of the imaging.

Conclusion:

A structured case-based and sequential evaluation of clinical and imaging data suggests a gap in the training of recently graduated rheumatologists, with over-interpretation of imaging leading to false positive diagnosis of axSpA.

AssessorsMean % Concordance (range) for diagnosis of axSpAStage 1Stage 2Stage 3Experts in axSpA64.2 (45-80)75.8 (65-85)84.2 (70-95)Local rheumatologist vs Experts in axSpA73.8 (70-80)83.8 (80-85)83.8 (80-90)pF rheumatologist 1 vs Experts consensus78.994.494.7pF rheumatologist 2 vs Experts consensus89.561.168.4pF rheumatologist 3 vs Experts consensus63.272.284.2pF rheumatologist 4 vs Experts consensus89.566.768.4

Disclosure of Interests:

Walter P. Maksymowych Grant/research support from: AbbVie, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer, and UCB, Employee of: Chief Medical Officer of CARE Arthritis Limited, Speakers bureau: AbbVie, Janssen, Novartis, Pfizer, and UCB, Liron Caplan: None declared, Atul Deodhar Grant/research support from: AbbVie, Eli Lilly, GSK, Novartis, Pfizer, UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myer Squibb (BMS), Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB, Speakers bureau: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myer Squibb (BMS), Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB, Soha Dolatabadi: None declared, Mark Hwang: None declared, Adam Carlson: None declared, Kelly Steed: None declared, Amanda Carapellucci: None declared, Joel Paschke: None declared, Lianne S. Gensler Grant/research support from: Pfizer, Novartis, UCB, Consultant of: AbbVie, Eli Lilly, GSK, Novartis, UCB