Techniques that decrease or eliminate ionizing radiation for evaluation of ventricular shunts in children with hydrocephalus

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.

Rapid-sequence MRI for evaluation of pediatric traumatic brain injury: a systematic review

OBJECTIVE

Rapid-sequence MRI (RSMRI) of the brain is a limited-sequence MRI protocol that eliminates ionizing radiation exposure and reduces imaging time. This systematic review sought to examine studies of clinical RSMRI use for pediatric traumatic brain injury (TBI) and to evaluate various RSMRI protocols used, including their reported accuracy as well as clinical and systems-based limitations to implementation.

METHODS

PubMed, EMBASE, and Web of Science databases were searched, and clinical articles reporting the use of a limited brain MRI protocol in the setting of pediatric head trauma were identified.

RESULTS

Of the 1639 articles initially identified and reviewed, 13 studies were included. An additional article that was in press at the time was provided by its authors. The average RSMRI study completion time was variable, spanning from 1 minute to 16 minutes. RSMRI with "blood-sensitive" sequences was more sensitive for detection of hemorrhage compared with head CT (HCT), but less sensitive for detection of skull fractures. Compared with standard MRI, RSMRI had decreased sensitivity for all evidence of trauma.

CONCLUSIONS

Protocols and uses of RSMRI for pediatric TBI were variable among the included studies. While traumatic pathology missed by RSMRI, such as small hemorrhages and linear, nondisplaced skull fractures, was frequently described as clinically insignificant, in some cases these findings may be prognostically and/or forensically significant. Institutions should integrate RSMRI into pediatric TBI management judiciously, relying on clinical context and institutional capabilities.

Radiation safety education and diagnostic imaging in pediatric patients with surgically treated hydrocephalus: the patient and family perspective

PURPOSE

Surgically treated hydrocephalus patients are frequently imaged with head computed tomography (CT), and risk/benefit communication with families is inconsistent and unknown. We aimed to educate patients and caregivers about radiation safety in CT and explore their communication preferences.

METHODS

We conducted a pediatric CT radiation safety and diagnostic imaging educational workshop for patients and caregivers at a national conference on hydrocephalus to characterize current practice and desired communication about CT imaging. Our workshop consisted of an interactive educational intervention with pre-/post-session surveys followed by feedback from participants.

RESULTS

Our session included 34 participants (100% response rate for surveys) with 28 being parents of individuals with hydrocephalus. A total of 76% (n = 26) participants showed an increase in knowledge after the session (p < 0.01). All participants (N = 34) uniformly desired risk/benefit discussions before CT scans. However, 71% stated that they were not informed of risks/benefits of CT scans by a medical professional. Following the session, the number of participants indicating that informed consent should be obtained before CT scans increased from 30 to 33. Respondents also revealed that 14% of children and young adults had received > 100 CT scans for shunt evaluation with the median being 25 scans (IQR 20).

CONCLUSIONS

Caregivers desire and deserve to be empowered through education and social support, and continuously engaged through sharing decisions and co-designing care plans. The neurosurgical community is in an ideal position to collaborate with radiologists, primary care providers, and parents in the development and testing of credible, high-quality online and social media resources.

Artificial intelligence for automatic cerebral ventricle segmentation and volume calculation: a clinical tool for the evaluation of pediatric hydrocephalus

OBJECTIVE

Imaging evaluation of the cerebral ventricles is important for clinical decision-making in pediatric hydrocephalus. Although quantitative measurements of ventricular size, over time, can facilitate objective comparison, automated tools for calculating ventricular volume are not structured for clinical use. The authors aimed to develop a fully automated deep learning (DL) model for pediatric cerebral ventricle segmentation and volume calculation for widespread clinical implementation across multiple hospitals.

METHODS

The study cohort consisted of 200 children with obstructive hydrocephalus from four pediatric hospitals, along with 199 controls. Manual ventricle segmentation and volume calculation values served as "ground truth" data. An encoder-decoder convolutional neural network architecture, in which T2-weighted MR images were used as input, automatically delineated the ventricles and output volumetric measurements. On a held-out test set, segmentation accuracy was assessed using the Dice similarity coefficient (0 to 1) and volume calculation was assessed using linear regression. Model generalizability was evaluated on an external MRI data set from a fifth hospital. The DL model performance was compared against FreeSurfer research segmentation software.

RESULTS

Model segmentation performed with an overall Dice score of 0.901 (0.946 in hydrocephalus, 0.856 in controls). The model generalized to external MR images from a fifth pediatric hospital with a Dice score of 0.926. The model was more accurate than FreeSurfer, with faster operating times (1.48 seconds per scan).

CONCLUSIONS

The authors present a DL model for automatic ventricle segmentation and volume calculation that is more accurate and rapid than currently available methods. With near-immediate volumetric output and reliable performance across institutional scanner types, this model can be adapted to the real-time clinical evaluation of hydrocephalus and improve clinician workflow.

Trends in Use of Advanced Imaging in Pediatric Emergency Departments, 2009-2018

Importance

There is increased awareness of radiation risks from computed tomography (CT) in pediatric patients. In emergency departments (EDs), evidence-based guidelines, improvements in imaging technology, and availability of nonradiating modalities have potentially reduced CT use.

Objective

To evaluate changes over time and hospital variation in advanced imaging use.

Design, Setting, and Participants

This cross-sectional study assessed 26 082 062 ED visits by children younger than 18 years from the Pediatric Health Information System administrative database from January 1, 2009, through December 31, 2018.

Exposures

Imaging.

Main Outcomes and Measures

The primary outcome was the change in CT, ultrasonography, and magnetic resonance imaging (MRI) rates from January 1, 2009, to December 31, 2018. Imaging for specific diagnoses was examined using all patient-refined diagnosis related groups. Secondary outcomes were hospital admission and 3-day ED revisit rates and ED length of stay.

Results

There were a total of 26 082 062 visits by 9 868 406 children (mean [SD] age, 5.59 [5.15] years; 13 842 567 [53.1%] male; 9 273 181 [35.6%] non-Hispanic white) to 32 US pediatric EDs during the 10-year study period, with 1 or more advanced imaging studies used in 1 919 283 encounters (7.4%). The proportion of ED encounters with any advanced imaging increased from 6.4% (95% CI, 6.2%-6.2%) in 2009 to 8.7% (95% CI, 8.7%-8.8%) in 2018. The proportion of ED encounters with CT decreased from 3.9% (95% CI, 3.9%-3.9%) to 2.9% (95% CI, 2.9%-3.0%) (P < .001 for trend), with ultrasonography increased from 2.5% (95% CI, 2.5%-2.6%) to 5.8% (95% CI, 5.8%-5.9%) (P < .001 for trend), and with MRI increased from 0.3% (95% CI, 0.3%-0.4%) to 0.6% (95% CI, 0.6%-0.6%) (P < .001 for trend). The largest decreases in CT rates were for concussion (-23.0%), appendectomy (-14.9%), ventricular shunt procedures (-13.3%), and headaches (-12.4%). Factors associated with increased use of nonradiating imaging modalities included ultrasonography for abdominal pain (20.3%) and appendectomy (42.5%) and MRI for ventricular shunt procedures (17.9%) (P < .001 for trend). Across the study period, EDs varied widely in the use of ultrasonography for appendectomy (median, 57.5%; interquartile range [IQR], 40.4%-69.8%) and MRI (median, 15.8%; IQR, 8.3%-35.1%) and CT (median, 69.5%; IQR, 54.5%-76.4%) for ventricular shunt procedures. Overall, ED length of stay did not change, and hospitalization and 3-day ED revisit rates decreased during the study period.

Conclusions and Relevance

This study found that use of advanced imaging increased from 2009 to 2018. Although CT use decreased, this decrease was accompanied by a greater increase in the use of ultrasonography and MRI. There appears to be substantial variation in practice and a need to standardize imaging practices.

National Imaging Trends in Pediatric Traumatic Brain Injury and Hydrocephalus

OBJECTIVE

Reduction in use of computed tomography (CT) in favor of rapid-sequence magnetic resonance imaging (MRI) to decrease pediatric radiation exposure has varied across institutions in the United States. The aims of this study were to understand national trends in CT and rapid-sequence MRI usage and identify variables affecting imaging practices and obstacles to CT reduction.

METHODS

This was a retrospective review of deidentified discharge data for children with hydrocephalus and traumatic brain injury (TBI) in the Healthcare Cost and Utilization Project Kids' Inpatient Database in 2000, 2003, 2006, 2009, 2012, and 2016. Utilization of MRI without contrast and CT was extracted using International Classification of Diseases, Ninth Revision, and International Classification of Diseases, Tenth Revision, codes. Hospital region and age cohorts were extracted and used to categorize data. χ2 tests and logistic regression were used for analysis.

RESULTS

Hospitalizations utilizing CT decreased (P < 0.05) and hospitalizations utilizing MRI increased (P < 0.05) overall in both diagnosis groups throughout the years analyzed. However, there was significant regional variation in imaging. The Northeast had higher CT rates (P < 0.05) and the South had lower CT rates in patients with hydrocephalus and TBI (P < 0.05). No regional variation was found for rates of MRI use in patients with TBI.

CONCLUSIONS

Nationwide, the average number of discharges after hospitalizations utilizing CT in patients with hydrocephalus and TBI has decreased, while discharges after hospitalizations utilizing MRI as an alternative imaging modality have increased. Despite successful overall CT reduction, significant regional variation exists within this trend showing inconsistent reduction of CT use.

An Infant Diagnosed With Hydrocephalus by Point-of-Care Ultrasound

Point-of-care ultrasound has become a valuable tool for pediatric emergency physicians, with an increasing number of indications being described. In this case presentation, we demonstrate the use of point-of-care ultrasound in the pediatric emergency department to diagnose ventriculomegaly in an infant presenting with a seizure.

The Burden of Ionizing Radiation Studies in Children with Ventricular Shunts

OBJECTIVES

To quantify the number of shunt-related imaging studies that patients with ventricular shunts undergo and to calculate the proportion of computed tomography (CT) scans associated with a surgical intervention.

STUDY DESIGN

Retrospective longitudinal cohort analysis of patients up to age 22 years with a shunt placed January 2002 through December 2003 at a pediatric hospital. Primary outcome was the number of head CT scans, shunt series radiograph, skull radiographs, nuclear medicine, and brain magnetic resonance imaging studies for 10 years following shunt placement. Secondary outcome was surgical interventions performed within 7 days of a head CT. Descriptive statistics were used for analysis.

RESULTS

Patients (n = 130) followed over 10 years comprised the study cohort. The most common reasons for shunt placement were congenital hydrocephalus (30%), obstructive hydrocephalus (19%), and atraumatic hemorrhage (18%), and 97% of shunts were ventriculoperitoneal. Patients underwent a median of 8.5 head CTs, 3.0 shunt series radiographs, 1.0 skull radiographs, 0 nuclear medicine studies, and 1.0 brain magnetic resonance imaging scans over the 10 years following shunt placement. The frequency of head CT scans was greatest in the first year after shunt placement (median 2.0 CTs). Of 1411 head CTs in the cohort, 237 resulted in surgical intervention within 7 days (17%, 95% CI 15%-19%).

CONCLUSIONS

Children with ventricular shunts have been exposed to large numbers of imaging studies that deliver radiation and most do not result in a surgical procedure. This suggests a need to improve the process of evaluating for ventricular shunt malfunction and minimize radiation exposure.