Artificial Intelligence in the Future Landscape of Pediatric Neuroradiology: Opportunities and Challenges

This paper will review how artificial intelligence (AI) will play an increasingly important role in pediatric neuroradiology in the future. A safe, transparent, and human-centric AI is needed to tackle the quadruple aim of improved health outcomes, enhanced patient and family experience, reduced costs, and improved well-being of the healthcare team in pediatric neuroradiology. Equity, diversity and inclusion, data safety, and access to care will need to always be considered. In the next decade, AI algorithms are expected to play an increasingly important role in access to care, workflow management, abnormality detection, classification, response prediction, prognostication, report generation, as well as in the patient and family experience in pediatric neuroradiology. Also, AI algorithms will likely play a role in recognizing and flagging rare diseases and in pattern recognition to identify previously unknown disorders. While AI algorithms will play an important role, humans will not only need to be in the loop, but in the center of pediatric neuroimaging. AI development and deployment will need to be closely watched and monitored by experts in the field. Patient and data safety need to be at the forefront, and the risks of a dependency on technology will need to be contained. The applications and implications of AI in pediatric neuroradiology will differ from adult neuroradiology.

Imaging Review of Pediatric Monogenic CNS Vasculopathy with Genetic Correlation

Monogenic cerebral vasculopathy is a rare but progressively recognizable cause of pediatric cerebral vasculopathy manifesting as early as fetal life. These monogenic cerebral vasculopathies can be silent or manifest variably as fetal or neonatal distress, neurologic deficit, developmental delay, cerebral palsy, seizures, or stroke. The radiologic findings can be nonspecific, but the presence of disease-specific cerebral and extracerebral imaging features can point to a diagnosis and guide genetic testing, allowing targeted treatment. The authors review the existing literature describing the frequently encountered and rare monogenic cerebral vascular disorders affecting young patients and describe the relevant pathogenesis, with an attempt to categorize them based on the defective step in vascular homeostasis and/or signaling pathways and characteristic cerebrovascular imaging findings. The authors also highlight the role of imaging and a dedicated imaging protocol in identification of distinct cerebral and extracerebral findings crucial in the diagnostic algorithm and selection of genetic testing. Early and precise recognition of these entities allows timely intervention, preventing or delaying complications and thereby improving quality of life. It is also imperative to identify the specific pathogenic variant and pattern of inheritance for satisfactory genetic counseling and care of at-risk family members. Last, the authors present an image-based approach to these young-onset monogenic cerebral vasculopathies that is guided by the size and predominant radiologic characteristics of the affected vessel with reasonable overlap. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Navigating an unexpected diagnosis - experience of a tertiary referral centre with two cases of intraplacental choriocarcinoma

Intraplacental choriocarcinoma is a rare tumour, with approximately 62 reported cases. It may manifest as a spectrum of disease ranging from an incidental lesion diagnosed on routine placental examination to disseminated maternal and/or neonatal disease. In this case series, we presented two rare cases of intraplacental choriocarcinoma with extremely varied clinical presentations. The extremely varied clinical presentations of both patients described in the case series complicated the process of arriving at the diagnosis. In both cases, subsequent investigations showed no maternal or neonatal metastasis, and maternal serum beta-hCG levels downtrended with conservative management. We aim to highlight the importance of performing a detailed physical examination and evaluation of the patient and multidisciplinary management with oncology opinion. A detailed examination of the placenta should also be considered when faced with obstetric complications so that early diagnosis and the required management can be executed in a prompt fashion.

The use of sodium MRI in the diagnosis of an anaplastic astrocytoma during immunotherapy: a case report

Gliomas in the pediatric population are targeted with immune-modulating therapies. The gold standard imaging modality for diagnosis and monitoring treatment response is magnetic resonance imaging (MRI); however, the complex post-therapy-induced changes can make treatment response assessment difficult. These include radiation necrosis, pseudoresponse, and pseudoprogression, as well as more complex responses in the setting of immunotherapy. We report a case of an 11-year-old male with a supratentorial astrocytoma (WHO grade 3) that underwent treatment with immunotherapy. There was a clinical concern for progression due to increased fluid-attenuated inversion recovery (FLAIR) hyperintensity at the site of the primary neoplasm during immunotherapy. However, the Sodium (23Na) MRI continued demonstrating decreased total sodium concentrations, supporting pseudoprogression over true progression, which was confirmed clinicaly. This case reports the capability of 23Na MRI to differentiate between progression, recurrence, and other posttreatment changes.

Review of imaging recommendations from Response Assessment in Pediatric Neuro-Oncology (RAPNO)

The Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group includes neuroradiologists, neuro-oncologists, neurosurgeons, radiation oncologists, and clinicians in various additional specialties. This review paper will summarize the imaging recommendations from RAPNO for the six RAPNO publications to date covering pediatric low-grade glioma, pediatric high-grade glioma, medulloblastoma and other leptomeningeal seeding tumors, diffuse intrinsic pontine glioma, ependymoma, and craniopharyngioma.

Artificial Intelligence Automation of Proptosis Measurement: An Indicator for Pediatric Orbital Abscess Surgery

INTRODUCTION

To evaluate the ability of artificial intelligence (AI) software to quantify proptosis for identifying patients who need surgical drainage.

METHODS

We pursued a retrospective study including 56 subjects with a clinical diagnosis of subperiosteal orbital abscess (SPOA) secondary to sinusitis at a tertiary pediatric hospital from 2002 to 2016. AI computer software was developed to perform 3D visualization and quantitative assessment of proptosis from computed tomography (CT) images acquired at the time of hospital admission. The AI software automatically computed linear and volume metrics of proptosis to provide more practice-consistent and informative measures. Two experienced physicians independently measured proptosis using the interzygomatic line method on axial CT images. The AI software and physician proptosis assessments were evaluated for association with eventual treatment procedures as standalone markers and in combination with the standard predictors.

RESULTS

To treat the SPOA, 31 of 56 (55%) children underwent surgical intervention, including 18 early surgeries (performed within 24 h of admission), and 25 (45%) were managed medically. The physician measurements of proptosis were strongly correlated (Spearman r = 0.89, 95% CI 0.82-0.93) with 95% limits of agreement of ± 1.8 mm. The AI linear measurement was on average 1.2 mm larger (p = 0.007) and only moderately correlated with the average physicians' measurements (r = 0.53, 95% CI 0.31-0.69). Increased proptosis of both AI volumetric and linear measurements were moderately predictive of surgery (AUCs of 0.79, 95% CI 0.68-0.91, and 0.78, 95% CI 0.65-0.90, respectively) with the average physician measurement being poorly to fairly predictive (AUC of 0.70, 95% CI 0.56-0.84). The AI proptosis measures were also significantly greater in the early as compared to the late surgery groups (p = 0.02, and p = 0.04, respectively). The surgical and medical groups showed a substantial difference in the abscess volume (p < 0.001).

CONCLUSION

AI proptosis measures significantly differed from physician assessments and showed a good overall ability to predict the eventual treatment. The volumetric AI proptosis measurement significantly improved the ability to predict the likelihood of surgery compared to abscess volume alone. Further studies are needed to better characterize and incorporate the AI proptosis measurements for assisting in clinical decision-making.

Pulsed Reduced Dose Rate Re-Irradiation for Recurrent Grade 4 Gliomas: A Retrospective Analysis of Safety and Efficacy

PURPOSE/OBJECTIVE(S)

Despite maximal treatment, nearly all patients with grade 4 gliomas develop recurrent disease. Treatment options for these patients are limited and overall survival is poor. Re-irradiation may be considered in certain patients, though risk of side effects often limits the effective dose able to be delivered. Pulsed reduced dose rate (PRDR) radiation is a treatment technique that reduces effective dose rate and increases treatment time allowing for intrafraction repair. Here, we report safety and efficacy of PRDR re-irradiation for recurrent grade 4 gliomas.

MATERIALS/METHODS

We performed a retrospective review of patients treated with PRDR between 2001 and 2022. Patients were treated with reduced dose rate radiation delivered in 0.2 Gy pulses every 3 minutes in 2 Gy daily fractions. Both 3D conformal and step and shoot IMRT radiation plans were utilized. Toxicities were evaluated based on Common Terminology Criteria for Adverse Events (CTCAE) v5.0 criteria. Kaplan Meier analysis was used to calculate overall survival (OS). Cox regression analysis was performed for multivariate analysis.

RESULTS

A total of 168 grade 4 glioma patients treated with PRDR re-irradiation were identified. The median age was 55 years old. The median initial radiation dose was 60 Gy (range 36 Gy - 72 Gy) and the median PRDR dose was 54 Gy (range 37.5 - 60 Gy). Seventy percent of patients received systemic therapy for recurrent disease prior to PRDR, while 30% received PRDR as first treatment for recurrent disease (or following re-resection without other treatment). The median survival following PRDR was 6.3 months. Multivariate analysis showed time since initial radiation of 14+ months (HR 0.66, p = 0.005, 95% CI 0.44 - 0.98), pre-PRDR use of steroids (HR 1.78, p = 0.005, 95% CI 1.2 - 2.66), and Karnofsky performance status of 70 or greater to be a significant predictor of survival (HR = 0.6, p = 0.008, 95% CI 0.44 - 0.98). No grade 4 or 5 toxicity was noted. Grade 3 new onset seizures was noted in 6% of patients, all subsequently controlled with medication. The most common grade 1-2 side effect after treatment was fatigue.

CONCLUSION

In this large, retrospective cohort, PRDR re-irradiation for recurrent grade 4 gliomas was well tolerated with low rates of grade 3 toxicity. Overall survival outcomes were encouraging, especially in heavily pre-treated patients. Prospective studies are ongoing to further evaluate the efficacy of PRDR for recurrent glioma treatment.

Current state of radiomics in pediatric neuro-oncology practice: a systematic review

BACKGROUND

Radiomics is the process of converting radiological images into high-dimensional data that may be used to create machine learning models capable of predicting clinical outcomes, such as disease progression, treatment response and survival. Pediatric central nervous system (CNS) tumors differ from adult CNS tumors in terms of their tissue morphology, molecular subtype and textural features. We set out to appraise the current impact of this technology in clinical pediatric neuro-oncology practice.

OBJECTIVES

The aims of the study were to assess radiomics' current impact and potential utility in pediatric neuro-oncology practice; to evaluate the accuracy of radiomics-based machine learning models and compare this to the current standard which is stereotactic brain biopsy; and finally, to identify the current limitations of radiomics applications in pediatric neuro-oncology.

MATERIALS AND METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards, a systematic review of the literature was carried out with protocol number CRD42022372485 in the prospective register of systematic reviews (PROSPERO). We performed a systematic literature search via PubMed, Embase, Web of Science and Google Scholar. Studies involving CNS tumors, studies that utilized radiomics and studies involving pediatric patients (age<18 years) were included. Several parameters were collected including imaging modality, sample size, image segmentation technique, machine learning model used, tumor type, radiomics utility, model accuracy, radiomics quality score and reported limitations.

RESULTS

The study included a total of 17 articles that underwent full-text review, after excluding duplicates, conference abstracts and studies that did not meet the inclusion criteria. The most commonly used machine learning models were support vector machines (n=7) and random forests (n=6), with an area under the curve (AUC) range of 0.60-0.94. The included studies investigated several pediatric CNS tumors, with ependymoma and medulloblastoma being the most frequently studied. Radiomics was primarily used for lesion identification, molecular subtyping, survival prognostication and metastasis prediction in pediatric neuro-oncology. The low sample size of studies was a commonly reported limitation.

CONCLUSION

The current state of radiomics in pediatric neuro-oncology is promising, in terms of distinguishing between tumor types; however, its utility in response assessment requires further evaluation which, given the relatively low number of pediatric tumors, calls for multicenter collaboration.

Progression of Subperiosteal Orbital Abscess after Clinical Resolution on Intravenous Antibiotics and Steroids

We present a case of a 7-year-old boy who was presented with a small medial subperiosteal orbital abscess (SPOA) and trace superior phlegmon and who was initially treated with intravenous (IV) antibiotics, corticosteroids, and observation. After clinical resolution and discharge, the patient returned with superior migration of his abscess requiring surgical drainage. Potential factors leading to readmission are discussed, including the anti-inflammatory and immunosuppressant effects of steroids, and presence of early surgical indictors such as bony dehiscence and proptosis. This case highlights the need for careful consideration of initial imaging and presence of a non-medial phlegmon prior to initiation of steroids.

Imaging of pediatric hematopoietic stem cell transplant recipients: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Imaging in hematopoietic stem cell transplantation patients is not targeted at evaluating the transplant per se. Rather, imaging is largely confined to evaluating peri-procedural and post-procedural complications. Alternatively, imaging may be performed to establish a baseline study for comparison should the patient develop certain post-procedural complications. This article looks to describe the various imaging modalities available with recommendations for which imaging study should be performed in specific complications. We also provide select imaging protocols for different indications and modalities for the purpose of establishing a set minimal standard for imaging in these complex patients.

Imaging of pediatric neuroblastoma: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Neuroblastoma is the most common extracranial solid neoplasm in children. This manuscript provides consensus-based imaging recommendations for pediatric neuroblastoma patients at diagnosis and during follow-up.

Imaging of pediatric brain tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper

Tumors of the central nervous system are the most common solid malignancies in children and the most common cause of pediatric cancer-related mortality. Imaging plays a central role in diagnosis, staging, treatment planning, and response assessment of pediatric brain tumors. However, the substantial variability in brain tumor imaging protocols across institutions leads to variability in patient risk stratification and treatment decisions, and complicates comparisons of clinical trial results. This White Paper provides consensus-based imaging recommendations for evaluating pediatric patients with primary brain tumors. The proposed brain magnetic resonance imaging protocol recommendations balance advancements in imaging techniques with the practicality of deployment across most imaging centers.

Migrated and Impacted Foreign Body of Retropharyngeal Space: A Case Report

Foreign body upper aerodigestive tract is a common presentation but foreign body migrating into retropharyngeal space is not only uncommon, but its management also differs and is challenging too. Here we present a case of a foreign body migrating into the retropharyngeal space which was removed intraorally. A 28- year old male patient presented with complaints of pain while swallowing following consumption of sausage and pork two days earlier to the onset of symptoms. X-Ray Neck AP and lateral view were done which revealed a thin metallic foreign body at the level of the T4 vertebra. Upper gastrointestinal endoscopy and rigid esophagoscopy were done in which a foreign body was not visualized in the esophageal lumen. NCCT neck was done which gave precise location and was removed intraorally with the patient in Rose position. A repeat x-ray was done on the 5th day which revealed no foreign body, the patient was discharged on the 7th day. Although the upper aerodigestive tract foreign body is common, foreign body migrating to the posterior pharyngeal wall or into the retropharyngeal space is not common and it is difficult to remove a migrated foreign body many cases requiring open procedures, thoracoscopy, thoracotomy.

GCT-02. Imaging response assessment for Central Nervous System Germ Cell Tumours: consensus recommendations from the European Society for Paediatric Oncology Brain Tumour Group (SIOPE-BTG) and North American Children’s Oncology Group (COG)

BACKGROUND: Central nervous system (CNS) germ cell tumours (GCT) comprise a heterogeneous and relatively rare group of neoplasms. Improving the ability to conduct international clinical trials for CNS GCT requires use of homogeneous, common objective disease assessments and standardised response criteria. Currently, different criteria are employed between European and North American protocols for assessing radiological disease response. METHODS: An international working group of the European Society for Paediatric Oncology (SIOPE) Brain Tumour Group (BTG) and North American Children’s Oncology Group (COG) was therefore established to develop consensus recommendations for imaging response assessment for CNS GCT. The working group first reviewed existing literature and current practices and identified major challenges regarding imaging assessment. RESULTS: New clinical imaging standards were defined for the most common sites of intracranial GCT disease (suprasellar/pineal/bifocal), as well as for definition of loco-regional extension. In particular, clear standards were highlighted for definition of partial response (PR) and complete response (CR) to induction chemotherapy at different sites. Furthermore, growing teratoma syndrome (GTS) was clearly defined [apparent radiological increase in non-germinomatous GCT (NGGCT) size during induction chemotherapy despite normalising/normalised AFP/HCG markers – requiring surgery], to avoid such potential cases being classified as progressive disease (PD). CONCLUSION: This consensus will allow more consistent prospective neuroradiological evaluation of response to therapy for patients with CNS GCT and facilitate direct comparison of treatment outcomes across international studies. Ultimately, it may allow international trials to be developed and undertaken across a larger group of collaborating nations, which will be essential to answer many of the remaining questions for this rare but diverse group of tumours.

EPEN-01. Response assessment in pediatric intracranial ependymoma: recommendations from the Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group

INTRODUCTION: Ependymomas remain a major cause of cancer-related death in childhood and adolescence, with recurrence occurring in up to 50% of patients. Despite exciting molecular advances in understanding ependymoma tumorigenesis and recurrence, MRI remains the mainstay for assessing objective response to therapy and duration of disease stability. Standardized response assessment criteria for clinical trials studying pediatric intracranial ependymoma are critically needed in order to accurately compare results between studies. METHODS: To generate these standardized response criteria in pediatric intracranial ependymoma, a multidisciplinary team of pediatric neuro-oncologists, neuroradiologists, neurosurgeons, radiation oncologists, and molecular biologists formed the Response Assessment in Pediatric Neuro-Oncology (RAPNO) working group. The expert members reviewed relevant published literature, assessed current clinical practices, and engaged in iterative discussions to provide consensus recommendations for objective response assessment in pediatric intracranial ependymoma for use in prospective clinical trials. RECOMMENDATIONS AND CONCLUSIONS: The primary sequences for detecting and measuring disease and assessing radiologic response to therapy should be the contrast-enhanced T1-weighted sequence or T2-weighted sequence (T2 or T2-FLAIR) depending on which sequence the tumor is best visualized. When metastatic disease is present, only the three largest lesions will be followed in addition to any residual disease at the primary tumor focus. Importantly, the RAPNO working group notes that radiologic response to therapy is of limited value in clinical trials of patients with ependymoma, since most patients enroll on clinical trials with either no evidence of disease or only minimal disease. In recurrent or progressive disease that cannot be resected, true radiologic disease response to therapy is less clinically meaningful as a study endpoint than event-free and/or overall survival (representing prolonged stable disease) but may provide a signal of efficacy worthy of future exploration in patients with complete to near complete resections.

IMG-01. Quantitative Direct Sodium (23Na) MRI in Pediatric Gliomas

BACKGROUND: The treatment of pediatric gliomas is typically assessed with proton (¹H) MRI, which can have limitations. ²³Na MRI has been shown in adult brain tumors to measure intra-tumoral total sodium concentration as a correlate of tumor proliferation. ²³Na MRI sodium studies in pediatric patients are lacking. PURPOSE: (1) To compare total sodium concentration (TSC) between pediatric glioma and non-neoplastic brain tissue using ²³Na MRI; (2) Compare tissue conspicuity of bound sodium concentration (BSC) using ²³Na MRI dual echo relative to TSC imaging. MATERIALS AND METHODS: TSC was measured in: (1) non-neoplastic brain tissues and (2) three types of manually segmented gliomas [diffuse intrinsic brainstem glioma (DIPG), recurrent supratentorial low-grade glioma (LGG), and high-grade glioma (HGG)] on sodium MRI images co-registered with proton MRI. In a subset of patients, serial changes in both TSC and BSC (dual echo ²³Na MRI) were assessed for tissue conspicuity using voxel-based parametric maps. RESULTS: Twenty-six pediatric patients with gliomas (median age of 12.0 years, range 4.9 – 23.3 years) were scanned with ²³Na MRI. Uninvolved tissues demonstrated a range of TSC values similar to published adult values. DIPG treated with RT demonstrated higher TSC values than the uninvolved infratentorial tissues (P<0.001). Recurrent supratentorial LGG and HGG exhibited higher TSC values than the uninvolved white matter (WM) and gray matter (GM) (P<0.002 for LGG, and P<0.02 for HGG). The dual echo ²³Na MRI suppresses the sodium signal within both CSF and necrotic foci, resulting in improved conspicuity of both non-neoplastic and neoplastic, compared to serial TSC imaging. CONCLUSION: Quantitative ²³Na MRI of pediatric gliomas demonstrates a range of values that are higher than non-neoplastic tissues. Dual echo ²³Na MRI of BCS improves tissue conspicuity relative to TSC imaging. Future studies are needed to determine the value of ²³Na MRI in delineating therapeutic responses in pediatric gliomas.

GCT-18. Endoscopic third ventriculostomy (ETV) and tumor biopsy are not associated with relapse rate or patterns in primary central nervous system (CNS) germ cell tumor (GCT)

BACKGROUND: ETV and tumor biopsy are central to the surgical management of children with primary CNS GCT. An ETV creates a communication between the intraventricular compartment and the subarachnoid spaces and decompartmentalizes the ventricular system. “Tumor spill” or shedding may result from surgical interventions, such as biopsy. ETV with simultaneous biopsy may impart a greater tendency for dissemination and possible distant relapse. This is a concern in CNS GCT given the attempts of irradiation field and dose reduction following chemotherapy. METHODS: We performed a retrospective review of the prospective database for the Children’s Oncology Group (COG) ACNS1123 study. Possible associations were explored among ETV, endoscopic biopsy, and combined ETV+biopsy with relapse, distant relapse, progression free survival (PFS), and time to distant relapse. RESULTS: Among 244 eligible patients, 97 ETV+/-biopsies were performed, and 30 relapses occurred. There were no associations among ETV and/or biopsy with relapse (Cochran-Mantel-Haenszel [CMH] test, with histology (germinoma vs. nongerminomatous germ cell tumor (NGGCT)) as stratification variable: ETV: p=0.3167, biopsy: p=0.3375, combined: p=0.3066), distant relapse (CMH test, ETV: p=0.4631, ETV+biopsy: p=0.6795), PFS (log-rank test, ETV: NGGCT p=0.1632, germinoma p=0.9288; biopsy: NGGCT p=0.1682, germinoma p=0.9701; ETV+Biopsy: NGGCT p=0.1306, germinoma p=0.7758), or time to distant relapse with death/local relapse as competing risk (Gray’s test, ETV: NGGCT p=0.5694, germinoma p=0.2327; biopsy: NGGCT p=0.3505, germinoma p=0.5747; ETV+Biopsy: NGGCT p=0.3988, germinoma p=0.6839). CONCLUSIONS: Based on a secondary analysis of prospective data from the ACNS1123 trial, ETV and biopsy did not impart a greater likelihood of relapse in children with primary CNS GCT treated with combined chemotherapy and irradiation. However, three tract recurrences did occur (all germinoma), suggesting that they may affect pattern of relapse. Current and future prospective trials should continue to explore associations among these variables and relapse, including patterns of relapse.

SURG-12. Endoscopic evaluation of ventricular dissemination in primary central nervous system (CNS) germ cell tumors (GCTs)

INTRODUCTION: Endoscopic third ventriculostomy and endoscopic tumor biopsy have become integral to the surgical management of children with primary CNS GCTs. Observing ependymal tumor dissemination at the time of endoscopic surgery has been anecdotally reported. The incidence and impact of this finding in CNS GCT has not been reported. METHODS: Baseline neurosurgery data capture forms and operative reports from the Children’s Oncology Group (COG) ACNS1123 study were reviewed for ventriculoscopic findings of suspected tumor dissemination. The association between these findings and relapse was determined using Fisher’s exact test for each stratum and the Cochran-Mantel-Haenszel test for the entire cohort. Progression-free survival (PFS) was defined as time from enrollment to relapse, progression, death, or last follow-up; and survival probabilities were estimated using the Kaplan-Meier method with log-rank tests for outcome comparisons. RESULTS: 110/244 patients (45.1%) underwent endoscopic neurosurgery. Twelve patients (10.9%) had a documented observation suggestive of metastatic disease within the ventricular compartment. Ten were in the third ventricle and two were in the lateral ventricle. Nine of 12 were nongerminomatous germ cell tumors (NGGCTs) and three were germinoma. Ventriculoscopic findings of metastatic tumor were not significantly associated with relapse in NGGCT (p=0.4091), germinoma (p=0.1832), or overall (p=0.1540); odds ratio 2.57 (95%CI:0.66–10.11). PFS was not influenced in NGGCT (Log-rank test, p=0.1953) but was negatively impacted in germinoma (p=0.0250) when tumor dissemination was found during ventriculoscopy. CONCLUSIONS: Ventriculoscopic observation of tumor dissemination was reported in 10.9% of cases. This may negatively influence outcomes in children with germinoma, though due to the small number of relapses, more data is needed to verify these findings. Ventriculoscopic observation of tumor dissemination may contribute toward more accurate staging and influence future therapy, but a larger sample size is needed. Prospective studies should routinely integrate documentation of endoscopic observation in the study protocol.

Quantitative Sodium (23Na) MRI in Pediatric Gliomas: Initial Experience

Background: 23Na MRI correlates with tumor proliferation, and studies in pediatric patients are lacking. The purpose of the study: (1) to compare total sodium concentration (TSC) between pediatric glioma and non-neoplastic brain tissue using 23Na MRI; (2) compare tissue conspicuity of bound sodium concentration (BSC) using 23Na MRI dual echo relative to TSC imaging. Methods: TSC was measured in: (1) non-neoplastic brain tissues and (2) three types of manually segmented gliomas (diffuse intrinsic brainstem glioma (DIPG), recurrent supratentorial low-grade glioma (LGG), and high-grade glioma (HGG)). In a subset of patients, serial changes in both TSC and BSC (dual echo 23Na MRI) were assessed. Results: Twenty-six pediatric patients with gliomas (median age of 12.0 years, range 4.9−23.3 years) were scanned with 23Na MRI. DIPG treated with RT demonstrated higher TSC values than the uninvolved infratentorial tissues (p < 0.001). Recurrent supratentorial LGG and HGG exhibited higher TSC values than the uninvolved white matter (WM) and gray matter (GM) (p < 0.002 for LGG, and p < 0.02 for HGG). The dual echo 23Na MRI suppressed the sodium signal within both CSF and necrotic foci. Conclusion: Quantitative 23Na MRI of pediatric gliomas demonstrates a range of values that are higher than non-neoplastic tissues. Dual echo 23Na MRI of BCS improves tissue conspicuity relative to TSC imaging.

Imaging response assessment for CNS germ cell tumours: consensus recommendations from the European Society for Paediatric Oncology Brain Tumour Group and North American Children's Oncology Group

Homogeneous and common objective disease assessments and standardised response criteria are important for better international clinical trials for CNS germ cell tumours. Currently, European protocols differ from those of North America (the USA and Canada) in terms of criteria to assess radiological disease response. An international working group of the European Society for Paediatric Oncology Brain Tumour Group and North American Children's Oncology Group was therefore established to review existing literature and current practices, identify major challenges regarding imaging assessment, and develop consensus recommendations for imaging response assessment for patients with CNS germ cell tumours. New clinical imaging standards were defined for the most common sites of CNS germ cell tumour and for the definition of locoregional extension. These new standards will allow the evaluation of response to therapy in patients with CNS germ cell tumours to be more consistent, and facilitate direct comparison of treatment outcomes across international studies.

Lower uterine segment scar assessment at 11-14 weeks' gestation to screen for placenta accreta spectrum in women with prior Cesarean delivery

OBJECTIVES

To validate prospectively transvaginal ultrasound assessment of the lower uterine segment (LUS) scar at the time of first-trimester screening in women with previous Cesarean section (CS) and to determine its feasibility and accuracy in stratifying women according to the risk for placenta accreta spectrum (PAS) disorder.

METHODS

Women with a history of CS were recruited between 11 + 0 and 13 + 6 weeks' gestation and underwent LUS scar assessment using transvaginal ultrasound. A standardized midsagittal plane, which included the cervicoisthmic canal (CIC), the uterine scar and the placental site, was obtained. The scar was described in terms of its size (narrow or dehiscent) and its location in relation to the CIC (within or above), with each LUS scar classified into one of four groups based on these features. Placental location was assessed and classified as high- or low-lying. Women were stratified according to the risk of PAS, based on the relationship between the scar location and placental site. Women were considered high risk when the scar was above the CIC and the placenta was low-lying (i.e. when the placenta was overlying an exposed scar) and low risk when the scar was within the CIC and/or the placenta was high. High-risk patients were followed up at 20 weeks and 28-30 weeks for the development of PAS. Maternal demographics, detailed obstetric history and obstetric outcome were collected.

RESULTS

First-trimester transvaginal ultrasound was offered to 535 women with prior CS during the study period. A LUS scar was visualized in 79.9% (401/502) of those who agreed to undergo the examination. At this scan, the LUS scar was above the CIC in 9.0% (36/401) of women, but only 5.7% (23/401) additionally had a low-lying placenta overlying the scar. Of these 23 high-risk women, two were found to have PAS on the mid-trimester screening scan and one was noted to have placental adherence during evacuation following mid-trimester termination of pregnancy. On the first-trimester scan, 94.3% (378/401) of women were at low risk of PAS. This screening protocol yielded a positive likelihood ratio of 21.33 (95% CI, 13.02-34.96), sensitivity of 100% (95% CI, 29.24-100%), specificity of 95.31% (95% CI, 92.39-97.35%), positive predictive value of 16.7% (95% CI, 5.8-39.2%) and negative predictive value of 100% (95% CI, 98.4-100%). On multivariable regression analysis performed to identify confounding variables associated with a LUS scar above the CIC, only maternal body mass index ≥ 30 kg/m² was significant (odds ratio (OR), 2.42 (95% CI, 1.04-5.39); P = 0.03). Although there was a trend towards an increased risk of a LUS scar above the CIC in women with prior elective prelabor CS (OR, 1.72 (95% CI, 0.80-3.68)), this association did not reach statistical significance.

CONCLUSIONS

Routine transvaginal ultrasound assessment of the location of the LUS scar and placenta at the time of first-trimester screening between 11 + 0 and 13 + 6 weeks' gestation in women with prior CS is a feasible and effective tool to identify those at risk of subsequent development of PAS disorder. A finding of placental implantation over an exposed LUS scar seems to be cardinal in predicting the risk of PAS disorder in women with prior CS, with an excellent negative predictive value. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Mapping Pediatric Spinal Cord Development with Age

Pediatric spinal cord morphometry has been relatively understudied because of non-optimal image quality due to the difficulty of spine imaging, rarity of post-mortem analysis, motion artifacts, and pediatric MR imaging research focus on understanding spinal injury or pathology. The pediatric brain has been comparatively well-studied with white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) differences observed with age and gender. Therefore, a greater understanding of pediatric cervical and thoracic spinal cord morphometry would be beneficial for developing clinically relevant cord growth models. We focused on retrospectively characterizing cervical and thoracic spinal cord growth and morphometry changes in a healthy pediatric population. High resolution multi-echo gradient echo (mFFE) images were acquired from pediatric spinal cord scans from 63 patients (mean: 9.24 years, range: 0.83-17.67 years). The mFFE scans were then registered to the template space for uniform viewing and analysis by using a customized semi-automatic processing pipeline involving Spinal Cord Toolbox (SCT). Jacobian control determinants were calculated, and subsequent WM, GM, dorsal column, lateral funiculi, and ventral funiculi scalar averaging was conducted. Random effects models were used to model age-related Jacobian scalar differences. Observing the growth of cord matter by patient age and vertebral level suggests that the upper cervical spinal cord, specifically C2-C3, and mid-thoracic spinal cord, T3-T8, grow faster than other cervical levels and thoracic levels, respectively. This knowledge will facilitate clinical decision making when considering spine interventions and conducting radiological analysis in children with cervical and thoracic spine abnormalities.

Phase II trial of response-based radiation therapy for patients with localized germinoma: a Children's Oncology Group study

BACKGROUND

The study aimed to evaluate whether simplified chemotherapy followed by dose-reduced irradiation was effective for treating patients (ages 3-21 years) with localized germinoma. The primary endpoint was 3-year progression-free survival (PFS) rate.

METHODS

Patients with a complete response to chemotherapy with carboplatin and etoposide received 18 Gy WVI + 12 Gy boost to the tumor bed. Patients with partial response proceeded to 24 Gy WVI + 12 Gy. Longitudinal cognitive functioning was evaluated prospectively on ALTE07C1 and was a primary study aim.

RESULTS

One hundred and fifty-one patients were enrolled; 137 were eligible. Among 90 evaluable patients, 74 were treated with 18 Gy and 16 with 24 Gy WVI. The study failed to demonstrate noninferiority of the 18 Gy WVI regimen compared to the design threshold of 95% 3-year PFS rate, where, per design, patients who could not be assessed for progression at 3 years were counted as failures. The Kaplan-Meier (KM)-based 3-year PFS estimates were 94.5 ± 2.7% and 93.75 ± 6.1% for the 18 Gy and 24 Gy WVI cohorts, respectively. Collectively, estimated mean IQ and attention/concentration were within normal range. A lower mean attention score was observed at 9 months for patients treated with 24 Gy. Acute effects in processing speed were observed in the 18 Gy cohort at 9 months which improved at 30-month assessment.

CONCLUSIONS

While a failure according to the prospective statistical noninferiority design, this study demonstrated high rates of chemotherapy responses, favorable KM-based PFS and OS estimates in the context of reduced irradiation doses and holds promise for lower long-term morbidities for patients with germinoma.

Neuroaxial Infantile Hemangiomas: Imaging Manifestations and Association with Hemangioma Syndromes

BACKGROUND AND PURPOSE

Infantile hemangiomas are common lesions in the pediatric population; in rare cases, an infantile hemangioma can be detected along the neural axis. The purposes of our study included determination of the incidence, location, and imaging appearance of neuroaxial infantile hemangiomas and their syndromic association. We also assessed additional features of cerebral and cardiovascular anomalies that may be associated with neuroaxial lesions.

MATERIALS AND METHODS

A retrospective cohort study was performed, searching the radiology database for patients with segmental infantile hemangiomas referred for assessment of possible hemangioma syndromes. We retrospectively reviewed brain and spine MR imaging studies, with particular attention paid to neuroaxial vascular lesions, as well as the relevant clinical data. Neuroaxial hemangioma imaging findings were described, and comparison of segmental cutaneous infantile hemangioma location with the imaging findings was performed in patients with confirmed hemangioma syndromes and in patients with isolated skin infantile hemangioma.

RESULTS

Ninety-five patients with segmental infantile hemangioma were included in the study, 42 of whom had a hemangioma syndrome; of those, 41 had posterior fossa brain malformations, hemangioma, arterial lesions, cardiac abnormalities, and eye abnormalities (PHACE) syndrome and 1 had diffuse neonatal hemangiomatosis. Neuroaxial involvement was detected in 20/42 patients (48%) with hemangioma syndromes and in no subjects with isolated segmental infantile hemangioma (P < .001). The most common intracranial hemangioma location was within the ipsilateral internal auditory canal (83%).

CONCLUSIONS

Many pediatric patients with segmental infantile hemangioma in the setting of hemangioma syndromes, especially those with PHACE, had neuroaxial hemangiomas. This finding may potentially lead to requiring additional clinical evaluation and management of these patients.

Maternal diabetes and fetal cardiac output

BACKGROUND

The intrauterine environment is a key determinant for long-term health outcomes. Adverse fetal environments, such as maternal diabetes, obesity and placental insufficiency are strongly associated with long-term health risks in children. Little is known about differences in fetal cardiac output hemodynamics of diabetic mothers (DM) vs. non-diabetic mothers (NDM). Our study aims to investigate the left-sided, right-sided, and combined cardiac output (CCO) in fetuses of DM vs. NDM.

METHODS

Retrospective data were collected in fetuses of DM (N = 532) and NDM (103) at mean gestational age 24 weeks. Examination included 2D echo and pulse wave Doppler. Wilcoxon rank sum tests and Chi-square tests were used to test for distribution difference of maternal and fetal continuous and categorical measures respectively between DM and NDM. Intraclass correlation coefficients were calculated to assess intra-observer reliability of fetal cardiac measurements.

RESULTS

DM mothers had higher mean weight (89.7±22.2 kg) than NDM (76.8±19.8 kg), p <  0.0001 and higher mean BMI (33.4±7.5) than NDM (28.3±5.8), p <  0.0001. C-section delivery occurred in 66% of DM vs. 35% of NDM fetuses. Fetuses of DM mothers had significantly larger semilunar valve diameter, higher left ventricular (LV) output, higher combined cardiac output and lower right ventricle /left ventricle ratio compared to NDM.

CONCLUSION

The greater CCO (adjusted for fetal weight), left sided cardiac output in the fetuses of DM, compared to NDM, represent differences in cardiac adaptation to the diabetic environment.

EPCT-20. TECHNICAL FEASIBILITY SODIUM (23NA) MRI OF PEDIATRIC GLIOMAS

Pediatric glioma response to novel targeted therapy can be heterogeneous on conventional proton (1H) MRI. Sodium concentration, as measured with 23Na MRI in adult brain tumors can provide complementary assessment of tumor proliferation to conventional MRI. However, 23Na MRI pediatric brain tumor studies are lacking. Determine the technical feasibility of performing sodium23Na MRI on pediatric glioma patients. Prospective study of an immunotherapy trial for newly diagnosed and recurrent gliomas (high-grade gliomas, low-grade gliomas, brainstem gliomas) in which participants were imaged with 23Na MRI at 3.0 Tesla. The participants (n=26, 14 males) with median age of 11 years (range = 4–23 years of age) were prospectively evaluated with sodium. 23Na MRI is technically feasible in the pediatric population and can distinguish different types of pediatric gliomas at baseline.

Abusive head trauma: neuroimaging mimics and diagnostic complexities

Traumatic brain injury is responsible for approximately half of all childhood deaths from infancy to puberty, the majority of which are attributable to abusive head trauma (AHT). Due to the broad way patients present and the lack of a clear mechanism of injury in some cases, neuroimaging plays an integral role in the diagnostic pathway of these children. However, this nonspecific nature also presages the existence of numerous conditions that mimic both the clinical and neuroimaging findings seen in AHT. This propensity for misdiagnosis is compounded by the lack of pathognomonic patterns and clear diagnostic criteria. The repercussions of this are severe and have a profound stigmatic effect. The authors present an exhaustive review of the literature complemented by illustrative cases from their institutions with the aim of providing a framework with which to approach the neuroimaging and diagnosis of AHT.

Magnetic resonance imaging of the brainstem in children, part 2: acquired pathology of the pediatric brainstem

Part 1 of this series of two articles describes conventional and advanced MRI techniques that are useful for evaluating brainstem pathologies. In addition, it provides a review of the embryology, normal progression of myelination, and clinically and radiologically salient imaging anatomy of the normal brainstem. Finally, it discusses congenital diseases of the brainstem with a focus on distinctive imaging features that allow for differentiating pathologies. Part 2 of this series of two articles includes discussion of neoplasms; infections; and vascular, demyelinating, toxic, metabolic and miscellaneous disease processes affecting the brainstem. The ultimate goal of this pair of articles is to empower the radiologist to add clinical value in the care of pediatric patients with brainstem pathologies.

GCT-41. RESPONSE-BASED RADIATION THERAPY IN PATIENTS WITH NEWLY DIAGNOSED CENTRAL NERVOUS SYSTEM LOCALIZED GERMINOMA: A CHILDREN’S ONCOLOGY GROUP (COG) PROSPECTIVE PHASE 2 CLINICAL TRIAL

BACKGROUND

The objective of stratum 2 of COG ACNS1123 was to evaluate children and young adults (3–21 years) with localized central nervous system (CNS) germinoma and investigate whether simplified pre-irradiation chemotherapy followed by response based dose-reduced whole ventricular irradiation (WVI) would maintain a high progression-free survival (PFS) while reducing long term treatment burden.

METHODS

Pre-irradiation chemotherapy consisted of 4 cycles of carboplatin and etoposide every 21 days followed by response-based irradiation (XRT). Patients with a complete response (CR) to pre-XRT chemotherapy received 18Gy WVI + 12Gy boost to the tumor bed. Patients with partial response (PR) but less than 1.5 cm residual proceeded to 24Gy WVI + 12Gy boost. All patients were also enrolled on COG ALTE07C1 to prospectively evaluate and longitudinally model the cognitive, social and behavioral functioning.

RESULTS

During a total accrual time of 45.5 months from 05/2012 to 06/2018, 137 eligible patients were enrolled. Median age was 14.09 years (4.95–21.46), 73% were male, and 45.26% had elevated βhCG in serum and/or cerebrospinal fluid. Twenty-nine patients (21.17%) did not have tissue biopsy. Eleven patients underwent second-look surgery; 7 had mature teratoma and 4 had non-viable tumor. Eighty-one patients (59.13%) had a CR. There were 4 relapses in patients receiving 18Gy WVI + boost, but no deaths. No unexpected treatment-related events were observed. The estimated 3-year PFS was 94.4 ±2.7% among 74 evaluable subjects.

CONCLUSION

This study shows promise in XRT reduction for patients with localized CNS germinoma and CR. Long-term survival outcomes and ALTE07C1 data are being evaluated.

Ocular findings of albinism in DYRK1A-related intellectual disability syndrome

BACKGROUND

Pathogenic variants in DYRK1A are associated with DYRK1A-related intellectual disability syndrome (DIDS). Common features of this diagnosis include microcephaly, intellectual disability, speech impairment, and distinct facial features. Reported ocular features include deep-set eyes, myopia, and strabismus. We present a case of DYRK1A-related intellectual disability syndrome with ocular findings of albinism and explore the possible pathogenesis of this previously unreported manifestation.

MATERIALS AND METHODS

This is a single, retrospective case report of a child with DIDS who underwent an ophthalmic exam including detailed visual electrophysiology. Results: A 21-month-old female with microcephaly, failure to thrive, language delay, cleft palate, and cardiac defects had an ophthalmic exam showing myopia, strabismus, a hypopigmented fundus and crossed asymmetry on visual evoked potential (VEP), consistent with ocular findings of albinism. Whole exome sequencing identified a pathogenic DYRK1A variant; no albinism gene variants were reported. Her constellation of features is consistent with a diagnosis of DYRK1A-related intellectual disability syndrome; however, ocular features of albinism have not previously been reported in this condition.

CONCLUSIONS

This is, to the best of our knowledge, the first report of ocular findings of albinism in a case of DYRK1A-related intellectual disability syndrome. We propose that ocular albinism is a novel ocular phenotype of DYRK1A-related disease. Ophthalmic exams in patients with this diagnosis should include thorough evaluation for ocular albinism, including VEPs.

Non-congenital viral infections of the central nervous system: from the immunocompetent to the immunocompromised child

Non-congenital viral infections of the central nervous system in children can represent a severe clinical condition that needs a prompt diagnosis and management. However, the aetiological diagnosis can be challenging because symptoms are often nonspecific and cerebrospinal fluid analysis is not always diagnostic. In this context, neuroimaging represents a helpful tool, even though radiologic patterns sometimes overlap. The purpose of this pictorial essay is to suggest a schematic representation of different radiologic patterns of non-congenital viral encephalomyelitis based on the predominant viral tropism and vulnerability of specific regions: cortical grey matter, deep grey matter, white matter, brainstem, cerebellum and spine.

Efficacy and Safety of a Novel Broad-Spectrum Anti-MRSA Agent Levonadifloxacin Compared with Linezolid for Acute Bacterial Skin and Skin Structure Infections: A Phase 3, Openlabel, Randomized Study

BACKGROUND

Levonadifloxacin is a novel broad-spectrum anti-MRSA agents belonging to the benzoquinolizine subclass of quinolone. It is developed for oral or intravenous administration for the treatment of infections caused by Gram-positive organisms including methicillin-resistant Staphylococcus aureus (MRSA).

OBJECTIVES

To establish the non-inferiority of levonadifloxacin compared with linezolid for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and to compare the safety of the two antimicrobials.

SUBJECTS AND METHODS

This was a Phase 3, multicentre, randomized, open-label, active- comparator study with 500 subjects. Oral levonadifloxacin 1000 mg was compared with oral linezolid 600 mg whereas IV levonadifloxacin 800mg was compared with IV linezolid 600 mg, each treatment was administered twice daily for 7-10 days. Non-inferiority was evaluated by comparing oral levonadifloxacin to oral linezolid and IV levonadifloxacin to IV linezolid for overall clinical response at TOC (Test of Cure) Visit.

RESULTS

The clinical cure rates observed at the TOC in the mITT (modified Intent to treat) populations for levonadifloxacin was numerically higher compared to linezolid in the IV sub-group [(91.0% verses 87.8%); treatment difference of 3.2% (95%CI, -4.5 to 10.9)] and in the oral sub-group (95.2% versus 93.6%); treatment difference of 1.6 % [95%CI, -4.2 to 7.3]). As the lowerbound of the 95% CI around the treatment difference was greater than -15% for both subgroups, the primary objective of the study was met. Therefore, both IV levonadifloxacin and oral levonadifloxacin were non-inferior to IV linezolid and oral linezolid, respectively. The majority of subjects in the micro-ITT population had a baseline infection caused by S. aureus with approximately 30% of subjects having MRSA. Levonadifloxacin (IV and oral) had a higher clinical cure rate at TOC for MRSA patients compared with linezolid (IV and oral), (95.0% vs. 89.3% respectively). Levonadifloxacin showed evidence of favourable clinical and microbiological efficacy in subjects with concurrent bacteraemia as well as in subjects with diabetes including diabetic foot infections caused by Gram-positive pathogens including MRSA. Pharmacokinetic analysis showed that bioavailability of oral levonadifloxacin was 90% and similar pharmacokinetic profile of levonadifloxacin by both routes provide an option for IV to oral switch for the treatment of subjects. Incidences of treatment-emergent adverse events (TEAEs) were similar between treatment groups and between IV (20.8% vs. 22.4%, for levonadifloxacin and linezolid, respectively) and oral therapy (16.0% vs. 13.5%, respectively), There were no SAEs or deaths related to study drug and the majority of the AEs observed were mild in nature. Overall, the administration of both IV and oral levonadifloxacin was well-tolerated in subjects with ABSSSI.

CONCLUSIONS

The results demonstrate that IV and oral levonadifloxacin therapy has excellent clinical activity against MRSA and offers advantage compared to other quinolones which generally lack MRSA coverage. Levonadifloxacin is safe and well tolerated in the treatment of ABSSSI caused by Gram -positive pathogens including MRSA as well as non-inferior to IV and oral linezolid, respectively. Similar pharmacokinetic profile of IV and oral levonadifloxacin provides an option for IV to oral switch for the treatment of subjects. Both oral and IV levonadifloxacin have recently been granted approval in India for the treatment of ABSSSI including diabetic foot infections and concurrent bacteraemia in adults (18 years of age or older). ClinicalTrials.gov Registration: NCT03405064. CTRI No.: CTRI/2017/06/008843.

Caring for patients with pain during the COVID-19 pandemic: consensus recommendations from an international expert panel

Chronic pain causes significant suffering, limitation of daily activities and reduced quality of life. Infection from COVID-19 is responsible for an ongoing pandemic that causes severe acute respiratory syndrome, leading to systemic complications and death. Led by the World Health Organization, healthcare systems across the world are engaged in limiting the spread of infection. As a result, all elective surgical procedures, outpatient procedures and patient visits, including pain management services, have been postponed or cancelled. This has affected the care of chronic pain patients. Most are elderly with multiple comorbidities, which puts them at risk of COVID-19 infection. Important considerations that need to be recognised during this pandemic for chronic pain patients include: ensuring continuity of care and pain medications, especially opioids; use of telemedicine; maintaining biopsychosocial management; use of anti-inflammatory drugs; use of steroids; and prioritising necessary procedural visits. There are no guidelines to inform physicians and healthcare providers engaged in caring for patients with pain during this period of crisis. We assembled an expert panel of pain physicians, psychologists and researchers from North America and Europe to formulate recommendations to guide practice. As the COVID-19 situation continues to evolve rapidly, these recommendations are based on the best available evidence and expert opinion at this present time and may need adapting to local workplace policies.

Magnetic Resonance Imaging characteristics in case of TOR1AIP1 muscular dystrophy

Mutations in the torsinA-interacting protein 1 (TOR1AIP1) gene result in a severe muscular dystrophy with minimal literature in the pediatric population. We review a case of TOR1AIP1 gene mutation in a 16-year-old Caucasian female with a long history of muscle weakness. Extensive clinical workup was performed and MRI at time of initial presentation demonstrated no significant muscular atrophy with heterogenous STIR hyperintensity of the lower extremity muscles. MRI findings seven years later included extensive atrophy of the lower extremities, with severe progression, including the gluteal muscles, iliopsoas, rectus femoris, and obturator internus. There was also significant atrophy of the rectus abdominis and internal and external oblique muscles, and iliacus muscles. The MRI findings showed more proximal involvement of lower extremities and no atrophy of the tibialis anterior, making TOR1AIP1 the more likely genetic cause. Muscle biopsy findings supported TOR1AIP1 limb-girdle muscular dystrophy. Though rare, TOR1AIP1 gene mutation occurs in pediatric patients and MRI can aid in diagnosis and help differentiate from other types of muscular dystrophy. Genetic and pathology workup is also crucial to accurate diagnosis and possible treatment of these patients.

Interrater reliability of a method to assess hypothalamic involvement in pediatric adamantinomatous craniopharyngioma

OBJECTIVE

Pediatric adamantinomatous craniopharyngiomas (ACPs) are histologically benign brain tumors that confer significant neuroendocrine morbidity. Previous studies have demonstrated that injury to the hypothalamus is associated with worsened quality of life and a shorter lifespan. This insight helps many surgeons define the goals of surgery for patients with ACP. Puget and colleagues proposed a 3-tiered preoperative and postoperative grading system based on the degree of hypothalamic involvement identified on MRI. In a prospective cohort from their institution, the authors found that use of the system to guide operative goals was associated with decreased morbidity. To date, however, the Puget system has not been externally validated. Here, the authors present an interrater reliability study that assesses the generalizability of this system for surgeons planning initial operative intervention for children with craniopharyngiomas.

METHODS

A panel of 6 experts, consisting of pediatric neurosurgeons and pediatric neuroradiologists, graded 30 preoperative and postoperative MRI scans according to the Puget system. Interrater reliability was calculated using Fleiss' κ and Krippendorff's α statistics.

RESULTS

Interrater reliability in the preoperative context demonstrated moderate agreement (κ = 0.50, α = 0.51). Interrater reliability in the postoperative context was 0.27 for both methods of statistical evaluation.

CONCLUSIONS

Interrater reliability for the system as defined is moderate. Slight refinements of the Puget MRI grading system, such as collapsing the 3 grades into 2, may improve its reliability, making the system more generalizable.

P5658Incorporation of severity of left atrial enlargement in clinical risk factors improves identification of patients at risk for development of atrial fibrillation

Background

Early identification of patients at risk for atrial fibrillation (AF) is desirable to prevent its development and complications. Clinical predictors have been recognized but need refinement to improve predictability. We evaluated whether severity of left atrial enlargement (LAE) added to a scoring system (CHA2DS2VASC) in an unselected non-AF population improves risk stratification for incident AF.

Purpose

To assess the incremental benefit of LAE severity added to CHA2DS2VASc in predicting future AF in non-AF patients.

Methods

From 2012–2017, consecutive adult patients with an echocardiogram and no prior AF were identified. CHA2DS2VASc was used to define baseline AF risk, and the incremental risk of AF with addition of LAE was assessed through increased LA volume index (LAVI; moderate 42–48 ml/m2, severe >48 ml/m2). To quantify improvement in risk prediction, logistic regression model was fitted and odds ratios (OR) and ROC curves obtained.

Results

Out of 155,597 patients with no prior AF, 13.8% developed AF over 1.5±1.3 years. OR for AF with CHA2DS2VASc was 1.68 (95% CI 1.66–1.69). With addition of moderately or severely increased LAVI to the model, OR for AF increased to 2.3 (2.2–2.5) and 3.8 (3.6–4.0), respectively. ROC analysis showed c-statistics of 0.66 with CHA2DS2VASc, 0.63 with LAVI, and 0.71 with incorporation of both (Fig).

AF CHAD score

Conclusion(s)

In non-AF patients, predictability for future AF can be improved by using clinical factors (CHA2DS2VASc) and increased LAVI. This information may guide closer monitoring and initiation of therapies to prevent progression to AF or stroke.

Acknowledgement/Funding

None

The Clinical Utility of Flexion-extension Cervical Spine MRI in 22q11.2 Deletion Syndrome

BACKGROUND

Our goal is to correlate the findings on flexion and extension radiographs with dynamic magnetic resonance imaging (MRI), and the clinical history, in a nonrandomly selected cohort of patients with 22q11.2 deletion syndrome (22q).

METHODS

All patients with the 22q who had a dynamic MRI from January 2004 to March 2015 were included. We analyzed multiple radiographic measurements on both the dynamic plain films and the MRIs, and correlated these findings with a review of each patient's medical record.

RESULTS

Multiple congenital anomalies were identified as noted in previous studies, and 61% of the patients had a failure of fusion of the anterior (n=2, 9%), posterior (n=2, 9%), or anterior and posterior arches (n=10, 43%). Quantitative measurements were impossible to report with certainty because of the upper cervical anomalies, and no cases of instability were identified using a qualitative assessment. We identified spinal cord encroachment (30%) and impingement (18%); however, none of the patients had any signal change in their spinal cord. None of these findings could be definitively correlated with any clinical symptoms. A single patient was diagnosed with a Chiari I malformation, while another had cerebellar ectopia.

CONCLUSIONS

Although the upper cervical anomalies are extremely common in 22q, we did not identify cases of instability on dynamic plain radiographs and MRI. Although our findings do not support routine screening with flexion and extension MRI, this study may be required in patients with neurological symptoms and/or findings or abnormalities on dynamic plain radiographs.

LEVEL OF EVIDENCE

Level III.

Multiple sclerosis lesions affect intrinsic functional connectivity of the spinal cord

Patients with multiple sclerosis present with focal lesions throughout the spinal cord. There is a clinical need for non-invasive measurements of spinal cord activity and functional organization in multiple sclerosis, given the cord's critical role in the disease. Recent reports of spontaneous blood oxygenation level-dependent fluctuations in the spinal cord using functional MRI suggest that, like the brain, cord activity at rest is organized into distinct, synchronized functional networks among grey matter regions, likely related to motor and sensory systems. Previous studies looking at stimulus-evoked activity in the spinal cord of patients with multiple sclerosis have demonstrated increased levels of activation as well as a more bilateral distribution of activity compared to controls. Functional connectivity studies of brain networks in multiple sclerosis have revealed widespread alterations, which may take on a dynamic trajectory over the course of the disease, with compensatory increases in connectivity followed by decreases associated with structural damage. We build upon this literature by examining functional connectivity in the spinal cord of patients with multiple sclerosis. Using ultra-high field 7 T imaging along with processing strategies for robust spinal cord functional MRI and lesion identification, the present study assessed functional connectivity within cervical cord grey matter of patients with relapsing-remitting multiple sclerosis (n = 22) compared to a large sample of healthy controls (n = 56). Patient anatomical images were rated for lesions by three independent raters, with consensus ratings revealing 19 of 22 patients presented with lesions somewhere in the imaged volume. Linear mixed models were used to assess effects of lesion location on functional connectivity. Analysis in control subjects demonstrated a robust pattern of connectivity among ventral grey matter regions as well as a distinct network among dorsal regions. A gender effect was also observed in controls whereby females demonstrated higher ventral network connectivity. Wilcoxon rank-sum tests detected no differences in average connectivity or power of low frequency fluctuations in patients compared to controls. The presence of lesions was, however, associated with local alterations in connectivity with differential effects depending on columnar location. The patient results suggest that spinal cord functional networks are generally intact in relapsing-remitting multiple sclerosis but that lesions are associated with focal abnormalities in intrinsic connectivity. These findings are discussed in light of the current literature on spinal cord functional MRI and the potential neurological underpinnings.

Quantification of DTI in the Pediatric Spinal Cord: Application to Clinical Evaluation in a Healthy Patient Population

BACKGROUND AND PURPOSE

The purpose of the study is to characterize diffusion tensor imaging indices in the developing spinal cord, evaluating differences based on age and cord region. Describing the progression of DTI indices in the pediatric cord increases our understanding of spinal cord development.

MATERIALS AND METHODS

A retrospective analysis was performed on DTI acquired in 121 pediatric patients (mean, 8.6 years; range, 0.3-18.0 years) at Monroe Carell Jr. Children's Hospital at Vanderbilt from 2017 to 2018. Diffusion-weighted images (15 directions; b = 750 s/mm²; slice thickness, 5 mm; in-plane resolution, 1.0 × 1.0 mm²) were acquired on a 3T scanner in the cervicothoracic and/or thoracolumbar cord. Manual whole-cord segmentation was performed. Images were masked and further segmented into cervical, upper thoracic, thoracolumbar, and conus regions. Analyses of covariance were performed for each DTI-derived index to investigate how age affects diffusion across cord regions, and 95% confidence intervals were calculated across age for each derived index and region. Post hoc testing was performed to analyze regional differences.

RESULTS

Analyses of covariance revealed significant correlations of age with axial diffusivity, mean diffusivity, and fractional anisotropy (all, P < .001). There were also significant differences among cord regions for axial diffusivity, radial diffusivity, mean diffusivity, and fractional anisotropy (all, P < .001).

CONCLUSIONS

This research demonstrates that diffusion evolves in the pediatric spinal cord during development, dependent on both cord region and the diffusion index of interest. Future research could investigate how diffusion may be affected by common pediatric spinal pathologies.