Search

Modern hyperacute reperfusion therapies including intravenous thrombolysis and mechanical thrombectomy have transformed the management of arterial ischemic stroke (AIS) in adults. Multiple randomized clinical trials have demonstrated that these therapies enable remarkable improvements in clinical outcome for properly selected patients with AIS. Because pediatric patients were excluded from predicate clinical trials, there is a conspicuous lack of data to guide selection of therapies and inform age-adjusted and pathology-oriented treatment modifications for children. Specifically, technical guidance concerning treatment eligibility, drug dosing, and device implementation is lacking. This review aims to outline important features that differentiate pediatric AIS from adult AIS and provide practical strategies that will assist the stroke specialist with therapeutic decision making.

In children with arterial ischemic stroke (AIS), the definitive diagnosis of stroke subtype and confirmation of stroke etiology is necessary to mitigate stroke morbidity and prevent recurrent stroke. The common causes of AIS in children are sharply differentiated from the common causes of adult AIS. A comprehensive, structured diagnostic approach will identify the etiology of stroke in most children. Adequate diagnostic evaluation relies on advanced brain imaging and vascular imaging studies. A variety of medical and surgical secondary stroke prevention strategies directed at the underlying cause of stroke are available. This review aims to outline strategies for definitive diagnosis and secondary stroke prevention in children with AIS, emphasizing the critical role of neuroimaging.

OBJECTIVE Torcular dural sinus malformations (tDSMs) are rare pediatric cerebrovascular malformations characterized by giant venous lakes localized to the midline confluence of sinuses. Historical clinical outcomes of patients with these lesions were poor, though better prognoses have been reported in the more recent literature. Long-term outcomes in children with tDSMs are uncertain and require further characterization. The goal of this study was to review a cohort of tDSM patients with an emphasis on long-term outcomes and to describe the treatment strategy. METHODS This study is a single-center retrospective review of a prospectively maintained data bank including patients referred to and cared for at The Hospital for Sick Children for tDSM from January 1996 to March 2019. Each patient’s clinical, radiological, and demographic information, as well as their mother’s demographic information, was collected for review. RESULTS Ten patients with tDSM, with a mean follow-up of 58 months, were included in the study. Diagnoses were made antenatally in 8 patients, and among those cases, 4 families opted for either elective termination (n = 1) or no further care following delivery (n = 3). Of the 6 patients treated, 5 had a favorable long-term neurological outcome, and follow-up imaging demonstrated a decrease or stability in the size of the tDSM over time. Staged embolization was performed in 3 patients, and anticoagulation was utilized in 5 treated patients. CONCLUSIONS The authors add to a growing body of literature indicating that clinical outcomes in tDSM may not be as poor as initially perceived. Greater awareness of the lesion’s natural history and pathophysiology, advancing endovascular techniques, and individualized anticoagulation regimens may lead to continued improvement in outcomes.

Hemorrhage from brain arteriovenous malformations (bAVMs) is estimated at 3% per annum. Features influencing risk of hemorrhage include perforator/posterior circulation supply, associated aneurysms, and deep drainage. Children are more likely to present with bAVM bleeds.To analyze differences in bAVM angioarchitecture between children and adults and describe predictors of poor outcome.Data were collected from adult and pediatric tertiary referral hospitals. Demographic data, bleed location, treatment, and follow-up modified Rankin Scale (mRS) were collected. Angioarchitectural assessment included aneurysm presence, nidus morphology, perinidal angiogenesis, intranidal shunting, steal phenomenon, venous ectasia, venous stenosis, venous reflux, and pseudophlebitic pattern. Regression analyses conducted to determine predictors of mRS 2.A total of 270 adult and 135 pediatric ruptured bAVMs were assessed. Median age was 42 (adults) and 10.9 (children) yr. Intranidal aneurysms were more frequent in children (P = .012), whereas prenidal aneurysms were more common in adults (P .01). Children demonstrated more perinidal angiogenesis (P = .04), whereas steal phenomenon was commoner in adults (P .01). Venous ectasia (P .01), reflux (P .01), and pseudophlebitic pattern (P = .012) were more frequent in adults. Children had better outcome (mRS score ≤ 2) (P .01). Older age (odds ratio [OR] = 1.02), eloquent location (OR = 2.5), multicompartmental hemorrhage (OR = 1.98), venous reflux (OR = 2.5), diffuse nidus (OR = 1.83), pseudophlebitic pattern (OR = 1.96), intranidal shunts (OR = 2), and no treatment (OR = 3.68) were significant predictors of mRS 2.Children are more likely to have intranidal aneurysms and perinidal angiogenesis, whereas adults have more prenidal aneurysms, venous ectasia, corticovenous reflux, and pseudophlebitic pattern. Eloquent location, diffuse nidus, intranidal shunts, venous reflux, and pseudophlebitic pattern predict poorer outcome.

Background Given the expanding evidence of clinico-radiological differences between moyamoya disease (MMD) and moyamoya syndrome (MMS), we compared the clinical and radiographic features of childhood MMD and MMS to identify predictors of ischemic event recurrence. Methods We reviewed a pediatric moyamoya cohort followed between 2003 and 2019. Clinical and radiographic characteristics at diagnosis and follow-up were abstracted. Comparisons between MMD and MMS as well as between MMD and two MMS subgroups (neurofibromatosis [MMS-NF1] and sickle cell disease [MMS-SCD]) were performed. Results A total of 111 patients were identified. Patients with MMD presented commonly with transient ischemic attacks (TIAs) (35 % MMD versus 13% MMS-NF1 versus 9.5% MMS-SCD; P = 0.047). Symptomatic stroke presentation (MMD 37% versus MMS-NF1 4% versus 33%; P = 0.0147) and bilateral disease at diagnosis (MMD 73% versus MMS-NF1 22 % versus MMS-SCD 67%; P = 0.0002) were uncommon in MMS-NF1. TIA recurrence was common in MMD (hazard ratio 2.86; P = 0.001). The ivy sign was absent on neuroimaging in a majority of patients with MMS-SCD (MMD 67% versus MMS-NF1 52% versus MMS-SCD 9.5%; P = 0.0002). Predictors of poor motor outcome included early age at diagnosis (odds ratio [OR] 8.45; P = 0.0014), symptomatic stroke presentation (OR 6.6; P = 0.019), and advanced Suzuki stage (OR 3.59; P = 0.019). Conclusions Moyamoya exhibits different phenotypes based on underlying etiologies. Frequent TIAs is a common phenotype of MMD and symptomatic stroke presentation a common feature of MMD and MMS-SCD, whereas unilateral disease and low infarct burden are common in MMS-NF1. In addition, absence of ivy sign is a common phenotype in MMS-SCD.

Thromboembolic events post left ventricular assist devices (LVAD) implantation remain a major cause of morbidity and mortality. Mechanical thrombectomy for the treatment of pediatric intracranial thromboembolic events have been reported in LVADs, but never following HeartMate 3 (HM3) implantation. We present the case of an 8-year-old, 26.5 kg male with dilated cardiomyopathy and decompensated heart failure who presented with extensive intracranial thromboembolism in the early postoperative period following HM3 implantation and underwent successful mechanical thrombectomy with a favorable neurological outcome.

Knowledge of radiation quantities delivered in routine practice is an essential responsibility of a pediatric interventional radiology department.To review radiation indices in frequently performed vascular and enterostomy access procedures at a quaternary pediatric hospital to formulate dosimetric reference levels and achievable levels.A retrospective review of patient demographics, procedure information and quantitative dose metrics over a 2-year period was performed. Dosimetric details for common procedures (central line insertions, gastrostomy/gastrojejunostomy insertions and maintenance) were evaluated, correlated with demographic data and stratified across five weight groups (0-5 kg, 5-15 kg, 15-30 kg, 30-50 kg, 50-80 kg). Achievable (50th percentile) and reference (75th percentile) levels with confidence intervals were established for each procedure.Within the evaluation period, 3,165 studies satisfied the inclusion criteria. Five were classified as device insertions (peripherally inserted central catheter, n=1,145; port-a-catheter, n=321; central venous line, n=285; gastrostomy-tube [G-tube], n=262, and gastrojejunostomy-tube [GJ-tube], n=66), and two were classified as maintenance procedures (G-tube, n=358, and GJ-tube, n=728, checks, exchanges and reinsertions). Representative reference and achievable levels were calculated for each procedure category and weight group.This work highlights the creation of local reference and achievable levels for common pediatric interventional procedures. These data establish a dosimetric reference to understand the quantity of radiation routinely applied, allowing for improved relative radiation risk assessment and enriched communication to interventionalists, health care providers, parents and patients.

In children, chylothorax post cardiac surgery can be difficult to treat, may run a protracted course, and remains a source of morbidity and mortality. To analyze the experience with percutaneous image-guided chest-tube drainage in the management of post-cardiac-surgery chylothoraces in children. We conducted a single-center retrospective case series of 37 post-cardiac-surgery chylothoraces in 34 children (20 boys; 59%), requiring 48 drainage procedures with placement of 53 image-guided chest tubes over the time period 2004 to 2015. We analyzed clinical and procedural details, adverse events and outcomes. Median age was 0.6 years, median weight 7.2 kg. Attempted treatments of chylothoraces prior to image-guided chest tubes included dietary restrictions (32/37, 86%), octreotide (12/37, 32%), steroids (7/37, 19%) and thoracic duct ligation (5/37, 14%). Image-guided chest tubes (n=43/53, 81%) were single unilateral in 29 children, bilateral in 4 (n=8/53, 15%), and there were two ipsilateral tubes in one (2/53, 4%). Effusions were isolated, walled-off, in 33/53 (62%). In 20/48 procedures (42%) effusions were septated/complex. The mean drainage through image-guided chest tubes was 17.3 mL/kg in the first 24 h, and 13.4 mL/kg/day from diagnosis to chest tube removal; total mean drainage from all chest tubes was 19.6 mL/kg/day. Nine major and 27 minor maintenance procedures were required during 1,207 tube-days (rate: 30 maintenance/1,000 tube-days). Median tube dwell time was 21 days (range 4–57 days). There were eight mild adverse events, three moderate adverse events and no severe adverse events related to image-guided chest tubes. Radiologic resolution was achieved in 26/37 (70%). Twenty-three children (68%) survived to discharge; 11 children (32%) died from underlying cardiac disease. Management of chylothorax post-cardiac-surgery in children is multidisciplinary, requiring concomitant multipronged approaches, often through a protracted course. Multiple image-guided chest tube drainages can help achieve resolution with few complications. Interventional radiology involvement in tube care and maintenance is required. Overall, mortality remains high.

BackgroundFailure to appreciate deep venous drainage pathways is a major cause of severe complications in the endovascular treatment of vein of Galen aneurysmal malformations (VOGMs).ObjectiveTo report deep venous drainage patterns in patients with VOGM, emphasizing the internal cerebral veins, and to describe the challenges in evaluating these.MethodsPatients with VOGM presenting to our institute between 2000 and 2018 were retrospectively analyzed. Patients with complete and good quality imaging datasets were included in the study. Three neuroradiologists with expertise in the subject independently analyzed the deep venous drainage patterns on multi-sequence MRI and digital subtraction angiography. Follow-up imaging studies were analyzed for alterations in deep venous drainage patterns that occurred following endovascular treatment. Descriptive statistics were used to report findings.ResultsTwenty-three patients had optimal quality MRI imaging and 25 had optimal quality DSA imaging available. In 14/23 (61%) patients, internal cerebral vein (ICV) communication could be reliably identified on MRI and in 8/25 (32%) patients on DSA. Deep venous communication with the VOGM was demonstrated in 8/26 (30.8%) patients. One (3.8%) patient demonstrated ICV communication with the VOGM only on postoperative imaging, while in 2 (8%) patients the ICV drainage route changed from VOGM to alternative pathways after the procedure. Other variant pathways included lateral mesencephalic vein, superior or inferior sagittal sinus, anterior mesencephalic vein, tentorial sinus, deep Sylvian vein, and superior vermian vein.ConclusionICV communication with the VOGM is not uncommon and requires dedicated preprocedural imaging to identify it. However, there are significant challenges in assessing this communication in the presence of high-flow fistulae, vessel tortuosity and size, and contrast limitations in this population.

IMPORTANCE: The incidence and natural history of large vessel occlusion (LVO) stroke in children is largely unknown. These knowledge gaps limit the uptake of reperfusion therapies and reduce the efficiency of pediatric acute stroke pathways. OBJECTIVE: To determine the incidence and natural history of pediatric LVO stroke. DESIGN, SETTING, AND PARTICIPANTS: This retrospective population-based cohort study was conducted between January 2010 and December 2019, with a mean (SD) follow-up of 37.0 (28.8) months. Admissions from all pediatric hospitals in the state of New South Wales, Australia, with a final diagnosis of arterial ischemic stroke (AIS) in patients 1 month to younger than 17 years were included. A total of 85 of 251 identified cases were excluded based on selection criteria. Data were analyzed from July 2020 to June 2021. EXPOSURES: One-third of patients with LVO received mechanical thrombectomy with or without intravenous thrombolysis while the remainder were treated conservatively. MAIN OUTCOMES AND MEASURES: The primary outcome was the pediatric modified Rankin Scale (ped-mRS) score 3 months after stroke. Ordinal logistic regression was used to compare non-LVO, LVO without thrombectomy, and LVO with thrombectomy groups. RESULTS: Of 161 included patients, 56 (34.8%) were female, and the mean (SD) age was 6.1 (5.4) years. A total of 166 AIS admissions were studied, and clinical follow-up was available for 164 of 166 admissions. LVO was present in 39 admissions (23.5%). The incidence of LVO stroke was 0.24 per 100 000 patients per year (95% CI, 0.13-0.35). Patients with LVO who did not receive thrombectomy (n = 26) had poor neurological outcomes, with 19 (73.1%) experiencing moderate to severe disability or death (ped-mRS score of 3 to 6) at 3 months (6 of 12 patients receiving thrombectomy [50.0%]; 25 of 38 patients with LVO [65.8%]). Patients with LVO without thrombectomy had significantly worse clinical outcomes than patients with non-LVO at 3 months (odds ratio, 3.64; 95% CI, 1.68-7.87; P = .001). Most patients with LVO presented within time windows suitable for thrombectomy (27 of 39 [69.2%] within 6 hours; 35 of 39 [89.7%] within 24 hours). CONCLUSIONS AND RELEVANCE: In this population-based cohort study, the natural history of pediatric patients with LVO stroke treated conservatively was poor, with most experiencing lifelong disability or death. Nearly 90% of pediatric patients with LVO presented within time windows suitable for thrombectomy.

Introduction: Moyamoya is a progressive cerebral arteriopathy affecting the arteries in the circle of Willis. Suzuki grade for moyamoya using catheter angiogram has been gold standard for the evaluation of moyamoya both in children and adults. Suzuki grade evaluates the amount of stenosis and collateral formation in the cerebral arteries. Magnetic resonance angiography (MRA) non-luminal imaging can overestimate stenosis and underestimate collaterals. With greater use of MRA for diagnosis and follow-up, it is important to understand MRA staging is truly comparable to catheter angiogram. Methods: Study neurologist and interventional radiologist reviewed both catheter angiograms and MRAs without clinical information. The modified Suzuki stage was used to evaluate the MRA. Median time from MRA to catheter angiogram was calculated. Cohen’s Kappa was used to compare modalities of Suzuki grade based on catheter angiogram to modified Suzuki grade by MRA on the same patients. Results: A total of 29 patients with moyamoya were reviewed. Median time between MRA and catheter angiogram was 2.4 months with interquartile range from 0.6-5.3 months. Unweighted Cohen’s Kappa was 0.34 (p Conclusion: Using Cohen’s kappa to compare two methods of evaluating cerebral artery stenosis in children with moyamoya, we demonstrated that there is only moderate correlation between catheter angiogram Suzuki staging compared to modified Suzuki staging with MRA. In conclusion, we suggest caution in the reliance of MRA for diagnosis and follow-up of children with moyamoya. We recommend consideration catheter angiograms at time of diagnosis and with surgical planning.

Background: Moyamoya is a progressive arteriopathy condition characterized by steno-occlusion of the arteries of the circle of Willis. MRI performed with hypercapnic challenge can image blood-oxygen-level-dependent cerebrovascular reactivity (BOLD-CVR) thereby assessing cerebrovascular reserve. MRI studies of children Methods: Children with moyamoya underwent two BOLD-CVR imaging in the same session under GA (GA-CVR). Differences in CVR estimates and intraclass correlation coefficient (ICC) between repeated scans were examined to determine repeatability across grey and white matter tissue and vascular territories. Bland-Altman plots were used to visulaize the overall variation between the scans. The associations with age, moyamoya types, and stroke presentation were also examined. Qualitative scoring by visual inspection was also conducted by trained neurologists. Results: Thirty-two paired GA-CVR studies (sixty-four scans in total) were analyzed (mean age: 7.07 (2.74 -17.95) years, 13 females). Forty-one percent (41%) were under 7 and 77%, under 10. No significant differences between repeated scans were found for any of the CVR estimates, when summarized by tissue and vascular territory. Of the paired studies, repeatability (ICC) for the whole-brain CVR estimates was excellent (≥0.74) in 14 (43.8%), good (≤0.59, >0.74) in 7 (21.9%), fair (≤0.41, >0.59) in 6 (18.8%) and poor ( Conclusion: Our study support the clinical use of GA-CVR across all ages and disease conditions. The GA-CVR provides a feasible, repeatable, and reliably interpretable tool for the assessment of cerebrovascular reserve of very young and behaviourally challenged children with moyamoya.

Background: Moyamoya disease is a progressive steno-occlusive arteriopathy that increases stroke risk. Clinically, cognitive decline is known to occur over time, even in the absence of stroke. MRI measures of cerebrovascular reactivity (CVR) provide an in vivo assessment of cerebrovascular reserve and stroke risk. Typically, in normal-appearing white matter (WM) lower (quantified as negative) CVR is associated with increased apparent diffusion coefficient (ADC). However, the association between negative CVR and ADC in children is not well understood. Objectives: To determine (i) whether negative CVR is associated with changes in ADC in normal-appearing WM of children with Moyamoya, ii) whether there is an association between CVR and ADC with structural damage to the brain (by measuring the volume of subcortical structures). Methods: Retrospective analysis of a consecutive cohort of nine children with Moyamoya (male = 4, median age = 12.1) with no history of stroke, and seven age and sex-matched controls. ADC values and fractional negativity (fneg), calculated from CVR parametric maps as the fraction of negative CVR voxels within a region of interest (ROI), were extracted from WM and subcortical GM ROIs. Volumes from the subcortical GM regions were extracted and normalized for head size. Analyses of differences was calculated per hemisphere (n=18, bilateral disease n = 4, unilateral n=5) and categorized as affected and unaffected and compared to controls. Results: Mean (m) ADC in WM of affected hemispheres (m=807.05, p Conclusions: ADC in normal appearing WM in children with Moyamoya is elevated, and is associated with volume of the caudate in this cohort demonstrating the association between abnormal CVR, perfusion and structural damage in children with Moyamoya and no stroke.

Numerous factors make the initial diagnostic evaluation of children with suspected arterial ischemic stroke (AIS) a relatively unsettling challenge, even for the experienced stroke specialist. The low frequency of pediatric AIS, diversity of unique age-oriented stroke phenotypes, and unconventional approaches required for diagnosis and treatment all contribute difficulty to the process. This review aims to outline important features that differentiate pediatric AIS from adult AIS and provide practical strategies that will assist the stroke specialist with diagnostic decision making in the initial phase of care.

Radiation-associated aneurysms are rare, difficult to treat, and associated with high morbidity and mortality when ruptured, compared with aneurysms unrelated to radiation treatment. We present a 16-year-old patient with a radiation-induced intracranial aneurysm arising from the left posterior inferior cerebellar artery (PICA), 10 years following radiotherapy for medulloblastoma. The patient successfully underwent endovascular coil embolization of the parent artery across the neck of the aneurysm. CT angiography and MRI in the days following the procedure demonstrated maintained flow in the anterior and lateral medullary PICA segments with no brainstem infarct.

The interpretation of cerebral venous pathologies in paediatric practice is challenging as there are several normal anatomical variants, and the pathologies are diverse, involving the venous system through direct and indirect mechanisms. This paper aims to provide a comprehensive review of these entities, as their awareness can avoid potential diagnostic pitfalls. We also propose a practical classification system of paediatric cerebral venous pathologies, which will enable more accurate reporting of the neuroimaging findings, as relevant to the underlying pathogenesis of these conditions. The proposed classification system comprises of the following main groups: arterio-venous shunting-related disorders, primary venous malformations and veno-occlusive disorders. A multimodal imaging approach has been included in the relevant subsections, with a brief overview of the modality-specific pitfalls that can also limit interpretation of the neuroimaging. The article also summarises the current literature and international practices in terms of management options and outcomes in specific disease entities.

Congenital hemangiomas comprise a subset of vascular tumors with clinicopathologic features that are distinct from the more common infantile hemangioma. The authors present a patient with a large congenital hemangioma involving the forehead and brow which obstructed the visual axis and created significant risk for deprivational amblyopia. Management of the congenital hemangioma involved customized headgear to clear the visual axis and early vascular embolization of feeder vessels with the subsequent successful surgical resection at 23 days of life.A large amblyogenic congenital hemangioma required a multidisciplinary approach involving early vascular embolization of feeder vessels and subsequent surgical resection at 23 days of life.

Children with medical complexity and associated neurologic impairment frequently face difficulties with venous access. Intermittently they require urgent intravenous administration of fluids and medication. To analyze the use of implanted port-a-caths in children with medical complexity who have neurologic impairment and difficult venous access. We performed a single-center observational study of port-a-caths placed by interventional radiologists in children with medical complexity with neurologic impairment. We analyzed peripheral intravenous access attempts, peripheral intravenous starts, peripheral intravenous complications, alternative temporary central venous access devices, port-a-cath insertions, catheter days, access days, port-a-cath-related complications, hospital admissions and emergency department visits. We compared the year pre port-a-cath to the year post port-a-cath. Twenty-one children with medical complexity with neurologic impairment (10 boys, 11 girls; median age 4.1 years; median weight 13.7 kg) underwent 26 port-a-cath insertions (median catheter days 787). In the year post port-a-cath compared to pre port-a-cath there was a highly significant reduction (P

BACKGROUND AND PURPOSE: The feasibility and safety of transradial angiography is not established outside the adult literature. The objective of this study was to assess the feasibility and safety of transradial access for neuroangiography in adolescents. MATERIALS AND METHODS: A retrospective case-control study was performed, comparing transradial neuroendovascular procedures in adolescents (age range, 10–18 years) with an age- and procedure-matched cohort of transfemoral neuroendovascular procedures. Clinical and procedural details, including type of procedure, conversion rate, fluoroscopy time, radiation dose, complications, and readmissions, were reported by descriptive statistics or measures of central tendency and compared using a t test or nonparametric equivalent. A P value < .05 was considered statistically significant. RESULTS: Twenty adolescents (mean age, 14.6 [SD, 1.7] years, M/F ratio = 9:11) who underwent transradial neuroangiography were compared against 20 adolescents (mean age, 14.4 [SD, 2.1 ] years, M/F ratio = 12:8) who underwent transfemoral neuroangiography. We found no significant difference in procedural success (0% conversion rate), fluoroscopy times (33.7 [SD, 40.2] minutes versus 23.3 [SD, 26.2] minutes, P = .34) and radiation dose (150.9 [SD, 133.7] Gy×cm(2) and 122.9 [SD, 79.7] Gy×cm,(2) P = .43) There were 2 self-limiting postprocedural complications in the transradial group. There were no major hemorrhages, need for further interventions, or readmissions in either group. CONCLUSIONS: The benefits of transradial angiography described for adults can likely be safely extended to adolescents. These are important data before transitioning to smaller children and should be prospectively evaluated in a larger cohort.

Pediatric neuroendovascular procedures require special considerations. Given small vessel sizes, risk for arterial injury must be weighed against use of larger devices, with the diameter of the sheath being a known association with arterial complications. We recently transitioned to using thin-walled radial sheaths for transfemoral angiography in children, given their lower profile. Here, we report on these sheaths’ technical success and complications, comparing against a historical cohort where regular vascular sheaths were employed. We retrospectively recorded patient and procedural data from 168 consecutive procedures from September 2017 to January 2019 when radial-specific sheaths were exclusively used at our tertiary pediatric hospital. These results were compared to data from September 2015 to January 2017, when regular vascular sheaths were exclusively used in 152 consecutive procedures. Statistical analysis was performed using unpaired t test or chi-square test, with p < 0.05 considered statistically significant. Patient characteristics (age, sex, weight) were not statistically different between the case and control group. No significant differences were found in the procedural data with the exception of heparin use which was higher in the radial-sheath cohort. There was a decrease in the rate of complications in the case group (1.2%) versus control group (2.6%), though not statistically different. Radial-specific sheaths have numerous beneficial characteristics that make them well-suited to the pediatric population. In our study, we show that radial sheaths are equally effective and safe perioperatively. Follow-up research may show if radial sheaths used transfemorally decrease long-term complications such as limb-length discrepancy and mortality.

Background: Transradial intervention is increasingly replacing approaches, due to lower access complications, cost, and improved patient satisfaction. There are limited supporting data in the pediatric literature, largely due to concerns regarding arterial size. The objective of this study was to measure radial artery diameters in children across all age groups, to establish reference ranges for clinical use. Methods: This prospective study was carried out in children ≤18 years of age who underwent ultrasound for measuring radial artery diameters from November 2018 to November 2019. The cohort was divided into age groups: ≤2, 3 to 5, 6 to 8, 9 to 11, 12 to 14, 15 to 18 years, and into pre- and post-adolescent (≥12 years) groups. Results: One hundred thirty-four children (M:F=63:71) were included, with bilateral measurements resulting in 268 data points. Mean age was 8.9±5.8 years (range, 29 days to 18 years), mean weight 37.2±27.5 kg (range, 1.7–149.1 kg). Mean-corrected radial artery diameter was 1.86±0.44 mm. There was no difference in arterial diameters between males and females (1.90±0.50 versus 1.81±0.53 mm; P =0.73) or between right and left sides (1.87±0.46 versus 1.87±0.47, P =0.98). There was a strong correlation of diameter with age (R=0.75; P P Conclusions: We provide a reference range for radial artery diameters across childhood ages, which can be used for decision-making. This could be the basis for designing a trial of transradial intervention in children, to establish clinical safety and efficacy.

Radiation-associated aneurysms are rare, difficult to treat, and associated with high morbidity and mortality when ruptured, compared with aneurysms unrelated to radiation treatment. We present a 16-year-old patient with a radiation-induced intracranial aneurysm arising from the left posterior inferior cerebellar artery (PICA), 10 years following radiotherapy for medulloblastoma. The patient successfully underwent endovascular coil embolization of the parent artery across the neck of the aneurysm. CT angiography and MRI in the days following the procedure demonstrated maintained flow in the anterior and lateral medullary PICA segments with no brainstem infarct.

OBJECTIVE. The objective of this study was to assess the available evidence in the literature regarding treatment outcomes for pediatric patients with brain arteriovenous malformation (bAVM) with the aim of providing practice guidelines for treatment decisions and highlighting research areas that need attention. MATERIALS AND METHODS. Keyword searches for studies published from January 1, 1981, to April 16, 2018, were performed in MEDLINE, Embase, and Web of Science. Predefined inclusion criteria were used to identify studies. Poisson regression analysis for associations between patient and bAVM characteristics and treatment outcomes. RESULTS. We identified 34 articles comprising 2158 children with bAVM who underwent treatment or observation. The mean age of the study cohort was 12.0 ± 1.6 (SD) years, and 48.1% of the patients were female; 64.3% of bAVMs were hemorrhagic at presentation. The mean follow-up was 50.6 ± 32.3 months. Overall, the meta-analysis of pooled data showed an obliteration rate of 69.8% (95% CI, 62.9-75.9%), recurrence rate of 2.2% (95% CI, 1.1-4.3%), and mortality rate of 2.4%. The pooled complication rate was 22.5% (95% CI, 15.7-31.1%) after surgery, 26.4% (95% CI, 15.2-41.9%) after embolization, and 27.1% (95% CI, 18.1-38.4%) after radiosurgery. Mortality was not associated with age, sex, or hemorrhage; however, recurrence after treatment was inversely associated with age. Complication and mortality rates were reduced for multimodal treatments. For patients with bAVM treated with observation only, complication and mortality rates were 35.9% and 23.5%, respectively. CONCLUSION. Multimodality treatments for pediatric bAVM had lower mortality and complication rates than individual treatments. However, there is a lack of evidence for long-term outcomes. The mortality rate was highest in conservatively managed patients (i.e., observation only). Further research directly comparing different treatment modalities for recurrence and complications is warranted. Gathering data prospectively through multiinstitutional registries will be key to provide strong evidence.

Background Sacroiliitis is commonly seen in enthesitis-related arthritis (ERA), a subtype of juvenile idiopathic arthritis (JIA). Sacroiliitis is characterized by the inflammation of the sacroiliac (SI) joints (+/− adjacent tissues). The treatment options include systemic therapy with or without corticosteroid SI joint injections. Image guided SI joint injections are frequently requested in pediatric patients with sacroiliitis. The purpose of this study was to evaluate the feasibility and efficacy of SI joint injections in children with sacroiliitis. Methods A retrospective study of patients referred to Interventional Radiology (IR) for SI joint corticosteroid injections (2000–2018). Clinical information was collected from Electronic Patient Charts and procedural details from PACS. Efficacy was determined clinically, by MRI, or both when available. Results 50 patients (13.8 years; M:F = 35:15) underwent image-guided SI joint corticosteroid injections. Most common indications were JIA (84%) and inflammatory bowel disease (14%). 80% had bilateral injections. 80% were performed under general anesthesia and 20% under sedation. The corticosteroid of choice was triamcinolone hexacetonide in 98% of patients. Needle guidance and confirmation was performed using CT and fluoroscopy (54%), Cone Beam CT (CBCT, 46%), with initial ultrasound assistance in 34%. All procedures were technically successful without any complications. 32/50 patients had long-term follow-up (2 years); 21/32 (66%) had clinical improvement within 3-months. Of 15 patients who had both pre- and post-procedure MRIs, 93% showed short-term improvement. At 2 years, 6% of patients were in remission, 44% continued the same treatment and 47% escalated treatment. Conclusion Image-guided SI joint injections are safe and technically feasible in children. Imaging modalities for guidance have evolved, with CBCT being the current first choice. Most patients showed short-term clinical and imaging improvement, requiring long-term maintenance or escalation of medical treatment.

BACKGROUND AND PURPOSE: Conventional angiography is the criterion standard for measuring intracranial arterial stenosis. We evaluated signal intensity ratios from TOF-MRA as a measure of intracranial stenosis and infarct risk in pediatric stroke. MATERIALS AND METHODS: A retrospective study was undertaken in children with intracranial arterial stenosis, who had TOF-MRA and conventional angiography performed within 6 months. Arterial diameters were measured for percentage stenosis. ROI analysis on TOF-MRA measured signal intensity in pre- and poststenotic segments, with post-/pre-signal intensity ratios calculated. The Pearson correlation was used to compare percentage stenosis on MRA with conventional angiography and signal intensity ratios with percentage stenosis; the point-biserial correlation was used for infarcts compared with percentage stenosis and signal intensity ratios. Sensitivity, specificity, and positive and negative predictive values were calculated for determining severe (≥70%) stenosis from MRA and signal intensity ratios against the criterion standard conventional angiography. P 1.00: 97.1%, 77.8%, 71.7%, and 97.4%; combination: 75.5%, 100%, 100%, and 76.8%, respectively. Signal intensity ratios decreased with increasing grade of stenosis (none/mild-moderate/severe/complete, P

BACKGROUND AND PURPOSE: The benefit-risk assessment concerning radiation use in pediatric neuroangiography requires an extensive understanding of the doses delivered. This work evaluated the effective dose of 3D rotational angiography in a cohort of pediatric patients with complex neurovascular lesions and directly compared it with conventional 2D-biplane DSA. MATERIALS AND METHODS: Thirty-three 3D rotational angiography acquisitions were acquired in 24 pediatric patients (mean age, 10.4 years). When clinically indicated, following 2D-biplane DSA, 3D rotational angiography was performed with 1 of 3 technical protocols (2 subtracted, 1 unsubtracted). The protocols consisted of 1 factory and 2 customized techniques, with images subsequently reconstructed into CT volumes for clinical management. Raw projections and quantitative dose metrics were evaluated, and the effective dose was calculated. RESULTS: All 3D rotational angiography acquisitions were of diagnostic quality and assisted in patient management. The mean effective doses were 0.5, 0.12, and 0.06 mSv for the factory-subtracted, customized-subtracted, and customized-unsubtracted protocols, respectively. The mean effective dose for 2D-biplane DSA was 0.9 mSv. A direct intraprocedural comparison between 3D and 2D acquisitions indicated that customized 3D rotational angiography protocols delivered mean relative doses of 9% and 15% in unsubtracted and subtracted acquisitions, respectively, compared with biplane DSA, whereas the factory subtracted protocol delivered 68%. CONCLUSIONS: In pediatric neuroangiography, the effective dose for 3D rotational angiography can be significantly lower than for 2D-biplane DSA and can be an essential adjunct in the evaluation of neurovascular lesions. Additionally, available 3D rotational angiography protocols have significant room to be tailored for effectiveness and dose optimization, depending on the clinical question.

Background and Purpose— Literature is sparse on the frequency and significance of anatomical venous variants (AVVs) in pediatric cerebral sinovenous thrombosis (CSVT). Methods— We retrospectively reviewed children with CSVT and controls undergoing computed tomography/magnetic resonance venography from January 2008 to 2014. Clinical features examined included raised intracranial pressure, risk factors, and treatment. Radiological features examined included CSVT location, presence and type of AVVs, hemorrhagic venous infarction, and venous collateralization. Clinical outcome was measured by the pediatric stroke outcome measure and radiological outcome by thrombus recanalization. Results— Fifty-one children with CSVT were identified. Twenty-two (43%) had AVVs at presentation. Nineteen (86%) had hypoplasia/absence of major dural sinus, 5 (23%) had persistent fetal structures, 3 (14%) had duplications/fenestrations, and 1 (5%) had disconnected superficial and deep venous systems. Controls had a slightly higher but nonsignificant prevalence 26 (51%) of AVVs. No significant clinical and radiological differences were observed between children with CSVT and AVVs compared with those with typical venous anatomy. Conclusions— AVVs are seen in many children with and without CSVT and do not seem to alter the presentation or clinical course. The influence of these variations on the brain’s ability to tolerate venous congestion because of thrombosis merits further study.

Purpose To estimate reference ranges for blood flow volume (BFV) in major splanchnic, thoracoabdominal, and neck vessels by using phase-contrast magnetic resonance (MR) imaging in children and young adults in fasting and postprandial states. Materials and Methods In this institutional research ethics board-approved prospective study, healthy volunteers underwent phase-contrast MR imaging in a fasting state and again after a standardized meal. BFV values were reported as medians and ranges, and postmeal to premeal BFV ratios were calculated. BFVs in volunteers divided into two groups according to age (≤18 years old and18 years old) were compared by using the Mann-Whitney test adjusted for multiple comparisons. Linear regression for internal validation of BFV and Pearson correlation and Bland-Altman analysis for interobserver agreement were used. Results Reference ranges for BFVs were estimated in 39 volunteers (23 male and 16 female; mean age, 21.2 years ± 8.5; range, 9-40 years) and were indexed according to body surface area, with internal validation (R

Intracranial artery-to-artery antegrade revascularization is a poorly recognized entity, more so when it involves main stem arteries. The etiology, appearance, and significance of this condition are not described in the literature. We describe a case of spontaneous revascularization of a chronically occluded middle cerebral arterial branch by collaterals from the proximal segment reconstituting distal flow, mimicking a brain arteriovenous malformation in a 9-year old boy. We discuss the nature of these channels, presumed to be related to artery to artery collaterals that are either dilated adventitial vasa vasorum, or, more likely, leptomeningeal collaterals that are hypertrophied in response to cerebral demand. We review the literature regarding intracerebral vasa vasorum and leptomeningeal collaterals including their imaging. Recognizing the tortuous channels associated with this type of vascular abnormality as normal vessels reconsituting distal flow may prevent unnecessary and potentially dangerous treatments.

Introduction The influence of 4 commonly used fixed orthodontic appliances on artifact formation and diagnostic quality of magnetic resonance (MR) images of the head produced by a 3-T MR scanner was studied. Methods Stainless steel brackets, ceramic brackets, combination of ceramic brackets and steel molar tubes, and multistranded steel mandibular lingual retainers were embedded into custom-made trays for each of 10 adult subjects. Head MR scans of 9 regions were acquired for each subject wearing these trays. Sagittal T1-weighted, axial T2-weighted, axial gradient-recalled, axial diffusion-weighted, noncontrast axial MR angiography, and axial fluid-attenuated inversion recovery MR sequences were included. Two neuroradiologists evaluated image distortions and diagnostic qualities of the 1314 acquired images (13860 image slices). Results The images were affected by appliance, head region, and MR sequence. Stainless steel brackets and molar tubes affected the images the most, and ceramic brackets caused minimal image distortion. Conclusions Head MR images are differentially affected by orthodontic appliances. The appliance, region imaged, and MR sequence should be considered before imaging patients wearing fixed orthodontic appliances.

Background There has been a recent debate regarding the superiority of computed tomography angiography source images (CTASIs) over noncontrast computed tomography (NCCT) to predict the final infarct size in acute ischemic stroke (AIS). We hypothesized that the parenchymal abnormality on CTASI in faster scanners would overestimate ischemic core. Methods This prospective study assessed the correlation of Alberta Stroke Program Early CT Score (ASPECTS) on NCCT, CTASI, and computed tomography perfusion (CTP) with final infarct size in patients within 8 hours of AIS. Follow-up with NCCT or diffusion-weighted magnetic resonance imaging (MRI) was performed at 24 hours. Correlations of NCCT and CTASI with final infarct size and with CTP parameters were assessed. Subgroup analysis was performed in patients who underwent intravenous thrombolysis or mechanical thrombectomy. Inter-rater reliability was tested using Spearman's rank correlation. A P value less than .05 was considered statistically significant. Results A total of 105 patients were included in the final analysis. NCCT had a stronger correlation with the final infarct size than did CTASI (Spearman's ρ = .85 versus .78, P = .13). We found an overestimation of the final infarct size by CTASI in 47.6% of the cases, whereas NCCT underestimated infarct size in 60% of the patients. NCCT correlated most strongly with CBV (ρ = .93), whereas CTASI correlated most strongly with CBF (ρ = .87). Subgroup analysis showed less correlation of CTASI with final infarct size in the group that received thrombolysis versus the group that did not (ρ = .70 versus .88, P = .01). Conclusion In a 256-slice scanner, the CTASI parenchymal abnormality includes ischemic penumbra and thus overestimates final infarct size—this could result in inappropriate exclusion of patients from thrombolysis or thrombectomy.

A6-year-oldgirl presented with acute-onset headache andfluctuating right-sided weakness.HerPedNIHSSwas13. Brain MRI/MRA showed acute pontine arterial ischemic stroke(AIS)and remote right cerebellar and thalamic infarcts.No antecedent trauma or other stroke risk factors were identified. Clinical suspicion of bow hunter syndromewas raised. CTshowed congenital C2-C3 fusion and dynamic angiogramconfirmed the diagnosis. The management challenges of this rare condition are discussed below.