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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.

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.

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.

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.

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.

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.

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

The association of perfusion abnormalities with tissue architecture and myocardial function in Kawasaki disease (KD) is poorly understood [(1)][1]. The aims of this study were to quantify myocardial perfusion, measure extracellular volume (ECV) and left ventricular (LV) contractility, and assess

IMPORTANCE: Major neurological complications from the embolization of vein of Galen malformations (VOGMs) are poorly understood. We provide a detailed analysis of contributors to periprocedural neurological complications and lessons learned. OBJECTIVE: To assess the rate of major periprocedural neurological complications following VOGM embolization with major procedural and strategic contributors. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study was conducted at a quarternary referral pediatric hospital (Hospital for Sick Children; Toronto, Ontario, Canada) from January 1999 to December 2018 with a mean clinical follow-up of 44.7 months; all children with VOGM diagnosed and/or treated were eligible (n = 48). Thirty-three patients who underwent endovascular treatment were included. INTERVENTIONS: Endovascular staged transarterial embolization performed in 33 patients over 91 sessions. MAIN OUTCOMES AND MEASURES: The primary outcome was the rate of periprocedural neurological complications (occurring within 1 week of embolization). The secondary outcomes were mortality, long-term neurological outcomes, and contributing anatomical and management factors to neurological complications. RESULTS: Of 33 patients who underwent embolization (31 boys [64.6%]; 17 girls [35.4%]; median age at first embolization, 4 months [range, 0-29 months]), 10 patients (30.3%) developed major periprocedural neurological complications. Five of these patients died. Univariate logistic regression analyses identified internal cerebral vein drainage to the main venous sac of the VOGM and use of a microcatheter with a distal outer diameter of more than 2.0F as significant predictors of poor neurological outcomes. Lessons learned from our experience include the need to assess the internal cerebral vein drainage pattern on preprocedural magnetic resonance venography, avoidance of excessive embolization into the venous sac, treatment of more distal fistulae before proximal fistulae to avoid a sump effect, and preferably use of smaller (

Background and Purpose— Arteriopathy is common in childhood arterial ischemic stroke (AIS) and predicts stroke recurrence. Currently available vascular imaging techniques mainly image the arterial lumen rather than the vessel wall and have a limited ability to differentiate among common arteriopathies. We aimed to investigate the value of a magnetic resonance imaging-based technique, namely noninvasive arterial wall imaging (AWI), for distinguishing among arteriopathy subtypes in a consecutive cohort of children presenting with AIS. Methods— Children with confirmed AIS and magnetic resonance angiography underwent 3-Tesla AWI including T1-weighted 2-dimensional fluid-attenuated inversion recovery fast spin echo sequences pre- and post-gadolinium contrast. AWI characteristics, including wall enhancement, wall thickening, and luminal stenosis, were documented for all. Results— Twenty-six children with AIS had AWI. Of these, 9 (35%) had AWI enhancement. AWI enhancement was associated with anterior circulation magnetic resonance angiography abnormality and cortical infarction in 8 of 9 (89%) children and normal magnetic resonance angiography with posterior circulation subcortical infarction in 1 (1 of 9; 11%) child. AWI enhancement was not seen in 17 (65%), 10 (59%) of whom had an abnormal magnetic resonance angiography. Distinct patterns of pre- and postcontrast signal abnormality were demonstrated in the vessel wall in the region of interest in children with transient cerebral arteriopathy, arterial dissection, primary central nervous system angiitis, dissecting aneurysm, and cardioembolic stroke. Conclusions— AWI is a noninvasive, high-resolution magnetic resonance AWI technique, which can be successfully used in children presenting with AIS. Patterns of AWI enhancement are recognizable and associated with specific AIS pathogeneses. Further studies are required to assess the additional diagnostic utility of AWI over routine vascular imaging techniques, in childhood AIS.

Objectives: To describe Magnetic Resonance Urography (MRU) appearances of the circumcaval ureter, a rare congenital cause of hydronephrosis. Materials and Methods: Seven cases of circumcaval ureter, suspected on intravenous urography (IVU), underwent subsequent static MRU using heavily T2-weighted sequences. Results: The various appearances of circumcaval ureter on IVU and MRU were studied and compared. The circumcaval portion of the ureter was especially well seen on axial MRU sections, though this portion was routinely not visualized on IVU. In one case with a ureteric calculus, MRU also depicted a circumcaval course of the ureter, thus providing a complete diagnosis. In yet another case, where a circumcaval ureter was suspected on IVU, MRU proved the actual cause of ureteric obstruction to be a crossing vessel. Conclusion: Static MRU using heavily T2-weighted coronal and axial sequences can make or exclude the diagnosis of circumcaval ureter unequivocally.

Objective: Cerebral venous vessels a have unique morphology. No information is available regarding the presence of anomalous venous structure and related consequences in children. We aim to describe the frequency of anatomical variants (persistent fetal structures), and physiological changes (collateralization), in children with CSVT. We hypothesize that these variations impact in the re-distribution of venous drainage in the presence of stressors such as anemia or dehydration. Methods: We retrospectively reviewed children (1 month - 18 years), with CSVT over 5 years (Jan 2008 - Dec 2013). We excluded children with arterial ischemic stroke, trauma, compressive intracranial lesions and systemic venous hypertension. We reviewed for symptoms at presentation, risk factors, sinus involved, thrombus location, parenchymal lesions, antithrombotic therapy, outcome using the Paediatric Stroke Outcome Measure (PSOM) and recanalization rate at last follow-up. MRV/CTV reports were evaluated for anatomical variants and physiological changes in the venous systems. Results: Thirty-four children were identified. 17 boys (50%), with mean age at CSVT of 13.5 years (0.2 -17.6 years). 11 had anatomical variations (32%) vs. 23 (68%) with typical anatomy. These included 6 (54%) children with abnormal sinus morphology (hypoplasia/absence of a major dural sinus), 3 (27%) children with persistent fetal structures and 6 (54%) with prominent collateralization. Most of the cases had > 1 anatomical variant together. Signs of increased intracranial pressure were seen more frequently in children with anatomical variants 7(63%) than in those without variants 7(30%), although not statistically significant. 5 children (45%) with anatomical variations had brain parenchymal involvement vs. 5 (22%) with normal anatomy. Mean recanalization rate was the same between the two groups: 10(90%) at mean follow-up of 5.5mo (3 - 9mo) in the variant vs. 22(96%) at 4.2mo (1.5 - 9mo) in the normal anatomy group. Conclusion: The presence of anatomical variants in the cerebral venous structures may be associated with a more severe initial presentation in children with CSVT. Variant venous anatomy may be less efficient in compensating for the obstruction to venous outflow due to thrombosis.

Background Microstructural evidence of white matter (WM) dysmaturation in the brains of newborns with congenital heart disease (CHD) using MRI has been previously shown [1]. Further, delayed WM development confers an increased risk of WM injury before and after neonatal cardiac surgery [2]. WM injury is associated with a high incidence of subsequent neurodevelopmental deficits and fetal interventions to improve brain development in the setting of CHD are currently being investigated. We wished to compare the utility of our previously described parameters in another cohort of CHD newborns, and assess the performance of a new parameter (WM T2 relaxation) for discerning differences in WM maturation.

Background & objectives: Renal size is an important parameter used in the diagnosis and follow up of renal diseases. However, while making decisions, clinicians must be aware of the dependence of these dimensions on the ethnicity of the individual, independent of anthropometric indices. There is no established nomogram for renal sizes in the Indian population. The aim of this study was to assess the applicability of oft-quoted ranges of normal renal sizes in our population. Methods: Renal dimensions including length, width and parenchymal thickness were sonographically measured in 140 individuals with no renal disease. Analysis was done for differences due to age, gender and laterality. The correlation of renal dimensions with anthropometric parameters like weight, height, body mass index (BMI) and body surface area (BSA) was analyzed. Results: The means of length, width and parenchymal thickness of all 280 kidneys of 140 patients were 9.65 ± 0.63, 4.5 ± 0.42 and 2.04 ± 0.2 cm, respectively. There was a significant difference in parenchymal thickness between the right and left kidneys, while there was no significant right-left difference in length or width. Gender-wise analysis showed significant differences between male and female renal breadths but not length and parenchymal thickness. Age group-wise analysis showed significant decrease in renal length and parenchymal thickness beyond the seventh decade. There was a moderate positive correlation of bilateral renal length with body weight and BSA, and a weak positive correlation with body height and BMI. Interpretation & conclusions: Renal sizes in our population are in contrast to commonly quoted normal values in literature. Conclusions about renal sizes need to be made with reference to nomograms and should not be based upon data from other populations. We also present formulae whereby to derive renal sizes from anthropometric indices in our population.

Unilateral pulmonary artery agenesis is commonly seen associated with other congenital cardiovascular defects, when it is detected early in life, but isolated absence of the pulmonary artery is a rare entity, usually detected in adulthood. The latter patients are usually asymptomatic or might present with varied non-specific manifestations such as respiratory tract infections and hemoptysis. This report describes the imaging findings of a 67 year old female with absence of the right pulmonary artery. The embryology and clinical manifestations of the condition are reviewed.

Background Congenital heart disease (CHD) is associated with brain dysmaturation, increased risk of perioperative white matter (WM) injury and neurodevelopmental delay (1). Fetal Doppler studies have shown altered cerebrovascular flow dynamics in CHD, suggesting ‘brain-sparing physiology’. We sought to determine whether postnatal cerebral WM microstructural abnormality relates to abnormal fetal hemodynamics.