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Objective: The brain arteriovenous malformation (BAVM) nidus compactness score (CS), determined on angiography, predicts BAVM recurrence after surgical resection among children with sporadic BAVMs. We measured the angiographic CS for BAVMs among children with hereditary hemorrhagic telangiectasia (HHT) to determine CS characteristics in this population. Methods: A pediatric interventional neuroradiologist reviewed angiograms to determine the CS of BAVMs in children with HHT recruited to the BVMC. CS is based on overall nidus and perinidal anomalous vessel compactness. CS categories included 1 = diffuse nidus, 2 = intermediate nidus, and 3 = compact nidus. Results: Forty-eight of 78 children (61.5%) with HHT and brain vascular malformations had a conventional angiogram; 47 (97.9%) angiograms were available. Fifty-four BAVMs were identified in 40 of these 47 children (85.1%). Of 54 BAVMs in children with HHT, CS was 1 in 7 (13%), 2 in 29 (53.7%), and 3 in 18 BAVMs (33.3%) compared with CS of 1 in six (26.1%), 2 in 15 (65.2%), and 3 in 2 BAVMs (8.7%) among 23 previously reported children with sporadic BAVMs, p = 0.045 (Fisher's exact). Seven children with HHT had intracranial hemorrhage: 4 had CS = 3, 1 had CS = 2, and 2 had CS = 1. Conclusions: A range of CSs exists across HHT BAVMs, suggesting it may be an angiographic measure of interest for future studies of BAVM recurrence and hemorrhage risk. Children with HHT may have more compact niduses compared to children with sporadic BAVMs. Additional research should determine whether CS affects hemorrhage risk or post-surgical recurrence risk in HHT-associated BAVMs, which could be used to direct BAVM treatment. [ABSTRACT FROM AUTHOR]

Advanced magnetic resonance neuroimaging techniques play an important adjunct role to conventional MRI sequences for better depiction and characterization of a variety of brain disorders. In this article we briefly review the basic principles and clinical utility of a select number of these techniques, including clinical functional MRI for presurgical planning, clinical diffusion tensor imaging and related techniques, dynamic susceptibility contrast perfusion imaging using gadolinium injection, and arterial spin labeling perfusion imaging. The article focuses on general principles of clinical MRI acquisition protocols, relevant factors affecting image quality, and a general framework for obtaining images for each of these techniques. We also present relevant advances for acquiring these types of imaging sequences in a clinical setting. [ABSTRACT FROM AUTHOR]

Background: Moyamoya syndrome (MMS) is a progressive cerebral arteriopathy with increased incidence in children with neurofibromatosis type 1 (NF1). Despite the potential for significant neurological morbidity including stroke, little is known about the natural history, and no guidelines exist for screening and management of NF1-associated MMS.Methods: We identified 152 literature cases of children aged ≤18 years with NF1-associated MMS. A meta-analysis was performed evaluating clinical and neuroimaging findings and patient outcomes. Data from 19 patients with NF1-associated MMS from our center treated from January 1995 to July 2020 were abstracted via chart review and similarly analyzed for clinical and neuroimaging features.Results: Meta-analysis of literature cases showed a median age of MMS diagnosis of 6 years (interquartile range 3 to 10.8 years). Optic pathway gliomas were more common in patients with MMS (42%) compared with historical prevalence. Stroke or transient ischemic attack (TIA) was present at diagnosis in 46%. TIA and stroke were more common in patients with bilateral versus unilateral MMS (62% vs 34%, P = 0.001) and in children aged <4 years versus those aged ≥4 years (61% vs 40%, P = 0.02). Compared with the literature cases, our cohort was more frequently asymptomatic (42% vs 25%) and less likely to present with TIA or stroke (32% vs 46%) at diagnosis.Conclusions: These data suggest there is an aggressive form of MMS in children with NF1 <4 years of age. Therefore, early screening should be considered to facilitate early detection and treatment of cerebral arteriopathy. [ABSTRACT FROM AUTHOR]

Purpose: The spheno-occipital synchondrosis (SOS) is an important site of endochondral ossification in the cranial base that closes prematurely in Apert, Crouzon, and Pfeiffer syndromes, which contributes to varying degrees of midface hypoplasia. The facial dysmorphology of Muenke syndrome, in contrast, is less severe with low rates of midface hypoplasia. We thus evaluated the timing of SOS fusion and cephalometric landmarks in patients with Muenke syndrome compared to normal controls.Patients with Muenke syndrome who had at least one fine-cut head computed tomography scan performed from 2000 to 2020 were retrospectively reviewed. A case–control study was performed of patient scans and age- and sex-matched control scans. SOS fusion status was evaluated as open, partially closed, or closed.We included 28 patients and compared 77 patient scans with 77 control scans. Kaplan–Meier analysis demonstrated an insignificantly earlier timeline of SOS fusion in Muenke syndrome (p = 0.300). Mean sella-orbitale (SO) distance was shorter (44.0 ± 6.6 vs. 47.7 ± 6.7 mm, p < 0.001) and mean sella-nasion-Frankfort horizontal (SN-FH) angle was greater (12.1° ± 3.8° vs. 10.1° ± 3.2°, p < 0.001) in the Muenke group, whereas mean sella-nasion-A point (SNA) angle was similar and normal (81.1° ± 5.7° vs. 81.4° ± 4.7°, p = 0.762).Muenke syndrome is characterized by mild and often absent midfacial hypoplasia, with the exception of slight retropositioning of the infraorbital rim. Interestingly, SOS fusion patterns in these patients are not significantly different from age- and sex-matched controls despite an increased odds of fusion. It is possible that differences in timing of SOS fusion may manifest phenotypically at the infraorbital rim rather than at the maxilla.Methods: The spheno-occipital synchondrosis (SOS) is an important site of endochondral ossification in the cranial base that closes prematurely in Apert, Crouzon, and Pfeiffer syndromes, which contributes to varying degrees of midface hypoplasia. The facial dysmorphology of Muenke syndrome, in contrast, is less severe with low rates of midface hypoplasia. We thus evaluated the timing of SOS fusion and cephalometric landmarks in patients with Muenke syndrome compared to normal controls.Patients with Muenke syndrome who had at least one fine-cut head computed tomography scan performed from 2000 to 2020 were retrospectively reviewed. A case–control study was performed of patient scans and age- and sex-matched control scans. SOS fusion status was evaluated as open, partially closed, or closed.We included 28 patients and compared 77 patient scans with 77 control scans. Kaplan–Meier analysis demonstrated an insignificantly earlier timeline of SOS fusion in Muenke syndrome (p = 0.300). Mean sella-orbitale (SO) distance was shorter (44.0 ± 6.6 vs. 47.7 ± 6.7 mm, p < 0.001) and mean sella-nasion-Frankfort horizontal (SN-FH) angle was greater (12.1° ± 3.8° vs. 10.1° ± 3.2°, p < 0.001) in the Muenke group, whereas mean sella-nasion-A point (SNA) angle was similar and normal (81.1° ± 5.7° vs. 81.4° ± 4.7°, p = 0.762).Muenke syndrome is characterized by mild and often absent midfacial hypoplasia, with the exception of slight retropositioning of the infraorbital rim. Interestingly, SOS fusion patterns in these patients are not significantly different from age- and sex-matched controls despite an increased odds of fusion. It is possible that differences in timing of SOS fusion may manifest phenotypically at the infraorbital rim rather than at the maxilla.Results: The spheno-occipital synchondrosis (SOS) is an important site of endochondral ossification in the cranial base that closes prematurely in Apert, Crouzon, and Pfeiffer syndromes, which contributes to varying degrees of midface hypoplasia. The facial dysmorphology of Muenke syndrome, in contrast, is less severe with low rates of midface hypoplasia. We thus evaluated the timing of SOS fusion and cephalometric landmarks in patients with Muenke syndrome compared to normal controls.Patients with Muenke syndrome who had at least one fine-cut head computed tomography scan performed from 2000 to 2020 were retrospectively reviewed. A case–control study was performed of patient scans and age- and sex-matched control scans. SOS fusion status was evaluated as open, partially closed, or closed.We included 28 patients and compared 77 patient scans with 77 control scans. Kaplan–Meier analysis demonstrated an insignificantly earlier timeline of SOS fusion in Muenke syndrome (p = 0.300). Mean sella-orbitale (SO) distance was shorter (44.0 ± 6.6 vs. 47.7 ± 6.7 mm, p < 0.001) and mean sella-nasion-Frankfort horizontal (SN-FH) angle was greater (12.1° ± 3.8° vs. 10.1° ± 3.2°, p < 0.001) in the Muenke group, whereas mean sella-nasion-A point (SNA) angle was similar and normal (81.1° ± 5.7° vs. 81.4° ± 4.7°, p = 0.762).Muenke syndrome is characterized by mild and often absent midfacial hypoplasia, with the exception of slight retropositioning of the infraorbital rim. Interestingly, SOS fusion patterns in these patients are not significantly different from age- and sex-matched controls despite an increased odds of fusion. It is possible that differences in timing of SOS fusion may manifest phenotypically at the infraorbital rim rather than at the maxilla.Conclusion: The spheno-occipital synchondrosis (SOS) is an important site of endochondral ossification in the cranial base that closes prematurely in Apert, Crouzon, and Pfeiffer syndromes, which contributes to varying degrees of midface hypoplasia. The facial dysmorphology of Muenke syndrome, in contrast, is less severe with low rates of midface hypoplasia. We thus evaluated the timing of SOS fusion and cephalometric landmarks in patients with Muenke syndrome compared to normal controls.Patients with Muenke syndrome who had at least one fine-cut head computed tomography scan performed from 2000 to 2020 were retrospectively reviewed. A case–control study was performed of patient scans and age- and sex-matched control scans. SOS fusion status was evaluated as open, partially closed, or closed.We included 28 patients and compared 77 patient scans with 77 control scans. Kaplan–Meier analysis demonstrated an insignificantly earlier timeline of SOS fusion in Muenke syndrome (p = 0.300). Mean sella-orbitale (SO) distance was shorter (44.0 ± 6.6 vs. 47.7 ± 6.7 mm, p < 0.001) and mean sella-nasion-Frankfort horizontal (SN-FH) angle was greater (12.1° ± 3.8° vs. 10.1° ± 3.2°, p < 0.001) in the Muenke group, whereas mean sella-nasion-A point (SNA) angle was similar and normal (81.1° ± 5.7° vs. 81.4° ± 4.7°, p = 0.762).Muenke syndrome is characterized by mild and often absent midfacial hypoplasia, with the exception of slight retropositioning of the infraorbital rim. Interestingly, SOS fusion patterns in these patients are not significantly different from age- and sex-matched controls despite an increased odds of fusion. It is possible that differences in timing of SOS fusion may manifest phenotypically at the infraorbital rim rather than at the maxilla. [ABSTRACT FROM AUTHOR]

Introduction: Ultrasound (US)-based indexes such as fronto-occipital ratio (FOR) can be used to obtain an acceptable estimation of ventricular volume. Patients with colpocephaly present a unique challenge due to the shape of their ventricles. In the present study, we aimed to evaluate the validity and reproducibility of the modified US-FOR index in children with Chiari II-related ventriculomegaly. Methods: In this retrospective study, we evaluated Chiari II patients younger than 1 year who underwent head US and MR or CT scans for ventriculomegaly evaluation. MR/CT-based FOR was measured in the axial plane by identifying the widest diameter of frontal horns, occipital horns, and the interparietal diameter (IPD). US-based FOR (US-FOR) was measured using the largest diameter based on the following landmarks: frontal horn and IPD in the coronal plane at the level of the foramen of Monro, IPD just superior to the Sylvian fissures, and occipital horn posterior to the thalami and inferior to the superior margins of the thalami. Intraclass correlation coefficients (ICCs) were used to evaluate inter-rater reliability, and Pearson correlation coefficients and Bland-Altman plots were applied to assess agreement between US and other two modalities. Results: Sixty-three paired US and MR/CT exams were assessed for agreement between US-FOR and MR/CT-FOR measurements. ICC showed an excellent inter-rater reliability for US-FOR (ICC = 0.99, p < 0.001) and MR/CT-FOR (ICC = 0.99, p < 0.001) measurements. The mean (range) values based on US-FOR showed a slight overestimation in comparison with MR/CT-FOR (0.51 [0.36–0.68] vs. 0.46 [0.34–0.64]). The Pearson correlation coefficient showed high cross-modality agreement for the FOR index (r = 0.83, p < 0.001). The Bland-Altman plot showed excellent concordance between US-FOR and MR/CT-FOR with a bias of 0.05 (95% CI: −0.03 to 0.13). Conclusion: US-FOR in the coronal plane is a comparable tool for evaluating ventriculomegaly in Chiari II patients when compared with MR/CT-FOR, even in the context of colpocephaly. [ABSTRACT FROM AUTHOR]

Isolated tumefactive demyelinating lesions (≥2 cm) may be difficult to distinguish from contrast-enhancing brain tumors, central nervous system infections, and (rarely) tissue dysgenesis, which may all occur with increased signal on T2-weighted images. Establishing an accurate diagnosis is essential for management, and we delineate our single-center experience. We performed a retrospective review of medical records, imaging, and biopsy specimens for patients under 18 years presenting with isolated tumefactive demyelination over a 10-year period. Ten children (eight female) met inclusion criteria, with a median age of 14.1 years. Lesions were most likely to involve the thalamus (six of 10), brainstem (five of 10), basal ganglia (four of 10), or corpus callosum (four of 10). Eighty percent had perilesional edema at presentation, and 60% had midline shift. Biopsies demonstrated demyelination with perivascular lymphocytic infiltration and axonal damage ranging from mild to severe. All patients were initially treated with high-dose corticosteroids, and eight of 10 required additional medical therapies such as intravenous immunoglobulin, plasmapheresis, cyclophosphamide, or rituximab. Increased intracranial pressure was managed aggressively with two of 10 patients requiring decompressive craniectomies. Clinical outcomes varied. Solitary tumefactive demyelinating lesions are rare, and aggressive management of inflammation and increased intracranial pressure is essential. Biopsy is helpful to evaluate for other diagnoses on the differential and maximize therapies. Treatment beyond initial therapy with corticosteroids is often required. Isolated tumefactive demyelinating lesions are uncommon; multicenter natural history studies are needed to better delineate differential diagnoses and optimal therapies. [ABSTRACT FROM AUTHOR]

Although vast, the medical literature is deficient in reports of gastroesophageal junction (GEJ) involvement of mantle cell lymphoma (MCL). We present the unique case of a 76-year-old male who presented with worsening dysphagia, weight loss, and heartburn and who was found to have blastic variant of MCL in the GEJ. He had undergone extensive workup in the past for an ulcerative, gastric/GEJ lesion, found on four separate esophagogastroduodenoscopies (EGDs) and two esophageal ultrasounds, whose biopsies were repeatedly negative for malignancy. On admission, physical examination and labs were unremarkable, but computed tomography showed an irregular mass involving the GEJ. EGD on admission showed a large friable, ulcerated lesion with heaped-up margins involving the GEJ whose biopsies showed histological and immunohistochemical (IHC) findings consistent with blastic MCL. A bone marrow biopsy showed minimal involvement (<5%) of CD5+/CD23+ B cells and was negative for both cyclin D1 and t(11;14). The biopsy of the lesion was diffusely infiltrated by atypical lymphocytes with prominent nucleoli and IHC stains positive for CD20, cyclin D1, BCL-2, and BCL-6 as well as a Ki-67 proliferative index >90%, all consistent with blastic MCL, a rare and aggressive subtype of MCL. He was started on guideline-based chemoimmunotherapy as he was not a candidate for stem cell transplantation. Repeat imaging 1 year later showed improvement of the mass, with negative endoscopic biopsies for lymphoma. This case provides additional distinct features to the various clinical presentations associated with this rare proliferative disorder, thereby enhancing the medical literature on MCL. [ABSTRACT FROM AUTHOR]

Background: Revised diagnostic criteria for pseudotumor cerebri syndrome require three of four neuroimaging findings in the absence of papilledema. We examined the sensitivity and specificity of three or more of four of these magnetic resonance imaging (MRI) findings for pseudotumor cerebri syndrome in children.Methods: As part of clinical care, patients in whom there was suspicion for pseudotumor cerebri syndrome underwent neurological and fundoscopic examinations, lumbar puncture, MRI, or magnetic resonance venogram. For this retrospective study, we used this information to classify 119 subjects into definite (n = 66) or probable pseudotumor cerebri syndrome (n = 12), elevated opening pressure without papilledema (n = 23), or controls who had normal opening pressure without papilledema (n = 24). A neuroradiologist, unaware of the clinical findings or original MRI report, reviewed MRIs for pituitary gland flattening, flattening of the posterior sclera, optic nerve sheath distention, and transverse venous sinus stenosis.Results: The presence of three or more MRI findings has a sensitivity of 62% (95% confidence interval: 47% to 75%) and a specificity of 95% (95% confidence interval: 77% to 100%), compared with controls. Two of three (transverse venous sinus stenosis, pituitary gland flattening, flattening of the posterior sclera) had a similar sensitivity and specificity. Transverse venous sinus stenosis alone had a slightly higher sensitivity (74%, 95% confidence interval: 60% to 85%) and specificity (100%, 95% confidence interval: 80% to 100%).Conclusions: In children, three of four of the proposed neuroimaging criteria and transverse venous sinus stenosis alone have a moderate sensitivity and robust specificity for pseudotumor cerebri syndrome. MRIs should be reviewed for these criteria, and their presence should raise suspicion for pseudotumor cerebri syndrome in children, particularly if the presence of papilledema is uncertain. [ABSTRACT FROM AUTHOR]

Background: This article was written to provide clinicians and researchers with an overview of a number of advanced neuroimaging techniques in an effort to promote increased utility and the design of future studies using advanced neuroimaging in childhood stroke. The current capabilities of advanced magnetic resonance imaging techniques provide the opportunity to build on our knowledge of the consequences of stroke on the developing brain. These capabilities include providing information about the physiology, metabolism, structure, and function of the brain that are not routinely evaluated in the clinical setting.Methods: During the Proceedings of the Stroke Imaging Laboratory for Children Workshop in Toronto in June 2015, a subgroup of clinicians and imaging researchers discussed how the application of advanced neuroimaging techniques could further our understanding of the mechanisms of stroke injury and repair in the pediatric population. This subgroup was established based on their interest and commitment to design collaborative, advanced neuroimaging studies in the pediatric stroke population.Results: In working toward this goal, we first sought to describe here the magnetic resonance imaging techniques that are currently available for use, and how they have been applied in other stroke populations (e.g., adult and perinatal stroke).Conclusions: With the continued improvement in advanced neuroimaging techniques, including shorter acquisition times, there is an opportunity to apply these techniques to their full potential in the research setting and learn more about the effects of stroke in the developing brain. [ABSTRACT FROM AUTHOR]

Background Cerebral aneurysm formation is one of the cerebrovascular complications of sickle cell disease. Objective To report the clinical and imaging findings of intracerebral aneurysms and their treatment in pediatric and adult patients with sickle cell disease. Methods Review of clinical data via chart abstraction and radiologic features at the University of Pennsylvania and Children's Hospital of Philadelphia from 2000 to 2014 and review of the literature since 1942. Results Nineteen patients with aneurysms (2.7%) were found in 709 imaged patients, including 1.2% of imaged children and 10.8% of adults. A total of 44 aneurysms were detected (52.6% with multiple aneurysms, overall 2.3 per patient), 35 (79.5%) in the anterior circulation and 9 in the posterior circulation (20.4%). Thirty-eight unruptured aneurysms ranging in size from 2 to 6 mm and six ruptured aneurysms ranging in size from 3 to 9 mm in diameter were found. Of the patients with ruptured aneurysms, two were treated by stent-assisted coiling, two by clipping, and one patient with coiling. In the group without a rupture, one patient was treated by coil embolization and one patient with a peripheral middle cerebral artery aneurysm was treated by aneurysmectomy. Three pediatric patients with a previously normal MR angiogram demonstrated new aneurysm formation during the study. Conclusions Adult patients with sickle cell disease have a high prevalence of aneurysm formation. Both pediatric and adult patients with sickle cell disease tend to develop multiple aneurysms with frequent involvement of atypical locations, in both anterior and posterior circulations. [ABSTRACT FROM AUTHOR]

The article discusses the neuropathological confirmation of a rare case of pontine tegmental cap dysplasia. Topics covered include disease features including abnormalities of the cerebellar peduncles, vermal hypoplasia and multiple cranial nerve deficits, detection of ventricular septal defect and tetralogy of Fallot and the possible role of imperfect climbing fiber afferent pathway and the dysplastic dentate termination of Purkinje axons on the pathology of the disease.

Cerebral sinovenous thrombosis (CSVT) is a rare form of pediatric stroke with significant morbidity. We determined cumulative incidence and predictors of acute seizures, remote seizures, and epilepsy after pediatric CSVT. Retrospective analysis of 131 neonates and children with neuroimaging-confirmed CSVT enrolled between 2008 and 2020 from a single-center prospective consecutive cohort. Acute seizures occurred within 7 days of CSVT. Remote seizures occurred >7 days after CSVT. Epilepsy was defined as 2 or more remote seizures at least 24 hours apart. Survival methods determined the incidence of and risk factors for remote seizures and epilepsy. Acute seizures occurred in 14/33 neonates (42%) and 19/98 children (19%). Among children, hemorrhage predicted acute seizures (OR 6.6, 95% CI 1.9 to 22.4, P = 0.003). Remote seizures occurred in six neonates; five developed epilepsy. Remote seizures occurred in 14 children; 10 developed epilepsy. In neonates, 1- and 3-year epilepsy-free survival were 86% (95% CI 62% to 95%) and 66% (95% CI 32% to 87%). One- and 3-year epilepsy-free survival in children were 88% (95% CI 76% to 92%) and 84% (95% CI 59% to 86%). In multivariable analysis for children, acute seizures predicted epilepsy (HR 3.8, 95% CI 1.1-13.3, P = 0.039). In both cohorts, Pediatric Stroke Outcome Measure scores at last follow-up were worse in those with epilepsy compared to those without. Acute seizures occurred in approximately one quarter of our cohort and are an epilepsy risk factor in children with CSVT. Neonates and children with epilepsy had worse outcomes than those without. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) spine showed a small annular tear of the C4-C5 disc (Fig. Diagnosis is made radiographically by spine diffusion-weighted and T2-weighted MRI, which demonstrate signal change within the anterior spinal artery territory and can show evidence of disc injury. Pediatr Neurol. 2019, 99, 3 - 6 4 Beslow L. A., Ichord R. N., Zimmerman R. A., Smith S. E., Licht D. J. Role of diffusion MRI in diagnosis of spinal cord infarction in children. [Extracted from the article]

Background and purpose: This study aims to investigate the high-resolution 3-T MRI appearance and morphological variation of the temporal part of the caudate tail in pediatric subjects with normal brain MR examinations. Patients and methods: One hundred pediatric patients were retrospectively evaluated using a high-resolution 3-T imaging protocol. Different morphological parameters including shape, size, and symmetry were evaluated. The appearance and shape of the caudate tail were classified into nodular, linear, or imperceptible. The location and relation of the caudate tail to the temporal horn and adjacent brain parenchyma were categorized. Relationships between age, gender, shape, location, side, and the cross-sectional area of the caudate tail were investigated. Results: The caudate tail was imperceptible in 22 %, had a nodular shape in 66.5 %, and was flat in 11.5 %. There was asymmetry of the caudate tail between the two sides in 37 % of subjects. The caudate tail was completely embedded within the temporal lobe parenchyma in 8.3 %, completely protruding into the temporal horn in 27.5 %, or intermediate in 64.1 %. The mean cross-sectional area of the caudate tail was constant across ages despite the varied age range of the subjects. There was no difference in overall mean cross-sectional area of the caudate tail between the two sides. Conclusion: There is a wide variation in the appearance of the caudate tail adjacent to the temporal horn of the lateral ventricle. Identification of anatomical variation of the caudate tail may prevent potential diagnostic pitfalls, especially with respect to subependymal heterotopia. [ABSTRACT FROM AUTHOR]

The authors investigate the effect of filler particle size on the fatigue and low-temperature toughening mechanisms in bitumen mastics and polymer modified bitumen by using glass spheres and limestone filler with sufficiently different gradations. The fatigue performance of the mastics is investigated under constant torsional strain. Interfacial adhesion between polymer-modified bitumen and filler particles increases fatigue life. Crack healing was examined during prolonged rest periods following fatigue damage. Thermal stress restrained specimen tests on bitumen mastics indicate that particle size does not influence the failure stress or failure temperature. [ABSTRACT FROM AUTHOR]

In the present paper, electro-thermo nonlinear vibration of a piezo-polymeric rectangular micro plate made from polyvinylidene fluoride (PVDF) reinforced by zigzag double walled boron nitride nanotubes (DWBNNTs) is studied. This plate is embedded in an elastic medium which is simulated by Winkler and Pasternak foundation models. Using nonlinear strain-displacement relations and nonlocal elasticity plate theory as well as considering charge equation for coupling between electrical and mechanical fields, the motion equations are derived based on energy method and Hamilton's principle. The differential quadrature method (DQM) is employed to computation of nonlinear frequency for different mechanical and free-free electrical boundary conditions. The results indicate that smart composite and consequently the generated G4 improved sensor and actuator applications in several process industries, because it increases the nonlinear vibration frequency. Furthermore, it can be also found that the nonlinear frequency increases as the values of the elastic medium constants, the geometrical aspect ratios and DWBNNTs volume fraction increase but it decreases as nonlocal parameter increases. [ABSTRACT FROM AUTHOR]

We report the use of susceptibility-weighted imaging (SWI) in detection of red nucleus (rubral) degeneration and atrophy in children with hypertrophic olivary degeneration (HOD) after posterior fossa tumor resection. The use of this modality for this particular application has not been previously described. Detection of red nucleus changes seems to be facilitated by the contrast mechanism of SWI over conventional MRI sequences. SWI can be considered in the evaluation of these patients and in the future might provide a means for further classification of patients with HOD and related symptomatology. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates the effect of filler particle size on the fatigue and low temperature toughening mechanisms in bitumen mastics, polymer modified bitumen and asphalt mixtures by using glass spheres and limestone filler with sufficiently different gradations. The fatigue performance of the mastics investigated under constant torsional strain. Interfacial adhesion between polymer-modified bitumen and filler particles increases fatigue life. Crack healing examined during prolonged rests periods following fatigue damage. Considering the point that stiffness recovery is more rapid in mastics containing coarse filler; however, this does not translate into a significant recovery in fatigue life. Thermal stress restrained specimen tests on bitumen mastics indicate that particle size has not influence on the failure stress or failure temperature. Time to failure tests on asphalt mixtures also show no difference in low temperature performance between samples containing different sized filler. [Copyright &y& Elsevier]

Klinefelter syndrome is a chromosomal disorder characterized by one or more supernumerary X chromosomes, in addition to the normal 46,XY male karyotype. Whereas classic Klinefelter syndrome (47,XXY) occurs in 1:400 births, the most severe Klinefelter variant (49,XXXXY) occurs in only 1:85,000 births. The degree of cognitive impairment, specific skeletal changes, and genital abnormalities in Klinefelter syndrome variants is thought to correlate with the number of additional X-chromosomes present. Magnetic resonance imaging studies in individuals with classic Klinefelter syndrome show smaller brain volumes, but magnetic resonance imaging data are lacking for individuals with rarer and more severe Klinefelter variants. We present case reports and magnetic resonance imaging studies on 3 individuals with 49,XXXXY. All 3 patients exhibited varying degrees of volume loss and abnormalities in white matter. Changes in white matter may represent a specific finding in patients with severe Klinefelter variants such as 49,XXXXY, and karyotype analysis should be considered in patients with unexplained white-matter disease, especially when developmental delay or genital abnormalities are present. [ABSTRACT FROM AUTHOR]

The CT, MR, and diffusion-weighted initial and follow-up imaging findings in neonatal herpes simplex virus type 2 (HSV-2) encephalitis were assessed. The clinical, laboratory and imaging findings in 12 patients (eight girls and four boys) with proven neonatal HSV-2 encephalitis with follow-up were retrospectively reviewed. Patterns of brain involvement and distribution of lesions were studied and the contribution of diffusion-weighted imaging to the imaging diagnosis of this disease was explored. A total of 24 CT and 22 MRI studies were performed with a mean follow-up time of 38 months. Neonatal HSV-2 encephalitis can be multifocal or limited to only the temporal lobes, brainstem, or cerebellum. The deep gray matter structures were involved in 57% of patients, and hemorrhage was seen in more than half of the patients. CT images were normal or showed mild abnormalities in the early stages of the disease. Conventional MR images may be normal in the early stages of the disease. Lesions were initially seen only by diffusion-weighted imaging in 20% of the patients and this modality showed a substantially more extensive disease distribution in an additional 50% of patients. In 40% of patients, watershed distribution ischemic changes were observed in addition to areas of presumed direct herpetic necrosis. Neonatal HSV-2 encephalitis has a variable imaging appearance. Diffusion-weighted MRI is an important adjunct in the imaging evaluation of this disease. Watershed distribution ischemia in areas remote from the primary herpetic lesions may be seen. [ABSTRACT FROM AUTHOR]

Histiocytosis of Langerhans cells (class 1 histiocytosis) includes a range of clinical manifestations that have been described as bone eosinophilic granuloma, Hand-Schüller-Christian syndrome, and Letterer-Siwe diseases. This syndrome represents a spectrum of severity and prognosis of some underlying disorder which is usually sporadic. This report discribes three cases in one family, who developed the disease a few years after their brother was found to be suffering from histiocytosis. All 3 patients had the same clinical manifestations: hyperthermia, eczematic rash, and swelling in skull, hand, and foot. X rays showed lytic areas in the skull and metacarp of fourth finger. Serology for EBV infection was negative. Infiltratration of abnormal Langerhans cells histiocytes were demonstrated in bone biopsies. These patients were given chemotherapy. Case 1 (brother) died 1 year after chemotherapy, case 2 (girl) was given chemotherapy without success. She was given T-cell suppresor (cyclosporine), which induced remission, and case 3 was given chemotherapy, which was successful. [ABSTRACT FROM AUTHOR]

Ghosal-type hemato-diaphyseal dysplasia is a rare autosomal recessive disorder with distinctive diaphyseal and metaphyseal dysplasia of long bones and steroid-dependant anemia. The authors describe a 20-month-old girl who had had a severe transfusion-dependent anemia since late infancy and marked locomotion difficulties as a toddler. The diagnosis was established by X-ray bone survey. The anemia was treated with oral prednisolone. Since then, the patient has been doing well on steroid-maintenance therapy and has no more walking difficulties. The incidence of hemato-diaphyseal dysplasia in the Indian subcontinent and Middle East is notable. [ABSTRACT FROM AUTHOR]

Rare histologic variants of esophageal cancer account for about 5% of cases. As its name suggests, polypoid spindle cell carcinoma of the esophagus (carcinosarcoma, pseudosarcoma) is comprised of both epithelial and spindle cell elements. The nomenclature reflects both the historical controversy over the lesion's cell of origin as well as its characteristic fungating intraluminal growth pattern. The authors report a case of polypoid spindle cell carcinoma of the esophagus that was preoperatively diagnosed as a visceral sarcoma. [ABSTRACT FROM AUTHOR]

The authors report on 2 sisters with acute lymphoblastic leukemia diagnosed at age 30 months and 3.5 months. The younger one was referred 15 months after the first. The reason for reporting this case is family risk and also infant under 12 months, especially under 6 months, of age have extremely poor prognosis, but both sister are at present time on complete remission. [ABSTRACT FROM AUTHOR]

Acute lymphoblastic leukemia is the most common and hepatoblastoma is a rare malignancy diagnosed in children. Their report on an Iranian boy with acute lymphoblastic leukemia diagnosed at the age of 2 years; 20 months later his 10-month-old sister was referred to their hospital with hepatoblastoma. The occurrence of such two types of cancer is rare in a family. [ABSTRACT FROM AUTHOR]

Background: Gallbladder cancer (GBC) is an aggressive malignancy that is usually diagnosed at a late stage. Prior data showed increasing incidence of GBC in the US. However, little is known about race/ethnic‐specific incidence and mortality trends of GBC per stage at diagnosis. Therefore, we aimed to conduct a time‐trend analysis of GBC incidence and mortality rates categorized by race/ethnicity and stage‐at‐diagnosis. Methods: Age‐adjusted GBC incidence and mortality rates were calculated using SEER*Stat software from the United States Cancer Statistics database (covers ~98% of US population between 2001 and 2020) and NCHS (covers ~100% of the US population between 2000 and 2020) databases, respectively. Race/Ethnic groups were Non‐Hispanic‐White (NHW), Non‐Hispanic‐Black (NHB), Hispanic, Non‐Hispanic‐Asian/Pacific‐Islander (NHAPI), and Non‐Hispanic‐American‐Indian/Alaska‐Native (NHAIAN). Stage‐at‐diagnoses were all stages, early, regional, and distant stages. Joinpoint regression was used to generate time‐trends [annual percentage change (APC) and average APC (AAPC)] with parametric estimations and a two‐sided t‐test (p‐value cut‐off 0.05). Results: 76,873 patients were diagnosed with GBC with decreasing incidence rates in all races/ethnicities except NHB who experienced an increasing trend between 2001 and 2014 (APC = 2.08, p < 0.01) and plateauing afterward (APC = −1.21, p = 0.31); (AAPC = 1.03, p = 0.03). Among early‐stage tumors (9927 patients), incidence rates were decreasing only in Hispanic (AAPC = −4.24, p = 0.006) while stable in other races/ethnicities (NHW: AAPC = −2.61, p = 0.39; NHB: AAPC = −1.73, p = 0.36). For regional‐stage tumors (29,690 patients), GBC incidence rates were decreasing only in NHW (AAPC = −1.61, p < 0.001) while stable in other races/ethnicities (NHB: AAPC = 0.73, p = 0.34; Hispanic: AAPC = −1.58, p = 0.24; NHAPI: AAPC = −1.22, p = 0.07). For distant‐stage tumors (31,735 patients), incidence rates were increasing in NHB (AAPC = 2.72, p < 0.001), decreasing in Hispanic (AAPC = −0.64, p = 0.04), and stable in NHW (AAPC = 0.07, p = 0.84) and NHAPI (AAPC = 0.79, p = 0.13). There were 43,411 deaths attributed to GBC with decreasing mortality rates in all races/ethnicities except NHB who experienced a stable trend (AAPC = 0.25, p = 0.25). Conclusion: Nationwide data over the last two decades show that NHB patients experienced increasing GBC incidence between 2001 and 2014 followed by stabilization of the rates. This increase was driven by late‐stage tumors and occurred in the first decade. NHB also experienced non‐improving GBC mortality, compared to other race and ethnic groups who had decreasing mortality. This can be due to lack of timely‐access to healthcare leading to delayed diagnosis and worse outcomes. Future studies are warranted to investigate contributions to the revealed racial and ethnic disparities, especially in NHB, to improve early detection. [ABSTRACT FROM AUTHOR]

Background: Longitudinal T2-hyperintense signal is commonly seen in the spinal cord of infants and likely reflects normal unmyelinated white matter tracts, but it can be mistaken for pathology. Autopsy studies have described incomplete myelination of spinal cord in early childhood; however, the maturation timeline of the spinal cord has not been described on imaging. Objective: The purpose of this study was to retrospectively evaluate the maturation timeline of the spinal cord on MRI to provide a baseline for image interpretation. Materials and methods: We retrospectively reviewed axial T2-W images of the spinal cord acquired on 1.5-tesla (T) and 3.0-T MRI in children ages 0–2 years for presence of longitudinal T2-hyperintense signal, and we subjectively graded this signal as 0 (absent) to 3 (pronounced). Further, we reviewed a summary of medical records for confounding pathology in the brain or spine. Cord signal was interpreted as normal in the clinical report by subspecialized pediatric neuroradiologists for all included children. Results: We reviewed 437 MRI exams from 409 children and included 189 studies in the analysis. Longitudinal T2-hyperintense signal in the lateral cord was seen in 95% (19/20) of subjects <1 month of age and was not seen in subjects ages 21–24 months (0/15). Grade 3 signal was seen in 22% (11/50) of infants ages 0–2 months and was not seen infants older than 5 months. Conclusion: Characteristic symmetrical longitudinal T2 hyperintensity in the lateral spinal cord is common in infants and should not be mistaken for pathology, and it was not seen in children older than 21 months. [ABSTRACT FROM AUTHOR]

Pediatric posterior fossa tumors are a major cause of morbidity and mortality in children. In this 2-part series, we discuss the spectrum of posterior fossa tumors and their clinical and molecular characteristics. In Part 1, the authors discuss the 5 primary differential diagnoses of posterior fossa tumors: medulloblastoma, pilocytic astrocytoma, ependymoma, diffuse midline glioma, H3K27-altered, and atypical teratoid/rhabdoid tumors. Each posterior fossa tumor is clinically and histologically defined. Additionally, relevant epidemiology data, current genetics/molecular classification according to the fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System, and imaging findings are reviewed. The new version of the international standard for the classification of central nervous system tumors introduces major changes that advance the role of molecular diagnostics in the pediatric central nervous system tumor classification, particularly in posterior fossa tumors, which may impact management and outcomes. Learning Objective: To recognize the imaging appearance of the most common posterior fossa tumors in children. [ABSTRACT FROM AUTHOR]

A response of authors P. F. Weiss, R. Xiao and D. M. Biko et al to a letter to the editor about their article "Detection of inflammatory sacroiliitis in children with magnetic resonance imaging: is gadolinium contrast enhancement necessary?" is presented.

X-linked Charcot–Marie–Tooth disease (CMTX1) is the second most common form of Charcot–Marie–Tooth disease (CMT). It is caused by a mutation in the gap junction β 1 (GJB1) gene, which encodes for connexin-32. In addition to the peripheral neuropathy and foot deformities observed in classic CMT, central nervous system symptoms and magnetic resonance imaging (MRI) signal abnormalities in the brain have been reported in patients with CMTX1. Here we describe two cases of adolescent males who presented with stuttering neurologic deficits that were initially suggestive of acute ischemic stroke and were ultimately diagnosed with genetically confirmed CMTX1. Both patients had evidence of T2 hyperintensity and decreased diffusion on MRI in the centrum semiovale, posterior corona radiata, posterior periventricular white matter, and corpus callosum. Though rare, these cases illustrate the importance of comprehensive neurologic history, physical examination, and appropriate diagnostic evaluation. [ABSTRACT FROM AUTHOR]

A response from the author regarding morphology of the foramen magnum in syndromic and non-syndromic brachycephaly.

Subarachnoid hemorrhage (SAH) is one of the world's most life-threatening types of stroke. SAH can be classified into two main categories, aneurysmal (aSAH) and non-aneurysmal SAH (naSAH). In the present study, we aimed to prospectively evaluate SAH and its subcategories incidences, risk factors, complications, and outcomes in central Iran. All SAH patients diagnosed between 2016 and 2020 were included in Isfahan SAH Registry. Demographic, clinical characteristics, incidence rates (based on age categories), and laboratory/imaging findings were collected and compared between aSAH and naSAH subgroups. Complications during hospital stay and outcomes were also analyzed. Binary logistic regression analysis was performed to investigate the predictors of aSAH versus naSAH. Kaplan–Meier curves and Cox regression were used to evaluate the survival probability. A total of 461 SAH patients were included through Isfahan SAH Registry. The SAH annual incidence rate was 3.11 per 100,000 person-years. aSAH had higher incidence rate than naSAH (2.08/100,000 vs. 0.9/100,000 person-years, respectively). In-hospital mortality was 18.2%. Hypertension (P = 0.003) and smoking (P = 0.03) were significantly associated with aSAH, whereas diabetes mellitus (P < 0.001) was more associated with naSAH. After Cox regression analysis, there were higher hazard ratios for reduced in-hospital survival in conditions including altered mental status, Glasgow Coma Scale ≤13, rebleeding, and seizures. This study provided an updated estimation of SAH and its subgroups incidences in central Iran. Risk factors for aSAH are comparable to the ones reported in the literature. It is noteworthy that diabetes mellitus was associated with a higher incidence of naSAH in our cohort. [ABSTRACT FROM AUTHOR]

Background: Cerebrovascular diseases comprise a significant portion of neurological disorders related to coronavirus disease 2019 (COVID-19). We evaluated the clinical and imaging characteristics of a cohort of COVID-19 patients with stroke and also identified patients with watershed infarcts. Methods: In this cross-sectional study, seventy-three COVID-19 patients with ischemic stroke were included between October 2020 and January 2021. Patients were evaluated based on the following clinical and imaging features: severity of COVID-19 (critical/ non-critical), stroke type, presence/absence of clinical suspicion of stroke, medical risk factors, Fazekas scale, atherothrombosis, small vessel disease, cardiac pathology, other causes, and dissection (ASCOD) criteria classification, and presence or absence of watershed infarction. Clinical outcomes were assessed based on Modified Rankin Scale (MRS) and mortality. Results: Most cases of ischemic stroke were due to undetermined etiology (52.1%) and cardioembolism (32.9%). In terms of imaging pattern, 17 (23.0%) patients had watershed infarction. Watershed infarction was associated with the clinically nonsuspicious category [odds ratio (OR) = 4.67, P = 0.007] and death after discharge (OR = 7.1, P = 0.003). [ABSTRACT FROM AUTHOR]

Neuroimaging protocols play an important role in the timely evaluation and treatment of pediatric stroke and its mimics. MRI protocols for stroke in the pediatric population should be guided by the clinical scenario and neurologic examination, with consideration of age, suspected infarct type and underlying risk factors. Acute stroke diagnosis and causes in pediatric age groups can differ significantly from those in adult populations, and delay in stroke diagnosis among children is a common problem. An awareness of pediatric stroke presentations and risk factors among pediatric emergency physicians, neurologists, pediatricians, subspecialists and radiologists is critical to ensuring timely diagnosis. Given special considerations related to unique pediatric stroke risk factors and the need for sedation in some children, expert consensus guidelines for the imaging of suspected pediatric infarct have been proposed. In this article the authors review standard and rapid MRI protocols for the diagnosis of pediatric stroke, as well as the key differences between pediatric and adult stroke imaging. [ABSTRACT FROM AUTHOR]

Patients with hypoplastic left heart syndrome who have been palliated with the Fontan procedure are at risk for adverse neurodevelopmental outcomes, lower quality of life, and reduced employability. We describe the methods (including quality assurance and quality control protocols) and challenges of a multi-center observational ancillary study, SVRIII (Single Ventricle Reconstruction Trial) Brain Connectome. Our original goal was to obtain advanced neuroimaging (Diffusion Tensor Imaging and Resting-BOLD) in 140 SVR III participants and 100 healthy controls for brain connectome analyses. Linear regression and mediation statistical methods will be used to analyze associations of brain connectome measures with neurocognitive measures and clinical risk factors. Initial recruitment challenges occurred that were related to difficulties with: (1) coordinating brain MRI for participants already undergoing extensive testing in the parent study, and (2) recruiting healthy control subjects. The COVID-19 pandemic negatively affected enrollment late in the study. Enrollment challenges were addressed by: (1) adding additional study sites, (2) increasing the frequency of meetings with site coordinators, and (3) developing additional healthy control recruitment strategies, including using research registries and advertising the study to community-based groups. Technical challenges that emerged early in the study were related to the acquisition, harmonization, and transfer of neuroimages. These hurdles were successfully overcome with protocol modifications and frequent site visits that involved human and synthetic phantoms. [ABSTRACT FROM AUTHOR]

Wallerian degeneration (WD) is defined as progressive anterograde disintegration of axons and accompanying demyelination after an injury to the proximal axon or cell body. Since the 1980s and 1990s, conventional magnetic resonance imaging (MRI) sequences have been shown to be sensitive to changes of WD in the subacute to chronic phases. More recently, advanced MRI techniques, such as diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI), have demonstrated some of earliest changes attributed to acute WD, typically on the order of days. In addition, there is increasing evidence on the value of advanced MRI techniques in providing important prognostic information related to WD. This article reviews the utility of conventional and advanced MRI techniques for assessing WD, by focusing not only on the corticospinal tract but also other neural tracts less commonly thought of, including corticopontocerebellar tract, dentate-rubro-olivary pathway, posterior column of the spinal cord, corpus callosum, limbic circuit, and optic pathway. The basic anatomy of these neural pathways will be discussed, followed by a comprehensive review of existing literature supported by instructive clinical examples. The goal of this review is for readers to become more familiar with both conventional and advanced MRI findings of WD involving important neural pathways, as well as to illustrate increasing utility of advanced MRI techniques in providing important prognostic information for various pathologies. [ABSTRACT FROM AUTHOR]

Objective Hypoxic–ischemic encephalopathy (HIE) in infants can have long-term adverse neurodevelopmental effects and markedly reduce quality of life. Both the initial hypoperfusion and the subsequent rapid reperfusion can cause deleterious effects in brain tissue. Cerebral blood flow (CBF) assessment in newborns with HIE can help detect abnormalities in brain perfusion to guide therapy and prognosticate patient outcomes. Study Design The review will provide an overview of the pathophysiological implications of CBF derangements in neonatal HIE, current and emerging techniques for CBF quantification, and the potential to utilize CBF as a physiologic target in managing neonates with acute HIE. Conclusion The alterations of CBF in infants during hypoxia-ischemia have been studied by using different neuroimaging techniques, including nitrous oxide and xenon clearance, transcranial Doppler ultrasonography, contrast-enhanced ultrasound, arterial spin labeling MRI, 18F-FDG positron emission tomography, near-infrared spectroscopy (NIRS), functional NIRS, and diffuse correlation spectroscopy. Consensus is lacking regarding the clinical significance of CBF estimations detected by these different modalities. Heterogeneity in the imaging modality used, regional versus global estimations of CBF, time for the scan, and variables impacting brain perfusion and cohort clinical characteristics should be considered when translating the findings described in the literature to routine practice and implementation of therapeutic interventions. Key Points Hypoxic–ischemic injury in infants can result in adverse long-term neurologic sequelae. Cerebral blood flow is a useful biomarker in neonatal hypoxic–ischemic injury. Imaging modality, variables affecting cerebral blood flow, and patient characteristics affect cerebral blood flow assessment. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 15-year-old girl with ataxia and dysmetria seven days after she began treatment with metronidazole for Crohn's disease. The magnetic resonance imaging showed bilateral symmetric T2/FLAIR hyperintense lesions of the dentate nuclei. It indicates that after metronidazole was ceased, the lesions were resolved completely.

A letter to the editor is presented in response to the article regarding a 14-month-old girl with neurofibromatosis type 1 (NF-1) who was diagnosed with supratentorial malignant intracerebral nerve sheath tumor.

The management of patients with symptomatic rectal masses can be challenging and is further complicated in cases of advanced age, comorbidities, prior surgeries, and acute hemorrhage. In this report, we describe a patient who presented with massive hemorrhage from a 7 cm low rectal tumor with subsequent cardiac arrest. After return of spontaneous circulation, emergent pelvic angiography identified extensive tumor enhancement and blush off the anterior division of the right internal iliac artery from multiple parasitized vessels. The right internal iliac artery was embolized with multiple microcoils to decrease the tumor blood supply and slow the rate of bleeding. The patient was then taken directly from the angiography suite to radiation oncology for planning CT, and within several hours, underwent his first session of radiation. In conjunction with angioembolization, short-course radiation therapy can be an effective treatment modality for advanced bleeding rectal tumors not amenable to surgical resection. [ABSTRACT FROM AUTHOR]

Background: Medulloblastoma, a high-grade embryonal tumor, is the most common primary brain malignancy in the pediatric population. Molecular medulloblastoma groups have documented clinically and biologically relevant characteristics. Several authors have attempted to differentiate medulloblastoma molecular groups and histology variants using diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps. However, literature on the use of ADC histogram analysis in medulloblastomas is still scarce.Objective: This study presents data from a sizable group of pediatric patients with medulloblastoma from a single institution to determine the performance of ADC histogram metrics for differentiating medulloblastoma variants and groups based on both histological and molecular features.Materials and Methods: In this retrospective study, we evaluated the distribution of absolute and normalized ADC values of medulloblastomas. Tumors were manually segmented and diffusivity metrics calculated on a pixel-by-pixel basis. We calculated a variety of first-order histogram metrics from the ADC maps, including entropy, minimum, 10th percentile, 90th percentile, maximum, mean, median, skewness and kurtosis, to differentiate molecular and histological variants. ADC values of the tumors were also normalized to the bilateral cerebellar cortex and thalami. We used the Kruskal-Wallis and Mann-Whitney U tests to evaluate differences between the groups. We carried out receiver operating characteristic (ROC) curve analysis to evaluate the areas under the curves and to determine the cut-off values for differentiating tumor groups.Results: We found 65 children with confirmed histopathological diagnosis of medulloblastoma. Mean age was 8.3 ± 5.8 years, and 60% (n = 39) were male. One child was excluded because histopathological variant could not be determined. In terms of medulloblastoma variants, tumors were classified as classic (n = 47), desmoplastic/nodular (n = 9), large/cell anaplastic (n = 6) or as having extensive nodularity (n = 2). Seven other children were excluded from the study because of incomplete imaging or equivocal molecular diagnosis. Regarding medulloblastoma molecular groups, there were: wingless (WNT) group (n = 7), sonic hedgehog (SHH) group (n = 14) and non-WNT/non-SHH (n = 36). Our results showed significant differences among the molecular groups in terms of the median (P = 0.002), mean (P = 0.003) and 90th percentile (P = 0.002) ADC histogram metrics. No significant differences among the various medulloblastoma histological variants were found.Conclusion: ADC histogram analysis can be implemented as a complementary tool in the preoperative evaluation of medulloblastoma in children. This technique can provide valuable information for differentiating among medulloblastoma molecular groups. ADC histogram metrics can help predict medulloblastoma molecular classification preoperatively. [ABSTRACT FROM AUTHOR]

Developmental venous anomalies (DVAs) are the most common cerebral vascular malformations and are usually found incidentally on neuroimaging studies. Despite the benign nature of DVAs, occasionally, they can be symptomatic. The objective of this article is to review the spectrum of imaging findings of DVAs on conventional and advanced imaging studies. In addition, neuroimaging findings of symptomatic DVAs as well as imaging mimicks will also be described to assist in the approach to differential diagnosis. [ABSTRACT FROM AUTHOR]

Cerebral lipiodol embolization is a rare but known complication of lymphatic embolization for plastic bronchitis. The classic imaging finding on a noncontrast head computed tomography is multiple small areas of hyperdensity within the cerebral hemispheres, which represent lipiodol deposition in the brain. We report a case of lipiodol deposition in the middle cerebral artery following lymphatic embolization, producing an “ultradense” vessel sign on noncontrast computed tomography. [ABSTRACT FROM AUTHOR]

Accelerated maturation of brain parenchyma close to term‐equivalent age leads to rapid changes in diffusion‐weighted imaging (DWI) and diffusion tensor imaging (DTI) metrics of neonatal brains, which can complicate the evaluation and interpretation of these scans. In this study, we characterized the topography of age‐related evolution of diffusion metrics in neonatal brains. We included 565 neonates who had MRI between 0 and 3 months of age, with no structural or signal abnormality—including 162 who had DTI scans. We analyzed the age‐related changes of apparent diffusion coefficient (ADC) values throughout brain and DTI metrics (fractional anisotropy [FA] and mean diffusivity [MD]) along white matter (WM) tracts. Rate of change in ADC, FA, and MD values across 5 mm cubic voxels was calculated. There was significant reduction of ADC and MD values and increase of FA with increasing gestational age (GA) throughout neonates' brain, with the highest temporal rates in subcortical WM, corticospinal tract, cerebellar WM, and vermis. GA at birth had significant effect on ADC values in convexity cortex and corpus callosum as well as FA/MD values in corpus callosum, after correcting for GA at scan. We developed online interactive atlases depicting age‐specific normative values of ADC (ages 34–46 weeks), and FA/MD (35–41 weeks). Our results show a rapid decrease in diffusivity metrics of cerebral/cerebellar WM and vermis in the first few weeks of neonatal age, likely attributable to myelination. In addition, prematurity and low GA at birth may result in lasting delay in corpus callosum myelination and cerebral cortex cellularity. [ABSTRACT FROM AUTHOR]

Background: Torcular dural sinus malformations (tDSMs) are rare vascular malformations that present in fetuses and infants. Existing data on prognostic imaging features, as well as the associated morbidity and mortality, are limited and variable. We therefore reviewed cases of tDSMs diagnosed on fetal magnetic resonance imaging (MRI) at our referral center to identify pre- and postnatal MRI imaging features associated with long-term outcomes.Methods: We searched our imaging database for fetal and postnatal MRI reports of tDSM cases. The electronic medical record was then reviewed for pre- and postnatal clinical data, including follow-up imaging. Neurological outcomes were characterized using the previously reported scale based on the Bicêtre Score. Imaging features association with outcome scores were compared using the Fisher exact test.Results: Sixteen cases of tDMS diagnosed by fetal MRI with postnatal clinical follow-up were identified, 11 of whom underwent postnatal MRI. The majority of cases of tDSM (73%) decreased in size or resolved on postnatal follow-up study without treatment. Restricted diffusion and parenchymal hemorrhage on fetal MRI were the only imaging features identified significantly associated with unfavorable neurological outcome or death, present in two patients with poor outcomes (two of two) and only one with a normal outcome (one of 14) (P = 0.025).Conclusions: Findings of tDSM on fetal MRI most often regress and/or resolve with normal or mild neurological outcomes, with the most significant predictor of poor outcome being the presence of parenchymal injury on fetal MRI. In addition, a subset will present with venolymphatic malformations. [ABSTRACT FROM AUTHOR]