Publications by authors named "Tamrazi B"

Three distinct MN1::BEND2 fusion-positive tumors in pediatric patients. (A) Clinical course for each patient was variable in part due to differences in initial diagnosis. Each patient responded favorably to gross total resection and is stable at last follow-up.

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Article Synopsis
  • The study aimed to assess nnU-Net-based segmentation models for accurately identifying medulloblastoma tumors in pediatric patients using multi-institutional MRI scans.
  • It involved 78 patients aged 2 to 18 years and utilized various MRI protocols collected from three hospitals over 19 years, with tumor annotations prepared by expert neuroradiologists.
  • Results showed that both transfer learning and direct nnU-Net models achieved decent Dice scores for tumor segmentation, indicating their effectiveness and robustness across different clinical sites.
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Pineal parenchymal tumors are rare neoplasms for which evidence-based treatment recommendations are lacking. These tumors vary in biology, clinical characteristics, and prognosis, requiring treatment that ranges from surgical resection alone to intensive multimodal antineoplastic therapy. Recently, international collaborative studies have shed light on the genomic landscape of these tumors, leading to refinement in molecular-based disease classification in the 5th edition of the World Health Organization (WHO) classification of tumors of the central nervous system.

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Background: Children with neuromuscular early onset scoliosis (EOS) receive numerous radiographic studies both from orthopaedic and other specialties. Ionizing radiation doses delivered by computed tomography (CT) are reportedly 100 times higher than conventional radiography. The purpose of this study was to evaluate the number of radiographic studies ordered for neuromuscular EOS patients during their care.

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Background: There is no standard treatment for the recurrence of medulloblastoma, the most common malignant childhood brain tumor, and prognosis remains dismal. In this study, we introduce a regimen that is well-tolerated and effective at inducing remission.

Methods: The primary objectives of this study were to assess tolerability of the regimen and overall response rate (ORR).

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Medulloblastoma is the most common malignant brain tumor in childhood. Initial treatment generally includes surgery, irradiation, and chemotherapy. Approximately 20-30% of patients will experience a recurrence, which portends a very poor prognosis.

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Objective: Standard MRI protocols lack a quantitative sequence that can be used to evaluate shunt-treated patients with a history of hydrocephalus. The objective of this study was to investigate the use of phase-contrast MRI (PC-MRI), a quantitative MR sequence, to measure CSF flow through the shunt and demonstrate PC-MRI as a useful adjunct in the clinical monitoring of shunt-treated patients.

Methods: The rapid (96 seconds) PC-MRI sequence was calibrated using a flow phantom with known flow rates ranging from 0 to 24 mL/hr.

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Objective: To determine the prevalence of neuroimaging abnormalities in individuals with Down syndrome regression disorder (DSRD) and evaluate if neuroimaging abnormalities were predictive of therapeutic responses.

Methods: A multicenter, retrospective, case-control study which reviewed neuroimaging studies of individuals with DSRD and compared them to a control cohort of individuals with Down syndrome (DS) alone was performed. Individuals aged 10-30 years and meeting international consensus criteria for DSRD were included.

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Article Synopsis
  • Pediatric brain tumor prognosis is currently poor, but there is hope that CAR T cell therapy could improve outcomes, as indicated by a study involving the first six treated patients in a clinical trial (NCT04510051).
  • Interim results show that three out of five evaluable patients experienced some temporary clinical benefits, while overall there were no serious side effects from the treatment, despite some patients experiencing common issues like cytopenias.
  • Analysis of immune responses revealed interesting interactions between CAR T cells and the patient's immune system, highlighting differences in T cell populations in the cerebrospinal fluid compared to peripheral blood, suggesting the need for careful sampling in future studies.
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Study Design: Retrospective review.

Objective: Our goal was to investigate the incidence of cervical degenerative disk disease (DDD) in patients with adolescent idiopathic scoliosis (AIS), before surgical intervention.

Summary Of Background Data: AIS is often associated with thoracic hypokyphosis and compensatory cervical kyphosis.

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Chimeric antigen receptor (CAR) T cells targeting the CD19 (cluster of differentiation 19) cell surface glycoprotein have emerged as a highly effective immunologic therapy in patients with relapsed or refractory B-cell malignancies. The engagement of CAR T cells with CD19 on the surface of neoplastic B cells causes a systemic cytokine release, which can compromise the blood-brain barrier and cause an immune effector cell-associated neurotoxicity syndrome (ICANS). In a small proportion of ICANS patients who demonstrate neuroimaging abnormalities, certain distinct patterns have been recognized, including signal changes in the thalami, external capsule, and brainstem, the subcortical and/or periventricular white matter, the splenium of the corpus callosum, and the cerebellum.

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Objective: To determine cerebral glucose concentration and its relationship with glucose infusion rate (GIR) and blood glucose concentration in neonatal encephalopathy during therapeutic hypothermia (TH).

Methods: This was an observational study in which cerebral glucose during TH was quantified by magnetic resonance (MR) spectroscopy and compared with mean blood glucose at the time of scan. Clinical data (gestational age, birth weight, GIR, sedative use) that could affect glucose use were collected.

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Introduction: Medulloblastoma (MB) is a malignant, heterogenous brain tumor. Advances in molecular profiling have led to identifying four molecular subgroups of MB (WNT, SHH, Group 3, Group 4), each with distinct clinical behaviors. We hypothesize that (1) aggressive MB tumors, growing heterogeneously, induce pronounced local structural deformations in the surrounding parenchyma, and (b) these local deformations as captured on Gadolinium (Gd)-enhanced-T1w MRI are independently associated with molecular subgroups, as well as overall survival in MB patients.

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Quantitative susceptibility mapping (QSM) is an MRI-based technique for iron quantification of targeted tissue. QSM provides information relevant to clinicians in a broad range of diagnostic contexts, including sickle cell disease, inflammatory/demyelinating processes, and neoplasms. However, major MRI vendors do not offer QSM post-processing in a form ready for general use.

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Molecular subtypes of medulloblastoma [Sonic Hedgehog (SHH), Wingless/INT (WNT), Group 3, and Group 4] are defined by common patterns of gene expression. These differential gene expression patterns appear to result in different histomorphology and prognosis. Quantitative histomorphometry is a well-known method of computer-aided pathology image analysis.

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Purpose: To develop an MR multitasking-based dynamic imaging for cerebrovascular evaluation (MT-DICE) technique for simultaneous quantification of permeability and leakage-insensitive perfusion with a single-dose contrast injection.

Methods: MT-DICE builds on a saturation-recovery prepared multi-echo fast low-angle shot sequence. The k-space is randomly sampled for 7.

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Background: Craniopharyngioma is a histologically benign tumor of the suprasellar region for which survival is excellent but quality of life is often poor secondary to functional deficits from tumor and treatment. Standard therapy consists of maximal safe resection with or without radiation therapy. Few prospective trials have been performed, and response assessment has not been standardized.

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Purpose: Radiation-induced cerebrovascular toxicity is a well-documented sequelae that can be both life-altering and potentially fatal. We performed a meta-analysis of the relevant literature to create practical models for predicting the risk of cerebral vasculopathy after cranial irradiation.

Methods And Materials: A literature search was performed for studies reporting pediatric radiation therapy (RT) associated cerebral vasculopathy.

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In vivo MR spectroscopy is a non -invasive methodology that provides information about the biochemistry of tissues. It is available as a "push-button" application on state-of-the-art clinical MR scanners. MR spectroscopy has been used to study various brain diseases including tumors, stroke, trauma, degenerative disorders, epilepsy/seizures, inborn errors, neuropsychiatric disorders, and others.

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Variants in the mitochondrial genome can result in dysfunction of Complex I within the electron transport chain, thus causing disruptions in oxidative phosphorylation. Pathogenic variants in the (NADH:ubiquinone oxidoreductase core subunit 1) gene that result in Complex I dysfunction are a known cause of Leigh syndrome. The patient is a 4-yr-old female who initially presented with generalized tonic-clonic seizures, with other symptoms of Leigh syndrome becoming apparent after the seizures.

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Background And Purpose: Selumetinib is a promising MAP (mitogen-activated protein) kinase (MEK) 1/2 inhibitor treatment for pediatric low-grade gliomas. We hypothesized that MR imaging-derived ADC histogram metrics would be associated with survival and response to treatment with selumetinib.

Materials And Methods: Children with recurrent, refractory, or progressive pediatric low-grade gliomas who had World Health Organization grade I pilocytic astrocytoma with fusion or the V600E mutation (stratum 1), neurofibromatosis type 1-associated pediatric low-grade gliomas (stratum 3), or sporadic non-neurofibromatosis type 1 optic pathway and hypothalamic glioma (OPHG) (stratum 4) were treated with selumetinib for up to 2 years.

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Background And Purpose: ADC changes are useful in detecting ischemic brain injury, but mechanisms other than tissue pathology may affect the kinetic movement and diffusion of water molecules. We aimed to determine the effects of brain temperature on the corresponding ADC in infants undergoing therapeutic hypothermia.

Materials And Methods: Brain temperature and ADC values in the basal ganglia, thalamus, cortical GM, and WM were analyzed during and after therapeutic hypothermia.

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Article Synopsis
  • There are two types of childhood ependymomas: group A (PFAs) and group B (PFBs), and PFAs are harder to treat and have worse outcomes.
  • PFAs have a special protein called EZHIP, which makes some important changes in the cells that help the cancer grow faster.
  • Using a medicine called metformin, which is usually for diabetes, can help slow down the growth of these tumors by changing how the cancer cells use energy and by reducing the EZHIP protein.
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Isocitrate dehydrogenase (IDH) mutations are rare in pediatric and adolescent gliomas. We recently identified three adolescent/young adult (AYA) patients with IDH-mutant low grade gliomas of the brainstem with several key clinicopathologic and molecular features in common. We discuss these three cases and review the current literature.

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