Preoperative embolization improves local control and modulates gene expression in atypical WHO grade 2 meningioma.

Background: Preoperative embolization is hypothesized to reduce blood loss and operative time for meningioma resection, but the impact of preoperative embolization on long-term oncological outcomes and molecular features of meningiomas is incompletely understood. Here we investigate how preoperative embolization influences perioperative and long-term outcomes and molecular features of atypical WHO grade 2 meningiomas.

Methods: Patients who underwent resection of WHO grade 2 meningiomas from 1997 to 2021 were retrospectively identified from an institutional database.

Rescue management of recurrent or growing non-acute subdural hematoma following standalone or adjunctive middle meningeal artery embolization: A case series and systematic review.

ObjectiveRecurrent or growing non-acute subdural hematoma (SDH) following standalone or adjunctive middle meningeal artery embolization (MMAe) present a complex clinical challenge. This study aims to investigate the multifactorial causes of recurrence and growing SDH, including vascular and systemic contributors, and explores management strategies to improve outcomes.MethodsWe conducted a retrospective analysis of 22 patients with non-acute SDH requiring rescue treatment after adjunctive or stand-alone MMAe.

Oxygen Extraction Fraction on Baseline MRI Predicts Infarction Growth in Successfully Reperfused Patients.

Background: In patients with acute ischemic stroke, infarct growth occurs despite successful reperfusion. Oxygen extraction fraction (OEF) has shown promising results in evaluating ischemic tissue viability and can now be quantified from routinely performed dynamic susceptibility contrast perfusion. We aimed to determine the association of OEF alterations within the ischemic tissue on pretreatment magnetic resonance imaging and infarct growth in patients who underwent successful reperfusion.

4D flow MRI for noninvasive monitoring of high-flow vascular malformations in neonates and infants: A feasibility study.

BackgroundIntracranial high-flow vascular malformations greatly alter neonatal cerebral hemodynamics and can cause significant morbidity and mortality. X-ray digital subtraction angiography (DSA) is the standard of care to assess angioarchitecture and plan for intervention, but exposes patients to radiation and procedural risks, and only allows for subjective interpretation. Objective noninvasive assessment of hemodynamics could improve prognostication.

Intra-arterial chemotherapy for bleeding head and neck tumors: a single-center experience.

Background: Advanced-stage head and neck cancers are associated with high morbidity and mortality, often requiring complex therapeutic interventions. In cases of tumor-associated hemorrhage, intra-arterial (IA) chemotherapy combined with embolization offers a potential treatment strategy. This study assesses the safety and efficacy of this approach in a cohort of patients with bleeding head and neck malignancies.

State of Practice: A Report from the Inaugural SNIS Neurointerventional Oncology Summit.

Background: Over the past 25-years, progress in the treatment of central nervous system (CNS) tumors has been limited and outcomes for malignancies such as glioblastoma and diffuse intrinsic pontine glioma remain dismal. There has been great interest in harnessing endovascular neurointerventional techniques and to use the cerebral vasculature as a route for therapeutic delivery in neuro-oncology. Several selective intra-arterial clinical trials are currently underway targeting a range of CNS tumors with different therapeutic agents.

Iatrogenic dural arteriovenous fistula formation as a rare complication of external ventricular drain placement: institutional review of 16 cases.

Introduction: External ventricular drain (EVD) placement is a life-saving neurosurgical procedure used to divert cerebrospinal fluid and reduce intracranial pressure in conditions such as subarachnoid hemorrhage, intraparenchymal hemorrhage, and intraventricular hemorrhage. While known complications include infection and hemorrhage, the formation of iatrogenic dural arteriovenous fistulas (dAVFs) following ventriculostomy is under-reported.

Methods: We conducted a retrospective review of patients at our institution from 2002 to 2023 who developed dAVFs after EVD placement.

Remote Robotic Neurointervention: Overcoming Procedural and Connectivity Challenges.

Background And Purpose: Access to endovascular interventions for neurointerventional procedures remains concentrated in metropolitan centers, limiting availability in smaller cities, rural regions, and developing nations. The feasibility of remote robotic intervention faces several challenges, including enabling full robotic navigation, managing contrast injection, and maintaining stable network connectivity. This study addresses these key obstacles.

Focused ultrasound therapy as a strategy for improving glioma treatment.

The infiltrative and diffuse nature of gliomas makes complete resection unfeasible. Unfortunately, regions of brain parenchyma with residual, infiltrative tumor are protected by the blood-brain barrier (BBB), making systemic chemotherapies, small-molecule inhibitors, and immunotherapies of limited efficacy. Low-frequency focused ultrasound (FUS) in combination with intravascular microbubbles can be used to disrupt the BBB transiently and selectively within the tumor and peritumoral region.

A phase I study of convection-enhanced delivery (CED) of liposomal-irinotecan using real-time magnetic resonance imaging in patients with recurrent high-grade glioma.

Background: Irinotecan demonstrates anti-tumor efficacy in preclinical glioma models but clinical results are modest due to drug delivery limitations. Convection enhanced delivery (CED) improves drug delivery by increasing intratumoral drug concentration. Real-time magnetic resonance imaging of infusate delivery during CED may optimize tumor coverage.

State of Practice on Transcranial MR-Guided Focused Ultrasound: A Report from the ASNR Standards and Guidelines Committee and ACR Commission on Neuroradiology Workgroup.

Transcranial focused ultrasound (FUS) is a versatile, MR-guided, incisionless intervention with diagnostic and therapeutic applications for neurologic and psychiatric diseases. It is currently FDA-approved as a thermoablative treatment of essential tremor and Parkinson disease. However, other applications of FUS including BBB opening for diagnostic and therapeutic applications, sonodynamic therapy, histotripsy, and low-intensity focused ultrasound neuromodulation are all in clinical trials.

Monitoring Blood-Brain Barrier Opening in Rats with a Preclinical Focused Ultrasound System.

The brain has a highly selective semipermeable blood barrier, termed the blood-brain barrier (BBB), which prevents the delivery of therapeutic macromolecular agents to the brain. The integration of MR-guided low-intensity pulsed focused ultrasound (FUS) with microbubble pre-injection is a promising technique for non-invasive and non-toxic BBB modulation. MRI can offer superior soft-tissue contrast and various quantitative assessments, such as vascular permeability, perfusion, and the spatial-temporal distribution of MRI contrast agents.

Volumetric hyperthermia delivery using the ExAblate Body MR-guided focused ultrasound system.

Objectives: To investigate image-guided volumetric hyperthermia strategies using the ExAblate Body MR-guided focused ultrasound ablation system, involving mechanical transducer movement and sector-vortex beamforming.

Materials And Methods: Acoustic and thermal simulations were performed to investigate volumetric hyperthermia using mechanical transducer movement combined with sector-vortex beamforming, specifically for the ExAblate Body transducer. The system control in the ExAblate Body system was modified to achieve fast transducer movement and MR thermometry-based hyperthermia control, mechanical transducer movements and electronic sector-vortex beamforming were combined to optimize hyperthermia delivery.

Arteriovenous shunts of the cervical spine: patient demographics, presentation, patterns of high-risk venous drainage, and updated classification.

Background: Intracranial dural arteriovenous (AV) fistula classifications focus on presence/absence of retrograde flow in the cortical veins of the brain as this angiographic finding portends a worse prognosis. However, prior categorization systems of AV shunts in the spine do not incorporate these features. We propose an updated classification for spinal shunting lesions that terms any shunting lesion with retrograde flow in any cortical vein of the brain or spinal cord medullary vein as "high risk".

Strategies to Improve Drug Delivery Across the Blood-Brain Barrier for Glioblastoma.

Purpose Of Review: Glioblastoma remains resistant to most conventional treatments. Despite scientific advances in the past three decades, there has been a dearth of effective new treatments. New approaches to drug delivery and clinical trial design are needed.

Technical advances in motion-robust MR thermometry.

Proton resonance frequency shift (PRFS) MR thermometry is the most common method used in clinical thermal treatments because of its fast acquisition and high sensitivity to temperature. However, motion is the biggest obstacle in PRFS MR thermometry for monitoring thermal treatment in moving organs. This challenge arises because of the introduction of phase errors into the PRFS calculation through multiple methods, such as image misregistration, susceptibility changes in the magnetic field, and intraframe motion during MRI acquisition.

MR Thermometry during Transcranial MR Imaging-Guided Focused Ultrasound Procedures: A Review.

Interest in transcranial MR imaging-guided focused ultrasound procedures has recently grown. These incisionless procedures enable precise focal ablation of brain tissue using real-time monitoring by MR thermometry. This article will provide an updated review on clinically applicable technical underpinnings and considerations of proton resonance frequency MR thermometry, the most common clinically used MR thermometry sequence.

Robotic Diagnostic Cerebral Angiography: A Multicenter Experience of 113 Patients.

Background: Neurointerventional robotic systems have potential to reduce occupational radiation, improve procedural precision, and allow for future remote teleoperation. A limited number of single institution case reports and series have been published outlining the safety and feasibility of robot-assisted diagnostic cerebral angiography.

Methods: This is a multicenter, retrospective case series of patients undergoing diagnostic cerebral angiography at three separate institutions - University of California, Davis (UCD); University of California, Los Angeles (UCLA); and University of California, San Francisco (UCSF).

Clinical evaluation of pulsatile tinnitus: history and physical examination techniques to predict vascular etiology.

Background: Pulsatile tinnitus (PT) may be due to a spectrum of cerebrovascular etiologies, ranging from benign venous turbulence to life threatening dural arteriovenous fistulas. A focused clinical history and physical examination provide clues to the ultimate diagnosis; however, the predictive accuracy of these features in determining PT etiology remains uncertain.

Methods: Patients with clinical PT evaluation and DSA were included.