Infratentorial lesions in multiple sclerosis patients: intra- and inter-rater variability in comparison to a fully automated segmentation using 3D convolutional neural networks.

Objective: Automated quantification of infratentorial multiple sclerosis lesions on magnetic resonance imaging is clinically relevant but challenging. To overcome some of these problems, we propose a fully automated lesion segmentation algorithm using 3D convolutional neural networks (CNNs).

Methods: The CNN was trained on a FLAIR image alone or on FLAIR and T1-weighted images from 1809 patients acquired on 156 different scanners.

Multiple sclerosis lesion activity segmentation with attention-guided two-path CNNs.

Multiple sclerosis is an inflammatory autoimmune demyelinating disease that is characterized by lesions in the central nervous system. Typically, magnetic resonance imaging (MRI) is used for tracking disease progression. Automatic image processing methods can be used to segment lesions and derive quantitative lesion parameters.

MRI-Based Brain Volumetry at a Single Time Point Complements Clinical Evaluation of Patients With Multiple Sclerosis in an Outpatient Setting.

Thalamic atrophy and whole brain atrophy in multiple sclerosis (MS) are associated with disease progression. The motivation of this study was to propose and evaluate a new grouping scheme which is based on MS patients' whole brain and thalamus volumes measured on MRI at a single time point. In total, 185 MS patients (128 relapsing-remitting (RRMS) and 57 secondary-progressive MS (SPMS) patients) were included from an outpatient facility.

Comparative Analysis of Markers of Mass Effect after Ischemic Stroke.

Background And Purpose: Midline shift determined on magnetic resonance imaging (MRI) or computed tomography (CT) images is a well-validated marker of mass effect after large hemispheric infarction and associated with mortality. In this study, we targeted a population with moderately sized strokes. We compared midline shift to other imaging markers and determined their ability to predict long-term outcome.

Within-patient fluctuation of brain volume estimates from short-term repeated MRI measurements using SIENA/FSL.

Background: Measurements of brain volume loss (BVL) in individual patients are currently discussed controversially. One concern is the impact of short-term biological noise, like hydration status.

Methods: Three publicly available reliability MRI datasets with scan intervals of days to weeks were used.

Apparent Diffusion Coefficient Signal Intensity Ratio Predicts the Effect of Revascularization on Ischemic Cerebral Edema.

Background: Apparent diffusion coefficient (ADC) imaging is a biomarker of cytotoxic injury that predicts edema formation and outcome after ischemic stroke. It therefore has the potential to serve as a "tissue clock" to describe the extent of ischemic injury and potentially predict response to therapy. The goal of this study was to determine the relationship between baseline ADC signal intensity, revascularization, and edema formation.

Estimates of age-dependent cutoffs for pathological brain volume loss using SIENA/FSL-a longitudinal brain volumetry study in healthy adults.

Brain volume loss (BVL) has gained increasing interest for monitoring tissue damage in neurodegenerative diseases including multiple sclerosis (MS). In this longitudinal study, 117 healthy participants (age range 37.3-82.

Reperfusion after ischemic stroke is associated with reduced brain edema.

Rapid revascularization is highly effective for acute stroke, but animal studies suggest that reperfusion edema may attenuate its beneficial effects. We investigated the relationship between reperfusion and edema in patients from the Echoplanar Imaging Thrombolysis Evaluation Trial (EPITHET) and Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE) cohorts. Reperfusion percentage was measured as the difference in perfusion-weighted imaging lesion volume between baseline and follow-up (day 3-5 for EPITHET; day 6-8 for MR RESCUE).

Relationship Between Changes in the Temporal Dynamics of the Blood-Oxygen-Level-Dependent Signal and Hypoperfusion in Acute Ischemic Stroke.

Background And Purpose: Changes in the blood-oxygen-level-dependent (BOLD) signal provide a noninvasive measure of blood flow, but a detailed comparison with established perfusion parameters in acute stroke is lacking. We investigated the relationship between BOLD signal temporal delay and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) in stroke patients.

Methods: In 30 patients with acute (<24 hours) ischemic stroke, we performed Pearson correlation and multiple linear regression between DSC-MRI parameters (time to maximum [Tmax], mean transit time, cerebral blood flow, and cerebral blood volume) and BOLD-based parameters (BOLD delay and coefficient of BOLD variation).

Global and regional annual brain volume loss rates in physiological aging.

The objective is to estimate average global and regional percentage brain volume loss per year (BVL/year) of the physiologically ageing brain. Two independent, cross-sectional single scanner cohorts of healthy subjects were included. The first cohort (n = 248) was acquired at the Medical Prevention Center (MPCH) in Hamburg, Germany.

DCE-MRI blood-brain barrier assessment in acute ischemic stroke.

Objective: To quantitatively evaluate blood-brain barrier changes in ischemic stroke patients using dynamic contrast-enhanced (DCE) MRI.

Methods: We examined 54 stroke patients (clinicaltrials.gov NCT00715533, NCT02077582) in a 3T MRI scanner within 48 hours after symptom onset.

Safety and efficacy of intravenous glyburide on brain swelling after large hemispheric infarction (GAMES-RP): a randomised, double-blind, placebo-controlled phase 2 trial.

Background: Preclinical models of stroke have shown that intravenous glyburide reduces brain swelling and improves survival. We assessed whether intravenous glyburide (RP-1127; glibenclamide) would safely reduce brain swelling, decrease the need for decompressive craniectomy, and improve clinical outcomes in patients presenting with a large hemispheric infarction.

Methods: For this double-blind, randomised, placebo-controlled phase 2 trial, we enrolled patients (aged 18-80 years) with a clinical diagnosis of large anterior circulation hemispheric infarction for less than 10 h and baseline diffusion-weighted MRI image lesion volume of 82-300 cm(3) on MRI at 18 hospitals in the USA.

Early neurological stability predicts adverse outcome after acute ischemic stroke.

Background Deterioration in the National Institutes of Health Stroke Scale (NIHSS) in the early days after stroke is associated with progressive infarction, brain edema, and/or hemorrhage, leading to worse outcome. Aims We sought to determine whether a stable NIHSS score represents an adverse or favorable course. Methods Brain magnetic resonance images from a research cohort of acute ischemic stroke patients were analyzed.

Reliability of Two Diameters Method in Determining Acute Infarct Size. Validation as New Imaging Biomarker.

Background: In order to select patients most likely to benefit for thrombolysis and to predict patient outcome in acute ischemic stroke, the volumetric assessment of the infarcted tissue is used. However, infarct volume estimation on Diffusion weighted imaging (DWI) has moderate interrater variability despite the excellent contrast between ischemic lesion and healthy tissue. In this study, we compared volumetric measurements of DWI hyperintensity to a simple maximum orthogonal diameter approach to identify thresholds indicating infarct size >70 ml and >100 ml.

Case report of a young stroke patient showing interim normalization of the MRI diffusion-weighted imaging lesion.

Background: In acute ischemic stroke, diffusion weighted imaging (DWI) shows hyperintensities and is considered to indicate irreversibly damaged tissue. We present the case of a young stroke patient with unusual variability in the development of signal intensities within the same vessel territory.

Case Presentation: A 35-year-old patient presented with symptoms of global aphasia and hypesthesia of the left hand.

Natural course of total mismatch and predictors for tissue infarction.

Objective: We longitudinally assessed patients presenting with total mismatch and hypothesized that hypoperfusion intensity ratio (HIR), severity of stroke, and occlusion of blood vessel are predictors of tissue fate.

Methods: Patients with suspected stroke or TIA admitted to our emergency department between September 2008 and October 2012 with suspected stroke or TIA were eligible to participate in the ongoing stroke imaging study 1000Plus. Patients received acute and follow-up stroke MRI, basic demographics were collected, and stroke severity was rated according to the NIH Stroke Scale (NIHSS).

Subtracted Dynamic MR Perfusion Source Images (sMRP-SI) provide Collateral Blood Flow Assessment in MCA Occlusions and Predict Tissue Fate.

Objectives: Collateral blood flow is accepted as a predictive factor of tissue fate in ischemic stroke. Thus, we aimed to evaluate a new method derived from MR perfusion source images to assess collateral flow in patients with ICA/MCA occlusions.

Methods: A total of 132 patients of the prospective 1000+ study were examined.

Hyperintense acute reperfusion marker is associated with higher contrast agent dosage in acute ischaemic stroke.

Objective: The hyperintense acute reperfusion marker (HARM) on fluid-attenuated inversion recovery (FLAIR) images is associated with blood-brain barrier (BBB) permeability changes. The aim of this study was to examine the influence of contrast agent dosage on HARM incidence in acute ischaemic stroke patients.

Methods: We prospectively included 529 acute ischaemic stroke patients (204 females, median age 71 years).

Relative FLAIR Signal Intensities over Time in Acute Ischemic Stroke: Comparison of Two Methods.

Background And Purpose: Visibility of lesions on fluid attenuated inversion recovery (FLAIR) images appears indicative of the time window in acute ischemic stroke. We compared two published methods for calculation of relative FLAIR signal intensities (rSI) regarding their association with time from symptom onset in a longitudinal fashion.

Methods: We prospectively included patients receiving serial MRI examinations between 4.

Early time course of FLAIR signal intensity differs between acute ischemic stroke patients with and without hyperintense acute reperfusion marker.

Background: In animal models of stroke, the time course of blood-brain barrier (BBB) disruptions has been elaborately studied. In human patients, leakage of gadolinium into cerebrospinal fluid (CSF) space, visualized on MRI fluid attenuated inversion recovery (FLAIR) images, is considered a sign of BBB disruptions. It was termed 'hyperintense acute reperfusion marker' (HARM) and was associated with hemorrhages.

Automated vs manual delineations of regions of interest- a comparison in commercially available perfusion MRI software.

Background: In perfusion magnetic resonance imaging a manual approach to delineation of regions of interest is, due to rater bias and time intensive operator input, clinically less favorable than an automated approach would be. The goal of our study was to compare the performances of these approaches.

Methods: Using Stroketool, PMA and Perfscape/Neuroscape perfusion maps of cerebral blood flow, mean transit time and Tmax were created for 145 patients with acute ischemic stroke.

The potential of microvessel density in prediction of infarct growth: a two-month experimental study in vessel size imaging.

Objectives: Vessel size imaging is a novel technique to evaluate pathological changes of the microvessel density quantity Q and the mean vessel size index (VSI). As a follow-up study, we assessed these parameters for microscopic description of ischemic penumbra and their potentials in predicting lesion growth.

Methods: Seventy-five patients with a perfusion-diffusion mismatch were examined within 24 h from symptom onset.