Small vessel dysfunction at 7T MRI locally predicts white matter damage progression in CADASIL.

Cerebral small vessel diseases (cSVDs) contribute significantly to stroke and dementia. Advanced 7 T MRI techniques have revealed small vessel dysfunction in cSVD patients, linked to global white matter damage cross-sectionally. However, it remains unclear whether these vascular deficits predict progressive tissue damage.

Neuroinflammation in long-term cognitive impairment after aneurysmal subarachnoid hemorrhage.

Background: Survivors of aneurysmal subarachnoid hemorrhage (aSAH) often have cognitive impairment, which may be caused by long-term inflammation. We aimed to determine whether long-term neuroinflammation or microstructural brain damage is associated with cognitive impairment after aSAH.

Methods: In this prospective cohort study, we included patients >3 years after aSAH between 2020 and 2022.

The tractographer's dilemma: understanding sources of variability in tractography.

Tractography involves many steps, and as such can be heavily affected by data quality, operator decisions such as algorithm and parameter selection and/or biological variables - in addition to random effects such as noise and motion. Due to the interplay between sources of variability, even seemingly minor decisions or overlooked assumptions can lead to major variations in output that can potentially confound tractography results. This article summarizes the main sources of variability in tractography to remind both new and experienced users of the importance of making informed decisions at all stages of the tractography pipeline.

Acquisition matters - how do scan parameters affect apparent diffusion coefficient estimates in pediatric rhabdomyosarcoma.

Background: The apparent diffusion coefficient (ADC) derived from diffusion-weighted imaging (DWI) is a potential biomarker for treatment response in pediatric rhabdomyosarcoma. Due to its rarity, investigations into this marker require multicenter approaches, which can result in variability in acquisition parameters.

Objective: To evaluate the impact of different acquisition parameters on ADC estimates in a multicenter dataset of rhabdomyosarcoma patients.

MRI and non-MRI quantifiable neuroanatomical and functional parameters are useful for tractography.

Tractography provides a powerful framework to reconstruct white matter pathways from diffusion magnetic resonance imaging (dMRI) but remains challenged by its inherent ambiguity and lack of direct biological specificity. This short communication summarizes the key points of a debate held at the 2024 Tract-Anat Retreat on the utility of MRI and non-MRI quantifiable neuroanatomical and functional parameters for improving tractography. During the discussion, concerns were raised about the availability of histological properties only on post-mortem tissues, the disparity in scale between MRI and other modalities and the additional costs (both in time and money) of such additional parameters.

Ego Does Not Deplete Over Time.

The idea that self-control (or executive) functions depend on limited "mental resources" that can be depleted (aka ego-depletion) has generated a lot of interest, but both the empirical status of the phenomenon and its theoretical explanation remain controversial. Here, we tested a widely neglected but straightforward prediction of ego-depletion theory: The longer people work on a control-demanding task, the more should their ego deplete. If so, ego-depletion effects should become more pronounced as time on (control) task increases.

Cross-site harmonization of diffusion MRI data without matched training subjects.

Purpose: Diffusion MRI (dMRI) data typically suffer of significant cross-site variability, which prevents naively performing pooled analyses. To attenuate cross-site variability, harmonization methods such as the rotational invariant spherical harmonics (RISH) have been introduced to harmonize the dMRI data at the signal level. A common requirement of the RISH method is the availability of healthy individuals who are matched at the group level, which may not always be readily available, particularly retrospectively.

Individualized lesion-symptom mapping using explainable artificial intelligence for the cognitive impact of white matter hyperintensities.

Lesion-symptom mapping methods assess the relationship between lesions caused by cerebral small vessel disease and cognition, but current technology like support vector regression (SVR)) primarily provide group-level results. We propose a novel lesion-symptom mapping approach that can indicate how lesion patterns contribute to cognitive impairment on an individual level. A convolutional neural network (CNN) predicts cognitive scores and is combined with explainable artificial intelligence (XAI) to map the relation between cognition and vascular lesions.

The relation between cerebral small vessel function and white matter microstructure in monogenic and sporadic small vessel disease - the ZOOM@SVDs study.

In cerebral small vessel disease (cSVD), vascular dysfunction has been associated with cSVD-lesions across the brain. Here we further explore the relation between vascular dysfunction and cSVD-related brain injury. We tested two hypotheses: (1) that complementary measures of abnormal small vessel function relate to decreased white matter integrity, and (2) that local variance in vascular dysfunction relates to local variance in white matter integrity within individual patients.

Longitudinal changes in white matter free water in cerebral small vessel disease: Relationship to cerebral blood flow and white matter fiber alterations.

White matter (WM) free water (FW) is a potential imaging marker for cerebral small vessel disease (CSVD). This study aimed to characterize longitudinal changes in WM FW and investigate factors contributing to its elevation in CSVD. We included 80 CSVD patients and 40 normal controls (NCs) with multi-modality MRI data.

Vigabatrin-associated brain magnetic resonance imaging abnormalities and clinical symptoms in infants with tuberous sclerosis complex.

Objective: Previous retrospective studies have reported vigabatrin-associated brain abnormalities on magnetic resonance imaging (VABAM), although clinical impact is unknown. We evaluated the association between vigabatrin and predefined brain magnetic resonance imaging (MRI) changes in a large homogenous tuberous sclerosis complex (TSC) cohort and assessed to what extent VABAM-related symptoms were reported in TSC infants.

Methods: The Dutch TSC Registry and the EPISTOP cohort provided retrospective and prospective data from 80 TSC patients treated with vigabatrin (VGB) before the age of 2 years and 23 TSC patients without VGB.

Microstructural white matter damage on MRI is associated with disease severity in Dutch-type cerebral amyloid angiopathy.

Peak width of skeletonized mean diffusivity (PSMD) is an emerging diffusion-MRI based marker to study subtle early alterations to white matter microstructure. We assessed PSMD over the clinical continuum in Dutch-type hereditary CAA (D-CAA) and its association with other CAA-related MRI-markers and cognitive symptoms. We included (pre)symptomatic D-CAA mutation-carriers and calculated PSMD from diffusion-MRI data.

Enhancing Cognitive Performance Prediction through White Matter Hyperintensity Connectivity Assessment: A Multicenter Lesion Network Mapping Analysis of 3,485 Memory Clinic Patients.

Introduction: White matter hyperintensities of presumed vascular origin (WMH) are associated with cognitive impairment and are a key imaging marker in evaluating cognitive health. However, WMH volume alone does not fully account for the extent of cognitive deficits and the mechanisms linking WMH to these deficits remain unclear. We propose that lesion network mapping (LNM), enables to infer if brain networks are connected to lesions, and could be a promising technique for enhancing our understanding of the role of WMH in cognitive disorders.

Unraveling the relations between post-traumatic stress symptoms, neurocognitive functioning, and limbic white matter in pediatric brain tumor patients.

Background: Pediatric brain tumor patients are at risk of developing neurocognitive impairments and associated white matter alterations. In other populations, post-traumatic stress symptoms (PTSS) impact cognition and white matter. This study aims to investigate the effect of PTSS on neurocognitive functioning and limbic white matter in pediatric brain tumor patients.

Improving advanced intraoperative MRI methods during pediatric neurosurgery.

Advanced intraoperative MR images (ioMRI) acquired during the resection of pediatric brain tumors could offer additional physiological information to preserve healthy tissue. With this work, we aimed to develop a protocol for ioMRI with increased sensitivity for arterial spin labeling (ASL) and diffusion MRI (dMRI), optimized for patient positioning regularly used in the pediatric neurosurgery setting. For ethical reasons, ASL images were acquired in healthy adult subjects that were imaged in the prone and supine position.

Detectability and accuracy of computational measurements of in-silico and physical representations of enlarged perivascular spaces from magnetic resonance images.

Background: Magnetic Resonance Imaging (MRI) visible perivascular spaces (PVS) have been associated with age, decline in cognitive abilities, interrupted sleep, and markers of small vessel disease. But the limits of validity of their quantification have not been established.

New Method: We use a purpose-built digital reference object to construct an in-silico phantom for addressing this need, and validate it using a physical phantom.

Microstructural white matter integrity in relation to vascular reactivity in Dutch-type hereditary cerebral amyloid angiopathy.

Cerebral Amyloid Angiopathy (CAA) is characterized by cerebrovascular amyloid-β accumulation leading to hallmark cortical MRI markers, such as vascular reactivity, but white matter is also affected. By studying the relationship in different disease stages of Dutch-type CAA (D-CAA), we tested the relation between vascular reactivity and microstructural white matter integrity loss. In a cross-sectional study in D-CAA, 3 T MRI was performed with Blood-Oxygen-Level-Dependent (BOLD) fMRI upon visual activation to assess vascular reactivity and diffusion tensor imaging to assess microstructural white matter integrity through Peak Width of Skeletonized Mean Diffusivity (PSMD).

Quantitative diffusion-weighted MRI response assessment in rhabdomyosarcoma: an international retrospective study on behalf of the European paediatric Soft tissue sarcoma Study Group Imaging Committee.

Objective: To investigate the feasibility of diffusion-weighted magnetic resonance imaging (DW-MRI) as a predictive imaging marker after neoadjuvant chemotherapy in patients with rhabdomyosarcoma.

Material And Methods: We performed a multicenter retrospective study including pediatric, adolescent and young adult patients with rhabdomyosarcoma, Intergroup Rhabdomyosarcoma Study group III/IV, treated according to the European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS2005 or MTS2008 studies. DW-MRI was performed according to institutional protocols.

Neuroimaging standards for research into small vessel disease-advances since 2013.

Cerebral small vessel disease (SVD) is common during ageing and can present as stroke, cognitive decline, neurobehavioural symptoms, or functional impairment. SVD frequently coexists with neurodegenerative disease, and can exacerbate cognitive and other symptoms and affect activities of daily living. Standards for Reporting Vascular Changes on Neuroimaging 1 (STRIVE-1) categorised and standardised the diverse features of SVD that are visible on structural MRI.

Advanced intraoperative MRI in pediatric brain tumor surgery.

In the pediatric brain tumor surgery setting, intraoperative MRI (ioMRI) provides "real-time" imaging, allowing for evaluation of the extent of resection and detection of complications. The use of advanced MRI sequences could potentially provide additional physiological information that may aid in the preservation of healthy brain regions. This review aims to determine the added value of advanced imaging in ioMRI for pediatric brain tumor surgery compared to conventional imaging.

Corrigendum: Topology of diffusion changes in corpus callosum in Alzheimer's disease: An exploratory case-control study.

[This corrects the article DOI: 10.3389/fneur.2022.