Publications by authors named "Thibo Billiet"

Background And Objectives: Accumulating evidence points to worse clinical outcomes among adults with multiple sclerosis (MS) belonging to minority or poverty-affected groups. By contrast, little is known about the outcomes of these populations with pediatric-onset MS (POMS). Individuals with POMS represent 5% of the MS population and are more racially diverse yet have been understudied regarding socioeconomic environment or characteristics.

View Article and Find Full Text PDF

Automated quantification of brain tissues on MR images has greatly contributed to the diagnosis and follow-up of neurological pathologies across various life stages. However, existing solutions are specifically designed for certain age ranges, limiting their applicability in monitoring brain development from infancy to late adulthood. This retrospective study aims to develop and validate a brain segmentation model across pediatric and adult populations.

View Article and Find Full Text PDF

Background: The connectome, constituting a unique fingerprint of a person's brain, may be influenced by its prenatal environment, potentially affecting later-life resilience and mental health.

Methods: We conducted a prospective resting-state functional Magnetic Resonance Imaging study in 28-year-old offspring (N = 49) of mothers whose anxiety was monitored during pregnancy. Two offspring anxiety subgroups were defined: "High anxiety" (n = 13) group versus "low-to-medium anxiety" (n = 36) group, based on maternal self-reported state anxiety at 12-22 weeks of gestation.

View Article and Find Full Text PDF

Background: Relatively little is known about how global and regional brain volumes changes in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) compare with Multiple Sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD), and healthy controls (HC).

Objective: To compare global and regional brain volumes in MOGAD, MS, NMOSD, and HC cross-sectionally as well as longitudinally in a subset of patients.

Methods: We retrospectively reviewed all adult MOGAD and NMOSD patients with brain MRI performed in stable remission and compared them with MS patients and HC.

View Article and Find Full Text PDF

Background: We evaluated imaging features suggestive of neurodegeneration within the brainstem and upper cervical spinal cord (UCSC) in non-progressive multiple sclerosis (MS).

Methods: Standardized 3-Tesla three-dimensional brain magnetic resonance imaging (MRI) studies were prospectively acquired. Rates of change in volume, surface texture, curvature were quantified at the pons and medulla-UCSC.

View Article and Find Full Text PDF

The free water elimination (FWE) model and its kurtosis variant (DKI-FWE) can separate tissue and free water signal contributions, thus providing tissue-specific diffusional information. However, a downside of these models is that the associated parameter estimation problem is ill-conditioned, necessitating the use of advanced estimation techniques that can potentially bias the parameter estimates. In this work, we propose the T-DKI-FWE model that exploits the T relaxation properties of both compartments, thereby better conditioning the parameter estimation problem and providing, at the same time, an additional potential biomarker (the T of tissue).

View Article and Find Full Text PDF
Article Synopsis
  • This study investigates the connection between myelin water fraction (MWF) in white matter and reading ability in 10-year-old children, finding that lower MWF is linked to better reading scores in certain brain areas.
  • The researchers also looked at fractional anisotropy (FA), a measure commonly used in diffusion-weighted imaging, but found no direct relationship between FA and reading skills.
  • These results challenge previous beliefs that poor reading might be linked to lower myelination and highlight the need for more long-term studies to understand how these relationships change as reading skills develop.
View Article and Find Full Text PDF

Background And Purpose: Diffusion tensor imaging (DTI) can detect microstructural changes of white matter in multiple sclerosis (MS) and might clarify mechanisms responsible for disability. Thus, we aimed to compare DTI metrics in relapsing-remitting MS patients (RRMS) with healthy controls (HCs), and explore the correlations between DTI metrics, total brain white matter (TBWM) and white matter lesion (WML) with clinical parameters compared to volumetric measures.

Material And Methods: 37 RRMS patients and 19 age/sex-matched HCs were included.

View Article and Find Full Text PDF

This retrospective correlation study investigated the putative link between methylene tetrahydrofolate reductase (MTHFR) A1298C mutations and chemotherapy-related brain function changes in adult childhood-leukemia survivors. To this end, we determined the relationship between the particular MTHFR1298 genotype (AA, AC or CC) of 31 adult childhood-leukemia survivors, and (1) their CSF Tau and phosphorylated Tau (pTau) levels at the time of treatment, (2) their adult performance intelligence quotient (PIQ), and (3) their regional brain connectivity using diffusion magnetic resonance imaging (dMRI) and resting-state functional MRI (rsfMRI). We confirmed that neuropathology markers Tau and pTau significantly increased in CSF of children after intrathecal methotrexate administration.

View Article and Find Full Text PDF
Article Synopsis
  • A study analyzed MRI data from multiple sclerosis patients treated with natalizumab over 5 years in Prague to evaluate therapy effects, particularly focusing on no evidence of disease activity (NEDA).
  • During the first year, approximately 79% of patients showed no new lesions, and this improved significantly to over 98% in subsequent years.
  • The proportion of patients achieving NEDA-3 rose from 52.2% in year 1 to at least 69.2% in years 2-5, indicating effective long-term disease control with natalizumab in real-world settings.
View Article and Find Full Text PDF

Objective: To longitudinally monitor remodeling of human autograft following anterior cruciate ligament (ACL) reconstruction with DTI.

Methods: Twenty-eight patients underwent DTI follow-up at 3, 8, and 14 months after clinically successful ACL reconstruction with tendon autograft. Among these, 18 patients had a concomitant lateral extra-articular procedure (LET).

View Article and Find Full Text PDF

MRI diffusion data suffers from significant inter- and intra-site variability, which hinders multi-site and/or longitudinal diffusion studies. This variability may arise from a range of factors, such as hardware, reconstruction algorithms and acquisition settings. To allow a reliable comparison and joint analysis of diffusion data across sites and over time, there is a clear need for robust data harmonization methods.

View Article and Find Full Text PDF

Diffusion tensor imaging (DTI) provides information about tissue microstructure and its degree of organization by quantifying water diffusion. We aimed to monitor longitudinal changes in DTI parameters (fractional isotropy, FA; mean diffusivity, MD; axial diffusivity, AD; radial diffusivity, RD) of the anterior cruciate ligament (ACL) following primary repair with internal bracing (IBLA). Fourteen patients undergoing IBLA were enrolled prospectively and scheduled for clinical follow-up, including instrumented laxity testing, and DTI at 3, 6, 12, and 24 months postoperatively.

View Article and Find Full Text PDF

Objective: In a previous pilot monocentric study, we investigated the relation between human leukocyte antigen (HLA) genotype and multiple sclerosis (MS) disease progression over 2 years. HLA-A*02 allele was correlated with better outcomes, whereas HLA-B*07 and HLA-B*44 were correlated with worse outcomes. The objective of this extension study was to further investigate the possible association of HLA genotype with disease status and progression in MS as measured by sensitive and complex clinical and imaging parameters.

View Article and Find Full Text PDF

Introduction: Based on the advances in the treatment of multiple sclerosis (MS), currently available disease-modifying treatments (DMT) have positively influenced the disease course of MS. However, the efficacy of DMT is highly variable and increasing treatment efficacy comes with a more severe risk profile. Hence, the unmet need for safer and more selective treatments remains.

View Article and Find Full Text PDF

With the increase of survival rates of pediatric cancer patients, the number of children facing potential cognitive sequelae has grown. Previous adult studies suggest that white matter (WM) microstructural changes may contribute to cognitive impairment. This study aims to investigate WM microstructure in childhood bone and soft tissue sarcoma.

View Article and Find Full Text PDF

Background: This study aimed to assess functional and structural brain connectivity in adult childhood leukemia survivors and the link with cognitive functioning and previously identified risk factors such as intrathecal methotrexate dose and age at start of therapy.

Methods: Thirty-one nonirradiated adult childhood leukemia survivors and 35 controls underwent cognitive testing and multimodal magnetic resonance imaging (resting state functional MRI, T1-weighted, diffusion-weighted, and myelin water imaging [MWI]). Analyses included dual regression, voxel-based morphometry, advanced diffusion, and MWI modeling techniques besides stepwise discriminant function analysis to identify the most affected executive cognitive domain.

View Article and Find Full Text PDF

Background: Differences in corpus callosum (CC) morphology and microstructure have been implicated in late-life depression and may distinguish between late and early-onset forms of the illness. However, a multimodal approach using complementary imaging techniques is required to disentangle microstructural alterations from macrostructural partial volume effects.

Methods: 107 older adults were assessed: 55 currently-depressed patients without dementia and 52 controls without cognitive impairment.

View Article and Find Full Text PDF

Objective: The identification of a biomarker with prognostic value is an unmet need in multiple sclerosis (MS). The objective of this study was to investigate a possible association of HLA genotype with disease status and progression in MS, based on comprehensive and sensitive clinical and magnetic resonance imaging (MRI) parameters to measure disease effects.

Method: A total of 118 MS patients (79 females, 39 males) underwent HLA typing.

View Article and Find Full Text PDF

In a previous longitudinal diffusion tensor imaging (DTI) study, we observed cerebral white matter (WM) alterations (reduced fractional anisotropy (FA)) related to decreased cognitive performance 3-5 months after chemotherapy-treatment (t2) when compared to baseline (t1) (Deprez et al. in Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology, 30(3), 274-281. doi:10.

View Article and Find Full Text PDF

Objective: Hippocampal volume is commonly decreased in late-life depression. According to the depression-as-late-life-neuropsychiatric-disorder model, lower hippocampal volume in late-life depression is associated with neurodegenerative changes. The purpose of this prospective study was to examine whether lower hippocampal volume in late-life depression is associated with Alzheimer's disease pathology.

View Article and Find Full Text PDF

Age-related microstructural differences have been detected using diffusion tensor imaging (DTI). Although DTI is sensitive to the effects of aging, it is not specific to any underlying biological mechanism, including demyelination. Combining multiexponential T2 relaxation (MET2) and multishell diffusion MRI (dMRI) techniques may elucidate such processes.

View Article and Find Full Text PDF

Diffusion tensor imaging (DTI) studies suggest abnormalities in the white matter microstructure of the fornix in schizophrenia patients. Research evaluating schizophrenia patient and relatives also suggests that the white matter microstructure of the fornix is heritable. However, previous studies have been hindered by limited DTI methodology.

View Article and Find Full Text PDF

Introduction: The histopathological basis of "unidentified bright objects" (UBOs) (hyperintense regions seen on T2-weighted magnetic resonance (MR) brain scans in neurofibromatosis-1 (NF1)) remains unclear. New in vivo MRI-based techniques (multi-exponential T2 relaxation (MET2) and diffusion MR imaging (dMRI)) provide measures relating to microstructural change. We combined these methods and present previously unreported data on in vivo UBO microstructure in NF1.

View Article and Find Full Text PDF