Contribution of diffusion-weighted imaging to distinguish herpetic encephalitis from auto-immune encephalitis at an early stage.

Objectives: To determine whether diffusion-weighted imaging (DWI) can help to distinguish early stage autoimmune (AI) and herpes simplex virus (HSV) encephalitides.

Methods: This case-control study included patients from a multi-center cohort of AI encephalitides whose initial MRI including DWI was performed within ten days after symptoms onset. They were compared with patients with HSV encephalitis enrolled prospectively in a single-center from June, 2020 to December, 2020.

Emerging MR Imaging and Spectroscopic Methods to Study Brain Tumor Metabolism.

Proton magnetic resonance spectroscopy (H-MRS) provides a non-invasive biochemical profile of brain tumors. The conventional H-MRS methods present a few challenges mainly related to limited spatial coverage and low spatial and spectral resolutions. In the recent past, the advent and development of more sophisticated metabolic imaging and spectroscopic sequences have revolutionized the field of neuro-oncologic metabolomics.

Update on brain MRI for the diagnosis and follow-up of MS patients.

Over the past decades, MRI has become a major tool in the diagnosis and the follow-up of patients with multiple sclerosis (MS), especially for monitoring the effectiveness of therapy. The recent international recommendations issued for the standardization of neurological and radiological clinical practices converge on many points. In this setting, recommendations made by the "Observatoire français de la sclérose en plaques", the French MS registry, can be distinguished by its interdisciplinary complementarity, its longevity, its size, and its positions in direct connection with the clinic.

Cerebral vasculitis of medium-sized vessels as a possible mechanism of brain damage in COVID-19 patients.

Background And Purpose: Cerebral complications related to COVID-19 were recently reported, and the underlying mechanisms of brain damage remain uncertain, probably multifactorial. Among various hypotheses suggested, a possible vasculitis was issued but never confirmed. Herein, we aimed to describe brain MRIs focused on the intracranial vessel wall in a population of COVID-19 patients with neurologic manifestations.

Cerebrospinal Fluid Features in Patients With Coronavirus Disease 2019 and Neurological Manifestations: Correlation with Brain Magnetic Resonance Imaging Findings in 58 Patients.

Background: Neurological manifestations are common in patients with coronavirus disease 2019 (COVID-19), but little is known about pathophysiological mechanisms. In this single-center study, we examined neurological manifestations in 58 patients, including cerebrospinal fluid (CSF) analysis and neuroimaging findings.

Methods: The study included 58 patients with COVID-19 and neurological manifestations in whom severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse-transcription polymerase chain reaction screening and on CSF analysis were performed.

Critical illness-associated cerebral microbleeds for patients with severe COVID-19: etiologic hypotheses.

Background And Purpose: During the COVID-19 outbreak, the presence of extensive white matter microhemorrhages was detected by brain MRIs. The goal of this study was to investigate the origin of this atypical hemorrhagic complication.

Methods: Between March 17 and May 18, 2020, 80 patients with severe COVID-19 infections were admitted for acute respiratory distress syndrome to intensive care units at the University Hospitals of Strasbourg for whom a brain MRI for neurologic manifestations was performed.

Neurologic and neuroimaging findings in patients with COVID-19: A retrospective multicenter study.

Objective: To describe neuroimaging findings and to report the epidemiologic and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) with neurologic manifestations.

Methods: In this retrospective multicenter study (11 hospitals), we included 64 patients with confirmed COVID-19 with neurologic manifestations who underwent a brain MRI.

Results: The cohort included 43 men (67%) and 21 women (33%); their median age was 66 (range 20-92) years.

New OFSEP recommendations for MRI assessment of multiple sclerosis patients: Special consideration for gadolinium deposition and frequent acquisitions.

Purpose: New multiple sclerosis (MS) disease-modifying therapies (DMTs), which exert beneficial effects through prevention of relapse, limitation of disability progression, and improvement of patients' quality of life, have recently emerged. Nonetheless, these DMTs are not without associated complications (severe adverse events like. progressive multifocal leukoencephalopathy).

Spatial distribution of multiple sclerosis lesions in the cervical spinal cord.

Spinal cord lesions detected on MRI hold important diagnostic and prognostic value for multiple sclerosis. Previous attempts to correlate lesion burden with clinical status have had limited success, however, suggesting that lesion location may be a contributor. Our aim was to explore the spatial distribution of multiple sclerosis lesions in the cervical spinal cord, with respect to clinical status.

Automatic segmentation of the spinal cord and intramedullary multiple sclerosis lesions with convolutional neural networks.

The spinal cord is frequently affected by atrophy and/or lesions in multiple sclerosis (MS) patients. Segmentation of the spinal cord and lesions from MRI data provides measures of damage, which are key criteria for the diagnosis, prognosis, and longitudinal monitoring in MS. Automating this operation eliminates inter-rater variability and increases the efficiency of large-throughput analysis pipelines.

Longitudinal study of multiple sclerosis lesions using ultra-high field (7T) multiparametric MR imaging.

Pathophysiology of multiple sclerosis (MS) lesions is dynamic and changes over time. The purpose of this exploratory study was to determine the longitudinal changes in MS lesions over time on ultra-high field MR imaging. Nine patients with MS underwent high-resolution 3D-susceptibility weighted imaging (SWI) and 2D-gradient-echo-T2*-weighted imaging on 7T MRI at baseline and after ~2.

Multimodal imaging provides insight into targeted therapy response in metastatic prostate cancer to the bone.

Metastatic prostate cancer to bone remains incurable, driving efforts to develop individualized, targeted therapies to improve clinical outcomes while limiting adverse side-effects. Due to the complexity in cellular signaling pathways and the interaction between cancer and its microenvironment, multiparametric imaging approaches for treatment response may improve understanding of the biological effects of therapy. An orthotopic model of castration resistant prostate cancer (CRPC) bone metastasis was treated with the tyrosine kinase inhibitor Cabozantinib (CABO).

Weekly enhanced T1-weighted MRI with Gadobutrol injections in MS patients: Is there a signal intensity increase in the dentate nucleus and the globus pallidus?

Background And Purpose: Gadolinium-based contrast agents (GBCAs) administration have drastically improved the accuracy of Multiple Sclerosis (MS) diagnosis by highlighting any damage to the brain blood barrier, thereby differentiating between active and non-active lesions. Following multiple administrations of GBCAs, several MS studies have reported a signal intensity (SI) increase on unenhanced T1-weighted images in certain brain regions such as the dentate nucleus (DN) and the globus pallidus (GP). Our aim was therefore to determine the accumulation of macrocyclic GBCAs on enhanced T1-weighted images SI in the DN and the GP of MS patients injected eight times.

Diagnostic value of 3DFLAIR in clinical practice for the detection of infratentorial lesions in multiple sclerosis in regard to dual echo T2 sequences.

Background And Purpose: The aim of this prospective study is to investigate and evaluate in clinical practice the diagnostic impact of 3DFLAIR in regards to 2DT2/PD in terms of infratentorial lesions detection in multiple sclerosis (MS).

Material And Methods: 164 MS patients from the OFSEP database were reviewed retrospectively. MR examinations were performed on 1.

Susceptibility weighted imaging and quantitative susceptibility mapping of the cerebral vasculature using ferumoxytol.

Purpose: To demonstrate the potential of imaging cerebral arteries and veins with ferumoxytol using susceptibility weighted imaging (SWI) and quantitative susceptibility mapping (QSM).

Materials And Methods: The relationships between ferumoxytol concentration and the apparent susceptibility at 1.5T, 3T, and 7T were determined using phantom data; the ability of visualizing subvoxel vessels was evaluated using simulations; and the feasibility of using ferumoxytol to enhance the visibility of small vessels was confirmed in three healthy volunteers at 7T(with doses 1 mg/kg to 4 mg/kg).

Integrated multimodal imaging of dynamic bone-tumor alterations associated with metastatic prostate cancer.

Bone metastasis occurs for men with advanced prostate cancer which promotes osseous growth and destruction driven by alterations in osteoblast and osteoclast homeostasis. Patients can experience pain, spontaneous fractures and morbidity eroding overall quality of life. The complex and dynamic cellular interactions within the bone microenvironment limit current treatment options thus prostate to bone metastases remains incurable.

Impaired cerebrovascular reactivity in multiple sclerosis.

Importance: Cerebrovascular reactivity (CVR) is an inherent indicator of the dilatory capacity of cerebral arterioles for a vasomotor stimulus for maintaining a spontaneous and instant increase of cerebral blood flow (CBF) in response to neural activation. The integrity of this mechanism is essential to preserving healthy neurovascular coupling; however, to our knowledge, no studies have investigated whether there are CVR abnormalities in multiple sclerosis (MS).

Objective: To use hypercapnic perfusion magnetic resonance imaging to assess CVR impairment in patients with MS.

Metastatic pancreatic cancer is dependent on oncogenic Kras in mice.

Pancreatic cancer is one of the deadliest human malignancies, and its prognosis has not improved over the past 40 years. Mouse models that spontaneously develop pancreatic adenocarcinoma and mimic the progression of the human disease are emerging as a new tool to investigate the basic biology of this disease and identify potential therapeutic targets. Here, we describe a new model of metastatic pancreatic adenocarcinoma based on pancreas-specific, inducible and reversible expression of an oncogenic form of Kras, together with pancreas-specific expression of a mutant form of the tumor suppressor p53.

Parametric response mapping of CT images provides early detection of local bone loss in a rat model of osteoporosis.

Loss of bone mass due to disease, such as osteoporosis and metastatic cancer to the bone, is a leading cause of orthopedic complications and hospitalization. Onset of bone loss resulting from disease increases the risk of incurring fractures and subsequent pain, increasing medical expenses while reducing quality of life. Although current standard CT-based protocols provide adequate prognostic information for assessing bone loss, many of the techniques for evaluating CT scans rely on measures based on whole-bone summary statistics.

Oncogenic Kras is required for both the initiation and maintenance of pancreatic cancer in mice.

Pancreatic cancer is almost invariably associated with mutations in the KRAS gene, most commonly KRASG12D, that result in a dominant-active form of the KRAS GTPase. However, how KRAS mutations promote pancreatic carcinogenesis is not fully understood, and whether oncogenic KRAS is required for the maintenance of pancreatic cancer has not been established. To address these questions, we generated two mouse models of pancreatic tumorigenesis: mice transgenic for inducible KrasG12D, which allows for inducible, pancreas-specific, and reversible expression of the oncogenic KrasG12D, with or without inactivation of one allele of the tumor suppressor gene p53.

Quantification of iron-labeled cells with positive contrast in mouse brains.

Purpose: To quantify small amounts of iron-labeled cells in mouse brains with magnetic resonance imaging (MRI).

Procedures: Iron-labeled cells (from 500 to 7,500) were stereotaxically transplanted into the brain of living mice that were subsequently imaged with MRI at 4.7 T.

Diffusion-weighted MRI for assessment of early cancer treatment response.

Recent clinical practice for the management for cancer patients has begun to change from a statistical "one-size fits all" approach to medicine to more individualized care. Pre-treatment biomarkers (i.e.