A5050491205- Advanced Neuroimaging Techniques and Applications
- Trigeminal Neuralgia and Treatments
- Advanced MRI Techniques and Applications
- Functional Brain Connectivity Studies
- Botulinum Toxin and Related Neurological Disorders
- Facial Nerve Paralysis Treatment and Research
- Fetal and Pediatric Neurological Disorders
- Peripheral Nerve Disorders
- Otolaryngology and Infectious Diseases
- Ophthalmology and Eye Disorders
- Pain Mechanisms and Treatments
- Multiple Sclerosis Research Studies
- MRI in cancer diagnosis
- Cerebrospinal fluid and hydrocephalus
- Photonic and Optical Devices
- Spinal Dysraphism and Malformations
- Eating Disorders and Behaviors
- Cerebral Palsy and Movement Disorders
- Neurological disorders and treatments
- Traumatic Brain Injury Research
- Neurotransmitter Receptor Influence on Behavior
- Semiconductor materials and devices
- Magnetic properties of thin films
- Neuroscience and Neuropharmacology Research
University of Toronto
2010-2020
University Health Network
2013-2018
Krembil Research Institute
2016-2017
Toronto Western Hospital
2010-2017
Queen's University
2010
Seagate (United States)
2000
Abstract Tractography based on non-invasive diffusion imaging is central to the study of human brain connectivity. To date, approach has not been systematically validated in ground truth studies. Based a simulated data set with tracts, we organized an open international tractography challenge, which resulted 96 distinct submissions from 20 research groups. Here, report encouraging finding that most state-of-the-art algorithms produce tractograms containing 90% bundles (to at least some...
Objective Idiopathic trigeminal neuralgia (TN) is characterized by paroxysms of severe facial pain but without the major sensory loss that commonly accompanies neuropathic pain. Since neurovascular compression nerve root entry zone does not fully explain pathogenesis TN, we determined whether there were brain gray matter abnormalities in a cohort idiopathic TN patients. We used structural MRI to test hypothesis associated with altered (GM) areas involved and affective aspects pain,...
Trigeminal neuralgia (TN) is a chronic neuropathic facial pain disorder that commonly responds to surgery. A proportion of patients, however, do not benefit and suffer ongoing pain. There are currently no imaging tools permit the prediction treatment response. To address this paucity, we used diffusion tensor (DTI) determine whether pre-surgical trigeminal nerve microstructural diffusivities can prognosticate response TN treatment. In 31 patients 16 healthy controls, multi-tensor...
Abstract Research in humans and animals has shown that negative childhood experiences (NCE) can have long‐term effects on the structure function of brain. Alterations been noted grey white matter, brain's resting state, glutamatergic system, neural behavioural responses to aversive stimuli. These be linked psychiatric disorder such as depression anxiety disorders are influenced by excessive exposure early life stressors. The aim current study was investigate effect NCEs these systems....
Background: Trigeminal neuralgia secondary to multiple sclerosis (MS-TN) is a facial neuropathic pain syndrome similar classic trigeminal (TN). While TN caused by neurovascular compression of the fifth cranial nerve (CN V), how MS-related demyelination correlates with in MS-TN not understood. Objectives: We aim examine diffusivities along CN V MS-TN, TN, and controls order reveal differential neuroimaging across groups. Methods: 3T MR diffusion weighted, T1, T2 FLAIR sequences were acquired...
Abstract Fiber tractography based on non-invasive diffusion imaging is at the heart of connectivity studies human brain. To date, approach has not been systematically validated in ground truth studies. Based a simulated brain dataset with white matter tracts, we organized an open international challenge, which resulted 96 distinct submissions from 20 research groups. While most state-of-the-art algorithms reconstructed 90% bundles to least some extent, average they produced four times more...
Diffusion-based tractography has emerged as a powerful technique for 3-dimensional tract reconstruction and imaging of white matter fibers; however, the cranial nerves not been well studied. In particular, feasibility individual previously assessed.3-Tesla magnetic resonance scans, including anatomic images diffusion tensor images, were used this study. Tractography was performed using 3D Slicer software. The reconstructed tracts overlaid onto determination location course intracranial...
BACKGROUND: Preservation of cranial nerves (CNs) is paramount concern in the treatment vestibular schwannomas, particularly large tumors with thinned and distorted CN fibers. However, imaging fibers surrounding schwannomas has been limited 2-dimensional alone. OBJECTIVE: To assess whether tractography combined anatomic magnetic resonance tumor can provide superior 3-dimensional (3D) visualization tumor/CN complexes. METHODS: Magnetic at 3 T, including diffusion tensor images, were analyzed...
Purpose Focal radiosurgery is a common treatment modality for trigeminal neuralgia (TN), neuropathic facial pain condition. Assessment of effectiveness primarily clinical, given the paucity investigational tools to assess nerve changes. Since diffusion tensor imaging (DTI) provides information on white matter microstructure, we explored feasibility tractography and assessment DTI parameters study microstructural changes after treatment. We hypothesized that more than 2D-MR imaging, allowing...
Multiple sclerosis (MS) is a debilitating neurodegenerative disease characterized by demyelination and neuronal loss. Traditional therapies often fail to halt progression or reverse neurological deficits. Ibogaine, psychoactive alkaloid, has been proposed as potential neuroregenerative agent due its multifaceted pharmacological profile. We present two case studies of MS patients who underwent novel ibogaine treatment, highlighting significant neuroimaging changes clinical improvements....
Trigeminal neuralgia (TN) is a severe chronic neuropathic facial pain disorder. Affect-related behavioural and structural brain changes have been noted across disorders, but not well-studied in TN. We examined the potential impact of TN (37 patients: 23 with right-sided TN, 14 left-sided TN), compared to age- sex-matched healthy controls, on three major white matter tracts responsible for carrying affect-related signals – i.e. cingulum, fornix, medial forebrain bundle. Diffusion magnetic...
BackgroundAnorexia nervosa is characterized by extreme low body weight and alterations in affective processing. The subcallosal cingulate regulates affect through wide-spread white matter connections implicated the pathophysiology of anorexia nervosa.ObjectivesWe examined whether those with treatment refractory undergoing deep brain stimulation (DBS) (SCC) show: 1) altered anatomical SCC connectivity compared to healthy controls, 2) microstructural changes, 3) changes associated...
Abstract Trigeminal neuralgia (TN) is a severe form of chronic facial neuropathic pain. Increasing interest in the neuroimaging pain has highlighted changes root entry zone TN, but also group-level central nervous system gray and white matter (WM) abnormalities. Group differences data are frequently evaluated with univariate statistics; however, this approach limited because it based on single, or clusters of, voxels. By contrast, multivariate pattern analyses consider all model's...
Diffusion-weighted imaging (DWI)-based tractography has gained increasing popularity as a method for detailed visualization of white matter (WM) tracts. Different techniques, and more novel, advanced methods provide significant WM structural detail. While there been greater focus on improving tract larger pathways, the relative value each cranial nerve reconstruction how this methodology can assist surgical decision-making is still understudied. Images from ten patients with posterior fossa...
<b><i>Objective:</i></b> White matter diffusivity measures of the fornix change with aging, which likely relates to changes in memory and cognition older adults. Subregional variations forniceal may exist, given its heterogeneous anatomy connectivity; however, these have not been closely examined vivo. We parameters (fractional anisotropy, FA; radial diffusivity, RD; axial AD) subregions healthy subjects correlated them age hippocampal volume....
1. Abstract The registration or alignment of diffusion weighted images (DWI) with other imaging modalities is a critical step in neuroimaging analysis. Within-subject T1-DWI co-registration particularly instrumental. DWI-derived scalar are commonly used as intermediates for co-registration, and the resulting transforms applied to all ideal intermediate should register well T1 multimodal be practically easy obtain. It however, currently unclear which image serves best intermediate. We aim...
Introduction: Tractography analysis in group-based studies across large populations is difficult to manage and assess. We propose Selective Automated Group Integrated (SAGIT), an automated group tractography software platform that incorporates proven dMRI practices, order for group-wise be more accessible researchers. use a merged approach permits evaluation of datasets at the level. also introduce image-based score (Normalized Overlapping Score (NOS)) can quantify quality results. deploy...
<b><i>Background:</i></b> Interest in the anatomy of insula is driven by its multifunctionality and need for accurate visualization surgical purposes. Few vivo studies human insular have been conducted due to methodological anatomical challenges. <b><i>Objective:</i></b> We used brain cortical morphometry tools accurately reconstruct topology permit a detailed gyri 3 dimensions. <b><i>Methods:</i></b> Sixty healthy...
An increasing number of applications use the postnatal piglet model in neuroimaging studies, however, these are based primarily on T1 weighted image templates. There is a growing need for multimodal structural brain template comprehensive depiction brain, particularly given diffusion imaging characterizing tissue microstructures and white matter organization. In this study, we present first which includes with segmentation probability maps, metric templates multiple diffusivity...
Imaging of trigeminal neuralgia (TN) has demonstrated key diffusion tensor imaging-based diffusivity alterations in the nerve; however, imaging primarily focused on peripheral nerve segment because previous limitations reliably segmenting small fiber bundles across multiple subjects. We used Selective Automated Group Integrated Tractography to study 36 subjects with TN (right-sided pain) and sex-matched controls examine (fifth cranial [CN V]), pontine decussation (TPT), thalamocortical...
We have demonstrated 23.8 Gb/in.2 areal density using a merged read-write grant magnetoresistive head, with an oriented thin film medium tested broadband electronics and enhanced EPR4 channels. The had high signal to noise ratio metrics that was robust unto temperatures as 75 °C. A unique aspect of the head design at such narrow track width is simultaneous enhancement transducer sensitivity while keeping product system manufacturability in forefront. 45.8 k tracks/in., photolithographically...