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Diffusion tensor imaging (DTI) is an exciting new MRI modality that can reveal detailed anatomy of the white matter. DTI also allows us to approximate the 3D trajectories of major white matter bundles. By combining the identified tract coordinates with various types of MR parameter maps, such as T2 and diffusion properties, we can perform tract-specific(More)
We describe a new fully automatic method for the segmentation of brain images that contain multiple sclerosis white matter lesions. Multichannel magnetic resonance images are used to delineate multiple sclerosis lesions while segmenting the brain into its major structures. The method is an atlas-based segmentation technique employing a topological atlas as(More)
Accurate clinical course descriptions (phenotypes) of multiple sclerosis (MS) are important for communication, prognostication, design and recruitment of clinical trials, and treatment decision-making. Standardized descriptions published in 1996 based on a survey of international MS experts provided purely clinical phenotypes based on data and consensus at(More)
Inflammation, demyelination, gliosis and axonal degeneration are pathological hallmarks of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis. Axonal damage is thought to contribute to irreversible damage and functional impairment, but is difficult to quantify. Conventional MRI has been used to assess the inflammatory and demyelinating(More)
Optical coherence tomography (OCT) is a new method that could aid analysis of neurodegeneration in multiple sclerosis (MS) by capturing thinning of the retinal nerve fibre layer (RNFL). Meta-analyses of data for time domain OCT show RNFL thinning of 20.38 microm (95% CI 17.91-22.86, n=2063, p<0.0001) after optic neuritis in MS, and of 7.08 microm(More)
Diffusion tensor imaging (DTI) and immunohistochemistry were used to examine axon injury in the rat spinal cord after unilateral L(2)-L(4) dorsal root axotomy at multiple time points (from 16 h to 30 d after surgery). Three days after axotomy, DTI revealed a lesion in the ipsilateral dorsal column extending from the lumbar to the cervical cord. The lesion(More)
Diffusion-tensor-imaging fiber tractography enables interrogation of brain white matter tracts that subserve different functions. However, tract reconstruction can be labor and time intensive and can yield variable results that may reduce the power to link imaging abnormalities with disability. Automated segmentation of these tracts would help make(More)
OBJECTIVE To determine the relationships between conventional and segmentation-derived optical coherence tomography (OCT) retinal layer thickness measures with intracranial volume (a surrogate of head size) and brain substructure volumes in multiple sclerosis (MS). DESIGN Cross-sectional study. SETTING Johns Hopkins University, Baltimore, Maryland. (More)
Damage to specific white matter tracts within the spinal cord can often result in the particular neurological syndromes that characterize myelopathies such as traumatic spinal cord injury. Noninvasive visualization of these tracts with imaging techniques that are sensitive to microstructural integrity is an important clinical goal. Diffusion tensor imaging(More)
Diffusion tensor imaging has been widely used in studying rodent models of white matter diseases. In this study, we examined the differences between in vivo and ex vivo fractional anisotropy and diffusivity measurements in the mouse cuprizone model. In the control mouse corpus callosum, ex vivo diffusivities were significantly lower than in vivo(More)