Neuroimaging clinics of North America
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Neuroimaging Clin. N. Am. · May 2017
ReviewMicrostructural MR Imaging Techniques in Multiple Sclerosis.
Due to its sensitivity in the detection of focal white matter (WM) lesions, MR imaging has become a paraclinical tool central to diagnosing multiple sclerosis (MS) and monitoring its evolution. Despite this, the correlation between patients' clinical status and conventional MR imaging measures is weak to moderate. Quantitative MR imaging-based techniques, such as magnetization transfer and diffusion tensor imaging, have a higher specificity toward the heterogeneous pathologic substrates of MS than MR imaging. This article discusses the main insights derived from the application of such MR imaging-based techniques to define MS pathophysiology and to quantify the progressive accumulation of structural damage in the central nervous system.
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Increased iron deposition in cerebral deep gray matter has been considered a global marker for neurodegeneration in multiple sclerosis (MS); it scales with disease duration and severity. Iron accumulation in white matter and MS lesions might be more directly related to disease activity and has been discussed as a contributor to the inflammatory and neurodegenerative cascade. ⋯ We discuss findings from MR iron mapping proposed. Because of the confounding magnetic properties of myelin, iron mapping in white matter remains an unresolved issue.
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Neuroimaging Clin. N. Am. · May 2017
ReviewInsights from Ultrahigh Field Imaging in Multiple Sclerosis.
Ultrahigh-field (≥7 T) magnetic resonance (MR) imaging is being used at many leading academic medical centers to study neurologic disorders. The improved spatial resolution and anatomic detail are due to the increase in signal-to-noise and contrast-to-noise ratio at higher magnetic field strengths. Ultrahigh-field MR imaging improves multiple sclerosis (MS) lesion detection, with particular sensitivity to detect cortical lesions. The increase in magnetic susceptibility effects inherent to ultrahigh field can be used to detect pathologic features of MS lesions, including a central vein, potentially useful for diagnostic considerations, and heterogeneity among MS lesions, potentially useful in determining lesion outcomes.
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Neuroimaging Clin. N. Am. · May 2017
ReviewRadiologically Isolated Syndrome: MR Imaging Features Suggestive of Multiple Sclerosis Prior to First Symptom Onset.
Remarkable advances in the understanding of the biology of multiple sclerosis have been achieved through the use of conventional and novel MR imaging techniques of the central nervous system. With improvements in access by patients and utilization of MR imaging technology in health care, an increasing number of unanticipated structural anomalies are being appreciated. In certain instances, white matter abnormalities within the brain and spinal cord are discovered in subjects with no prior history of neurologic symptoms supportive of inflammatory demyelinating events.