The central vein signSusceptibility-based MRI sequences enable the visualization of central veins within white-matter lesions (WMLs) that are not easily seen on T2-based sequences. The observed hypointensity is related to deoxyhemoglobin within WMLs which is often related to the presence of a central vein.
Leptomeningeal inflammation in MSLeptomeningeal inflammation is frequently observed in both early and late stages of MS, but difficult to visualize with conventional postcontrast T1-weighted MRI sequences. Recently, postcontrast fluid attenuation inversion recovery sequences have demonstrated significantly increased sensitivity to leptomeningeal enhancement in several neurologic disease states.
Spinal cord imagingThe spinal cord is highly relevant to clinical disability and commonly involved across the spectrum of MS disease subtypes, but particularly in progressive MS. In clinical practice, lesion-based measures in the spinal cord on MRI are frequently used in the diagnosis of MS as they can demonstrate “dissemination in space.” Improved MRI sequences, including T1-based sequences (magnetization-prepared rapid gradient echo and phase-sensitive inversion recovery) in the cervical spinal cord, improve lesion conspicuity, which can facilitate an earlier diagnosis of MS.
Paramagnetic rims in MSChronic lesions with active, “smoldering” inflammation and slow expansion are known to be an important substrate of neurologic disease progression in MS. These chronic, active lesions are seen across the spectrum of MS, but observed particularly in progressive MS. Susceptibility-weighted imaging sequences on high-field MRI platforms (7T) are sensitive to iron content in tissue, and persistent “paramagnetic rims” around lesions has been histopathologically validated to represent chronic inflammatory infiltration related to macrophages and microglia, as well as ongoing demyelination.
Ultrahigh-field MRIUltrahigh-field MRI platforms, including 7T MRI platforms, allow for increased spatial resolution in comparison to lower-field platforms, enabling improved visualization of anatomic detail of brain and spinal cord tissue in various neurologic disorders. In MS, high-field MRI has been utilized in a variety of applications, with the most common being in the identification and characterization of cortical lesions, which have been much more difficult to visualize on lower-field platforms.
Image credit: Medical Body Scans/Science Source
Top image credit: Living Art Enterprises, LLC/Science Source