This technology is an improvement on the ability to visualize cortical lesions in neurological diseases that cause focal tissue damage to the cortex, including multiple sclerosis (MS). Two approaches are used. The first approach includes optimization of routinely available diffusion-weighted sequences to maximize resolution and contrast, both of which are required to differentiate small cortical lesions from normal-appearing cortex. A second approach includes suppression of the cerebrospinal fluid (CSF) in an optimal high-resolution 3D-T2*-weighted image using inversion pulse (3D IR-T2*) along with appropriate T2-preparation for desired contrast and reduced scan time. The T2* signal changes that are measured are induced by changing iron concentrations. The combination of these techniques permits the visualization of cortical lesions more clearly than with standard 3T clinical MRI techniques.
Other MRI approaches for cortical lesion detection at clinical magnetic field strength are currently being used, including double-inversion, phase-sensitive inversion recovery MRI, and magnetization-transfer imaging. Published studies have shown these to be inaccurate for subpial cortical lesion detection.