Baló`s concentric sclerosis (BCS) is a rare, pathologically and radiographically distinct variant of multiple sclerosis, and it is characterized by alternating rings of demyelinated and myelinated axons. The myelinated rings correlate with the isointense areas on T2- and T1-weighted images and low signal intensity on DWI; these areas alternate with the demyelinated rings, which appear as hyperintense areas on T2-weighted images, hypointense rings on T1-weighted images, areas of enhancement on post-gadolinium contrast T1-weight images, and rings of restricted diffusion (high signal intensity) on DWI.

From the manuscript

Baló`s concentric sclerosis: imaging findings and pathological correlation

Abstract
Baló`s concentric sclerosis is a primary inflammatory central nervous system demyelinating disease that is considered a rare, radiographically and pathologically distinct variant of multiple sclerosis. Baló`s concentric sclerosis is characterized by alternating rings of demyelinated and myelinated axons, and it is most frequently diagnosed postmortem by autopsy or, more recently, by magnetic resonance imaging without pathologic verification. This report is of a case of Baló`s concentric sclerosis in which the patient presented with left-sided focal sensorimotor deficits. The patient`s lesion demonstrated characteristics of Baló`s concentric sclerosis by magnetic resonance imaging, but since a neoplastic process was also suspected initially, the patient underwent a surgical biopsy. This pathology sample now provides the opportunity to correlate the tissue diagnosis of demyelination with characteristic magnetic resonance imaging findings; this comparison is infrequently found in the literature.