Increased Intracortical T1w/T2w Ratio in Patients with Chronic Schizophrenia

Motivation: While dysmyelination is known to occur in white matter in schizophrenia, studies characterizing intracortical myelin in vivo are limited. Goal(s): Our goal was to quantify intracortical myelin in chronic schizophrenia (SZ) vs. healthy controls (HC), and to correlate myelination with volumetric changes. Approach: We used T1w/T2w ratio to map cortical myelin. Results: We found decreased cortical volume but increased T1w/T2w ratio in frontal and temporal regions in SZ vs. HC. Apart from potentially increased ectopic myelin content, increased T1w/T2w in patients may also reflect iron deposition or presence of glial cells which contain high intracellular iron. Impact: Characterizing intracortical myelin will help refine the dysmyelination hypothesis of schizophrenia. Our results in a chronic schizophrenia group support this hypothesis and further suggest potential abnormalities in cortical iron and glial cells.