Abstract #0498

Cortical Oxygen Extraction as a Marker of Disease Stage & Function in Multiple Sclerosis: A Quantitative Study Using 7 Tesla MRI Susceptibility.

Audrey P. Fan¹,², Revere P. Kinkel³,⁴, Nancy K. Madigan³,⁴, A Scott Nielson³, Thomas Benner², Emanuele Tinelli⁵, Bruce R. Rosen²,⁴, Elfar Adalsteinsson¹,², Caterina Mainero²,⁴

¹Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; ²Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States; ³Beth Israel Deaconess Medical Center, Boston, MA, United States; ⁴Harvard Medical School, Boston, MA, United States; ⁵Neurology and Psychiatry, University of Rome "La Sapienza", Rome, Italy

This study directly quantified OEF in individual cortical veins from patients at different stages of multiple sclerosis (MS) disease using MRI magnetic susceptibility measurements at 7 Tesla. Patients with late disease exhibited 6.2% absolute reduction in OEF compared to controls (p=0.024). Cortical OEF negatively correlated with disease duration (p=0.02) and white matter lesion volume (p<0.01). Across all patients, decreased OEF strongly associated with reduced cognitive performance, and cortical OEF was the main independent predictor of processing speed (p=0.03, stepwise regression). This study implicates metabolic deficiency early in the development of cognitive dysfunction in MS, and highlights OEF as a useful new metric of cortical pathology.