Katherine C. Gao1, Govind Nair1, Colin D. Shea1, Pietro Maggi1, 2, Souheil J. Inati3, Luca Massacesi2, Daniel S. Reich1
1National Institute of Neurological Disorders and Stroke, Bethesda, MD, United States; 2Department of Neurological and Psychiatric Sciences, University of Florence, Florence, Italy; 3Natiional Institute of Mental Health, Bethesda, MD, United States
Patients with MS typically develop lesions around inflamed blood vessels in the brain. Since permeability and perfusion of MS lesions have been shown to change with time, ascertaining these parameters within individual MS lesions at a particular time point may provide a snapshot of the underlying inflammatory and pathphysiological processes. By acquiring a dual-echo T1-weighted dynamic scan during a single bolus of MRI contrast, we simultaneously estimated permeability and perfusion of chronic and active lesions in MS patients. As expected, enhancing lesions had the highest permeability. Additionally, some chronic lesions had non-zero permeability, which may reflect inflammatory activity that is no longer visibly detectable as enhancement in post-contrast T1-weighted images. Longitudinal studies are underway to track changes in lesion permeability and perfusion over time and will determine whether this methodology can be used to assess the effects of disease-modifying therapies that reduce inflammation and maintain the blood-brain-barrier.