Evaluation of myelin content in the spinal cord of patients with multiple sclerosis: a positron emission tomography study - Lucena, Leticia Zorante de; Campanholo, Kenia Repiso; Pereira, Samira Luiza Apostolos; Tavora, Daniel Gurgel Fernandes; Callegaro, Dagoberto; Buchpiguel, Carlos Alberto; Pitombeira, Milena Sales; Faria, Daniele de Paula (Multiple sclerosis and related disorders, 2025)