Correlation between 18F-FDG PET/CT and diffusion-weighted MRI parameters in head and neck squamous cell carcinoma at baseline and after chemo-radiotherapy. A retrospective single institutional study - Garau, L M; Manca, G; Bola, S; Aringhieri, G; Faggioni, L; Volterrani, D (Oral Radiol, 2022)