Axial T1 fat-saturated postcontrast MR image on day 2 of admission. There is marked enhancement of the bilateral pterygoid muscles indicating infection. The red arrow shows non-enhancing portion of the pterygoid muscles indicating necrosis. Worsening mucosal thickening and enhancement of both maxillary sinuses from spreading infection. The blue arrow shows non-enhancing mucosa of the right maxillary sinus indicating mucosal necrosis.