Fig. 1

MR images of a 40-year old man with undifferentiated nonkeratinizing squamous cell nasopharyngeal carcinoma. MR images demonstrate NPC’s involvement of the MPM and LPM (long arrow), and the temporal muscle (arrowhead) as well as pterygopalatine fossa(star), which present a high signal intensity on axial PDWI image (a), a medium or low signal intensity on axial T1WI-TSE image (b), and an obvious enhancement on axial contrast-enhanced T1WI-TSE image with fat suppression (c). (MRI = Magnetic resonance imaging; NPC = Nasopharyngeal carcinoma; MPM = Medial pterygoid muscle; LPM = Lateral pterygoid muscle; PDWI = Proton density-weighted imaging; T1WI-TSE = T1 weighted imaging-Turbo spin echo)