FIG 1. Axial MR images of a 55-year-old man with a left maxillary sinus malignant fibrous histiocytoma.

A, Preoperative unenhanced T1-weighted (400/9/2 [TR/TE/excitations]) image shows large tumor opacifying and expanding the left maxillary sinus (asterisk). Note the normal fat signal and neurovascular contents within the compressed left PPF (arrows).

B–D, Obtained 4 months after radical maxillectomy, T1-weighted (500/9/2) (B), T2-weighted (5000/105/2) (C), and contrast-enhanced fat-suppressed T1-weighted (433/9/2) (D) images show soft-tissue thickening in the left PPF (asterisk). This is isointense to muscle (B), has heterogeneous but generally hyperintense T2 signal (C), and enhances brightly (D). None of these changes are present in the normal, contralateral PPF (arrows).

E and F, Unenhanced T1-weighted (616/9/2) (E) and contrast-enhanced fat-suppressed T1-weighted (583/9/2) (F) images obtained 20 months after radical maxillectomy show persistent soft-tissue thickening (E) and excessive enhancement (F) in the left PPF (asterisk).