MRI OF MALIGNANT-TUMORS OF THE ORAL CAVIT Y AND OROPHARYNX WITH FREQUENCY-SELECTIVE AND INVERSION-RECOVERY FAT SIGNAL SUPPRESSION

Purpose: Evaluation of frequency-selective fat saturation (FS) and Sho rt-Tau-Inversion-Recovery (STIR) fat suppression (FU) in MRI of patien ts with malignant tumours of the oral cavity or oropharynx. Methods: T wenty patients with biopsy-proven squamous cell carcinoma of the oral cavity or oropharynx were examined by MRI at 1.0 T. A T-2-weighted TSE -sequence with and without STIR-FU and a T-1-weighted SE-sequence with and without FS were compared in axial slices. Results: STIR-FU was su ccessful in all and FS in 29/33 (87.9%) of the examinations. When visu alisation and delineation of tumours were ranked on a four-point scale (0-3), respective mean values for images without/with FU or FS of 1.9 and 2.6 for T-2-TSE, 1.4 and 1.3 for T-1-SE without contrast media ad ministration (CM) and 2.0 and 2.5 with CM were found. Signal/noise-rat ios were inferior with FU and FS, but the tumour/muscle intensity rati o in CM-T-1-SE improved with FS. Conclusions: STIR-T-2-TSE and FS-T-1- SE with CM were most useful for MRI of carcinomas of the oral cavity a nd oropharynx.