DYNAMIC MRI OF TUMORS IN HEAD AND NECK WITH A CONTRAST-ENHANCED FLASH-2D SEQUENCE

The purpose of this study was to evaluate the utility of a dynamic con trast enhanced FLASH-2D sequence for differential diagnosis of tumours in head and neck in 93 patients. Initially, the localization of the l esion and the selection of four representative slices for the dynamic study were obtained by a T2-weighted spin-echo sequence (TR 2000-3000 ms; TE 25/90 ms). After IV bolus injection of the contrast agent 10 im ages were acquired during a period Of min by a FLASH-2D sequence (TR 6 0 ms, TE 6 ms; flip angle 40 degrees; matrix 256 x 256; one acquisitio n). The percentage signal intensity (SI) increase (r) and the slope (S ) of the curve were calculated on the basis of the SI time curve of th e pathological lesion and of muscle. Inflammatory processes could be d ifferentiated from malignant or benign tumours by means of a higher co ntrast enhancement. The time of the maximum SI was not specific for th e different lesions. In comparison with muscle the maximum SI change w as achieved earlier in a pathological process.