COMPARISON OF DYNAMIC CONTRAST-ENHANCED GRADIENT-ECHO AND SPIN-ECHO SEQUENCES IN MR OF HEAD AND NECK NEOPLASMS

PURPOSE: To investigate the utility of dynamic contrast-enhanced gradi ent-echo MR imaging of head and neck lesions and to compare this techn ique with the commonly used spin-echo contrast-enhanced fat-saturation technique. METHODS: Twenty-two patients with a total of 23 head and n eck neoplasms underwent dynamic gradient-echo and spin-echo MR imaging studies. The spin-echo and dynamic gradient-echo images were compared in each case by consensus of three observers for differences in tumor conspicuity and delineation of margins, particularly with regard to i nvasion of adjacent structures. When possible, pathologic and/or surgi cal confirmation of tumor extent was obtained. Relative contrast was a lso calculated to determine objectively the degree of tumor enhancemen t with respect to background mucosa. RESULTS: The dynamic gradient-ech o images showed better or equal delineation of the tumor margins by su bjective observation in all but two cases. Temporally different enhanc ement patterns were noted for lesions, background mucosa, and adjacent reaction and edema. The dynamic gradient-echo technique provided bett er relative contrast than the spin-echo technique in 17 (77%) of 22 le sions. CONCLUSION: Dynamic gradient-echo MR imaging is superior to con ventional contrast-enhanced spin-echo imaging in delineating the margi ns and extent of tumor. This technique provided observers with added c onfidence in their interpretations and suffered from fewer technical l imitations.