MRI AND CT OF TUMORS OF THE PHARYNX - COMPARISON OF THE 2 IMAGING PROCEDURES INCLUDING FAST AND ULTRAFAST MR SEQUENCES

The aim of this prospective study was to compare the diagnostic value of computed tomography (CT) and magnetic resonance imaging (MRI) in th e evaluation of tumors of the nasopharynx, oropharynx and hypopharynx. For this reason, we performed CT and MRI in a total of 473 patients w ith neoplasms of the nasopharynx [116], oropharynx [282] and hypophary nx [39]. Furthermore, the MR imaging protocol had to be optimized incl uding 2D and 3D gradient echo sequences. We compared the use of conven tional and fast spin echo and 3D gradient echo sequences for the evalu ation of tumors of the nasopharynx and the skull base, and we evaluate d 2D fast and ultrafast MR sequences for the detection and delineation of tumors of the oropharynx and hypopharynx. MRI yielded better resul ts than CT in the detection of pharyngeal neoplasms. The differentiati on of tumor and inflammatory tissue was best achieved using MRI. Contr ast-enhanced 3D GE sequences improved the diagnostic value of MRI of t he nasopharynx. Fast and ultrafast 2D MR sequences increased the contr ast between orofacial tumors and surrounding tissues. Functional MR im ages (phonation studies, Valsalva's maneuver) were attainable using ul trafast sequences thus enhancing the diagnostic value of MRI in the ca se of tumors of the hypopharynx. T2-weighted turbo (fast) spin echo se quences with relatively short acquisition times proved to be superior to conventional T2-weighted spin echo sequences. In conclusion, MRI is the imaging modality of choice in the evaluation of pharyngeal neopla sms. Conventional T2-weighted SE should be substituted by fast T2-weig hted SE sequences. 3D GE sequences should be integrated in the MR imag ing protocol of the nasopharynx. Fast and ultrafast 2D GE sequences sh ould be applied in the evaluation of tumors of the oropharynx and hypo pharynx.