SONOGRAPHY, CT, CT SIALOGRAPHY, MRI AND MRI SIALOGRAPHY IN INVESTIGATION OF THE FACIAL-NERVE AND THE DIFFERENTIATION BETWEEN DEEP AND SUPERFICIAL PAROTID LESIONS

Our aim was to explore the possibility of delineation of the facial ne rve within the parotid gland and to differentiate between superficial and deep parotid lesions in relationship to it, using ultrasound, CT, MRI, MRI sialography (MRIS) and CT sialography (CTS). We examined 47 p atients with clinically suspected parotid tumours by US, 31 of them al so by CT, MRI and CTS, and 13 by MRIS as well. Low-intensity curviline ar structures seen on T1-weighted MRI were delineated better after int raductal gadolinium injection and proved to represent parotid ducts on CTS. Using the main parotid duct as a landmark, we distinguished paro tid lesions as deep or superficial to the facial nerve by T1-weighted MRI images in 69 % and by MRIS in all cases. The facial nerve itself w as indistinguishable from the parotid gland in all our imaging methods .