ABSTRACT
The involvement of lymph nodes has hitherto been based on size criteria, using both CT and MR imaging, together with their internal appearance as demonstrated by lymphography (3,4). This is now changing as PET allows the identification of metabolic abnormalities (5). Nanoparticle-enhanced MR imaging allows internal architecture to be determined (6) and this has been shown to achieve high sensitivity and specificity in pilot studies (7). For the detection of lymph mode metastases in head and neck cancer ultrasound guided fine needle aspiration cytology is the most accurate imaging modality, but it does have an invasive element (8).
