Head and neck cancer accounts for around 4% of all malignancies. The presence of cervical lymph node metastases will reduce expected survival with approximately 50%. Therapy should thus be as effective as possible with a minimum of therapeutic side effects and depends next to tumour size on the presence or absence of nodal metastases. Physical examination and imaging with magnetic resonance imaging (MRI), positron emission tomography – computed tomography (PET-CT), ultrasound (US), ultrasound guided fine needle aspiration (USgFNAC) are commonly used to examine cervical lymph node metastases, but in 30% of the cases, they are still overlooked. New imaging techniques such as real time image fusion of ultrasound and PET-CT and micro flow imaging (MFI) are thus developed. The aim of this thesis was to improve the detection rate of lymph node metastases by improving the selection criteria of nodes for ultrasound guided fine needle aspiration to prove cytological malignancy.