Imaging of head and neck lymph nodes.

The cervical lymph nodes can be affected by a variety of infectious, inflammatory, benign, and malignant pathologic conditions. Clinical history and physical examination with the complementary use of imaging is essential to accurately make a diagnosis or appropriate differential. Knowledge of cervical lymph node anatomy, drainage pathways, morphologic variations, and common nodal pathology is key to correct interpretation of cervical lymph nodes on imaging. Computed tomography (CT), MR, ultrasound, and PET/CT are complementary imaging modalities that can be used in the evaluation of cervical lymph node pathology.