[(18)F]Fluorodeoxyglucose-PET/Computed Tomography, PET, and Magnetic Resonance Imaging: Normal Anatomy, Pitfalls, and Artifacts.

Each anatomic region of the head and neck has physiologic variations that can mimic a primary tumor or lymph node. Many of these variations can be recognized as reflecting benign lymphoid, salivary, brown fat, and muscular activity. A few artifacts are related to computed tomography (CT) attenuation.