Table 1.

The role of different magnetic resonance imaging (MRI) sequences in head and neck cancer imaging

MRI		T1	T2	Contrast
sequences
Bright	– Fat – Subacute blood products (methemoglobin) – Slow-flow blood – Melanin – Protein rich fluid – Paramagnetic substances (iron, ferritin, hemosiderin) – Calcification		– Fluid – Inflammation – Infarction – Subacute blood products	– Tumor – Pathological lymph nodes – Acute/subacute post-treat-ment changes – Inflammatory processes – Infection
Dark	– Fluid – Air – Hyperacute hemorrhage – Densely calcified/osseous lesions – Fibrous tissue – Vascular flow voids		– Fibrous tissue – Calcification – Protein-rich fluid – Paramagnetic substances – Vascular flow voids
Role in imaging	– Delineation of fat planes and optimal evalua-tion of the nasopharynx, parapharyngeal fat plane, floor of mouth, oropharynx, pre-epiglottic space, and false vocal cords – Assessment of bone marrow signal – Assessment of visible lymph node capsule		– Assessment of primary tumor – Assessment of pathological lymph nodes and extracapsular disease spread – Post-treatment changes – Inflammatory processes	– Delineation of primary tumor – Assessment of perineural spread – Assessment of pathological lymph nodes