**8. Imaging**

Imaging plays an essential role in the diagnosis and management of head and neck infections since, by clinical examination alone. It is often difficult to determine if a swollen neck is due to cellulitis or an abscess; the location, extent or source of the infection, and whether the process is self-limited or if it is potentially life-threatening is also clinically unclear.[21]

Radiographs of the cervical segment and the chest may be useful in the demonstration of subcutaneous emphysema in the form of vertical, linear, clear bands of gas extending from the cervical spaces into the mediastinum. The lateral radiograph of the neck can reveal a prever‐ tebral soft tissue opacity pushing the trachea anteriorly. Chest radiograph can demonstrate a widened mediastinum and pleural effusion. However, the modest diagnostic sensibility of cervical and chest plain film should call immediately for computed tomography scanning or a magnetic resonance of the cervicothoracic areas.[2, 17, 67, 68]

Any patient with neck swelling and/or pain from dental infection should have a comput‐ ed tomography exam of the neck and chest to evaluate the spread of infection. Comput‐ ed tomography examination and neck evaluation include: diffuse thickening of the cutis and subcutis and reticular enhancement of the subcutaneous fat of the face and neck; thickening and/or enhancement of cervical fasciae; asymmetric thickening or enhance‐ ment of cervical muscles, reactive lymphadenopathy; septic vascular thrombosis and fluid collections with or without gas. Mediastinal computed tomography findings include: streaky enhancement of mediastinal fat, fluid collections with or without gas, pericardial effusion and pleural effusion.[21]
