CT Chest Evaluation of the posterior fossa, neck, and upper chest is necessary for complete evaluation of the CN X, including the recurrent laryngeal nerve. Below the skull base, the vagus nerve is not directly imaged, although its course from the skull base to the carina can be imaged with contrast-enhanced neck CT extended through the aortopulmonary window. CT chest alone does cover the entire course of the vagus nerve, but it can be combined simultaneously and sequentially with CT neck to image the intrathoracic course of the vagus nerve. Preferably contrast should be administered. There is no relevant literature to support the use of combined pre- and postcontrast imaging. Although chest radiographs may detect large thoracic causes of vocal cord paralysis, chest CT is more sensitive, particularly for detecting aortopulmonary window and paratracheal lesions [158]. CT Head There is no relevant literature to support the use of routine CT head alone in the evaluation of unilateral isolated vagal nerve palsy. CT Maxillofacial There is no relevant literature to support the use of maxillofacial CT in the evaluation of isolated CN X palsy. Contrast-enhanced neck CT extended through the aortopulmonary window is useful for initial evaluation of isolated CN X palsy and allows imaging of the osseous integrity of the skull base and assessment of the full extent of the recurrent laryngeal nerve. CT Temporal Bone There is no relevant literature to support the use of temporal bone CT in the evaluation of isolated CN X palsy. CT Neck Evaluation of the posterior fossa, neck, and upper chest is necessary for complete evaluation of the CN X, including the recurrent laryngeal nerve, and can be achieved well with contrast-enhanced neck CT extended through the AP window. Below the skull base, the vagus nerve is not directly visualized, although its course from the skull base to the carina can be imaged with neck CT.
Cranial Neuropathy. CT Chest Evaluation of the posterior fossa, neck, and upper chest is necessary for complete evaluation of the CN X, including the recurrent laryngeal nerve. Below the skull base, the vagus nerve is not directly imaged, although its course from the skull base to the carina can be imaged with contrast-enhanced neck CT extended through the aortopulmonary window. CT chest alone does cover the entire course of the vagus nerve, but it can be combined simultaneously and sequentially with CT neck to image the intrathoracic course of the vagus nerve. Preferably contrast should be administered. There is no relevant literature to support the use of combined pre- and postcontrast imaging. Although chest radiographs may detect large thoracic causes of vocal cord paralysis, chest CT is more sensitive, particularly for detecting aortopulmonary window and paratracheal lesions [158]. CT Head There is no relevant literature to support the use of routine CT head alone in the evaluation of unilateral isolated vagal nerve palsy. CT Maxillofacial There is no relevant literature to support the use of maxillofacial CT in the evaluation of isolated CN X palsy. Contrast-enhanced neck CT extended through the aortopulmonary window is useful for initial evaluation of isolated CN X palsy and allows imaging of the osseous integrity of the skull base and assessment of the full extent of the recurrent laryngeal nerve. CT Temporal Bone There is no relevant literature to support the use of temporal bone CT in the evaluation of isolated CN X palsy. CT Neck Evaluation of the posterior fossa, neck, and upper chest is necessary for complete evaluation of the CN X, including the recurrent laryngeal nerve, and can be achieved well with contrast-enhanced neck CT extended through the AP window. Below the skull base, the vagus nerve is not directly visualized, although its course from the skull base to the carina can be imaged with neck CT.