Morphological and functional imaging of neck paragangliomas.

OBJECTIVE: To review the optimal techniques for localization and characterization of neck paragangliomas (PGL).

MATERIAL AND METHODS: Systematic review of the literature from the PubMed/Medline database.

RESULTS: Neck PGL are hypervascular tumours essentially arising from paraganglionic tissue situated at the carotid bifurcation (carotid body) and along the vagus nerve. Morphological and functional imaging are indicated to confirm the diagnosis, identify multifocal disease and for local and regional staging. MR angiography is the noninvasive technique of choice. CT scan and especially CT angiography are excellent alternatives for diagnosis and staging. Conventional arteriography remains useful preoperatively for embolization and occlusion tests. Functional imaging allows localization and characterization of PGLs. Somatostatin receptor scintigraphy (SRS) was the reference imaging technique for staging of sporadic PGLs. The indications for PET imaging have been extended over recent years in parallel with the development of new tracers such as [18 F]-FDOPA PET or 68 Gallium-labelled DOTA peptides. 68 Gallium-labelled DOTA peptides has become the first-line imaging modality in the evaluation of cervical PGLs, regardless of the genetic background.

CONCLUSION: Morphological and functional imaging is essential for the staging of neck PGL.