Table 1:
Imaging features of select head and neck paragangliomas.
| Imaging features of paraganglioma | Duplex ultrasound | Computed tomography | Magnetic resonance | Nuclear medicine |
|---|---|---|---|---|
| General description (all) | Solid, Heterogeneously-hypoechoic, and internal hyper-vascularity Adjacent structure displacement |
Avid mass enhancement with delayed contrast washout relative to adjacent structures | T1-weighted hypointense signal relative to adjacent structures T2-weighted isointense to hyperintense signal |
I-131 and I-123 metaiodobenzylguanidine 111 octreotide, and F-18 PET/CT commonly used Lesion demonstrates focally increased uptake |
| Carotid body (most common head and neck paraganglioma) | Splaying of ICA and ECA Must rule out vagal PG |
Enhanced soft-tissue mass attenuation; splaying of proximal ECA and ICA | T1-post contrast enhanced soft-tissue mass; splaying of proximal ECA and ICA T2-weighted *flow voids (multiple low-signal punctate foci); rule out schwannomas and/or neurofibromas in Carotid Space Angiography reveals “Lyre sign” (see US) |
FDG/PET focal mass uptake area of carotid bifurcation of ECA and ICA |
| Glomus vagale (least common head and neck paraganglioma) | Anteromedial displacement of ICA and ECA | Enhanced soft tissue mass attenuation; anteromedial displacement of ECA and ICA. Osseous erosion of anterior skull base (Proximal vagal) |
T1-post contrast enhanced soft-tissue mass; anteromedial displacement of ECA and ICA T2-weighted *flow voids (multiple low-signal punctate foci) along vagus nerve near jugular foramen |
FDG/PET focal mass uptake in area of proximal ECA and ICA to adjacent jugular foramen |
| Glomus jugulare (second most common head and neck paraganglioma) | Limited by skull base; only detectable by US when tumor extends inferiorly from jugular foramen | Erosion of jugular bulb Bony erosion of jugular foramen walls (temporal bone “moth-eaten appearance”) |
T1-post contrast well defined enhanced soft-tissue mass ; centered in jugular foramen T2-FSE well-defined, hyperintense mass centered in jugular foramen T2-weighted *flow voids (multiple low-signal punctate foci) |
FDG/PET focal mass uptake in jugular bulb within jugular fossa |
| Notes | Evaluation of Palpable HN tumors; location drives naming (i.e., carotid body, vagale, jugulare) | Soft-tissue attenuation, bony erosion, and axon thickening; suspicious for perineural tumor spread | Most sensitive Radiologist should describe degree of vascular encasement of ICA and ECA |
Evaluation for metastatic and or multicentric disease |
ICA: Internal carotid artery, ECA: External carotid artery, *a.k.a. “salt and pepper” appearance