Learning objectives
Learning objectives
-To learn the anatomy of the extracranial nerves and how to recognise these sites on sectional imaging.
-To learn the most important routes for spread of malignant disease and what radiological signs to assess.
Background
Introduction:
The extra-neurocranial anatomy is a challenging and complex area to master.
In the setting of head and neck malignancies it is very important to recognise specific signs and have knowledge of specific routes in order to scrutinise for possible perineural spread.
Knowledge of the imaging appearance of perineural spread is important,
for it can be very subte and easy to miss.
Also the majority of patients do not have clinical signs of perineural spread.
Perineural spread:
Perineural spread is spreading of tumorous cells along...
Findings and procedure details
Imaging findings of perineural spread as mentioned before can be very subtle.
Pay attention to:
- Obliteration of fat planes (on CT and MRI)
- Enlargement of the affected nerve (on MRI)
- Excessive enhancement (on MRI)
- Enlargement of the affected foramen (on CT)
Be aware that apart from intracranially,
the surrounding venous plexus and perineural tissue may enhance physiologically.
It is important to compare it with the contralateral side to detect pathological enhancement.
Normal Anatomy:
Trigeminal nerve:
The trigeminal nerve is the thickest...
Conclusion
Perineural extension routes of disease in the extra-neurocranial spaces are often overlooked and can be challenging to recognise.
Imaging findings of perineural spread as mentioned before can be very subtle.
Pay attention to
- Obliteration of fat planes (on CT and MRI)
- Enlargement of the affected nerve (on MRI)
- Excessive enhancement (on MRI)
- Enlargement of the affected foramen (on CT)
Certain "checkpoints" should always be scrutinised in the vicinity of head and neck malignancies:
Pterygopalatine fossa
Cavernous sinus
Foramen rotundum
Foramen ovale...
Personal information
C.O.
Martins Jarnalo,
M.D.
Department of Radiology,
Medisch Centrum Haaglanden,
The Hague,
the Netherlands and VU- Medisch Centrum,
Amsterdam,
the Netherlands.
G.J Lycklama à Nijeholt,
M.D.
Ph.D.
Department of Radiology,
Medisch Centrum Haaglanden,
The Hague,
the Netherlands
E.
Sanchez-Aliaga,
M.D.
VU- Medisch Centrum,
Amsterdam,
the Netherlands
prof.
J.A.
Castelijns,
M.D.
Ph.D.
VU- Medisch Centrum,
Amsterdam,
the Netherlands
References
Diagnostic imaging Head and Neck.
Harnsberger ©2005-2013,
Amirsys,
Inc.
Atlas of human anatomy Second Edition.
Netter