Learning objectives
To identify the anatomy of the pterygopalatine fossa (PPF),
its neurovascular content and all of its communications.
To understand and diagnose the presence of perineural tumor spread.
To be able to predict nerves at risk in PNS at the level of the PPF
Background
This paper will give a detailed review on the anatomy of the pterygopalatine fossa (PPF),
which can be considered a major crossroad of multiple head and neck neurovascular structures.
Knowledge of this anatomy is of great importance in disease spreading along the nerves connected to the PPF.
We'll present some cases of pathology involving the PPF.
The direct and indirect radiological signs of perineural spread will be discussed in this exhibition.
A.
ANATOMY OF THE PTERYGOPALATINE FOSSA
The pterygopalatine fossa is a fat-containing inverted pyramid-shaped...
Findings and procedure details
HRCT
High Resolution Computed Tomography (HRCT) is the modality of choice to evaluate the bony communications of the pterygopalatine fossa (PPF).
The normal PPF,
on non-contrast enhanced CT with soft window settings,
appears as a hypodense,
fat density,
space.
MRI
Magnetic Resonance Imaging is excellent for evaluation of pathology in the PPF,
especially for perineural tumor spread.
Small field-of-view MRI using a head-coil is recommended for evaluation of PPF and connections.
Following acquisitions are preferred:
- precontrast axial and coronal Spin EchoT1W
- precontrast axial...
Conclusion
The pterygopalatine fossa is a challenging anatomical space,
involved in a wide range of pathologies (tumoral,
inflammatory,
infectious).
The entity of perineural spread is very important since a lot of nerves connect to the pterygopalatine ganglion located in the PPF.
Any process involving the PPF may spread via several nerves and in an antegrade as well as a retrograde way.
The radiologist must be aware of this spreading pattern thus understanding and explaining PNS loops,
since this is of capital importance in treatment and prognosis...
Personal information
Gert-Jan AllemeerschMD
UZ BRUSSEL
Laarbeeklaan 101 - 1090 BRUSSEL
BELGIUM
[email protected]
Acknowledgements: many thanks to Robert Hermans MD,PhD (UZ Leuven) for the images of PPF schwannoma,
sarcoma and PNS from nasal SCC.
References
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