Learning objectives
The current poster aims to:
- Review the anatomy of the petrous apex
- Propose an algorithm that helps the radiologists narrow the differential diagnosis when encountered with a lesion within the petrous apex
- Discuss most typical imaging findings of commonly encountered PA lesion
Background
The petrous apex is a pyramid-shaped structure that is formed by the medial portions of the temporal bone.
It is obliquely positioned within the skull base,
with its apex pointing anteromedially and its base located posterolaterally.
What makes the petrous apex anatomically complex is its medial location in the skull base and its intimate relationship to other clinically important structures.
The petrous apex is bounded by the inner ear structures laterally,
the petro-occipital fissure medially,
the petrosphenoidal fissure anteriorly,
and the posterior cranial fossa behind....
Findings and procedure details
Several methods have been proposed for classifying lesions of the petrous apex.
For instance,
lesions may be classified as cystic or solid,
as surgically treatable or not surgically treatable,
as aggressive or nonaggressive,
or on the basis of their specific cause or origin.
We prefer to categorize petrous apex abnormalities into four groups: those that primarily arise within the petrous apex (developed within the apical structure or its walls),
those involving the ICA,
the meningeal envelope and the adjacent nerves,
a third group concerning areas...
Conclusion
In conclusion,
to understand the pathology of the petrous apex,
we should,
at first,
possess its anatomy and especially be familiar with its pseudolesions,
then evaluate the various pathological elements considering their origin either in intrinsic situation,
or involving its meningeal envelope or nearby nerves or the ICA,
or starting from adjacent regions.
References
1.Singh,
A.,
Smoker,
W.
and Policeni,
B.
(2012).
Imaging Algorithm of Petrous Apex Lesions.Neurographics,
2(3),
pp.126-138.
2.Ruscalleda,
J.,
De Juan,
M.,
Feliciani,
M.
and Guardia,
E.
(1994).
Lesions of the Petrous Apex Differential Diagnosis by Imaging.Rivista di Neuroradiologia,
7(3),
pp.471-483.
3.Harnsberger,
H.
(2006).Handbook of head and neck imaging.
St.
Louis: Mosby.
4.CONNOR,
S.,
LEUNG,
R.
and NATAS,
S.
(2008).
Imaging of the petrous apex: a pictorial review.The British Journal of Radiology,
81(965),
pp.427-435.
5.Razek,
A.
and Huang,
B.
(2012).
Lesions of the Petrous Apex: Classification...