Anatomic variants of the paranasal sinuses: A pictorial essay

71 Pages·2010·7.54 MB·English

Anatomic variants of the paranasal sinuses: A pictorial
essay
Poster No.: C-3325
Congress: ECR 2010
Type: Educational Exhibit
Topic: Head and Neck
Authors: F. G. Gonçalves; Montreal, QC/CA
Keywords: paranasal sinuses, anatomic variations, computed tomography
DOI: 10.1594/ecr2010/C-3325
Any information contained in this pdf file is automatically generated from digital material
submitted to EPOS by third parties in the form of scientific presentations. References
to any names, marks, products, or services of third parties or hypertext links to third-
party sites or information are provided solely as a convenience to you and do not in
any way constitute or imply ECR's endorsement, sponsorship or recommendation of the
third party, information, product or service. ECR is not responsible for the content of
these pages and does not make any representations regarding the content or accuracy
of material in this file.
As per copyright regulations, any unauthorised use of the material or parts thereof as
well as commercial reproduction or multiple distribution by any traditional or electronically
based reproduction/publication method ist strictly prohibited.
You agree to defend, indemnify, and hold ECR harmless from and against any and all
claims, damages, costs, and expenses, including attorneys' fees, arising from or related
to your use of these pages.
Please note: Links to movies, ppt slideshows and any other multimedia files are not
available in the pdf version of presentations.
www.myESR.org
Page 1 of 71
Learning objectives
After reading this educational exhibit you will:
• Have a comprehensive review of the normal variants of the paranasal
sinuses
• Be able to identify the most common and relevant anatomic variants of the
paranasal sinuses
• Deliver more detailed reports for the attending ORL doctor
Background
The development and pneumatization of the para-nasal sinuses occur in an orderly and
well-established sequence. This process starts in embryonic life around the 3rd and 5th
gestational months and concludes during early adulthood (Figure 1 on page 3)
Unknown factors can change this pattern and consequently lead to the formation
of anatomical variants. In some cases these anatomic variants may have clinical
implications (Figure 2 on page 3)
Computed tomography is the method of choice to evaluate the para-nasal sinuses. It
provides valuable information on the local anatomy (Figure 3 on page 4)
It is extremely useful to assess the underlying pathological processes, for treatment
planning, post surgical evaluation and to identify anatomic variations (Figure 3 on page
4)
Study Description (Figure 4 on page 5)
This pictorial essay is based on a retrospective review of CT scans of patients who had
undergone an evaluation of the sinuses at the University Hospital of Brasília
Page 2 of 71
The examinations were acquired with a multidetector CT with volumetric acquisition. The
images were reviewed and reformatted in multiple planes on workstations
The anatomic variants were classified into 5 groups regarding their location
Images for this section:
Fig. 1
Page 3 of 71
Fig. 2
Page 4 of 71
Fig. 3
Page 5 of 71
Fig. 4
Page 6 of 71
Imaging findings OR Procedure details
This pictorial essay is based on a retrospective review of CT scans of patients who had
undergone an evaluation of the sinuses at the University Hospital of Brasília
The examinations were acquired with a multidetector CT with volumetric acquisition.
These images were reviewed and reformatted in multiple planes on workstations
The anatomic variants were classified into 5 groups regarding their location
Groups:
1. Frontal sinuses on page 10
2. Ethmoid air cells on page 11
3. Sphenoid sinuses on page 11
4. Maxilary sinues on page 11
5. Other on page 11
Ostiomeatal Complex on page
Common pathway for the drainage of the paranasal sinuses. It acts a functional unit
controlling and regulating the mucocilliary drainage of the frontal and maxillary sinuses
and ethmoid air cells
It comprises the following structures: uncinate process, ethmoid bulla, middle turbinate.
Moreover it encompasses the ethmoid infundibulum, semilunar hiatus and middle
meatus)
Frontal Recess on page 13
The frontal recesses (FR) are the frontal sinuses drainage pathway (Figure 3 on page
12)
The boundaries and walls of the frontal recesses are:
- Anterior è Agger Nasi Cell (ANC)
Page 7 of 71
- Lateral è Medial orbital wall, ethmoidal bulla, medial turbinate
- Posterior è Basal lamella of the middle turbinate
- Posterior-superior è Anterior ethmoid cells
Agger Nasi Cells on page 14
The ANC are the most anteriorly located ethmoid air cells. They are considered the most
prevalent anatomic variant (up to 98,5% of the population)
ANC forms the superior and posterior walls of the frontal recess
Endoscopically the ANC is a focal bulging in the anterior aspect of the nasal fossa
anteriorly to the middle turbinate
By CT the ANC are better seen in coronal and sagittal views.
ANC related disease is a frequent cause of functional endoscopic sinus surgery (FESS)
revision
Agger nasi cells in coronal on page 15 and sagittal on page 16 views.
Frontal Cells on page 17
The Frontal Cells (FC) are anterior ethmoid cells that are located anterior and superiorly
to the ANC
The FR are classified according to Kuhn criteria in four types (I, II, III e IV)
They are important in the frontal sinuses drainage and are related with sinunasal
inflammatory processes
The FC are better seen in coronal and sagittal views
Page 8 of 71
Frontal Cell Type I on page 18
Single cell located above the ANC
FC type I does not reach the level of the frontal sinus
Frontal cells type I in coronal on page 19 and sagittal on page 20 views
Frontal Cell Type II on page 21
The FC type II are tier cells above the ANC
The FC type II are located above the ANC and may or may not extend to the frontal sinus
Frontal cells type II in coronal on page 22 and sagittal on page 23 views
Frontal Cell Type III on page 24
Single cell above the ANC which extends to the frontal sinus
Frontal cells type III in sagittal on page 25 and axial on page 26 views
Frontal Cell Type IV on page 27
Isolated single cell inside the frontal sinus
Frontal cells type IV in coronal on page 28 and sagittal on page 29 views
Supraorbital Ethmoid Air Cells on page 30
Page 9 of 71
Originates from the anterior ethmoid group and extends superior and laterally between
the ethmoid roof and medial orbital wall
Supra orbital ethmoid air cells coronal on page 31 and axial on page 32 views
Dehiscence of the Optic Nerves and Internal Carotid Arteries on page 54
Haller Cells on page 55
Anterior and Posterior Fontennele on page 56
Lamina Papiracea Defects on page 57
Maxillary Sinus Hypoplasia on page 58
Frontal Sinus Hypoplasia on page 59
Sphenoid Sinus Hypoplasia 1 on page 60 2 on page 61
Pneumatization of the crista Gall on page 62, nasal septum on page 63, pterygoid
process on page 64 and clinoid process on page 65
Images for this section:
Page 10 of 71