11. Axial image with arrows
pointing to the frontal sinuses.
Coronal image of
frontal sinuses (FS).
12. Sagittal image shows frontal sinus ostium
(*) and arrow pointing to the superior
compartment of the FSDP. (FS: frontal
sinus, AG: agger nasi, PE: posterior
ethmoid, SpS: sphenoid sinus, MT: middle
turbinate, IT: inferior turbinate)
Sagittal image with arrows
demonstrating frontal sinus drainage
pathway and hiatus semilunaris which
drains to middle meatus. (FS: frontal
sinus, SpS: sphenoid sinus, MT: middle
turbinate, IT: inferior turbinate)
13.
14.
15. Axial image demonstrating an Agger Nasi
air cell which is the most anterior ethmoid
air cell. (AE: anterior ethmoid, PE:
posterior ethmoid, SpS: sphenoid sinus).
Axial image showing normal ethmoid sinus
anatomy. Arrows point to the lateral attachment
of the basal lamellae to lamina papyracea
separating anterior and posterior ethmoid
sinuses (AE: anterior ethmoid, PE: posterior
ethmoid, NS: nasal septum, SpS: sphenoid sinus).
16.
17. Schematic representation of the cribriform plate and the olfactory nerve (a). Coronal
direction; upper limit and lateral limit (lamina papyracea) of the ethmoid sinus (b).
18.
19.
20.
21.
22. Onodi cells. Onodi cells (OC), or
sphenoethmoidal cells, represent
invasion of the postreme ethmoid
cells above the sphenoid sinus.
These cells can contact the optic
nerve (a, b) and internal carotid
artery(c). Pneumatization may
extend to the anterior clinoid
process (*).
23.
24.
25. Axial image of the maxillary sinuses at
the level of the nasal septum marked by
arrowhead. (MS: maxillary sinus, NLD:
nasolacrimal duct, IT: inferior turbinate)
Coronal image with arrow pointing to
maxillary sinus ostium (MO) with (..)
illustrating the infundibulum joining
the hiatus semilunaris (*). (MS:
maxillary sinus, MT: middle turbinate)
33. Haller's cells (asterisks) are ethmoid cells that pneumatize inferiorly
to the orbits towards the interior of the maxillary sinuses.
34. Superior insertion of
the uncinate process:
Into the lamina
papyracea (58%).
Into the middle
turbinate (27%).
Into the skull base (10%).
Multiple insertions
(superior turbinate,
ethmoid bulla) (5%).
35.
36.
37.
38.
39.
40.
41. Axial image shows sphenoid sinus (SpS) and the
sphenoethmoidal recess marked by the (*). (AE:
anterior ethmoid, PE: posterior ethmoid, CC:
carotid canal, NS: nasal septum).
Coronal image of the sphenoid sinus (SpS)
and neighboring structures. (FR: foramen
rotundum, VC: vidian canal, OC: optic canal,
AC: anterior clinoid, PtP: pterygoid plate).
42.
43. Sagittal image showing the sphenoid sinus
(SpS) with sinus ostium (*) and arrow
demonstrating the sphenoethmoidal recess
(SER). (PE: posterior ethmoid sinus).
52. Coronal computed tomography (CT) scans of paranasal sinus anatomy as shown on thin-section
coronal CT scans of a cadaver. The anterior osteomeatal unit is shown in images F through H.
The frontal recess (small curved lines), the middle meatus (dashed lines), the infundibulum
(small arrows), and the primary ostium of the maxillary sinus (large white arrows) are seen.
A, agger nasi cell; b, ethmoid bulla; F, Frontal sinus; M, maxillary sinus; S, sphenoid sinus; U,
uncinate process; 1, inferior turbinate; 2, middle turbinate; 3, superior turbinate.
57. Retention cyst.
Submucosal accumulation of serous fluid.
Smooth domed shaped structure.
Usually seen at the inferior aspect of the
maxillary sinus and cannot differentiated from
the polyp.
61. Silent sinus.
Silent sinus syndrome, which consists of painless facial asymmetry and
enophthalmos caused by chronic maxillary sinus atelectasis.
The most characteristic imaging feature of the silent sinus syndrome is the inward
retraction of the sinus walls into the sinus lumen with associated decrease in sinus
volume and enlargement of the middle meatus. (2). In many cases the
infundibulum is occluded due to lateral retraction of the uncinate process.
62. Paranasal sinus mucoceles represent complete opacification of one or more
paranasal sinuses by mucus, often associated with bony expansion due to obstruction
of the nasal sinus drainage.
Location: The frontal sinus is particularly prone to developing mucoceles, and up to
two-thirds of all mucoceles occur there. The ethmoidal sinuses are the next most
common, whereas the maxillary and sphenoidal sinuses are infrequently involved
Frontoethmoidal mucoceles.
65. Axial views and coronal sections of CT images showing a left
expansile mass in the maxillary sinus suggestive of a mucocele
66. Axial views and coronal sections of T1 and T2 weighted MRI images
showing an expansile sphenoid lesion suggestive of mucocele.
67. Right proptosis and the respective axial and coronal MRI sections revealing
expansile frontal sinus lesion with loss of scalloping suggestive of a mucocele.
82. Right sphenoid bone shows low
intensities on both T1- (a) and T2- (b)
weighted images. The right side SS and
foremen ovale are smaller than left
side due to fibrous dysplasia. Ground-
glass opacities, a characteristic finding
of fibrous dysplasia, demonstrated on
an axial CT image (c).
