Хамар, дайвар хөндийн КТГ анатоми.pptx

1. PARANASAL SINUSES
CT SCAN

2. Nasal cavity
Boundaries:
Roof : cribriform plate/
Floor :/hard, soft palate/
Lateral : /nasal wall/
Medial : /nasal septum/
Anterior : /pyriform aperture/
Posterior: Choanae

3. Turbinates (Chonchae)
Three paired turbinates
- Superior
- Middle
- Inferior
Define regions of superior middle and inferior
meati
Variant anatomy
-concha bullosa
-paradoxical turbinate

4. Superior turbinate
-smallest turbinate
Joint attachment with middle turbinate to the
ethmoid complex
-vertical portion basal lamella
Tail points toward sphenoid sinus ostium at
sphenoethmoidal recess
-Surgical landmark

5. Middle turbinate
Attachments
-Superior = cribriform plate via vertical portion
of basal lamella
-Lateral=lateral nasal wall
-Basal lamella also attaches to lamina papyracea

6. Inferior turbinate
-Largest turbinate
-Attachment=medial maxillary sinus wall below
uncinate process

7. Nasal Meati
• - Superior meatus
• - Middle meatus
• - Inferior meatus

8. Superior meatus
• Location
- between superior turbinate and lateral
nasal cavity wall
- Connected to pterygopalatine fossa via
sphenopalatine foramen
• Drainage
- Posterior ethmoid air cells
- Sphenoid sinus

9. Middle meatus
Location
- Between middle turbinate and lateral nasal
cavity wall
Drainage
-Maxillary sinus
-Frontal sinus
-Anterior ethmoid air cells

10. Inferior meatus
Location
- Between inferior turbinate and lateral nasal
cavity wall
Drainage
- Nasolacrimal duct

11. Paranasal sinuses
• Frontal
• Maxillary
• Ethmoid
• Sphenoid

12. Frontal sinus
- Air cells within frontal bone
Boundaries
- Anterior – frontal bone
- Posterior and superior – floor of anterior
cranial fossa
- Inferior – orbital roof
Drainage
- Middle meatus via frontal recess

13. Maxillary sinus
Air cells within maxilla
Boundaries
- Posterior – retromaxillary fat, PPF, masticator
space
- Superior - Orbital floor
- Inferior - Maxillary alveolus
Drainage
- Middle meatus via ostium -> infundibulum ->
hiatus semilunaris

14. Ethmoid sinus
Complex air cell labyrinth
Boundaries
- Superior – cribriform plate (and its lateral
lamella) + fovea ethmoidalis
- Lateral – lamina papyracea
- Posterior – sphenoid sinus
Anterior and posterior cells
- Seperated by basal lamella
- Different drainage routes

15. Ethmoid sinus
Anterior air cells
- Drains via anterior recess of hiatus semilunaris
into middle meatus
Posterior air cells
- Drains via sphenoethmoidal recess near
superior meatus

16. Sphenoid sinus
Air cells within sphenoid bone
• Boundaries
-Superior – Sella turcica
-Inferior – Nasopharynx roof
- Anterior – Post.ethmoids
-Posterior – clivus
• Drainage
- Sphenoethmoidal recess to superior meatus

17. Frontal recess cells
• -Agger nasi
• -Frontal(Kuhn) recess cells
• -Ethmoid bulla
• -Suprabullar cell
• -Frontal bullar cell
• -Interfrontal sinus septal cell
• -Supraorbital ethmoid cell

18. Agger nasi cell
• Nasal Mound
• Dominant, anterior-most ethmoid cell
• Forms anterior and lateral margins of frontal
recess inferiorly
• Surgical access point to frontal recess

19. Frontal (Kuhn) Recess Cells
• Sit above agger nasi
• Forms anterior and lateral margins of
frontal recess superiorly
• 4 types
-type 1 – single cell
-type 2- stack of 2+ cells
-type 3 – single large cell extending into
frontal sinus
-type 4 – cell in frontal sinus

20. Ethmoid bulla
-Dominant anterior air cell
-Lateral margin of ethmoid infundibulum
-Posterior margin of frontal recess
-Overlies hiatus semilunatis

21. Suprabullar cell
- Anteiror ethmoid cell
- Sits above ethmoid bulla, but lies below frontal
sinus
-Posterior margin of frontal recess
-Can be mistaken for skull base during FESS

22. Frontal bullar cell
-Similar to suprabullar cell
-Sits above ethmoid bulla, extends above frontal
sinus ostium into frontal sinus
-Posterior margin of frontal recess
-Can be mistaken for skull base during FESS

23. Interfrontal sinus septal cell
-Pneumatized interfrontal sinus septum
-May extend into crista galli
-Drains to frontal recess
-May contribute to obstruction

24. Supraorbital ethmoid cells
-Anterior ethmoid cells
-Extend superolaterally above orbit
-Posterior to frontal sinus
-Posterolateral to frontal recess
Drains to frontal recess
-Located above and may “uncover”anterior
ethmoidal artery notch

25. Paranasal sinus outflow
-Mucociliary clearance
-Outflow pathways
-Osteomeatal complex
-Sphenoethmoidal recess

26. Maxillary outflow – Ostium->infundibulum-
>hiatus semilunaris->middle meatus
Anterior ethmoid outflow- Ostia/ethmoid bulla -
> middle meatus
Frontal outflow – Ostium->frontal recess-
>middle meatus
Osteomeatal complex

27. Spenoethmoidal recess receives drainage from
– Sphenoid sinus
– Posteior ethmoids
Superior meatus
Sphenoethmoidal recess

28. Infundibular pattern of obstruciton
Opacified maxillary sinus, spares frontal and
ethmoid
Key anatomic structures
-Maxillary sinus ostium
-infundibulum
-uncinate process
-hiatus semilunaris

29. Frontal recess pattern of obstruction
Opacified frontal sinus, spare maxillary +/-
ethmoid
Key anatomic structures
-Frontal sinus ostium
-Frontal recess
-Agger nasi cell
-Frontal recess(Kuhn) cells
Causes
-Mass, mucosal thickening, polyp, debris,
trauma, etc.

30. Middle meatus pattern of obstruction
AKA osteomeatal pattern
- Opacified frontal, anterior ethmoid, and
maxillary sinus
Key anatomic structures
- Middle meatus
- Hiatus semilunaris
- Ethmoid bulla
Causes
-Mass, mucosal thickening, polyp, debris,
trauma, etc

31. Sphenoethmoidal recess pattern of
obstruction
Opacified sphenoid sinus and posterior ethmoid
air cells
Key anatomic structures
-Sphenoid sinus ostium
-Sphenoethmoidal recess
-Sphenoethmoidal cell
-Superior meatus
Causes
-Mass, mucosal thickening, polyp, debris,
trauma, etc

32. CLOSE (or CLOSET) Mnemonic
• Cribriform plate
• Lamina papyracea
• Onodi cell
• Sphenoid sinus pneumatization
• Ethmoidal artery
• Teeth

33. Cribriform plate
• Horizontal lamina cribrosa
• -Look for dehiscence!
• Olfactory fossa
• -Superior – fovea ethmoidalis
• -Inferior – horizontal lamina
• -Lateral – lateral lamella
• As olfactory fossa depth increases, risk of
surgical injury to lateral lamella also
increases
• -CSF leak, meningocele, etc

34. KEROS classification
As depth of olfactory fossa increases, so does risk of iatrogenic injury

35. Lamina papyracea
• Increased risk of orbital penetration
• remote orbital blowout fracture
• +/- Prolapse of retroorbital contents into
sinus
• Infraorbital ethmoid (Haller) cell
• Apposition of uncinate process to orbital
wall

36. Onodi cell
• Variant posterior ethmoid air cell
• Mimics sphenoid sinus
• -Use horizontal septum to ID
• Maycause confusion for surgical
decompression
• Optic nerve frequently has intrasinus course
in Onodi
• Increased risk of optic nerve injury during
FESS

37. Sphenoid sinus
• Pneumatization pattern
• -Conchal, presellar, or sellar
• Skull base and anterior clinoid
• Internal carotid artery
• Intrasphenoid sinus course or dehiscence
• Septum attachment

38. Ethmoid artery
• Variable ethmoid pneumatization around
the anterior ethmoid artery
• Uncovering of the osseous mesentery ->
increased risk of surgical injury

39. Teeth
• Important source of sinus infection
• Odontogenic sinus disease