CT scan of nose and PNS

CT images of nose and PNS

1. Road Map
To
Sinus Surgery
By
Dr.Muhammad A.Sherwani

2. Knowledge is Power
RedaKamel
Professor of Rhinology

3. Imaging modalities
CT Scan is choice of Imaging
PLAIN X-RAY CT Scan MRI
Ability to accurate demonstration of fine bone anatomy of
O.M.C & extent of the disease in & around the P.N.S .

4. Reading CT Films
Planes:Coronal / Axial /sagittal
Mark: R/L sides properly
Bone 1000-3000 (HU) or soft tissue window 400-800
(HU).
Read from Nasion to Sphenoid sinus (4-5)mm,extensive
disease and revision surgery (3mm)coronal cut and axial
cut should advised
Study following in all Sections
Nasal Septum
Lamina Papyracea
Skull Base
Native or contrast

5. Using contrast in CT-scan
Complicated sinusitis:
• Subperiosteal abscess!
• Cavernous sinus thrombosis!
• Epi / subdural abscess!
Tumours:
• Malignant
• Angiofibroma

6. systematic way of reading the CT film
anatomy
anatomical variations
pathology
structures which may be at risk
skull base
orbit
optic nerve
internal carotid artery

7. •Preparation and position of the patient:
1.not to be fasting
2.blow the nose to clear out any secretions
3.hyper extended neck
software found reconstruct the coronal and sagittal plane
from axial plane
Post op. CT-scan:
1.Not recommended as routine.
2.Done after 6months of ESS

9. Agger nasi:
is one of the air cells of the anterior ethmoid

10. Agger nasi with well pnumatized cell

11. Importance : Agger Nasi Cells
Agger causing disease Large Agger Nasi cell

12. Frontal cells:
are Ant.ethmoidal cell that pneumatize the
frontal recess above the agger nasi cell

13. Kuhn cell:
K1
single small cell above the Aggernasi

14. K2:
multiple small cells two or more cells
above the Agger cell

15. K3:
single large cell extend to frontal sinus

16. K4:
single small cell inside the frontal
sinus

17. Frontal bulla cell:
superior extension of BE into frontal
sinus

18. Supra orbital cell:
posterior to frontal sinus ostium

19. Uncinateprocess
attachments
attached to the L.P. 70%

20. Attached to skull base
30%

21. Attached to Middle Turbinate
30%

22. Uncinate process:
normal

23. Uncinate process:
Medially bent

24. Uncinate process:
laterally bent

25. Uncinate process
pneumatzation

26. Uncinate process
Absent

27. Middle turbinate :
important surgical landmark
attachments
Part I Part II Part III
Horizontal
ObliqueVertical

28. Middle turbinate:
Concha bullosa
Interlamellar cell

29. Middle turbinate:
paradoxically bent (C shape)

30. Bulla Ethmodalis:
is part of the air cells of the anterior ethmoid
pnumatized

31. Bulla ethmoidalis:
absent

32. Haller cell:
Its an ethmoidal air cells that project inferiorly into the floor of
the orbit in the region of the maxillary sinus ostium

33. Maxillary sinus:
Accessory ostium anterior

34. Maxillary sinus:
Accessory ostuim posterior

35. Maxillary sinus:
hypoplastic /aplastic maxilla

36. Roof of Ethmoid:
1.fovea ethmodalis
2.lateral lamella

37. : Anterior Skull Base

38. Ethmoid Roof :Anterior skull base
keros 1(1-3mm)shallow olfactory fossa

39. Ethmoid Roof :Anterior skull base
keros 2(4-7mm)average olfactory fossa

40. Ethmoid Roof :Anterior skull base
keros 3(8-16mm) deep olfactory fossa

41. Anterior Ethmoidal Artery: AEA
is orbital branch of ophthalmic artery

44. Posterior Ethmoidal cells:
are larger in size and fewer in number

45. Posterior Ethmoid cell:
Vertical height

46. SKULL BASE:
Height
Low skull base height
Normal skull base height

47. SKULL BASE:
slope

48. Post ethmoid cell:
sphenoethmoidal cell( Onodi cell) is a lateral
and superior extension of the post. ethmoids

49. Bilateral Onodi cells

50. Sphenoid sinus :
Size of the sinus
normal sphenoid sinus excessive pnumatiztion

51. Sphenoid Sinus
Absent Septa Multiple Septa

52. Asymmetrical situated septum of
sphenoid sinus

53. Variations : Sphenoid Sinus
Septa ending on OpticSepta ending on Carotid

54. Variations : Sphenoid Sinus
Dehiscent Optic NerveDehiscent Int. Carotid.a
22%6%

55. FAQ

56. Axial view:
Nasopharynx
Post. wall of the frontal sinus
Orbital content
Optic nerve
Internal carotid artery

57. Axial section at level of frontal sinus

58. Axial section at level of optic nerve

60. Thank for all

61. Axial section at level maxillary sinus

62. CT in Pathology

63. Pathology is
1.Homogenous/heterogenous
2.Densities (hypodense /isodense /hyperdense)
3.Calcification
4.Bone erosion around opacified area
5.Start on affected side Ant. To Post.
6.Look at opposite site Ant. To Post.
7.Look to the integrity of the vital structures.

64. Acute Sinusitis
Air Fluid level
Mucosal thickening
Complete opacification of the sinus

65. Chronic Sinusitis
Ethmoid sinus is commonly involved
Mucosal thickening
Bone remodeling due to osteitis
Polyposis

66. fungal sinusitis
Complete opacification of multiple sinuses
Sinus expansion & erosion of sinus wall
Focal area of increased attenuation that is
created within a diseased sinus

67. fungal sinusitis
When you suspect the fungal infection you
should ask for soft tissue window

68. Benign polyp
Homogenous, well circumscribed hypodense
/ isodense mass

69. AC Polyp

70. Mucocoele
Hypodense, non-enhancing mass that fills
and expands the sinus cavity

71. benign tumors:
Antrochoanal polyp
Angiofibroma
Inverting papilloma

72. Malignant tumor

73. malignant tumours"
adenocarcinoma