Radiology of Nasal Cavity and
Paranasal Sinuses
Radiology
• XRAY
• CT
• MRI
Normal Anatomy
Drainage system
Lamella:
1) uncinate
2) ethmoidal bulla
3) basal lamella
4) superior turb
lamella
Uncinate attachment variations
Agger Nasi
Frontal sinus outflow tract
• May be narrowed by
agger anteriorly or bulla
posteriorly
• Frontal cells (Type 1-4)
• Frontal recess
– Lateral: lamina papyracea
– Medial: middle turbinate
– Anterior: posterior wall of
agger nasi
– Posterior: ethmoid bulla
Basal lamella
B
L
U
Keros Classification
Sphenoid sinus
Haller cells
Other anatomic variations
• Concha bullosa
• Septal deviations
• Paradoxic middle turbinate
– convex curvature on the lateral, rather than medial side of the
turbinate
• Dehiscent lamina
• Aerated crista galli
• Optic nerve/carotid artery
MRI
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Helpful for evaluation of regional and intracranial complications
Detection and staging of neoplastic processes
Improved display between intraorbital and extraorbital compartments
Helpful for diagnosing fungal concretions which show low or no signal on
T2
• Helps for evaluation of mucoceles and cephaloceles
• Appearance varies with changing concentrations of proteins and free
water protons
– T2  more “watery”, higher signal
– T1  more protein, higher signal
• However, once protein content reaches too high signal decreases
Epistaxis
Epistaxis
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Most common otolaryngologic emergency
Majority idiopathic
60% of population in their lifetime
Maxillary sinus ostium serves as dividing line
between “anterior” and “posterior bleeds”
Vascular anatomy
Endoscopic SPA ligation
• Epistaxis controlled in 98%
• Locate SPA at level of crista ethmoidalis
• Key in surgery is to ligate all branches which
can vary
Embolization
• Risk of complications: CVA, hemiplegia,
ophthalmoplegia, facial nerve palsy, seizures,
soft tissue necrosis
• Effective only for ECA supply very dangerous
for ICA supply due to high risk of blindness
• Success rate 71-95%
• Complication rate 27%
Anterior ethmoid artery bleeding
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Associated with nasoethmoid fractures
Bleeding rarely subsides with conservative measures
Variable position
– Always seen between second and third lamellae
– Most common site in the suprabullar recess (85%)