Anatomical variations in sinonasal region (ct scan overview)

ANATOMICAL VARIATIONS
IN SINONASAL REGION (CT
SCAN DEMOSTRATION)
Prof. Dr. Bikash Lal Shrestha
Department of ENT-HNS
Dhulikhel Hospital
Kathmandu University Hospital
Nepal
7/19/2020 Prof.Dr. Bikash Lal Shrestha

• Anatomical variations are common in
the sinonasal region - BUT no
evidence that anatomical variants
result in rhinosinusitis.
• So, it is a matter of debate???
• Lloyd GA. CT of the paranasal sinuses: study of a control series in relation to endoscopic sinus surgery. J Laryngol
Otol. 1990;104(6):477-81.
• Zinreich SJ, Kennedy DW, Rosenbaum AE, Gayler BW, Kumar AJ, Stammberger H. Paranasal sinuses: CT imaging
requirements for endoscopic surgery. Radiology. 1987;163(3):769-75.

CONCHA BULLOSA
Concha bullosa on right
side
Concha bullosa on left side
Concha bullosa on right side

• Aeration within the vertical part of
the middle turbinate (or rarely
superior turbinate),usually bilateral
• When unilateral, often associated
with deviation of the nasal septum
(DNS) towards the contralateral side.
• Lloyd GA. CT of the paranasal sinuses: study of a control series in relation to endoscopic sinus surgery. J Laryngol
Otol. 1990;104(6):477-81.
• Zinreich SJ, Kennedy DW, Rosenbaum AE, Gayler BW, Kumar AJ, Stammberger H. Paranasal sinuses: CT imaging
requirements for endoscopic surgery. Radiology. 1987;163(3):769-75.
• Stallman JS, Lobo JN, Som PM. The incidence of concha bullosa and its relationship to nasal septal deviation and
paranasal sinus disease. AJNR Am J Neuroradiol. 2004;25(9):1613-8.

INTERLAMELLAR CELL
(LAMELLAR BULLA)
• Aeration of the vertical lamella of the middle
turbinate from the superior meatus.
• Stammberger HR, Kennedy DW. Paranasal sinuses:anatomic terminology and nomenclature. Ann Otol Rhinol Laryngol Suppl.995;167:7-
16.
Right
interlamellar
cell

INFRAORBITAL CELL (HALLER
CELL)
• Any ethmoidal cell that pneumatises
inferior to the orbital floor and lateral to a
line parallel with the lamina papyracea.
• It may narrow the adjacent maxillary sinus
ostium or infundibulum.
• Maroldi R, Nicolai P. Imaging in treatment planning for sinonasal diseases. Berlin, Heidelberg, New York: Springer; 2005.
• Lloyd GA. CT of the paranasal sinuses: study of a control series in relation to endoscopic sinus surgery. J Laryngol Otol. 1990;104(6):477-
81.
• Zinreich SJ, Kennedy DW, Rosenbaum AE, Gayler BW, Kumar AJ, Stammberger H. Paranasal sinuses: CT imaging requirements for
endoscopic surgery. Radiology. 1987;163(3):769-75.

Left haller cell

SPHENOETHMOIDAL CELL OR
ONODI CELL
• The posterior ethmoidal cell, develops lateral
and/ or superiorly to the sphenoid sinus.
• The sphenoid sinus is then more medial and/or
inferior than usual, and the optic nerve (and
sometimes the internal carotid artery) may lie
within the sphenoethmoidal cell.
• Stammberger HR, Kennedy DW. Paranasal sinuses:anatomic terminology and nomenclature.Ann Otol Rhinol Laryngol
Suppl.1995;167:7-16.
• Stammberger H, Lund V. Anatomy of the nose and paranasal sinuses. In: Gleeson M, Browning GG, Burton MJ, al e, editors.
Scott-
Brown’s Otorhinolaryngology, Head and Neck Surgery. 2. 7th ed. London: Hodder Arnold; 2008. p. 1315-43.
• Wormald P-J. Endoscopic sinus surgery: anatomy, three-dimensional reconstruction and surgical technique. 3rd ed. New
York:Thieme; 2012.

(Onodi cell)
(Onodi cell)
• Surgical importance: This cell causes the optic
nerve and internal carotid artery at risk.

Onodi cell
Onodi cells

Everted (Bent) Uncinate Process
• Curves medially towards the middle
turbinate.
Everted Uncinate process
right side
Middle
turbinate
Nasal septum

Left Everted Uncinate process
Surgical importance:
May be mistaken for
a ‘double’ middle
turbinate.
Kaufmann E. Uber eine typische Form von Schleimhautgeschwulst
(“lateralen Schleimhautwulst”) an der äusseren Nasenwand.
Monatsschr Ohrenheilkd. 1890:1-8.

Aerated (Pneumatized) Uncinate
Process
• Uncinate process contains an air-space
(rare variant)
Aerated Uncinate process bilateral
Nasolacrimal duct

Paradoxical middle turbinate
• Convex laterally, rather than the normal
outward concavity.
Paradoxical
middle turbinate

Right paradoxical middle turbinate
Surgical
importance:
It can obstruct
the middle meatus.

Maxillary sinus hypoplasia or
Aplasia
• 10% prevalence rate has been described.
• Can occur in the absence of disease or
surgery.
• This is often accompanied by hypoplasia of
the uncinate process.
• Kuntzler S, Jankowski R. Arrested pneumatisation: a possible marker of paranasal sinus development. Eur Ann ORL.

Hypoplastic right maxillary sinus Hypoplastic right Uncinate process
Surgical note:
When a hypoplastic maxillary sinus occurs, the risk of
inadvertent penetration of the orbit is increased.
Meyers RM, Valvassori G. Interpretation of anatomic variations of computed tomography scans of the sinuses: a surgeon’s
perspective. Laryngoscope. 1998;108(3):422-5.

Hypoplastic & Aplastic Sinuses
• The frontal sinus has greatest variation in
pneumatisation, being aplastic (absent) in 12-
52% depending on ethnicity (12% in European
races, 52% in Inuit people).
• The aplasia may be unilateral or bilateral.
• Turner A, Porter W. The skiagraphy of the accessory nasal sinuses: Edinburgh & London; 1912.

Right frontal sinus hypoplasia
Left frontal sinus aplasia
Surgical
importance:
This is often seen
in patients with
cystic fibrosis and
primary ciliary
dyskinesia.

Pneumosinus Dilatans
• It is progressive air-containing expansion of a sinus
cavity.
• Commoner in men and may be idiopathic or may be
associated with meningioma, fibro-osseous disease,
arachnoid cysts and cerebral hemiatrophy.

Pneumosinus dilatans of right maxillary sinus
Clinical
importance:
Extensive
pneumatisation can
result in cosmetic
deformity and orbital
damage (proptosis,
diplopia, reduced
vision).
• Lombardi G, Passerini A, Cecchini A.Pneumosinus dilatans. Acta radiologica: diagnosis. 1968;7(6):535-42.
• Papavasiliou A, Sawyer R, Lund V. Effects of meningiomas on the facial skeleton. Arch Otolaryngol. 1982;108(4):255-7.
• Vlckova I, White PS. Rapidly expanding maxillary pneumosinus dilatans. Rhinology. 2007;45(1):93-5.
• Jankowski R, Kuntzler S, Boulanger N, Morel O, Tisserant J, Benterkia N, et al. Is pneumosinus dilatans an osteogenic disease that mimics the
formation of a paranasal sinus? Surg Radiol Anat. 2013.
• Doucette-Preville S, Tamm A, Khetani J, Wright E, Emery D. Maxillary air cyst. J Radiol Case Rep. 2013;7(12):10-5.
• Abdullah A Alatar, Yazeed A AlSuliman, Maha S Alrajhi, and Fahad S Alfawwaz. Maxillary Pneumosinus Dilatans Presenting With Proptosis: A Case
Report and Review of the Literature. Clin Med Insights Ear Nose Throat. 2019; 12: 1179550618825149.

Pneumocoele
• It has sinus walls with either generalized or focal
thinning with total or partial loss of its integrity.
Pneumocoele of right frontal sinus
• Koifman Ana Célia Baptista, Ferraz Lívio de Oliveira, Blanco Bernardo
Teixeira, Prota Filho Luiz Eugênio Bustamante. Frontal sinus pneumocele:
case report and literature review . Radiol Bras [Internet]. 2013 Aug
[cited 2020 July 16] ; 46( 4 ): 259-260. Available from:
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-
39842013000400259&lng=en. https://doi.org/10.1590/S0100-
39842013000400015

REFERENCES
• Contents are taken mainly from:
Supplement 24: European Position Paper on the Anatomical Terminology of
the Internal Nose and Paranasal Sinuses.

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Anatomical variations in sinonasal region (ct scan overview)

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