CT SPN dengan penjelasan secara anatomi.pdf

Ct spn

1. CT SPN

2. Concha Nasalis Media:
interlamellar cell of Grunwald
•The attachment of the middle turbinate in three
planes, i.e., sagittal, coronal, and axial, provides
exceptional stability.
•The anterior most attachment to the cribriform
plate is vertically oriented and is best seen on
coronal images.
•Posteriorly, the middle turbinate is obliquely
oriented, forming the basal lamella, which is
commonly attached to the lamina papyracea.
•More posteriorly, it is horizontally oriented and
attached to the medial wall of the maxillary sinus.
•Normal variations that can cause a narrowing of
the middle meatus are concha bullosa,
interlamellar cell of Grunwald (Fig 1) and
paradoxical curvature of the middle turbinate

3. PROCESSUS UNCINATUS: The uncinate process is a superior extension of the lateral nasal wall and plays an important role, as
an anatomical landmark, in guiding drainage of the frontal recess. Inadvertent manipulation in insertion types 1 or 3 may
provoke lesion in the lamina papyracea, with herniation of the orbital contents and orbital hematoma, whereas inadvertent
manipulation of skull base insertions (tipe 3,4,5 can cause cerebrospinal fluid leak.

4. PROCESSUS UNCINATUS

5. PROCESSUS UNCINATUS

6. PROCESSUS UNCINATUS

7. Ostiomeatal complex

8. Infraorbitalethmoidcells(Hallercells)areethmoid
cellsthatarepneumatizedinferiorlytotheorbitalfloor,
andextendfromtheethmoidallabyrinthtotheinteriorof
themaxillarysinus,whichcancauseobstructionand
predisposition to sinus diseases.
Inadvertentmanipulationcandamagethelaminapapyracea.
Haller cell

9. Bilateral accessory maxillary ostium (AO) with mucosal thickening (MT) on the left
and mucus retention cyst (RC) on the right side, as seen in coronal section
Ostiomeatal complex
An accessory maxillary ostium is seen in 10-25% of the population and is located within the posterior fontanelle of the
maxillary sinus behind the natural ostium. It is important to surgically join both the natural and the accessory ostia to
prevent recurrent chronic sinusitis.

10. Sinus Maksillaris: Dehisense infraorbital foramen kanan kiri
•Theinfraorbitalnerve(abranch
ofthemaxillarydivisionofthe
trigeminalnerve)runsoverthe
roofofthesinusandexits
throughthisforamen.
•Thisnervemaybedehiscent
here,animportantpreoperative
findingfortheavoidanceof
intraoperativenerveinjury

11. Anterior-ethmoidal (Agger) cell
•Theaggernasicellisthemostanteriorethmoidalcell,presentin93%ofthepopulation
•Anteriorwallofthiscellformstheanteriorboundaryofthefrontalrecess,makingitanimportant
surgicallandmark.
•Oncoronalimages,theaggernasicellisidentifiedasanaircellbelowthefrontalbeak,beforethe
antero-superiorattachmentofthemiddleturbinate.
•However,itisbestviewedonparasagittalimages.

12. Kuhn Cell
•Found in 20–30% of patients, frontal ethmoid
cells, also known as Kuhn cells, are closely
related to agger nasi cells and are divided into
four types:

13. Jarak antara dinding superior sinus maksillaris dan roof
sinus ethmoid posterior
Itisimportanttodocumenttheverticaldistancefromthe
superiormarginofthemaxillarysinustotheroofofthe
posteriorethmoidcells,asmeasuredoncoronalCT.
Inadvertentintracranialpenetrationcanbeavoidedifthe
surgeonhaspriorknowledgeofareductioninthis
distance.

14. ONODI CELLS (SPHENOETHMOID CELL)
•The Onodi cell,or
sphenoethmoidalaircell,isa
variantposteriorethmoidaircell
thatextendsposteriorlyalongthe
superiorandlateralaspectofthe
sphenoidsinus.Itisbestevaluated
inthecoronalplane.
•Onodicellisanimportantvariant
toidentify,astheopticnerve
commonlycoursesthroughthe
Onodicell,withathinmarginof
boneseparatingtheopticnerve
fromtheunderlyingaircell.This
greatlyincreasestheriskofoptic
nerveinjuryduringposterior
ethmoidectomy,especiallywhen
surgeonsareunawarethatthey
areinasphenoethmoidalaircell.
•AnOnodicellisbestvisualizedon
coronalsequencesbyfirstlocating
anaircellabovethesphenoid
sinusandidentifyingitscontinuity
withaposteriorethmoidaircell.

15. Sphenoid sinus pneumatization
•Sphenoid sinus pneumatization with respect to the
clivus and sella may be characterized as conchal,
presellar, or sellar and is best evaluated in the sagittal
plane.
•The conchal variant refers to underpneumatization, with
a thick bony margin between the sphenoid sinus
anteriorly and the sella posteriorly.
•The presellar variant refers to pneumatization extending
posteriorly to the anterior margin of the sella.
•The sellar variant is most common and refers to
pneumatization that extends inferior and posterior to
the sella, resulting is a thin posterior bony margin of the
clivus
•The sellar variant is important to identify preoperatively,
since it places the thin posterior clival margin at risk for
inadvertent perforation due to supine positioning of the
patient, with the force of gravity directed posteriorly

16. Excessive pneumatization of the sphenoid sinus
•Excessive pneumatization of the sphenoid sinus
into the skull base and anterior clinoid processes
may result in dehiscence of the bony margins of
the carotid and optic nerve canals, rendering them
susceptible to injury during FESS. This is best
evaluated in both the coronal and axial planes.
•Fortunately, injuries to the carotid artery are rare;
however, when present, they may be catastrophic,
depending on the degree of injury and ability to
control the hemorrhage to obtain hemostasis is
essential.
•Optic nerve dehiscence may occur in the setting of
excessive pneumatization of the sphenoid sinuses
into the anterior clinoids or in the presence of an
Onodi (sphenoethmoidal) cell.

17. KEROS

18. •TheKerosclassificationisusedtodocumentthe
maximumdepthoftheolfactoryfossaand
resultantlengthofthelaterallamella.Kerostype
Iisdefinedaslessthanorequalto3mmin
depth,KerostypeIIisdefinedasadepthof4–7
mm,andKerostypeIIIisdefinedasgreaterthan
7mmindepth.TypeIIismostcommon,followed
bytypeI.TypeIIIistheleastcommonvariantand
portendsthegreatestriskofskullbaseinjury
duringFESS.Asymmetryinthedepthsofthe
olfactoryfossaisalsoimportanttoidentify,as
surgicalplanningwillneedtobetailoredtothe
appropriatedepthoneitherside.With
asymmetry,themoreinferiorlypositionedlateral
lamellaisatgreaterriskofinjuryduringFESS.

19. ARTERI ETHMOID ANTERIOR
Nipple sign

20. TERIMAKASIH