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CT & MR Imaging of the CT & MR Imaging of the Paranasal Sinuses with special Paranasal Sinuses with special
reference to FESSreference to FESS
Dr Himadri Sikhor Das,Dr Himadri Sikhor Das,Dr P.Hatimota,Dr P.Hazarika,Dr C.D.ChoudhuryDr P.Hatimota,Dr P.Hazarika,Dr C.D.Choudhury
MATRIXMATRIX
ContentsContents
CT anatomy of sinonasal cavity for CT anatomy of sinonasal cavity for FESS:FESS:
- Concept of FESS.Concept of FESS.- Ostiomeatal Complex (OMC) & normal Ostiomeatal Complex (OMC) & normal
variantsvariants- Complications of FESS.Complications of FESS.- Imaging findings of variousImaging findings of various
infectious/inflammatory sinonasal infectious/inflammatory sinonasal diseasedisease
Paranasal sinusesParanasal sinuses Functions of the PNS:Functions of the PNS:- Warms & humidifies Warms & humidifies
inspirated air.inspirated air.- Filters small airborne Filters small airborne
particulate matters particulate matters
- Drains secretions from - Drains secretions from paranasal sinuses to paranasal sinuses to the nasal cavity the nasal cavity
- Traps odor-bearing - Traps odor-bearing particles for olfactionparticles for olfaction
HRCT scan protocolHRCT scan protocol
Protocol: Axial Coronal: Protocol
Axial CTAxial CT
Coronal HRCT for OMUCoronal HRCT for OMU
Sagittal Sagittal
Coronal HRCTCoronal HRCT
Normal nasal cycle:Normal nasal cycle: periodic alternate functioningperiodic alternate functioning
of secretory activityof secretory activity
nonfunctioning
functioning
Basic Concept of FESS:Basic Concept of FESS:
Why Why “ Functional”“ Functional” “ “ Maintenance of Maintenance of
the normal pathway the normal pathway for mucociliary for mucociliary clearance by clearance by relieving the ostial relieving the ostial obstruction & obstruction & preserving the preserving the normal mucosa of normal mucosa of the sinonasal the sinonasal cavity”cavity”
Osteomeatal unit/complex Osteomeatal unit/complex (OMU/OMC)(OMU/OMC)
Anterior OMU drains Anterior OMU drains frontal maxillary , frontal maxillary , anterior and middle 1/3anterior and middle 1/3rdrd of ethmoid sinuses. of ethmoid sinuses.
The uncinate process ( UP The uncinate process ( UP ) and lateral wall of nasal ) and lateral wall of nasal cavity forms the ethmoid cavity forms the ethmoid infundibulum ( EI ). infundibulum ( EI ).
The above sinuses drain The above sinuses drain into the EI via various into the EI via various ostia.ostia.
The posterior OMC The posterior OMC located in spheno ethmoid located in spheno ethmoid recess, drains posterior recess, drains posterior 1/31/3rdsrds of ethmoid and of ethmoid and sphenoid sinuses. sphenoid sinuses.
HRCT-Sinonasal anatomyHRCT-Sinonasal anatomy
HRCT-Sinonasal anatomyHRCT-Sinonasal anatomy
Nasal EndoscopyNasal Endoscopy
Anatomical VariantsAnatomical Variants
Anatomical VariantsAnatomical Variants
Anatomical VariantsAnatomical Variants
Look for :Look for :
Concha bullosa with type-II Concha bullosa with type-II OFOF
Surgical therapy for sino-nasal Surgical therapy for sino-nasal diseasesdiseases
Indirect sinus procedure:Indirect sinus procedure: - - septoplastyseptoplasty - - adenoidectomyadenoidectomyDirect sinus procedure:Direct sinus procedure: - - antral lavage & sinus aspirationantral lavage & sinus aspiration - - Nasal antral windowsNasal antral windows - - Middle meatal antrostomyMiddle meatal antrostomyFunctional Sinus surgery:Functional Sinus surgery: - - Endoscopic (FESS)Endoscopic (FESS)
FESS: ComplicationsFESS: Complications Minor local complications:Minor local complications: periorbital emphysema, epistaxis, tooth periorbital emphysema, epistaxis, tooth
pain, post operative nasal synechiae.pain, post operative nasal synechiae. Orbital complications:Orbital complications: orbital emphysema, haematoma, orbital emphysema, haematoma,
abscessabscess injury to NLD/EOM/optic nerveinjury to NLD/EOM/optic nerve CSF leakage:CSF leakage: No trespassing the medial to vertical No trespassing the medial to vertical
lamella of middle turbinatelamella of middle turbinate Intracranial complications:Intracranial complications: Intracranial haematoma, abscess, Intracranial haematoma, abscess,
encephalocelesencephaloceles Injury to intracranial vesselsInjury to intracranial vessels
FESS: ComplicationsFESS: Complications
FESS: ComplicationsFESS: Complications
Sinusitis & Sino nasal Sinusitis & Sino nasal diseasesdiseases
PathophysiologyPathophysiology Most common cause of frontal and Most common cause of frontal and
maxillary sinusitis is anterior ethmoid maxillary sinusitis is anterior ethmoid disease with superimposed rhinitis. disease with superimposed rhinitis. ( viral / bacterial). ( viral / bacterial).
Diseased mucosa of the draining Diseased mucosa of the draining ostia leads to impairment of ostia leads to impairment of secretions and mucociliary clearance.secretions and mucociliary clearance.
Treating anterior ethmoid disease Treating anterior ethmoid disease clears frontal and maxillary sinusitis.clears frontal and maxillary sinusitis.
Sinusitis: Sinusitis: inflammation/infection of 1 or inflammation/infection of 1 or more paranasal sinusesmore paranasal sinuses
ACUTE:ACUTE: symptoms lasting <3 weekssymptoms lasting <3 weeks - Air fluid level- Air fluid level - Mucosal thickening - Mucosal thickening
SUBACUTE:SUBACUTE: symptoms lasting 3 wk to 3 symptoms lasting 3 wk to 3 monthsmonths - Mucosal thickening - Mucosal thickening
CHRONIC : CHRONIC : - - symptoms lasting >3 symptoms lasting >3 monthsmonths
- Ethmoid disease MC.- Ethmoid disease MC. - Mucosal thickening to sinus - Mucosal thickening to sinus opacificationopacification - Bony remodelling- Bony remodelling - Polyposis- Polyposis
““Acute or chronic can not be determined based Acute or chronic can not be determined based on a single examination”on a single examination”
Plain filmPlain film - Caldwell for frontal and ethmoids - Caldwell for frontal and ethmoids
- Water’s for maxillary and sphenoid - Water’s for maxillary and sphenoid
- - lateral and submentovertex for lateral and submentovertex for sphenoidsphenoid
SinusitisSinusitis
Inflammatory sinonasal Inflammatory sinonasal diseasedisease
TYPES:TYPES:
A.A. SIMPLE:SIMPLE:
B.B. ADVANCED:ADVANCED:
-Infundibular pattern-Infundibular pattern
-OMU pattern-OMU pattern
-Spheno-ethmoidal -Spheno-ethmoidal recess patternrecess pattern
-Sinonasal polyposis-Sinonasal polyposis
-Sporadic or -Sporadic or unclassifiable patternunclassifiable pattern
High dense foci in CT & High dense foci in CT & signal void on MRIsignal void on MRI
Fungal sinusitisFungal sinusitis Intrasinus hemorrhageIntrasinus hemorrhage Chronic inspissated mucusChronic inspissated mucus Long standing polypLong standing polyp MucoceleMucocele Sinolith/osteoma/intrasinus toothSinolith/osteoma/intrasinus tooth
Chronic inspissated Chronic inspissated mucusmucus
Normal sino nasal Normal sino nasal secretions:secretions:
- (Water 95% + (Water 95% + macromolecular macromolecular proteins(5%)proteins(5%)
Chronically Chronically obstructed sino-obstructed sino-nasal secretions:nasal secretions:
- - Increased proteinIncreased protein content & content & viscosityviscosity with with reduced free reduced free waterwater
Sinonasal polypoidal lesionsSinonasal polypoidal lesions
PolypsPolyps
AC & SC polypsAC & SC polyps
Antrochoanal polypAntrochoanal polyp
Spheno-choanal PolypSpheno-choanal Polyp
Sinonasal polyposisSinonasal polyposis
Sinusitis: Local Sinusitis: Local complicationscomplications
Mucus retention cyst:Mucus retention cyst:- - Inflammatory Inflammatory
obstruction of obstruction of seromucinous glandsseromucinous glands
Polyp:-Polyp:- - Mucosal folding with - Mucosal folding with
submucosal fluid submucosal fluid collectioncollection
-Allergy/atopy/Vasomotor -Allergy/atopy/Vasomotor impairment/DM/Cystic impairment/DM/Cystic fibrosis/aspirin /chronic fibrosis/aspirin /chronic nickel exposure may nickel exposure may cause bone erosioncause bone erosion..
Sinusitis: Local Sinusitis: Local complicationscomplications
Mucocele:Mucocele:
- Airless expanded sinuses surrounded - Airless expanded sinuses surrounded by mucous secreting respiratory by mucous secreting respiratory epithelium, resulting from ostial epithelium, resulting from ostial obstruction.obstruction.
- Frontal(60-65%),Ethmoid(20-- Frontal(60-65%),Ethmoid(20-25%),Maxillary(10%),sphenoid (1-2%)25%),Maxillary(10%),sphenoid (1-2%)
- Bony remodeling by pressure erosion.Bony remodeling by pressure erosion.- Varied density/SI on CT / MRVaried density/SI on CT / MR
MucoceleMucocele
Sinusitis: other Sinusitis: other complicationscomplications
Orbital complications:Orbital complications: E>S>F>ME>S>F>M - Preseptal or orbital cellulitis /subperiosteal - Preseptal or orbital cellulitis /subperiosteal
abscess or phlehmon/ thrombophlebitisabscess or phlehmon/ thrombophlebitis Intracranial complications:Intracranial complications: F>S>E>MF>S>E>M - Meningitis/epi or subdural - Meningitis/epi or subdural
abscess/cerebritisabscess/cerebritis - Venous sinus thrombosis/brain abscess- Venous sinus thrombosis/brain abscess Subgaleal abscess/Osteomyelitis / Pott’s Subgaleal abscess/Osteomyelitis / Pott’s
puffy tumorpuffy tumor /Osteo- thrombophlebitis due to frontal /Osteo- thrombophlebitis due to frontal
sinusitis.sinusitis.
Preseptal& orbital Preseptal& orbital cellulitiscellulitis
Fungal Sinusitis: Non Fungal Sinusitis: Non invasive formsinvasive forms
Mycetoma & Allergic Fungal SinusitisMycetoma & Allergic Fungal Sinusitis Maxillary>Ethmoid > Sphenoid>FrontalMaxillary>Ethmoid > Sphenoid>Frontal Imaging Findings:Imaging Findings: - Non specific mucosal inflammation- Non specific mucosal inflammation - Mixed sclerosis/erosion of bony walls- Mixed sclerosis/erosion of bony walls - High dense foci on CT- High dense foci on CT - Signal void on MR- Signal void on MR - Air fluid levels-- Air fluid levels-veryvery uncommonuncommon
Fungal Sinusitis: Fungal Sinusitis: Invasive formsInvasive forms
* * Immunocompromised hostsImmunocompromised hosts
- DM- DM
- Impaired neutrophil function- Impaired neutrophil function
* Rhino-cerebral mucormycosis * Rhino-cerebral mucormycosis /aspergillosis/aspergillosis
* Vascular invasion: * Vascular invasion:
- - Thrombosis & tissue necrosisThrombosis & tissue necrosis
Allergic Fungal Sinusitis
Thank You !!Thank You !!