Slide 1: Anatomy
Nose and paranasal sinuses
Imaging …AAMIR YOUSUF
PG ENT OBJECTIVES : OBJECTIVES EMBRYOLOGY
IMAGING EMBRYOLOGY IN BRIEF : EMBRYOLOGY IN BRIEF Slide 4: The development of NOSE starts at about 4th week of gestational age.
Three prominences appear around stomatodaeum(future mouth)….
FRONTONASAL PROCESS…mesoderm covering the developing forebrain proliferates,& forms downward projection that overlaps upper part of stomatodaeum.
MANDIBULAR ARCHES(Rt & Lt)….arising from 1st pharyngeal arch.
Mandibular arch divides into maxillary and mandibular process. Slide 5: 4th-5th week Slide 6: The Nose is derived from frontonasal process in 4th fetal week.
5th fetal week ectodermal plaques develop on lateral aspect of FNP & become paired NASAL PLACODES,early precursors of nares.
End of 5th week these convex placodes develop into concave nasal grooves, the medial & lateral sides of placodes protrudes forwards to become Medial & Lateral Nasal Process.
6th fetal week nasal grooves become blind-ending Nasal Pits with forward &downward growth of maxillary process.
7th fetal week nasal pit deepens forms Nasal Sac which forms future nasal cavity. Slide 7: 6th -7th week Slide 9: 7th-8th fetal week lateral wall of nasal capsule begins to form series of ridges of mesenchymal tissue.
1st ridge, the maxilloturbinal(7th week)…INFERIOR TURBINATE.
5 to 6 ridges appear superior to 1st (8th week)…through regression & fusion, these ridges 3 to 4 ethmoturbinals.
1st ethmoturbinal (nasoturbinal)…aggar nasi(ascending portion)…..uncinate process(descending portion).
2nd ethmoturbinal ….MIDDLE TURBINATE.
3rd forms …SUPERIOR TURBINATE, rest regress or join supreme turbinate. Slide 10: 8th week Slide 11: SUMMARY OF EMRYONIC PRECURSORS Slide 12: PARANASAL SINUSES
Appear as outgrowths from nasal cavity.
Frontal ,maxillary,& ethmoidal sinuses arise from evaginations of lateral nasal wall.
Sphenoid sinus arises from a posterior evagination of nasal capsule.
The sinuses begin to develop in 3rd fetal month & only ethmoidal & maxillary sinus, are present at birth.
Maxillary sinus begins as an outpounching of lateral nasal wall at 10th fetal week.
Ethmoidal sinus begins at 3rd month of fetal life. Slide 14: Frontal sinus develops during 4th fetal month as an outpounching medial the most superior aspect of uncinate process.
Sphenoid sinus are unique in that they arise from within the nasal capsule of embryonic nose.
undeveloped until 3 yrs
by 7 yrs pneumatization reaches sella tursica
by age 9 to 12 it is generally complete Gross anatomy : Gross anatomy EXTERNAL NOSE............ Slide 16: Anatomical landmarks.
Nasion : midline point at which nasal bones join the frontal bone.
Rhinion : inferior point of the midline suture between nasal bones where they meet the upper lateral cartilages.
Dorsum of nose: ridge formed by the union of lateral surfaces of nose in the midline.
Bridge of nose: anterior surface of nose formed by the nasal bones.
Columella: midline nasal soft tissue anterior to septum separating the two nares.
Alae nasi: wings of nose,(rounded eminences)at the inferior ends of the lateral nasal surfaces of nose. Nasal bony framework : Nasal bony framework :Is pyramidal in shape.. Slide 18: Nasal bones(two) articulate with the nasal process of frontal bone superiorly & with the ascending processes of maxilla laterally.
These bones are thicker superiorly than inferiorly. Slide 19: Their medial articular surfaces are wider & extend poster inferiorly into nasal cavity to form crest. This crest forms part of septum & articulates with :
spine of nasal process of frontal bone
perpendicular plate of ethmoid
septal cartilage of nose Slide 20: The piriform aperture is bounded by these bones and the alveolar processes of maxilla. The alveolar processes merge in midline to form the anterior nasal spine to which cartilaginous septum is attached. Nasal cartilages : Nasal cartilages Upper lateral cartilage
Lower lateral cartilage
Upper lateral (triangular)
∆ in shape
boundaries Slide 22: Lower lateral cartilage
(greater alar or lobular cartilage)
forms the shape of nasal tip &
maintains patency of nostrils.
Lateral crus Nasal septum : Nasal septum 7 components.
post.sup: per. plate of ethmoid.
medial crus of greater alar cart.
crest of maxillary bone
crest of palatine bone Slide 25: Perpendicular plate of ethmoid…
forms upper 1/3 or more of the nasal septum
Unites sup. with cribrifom plate of ethmoid.
post…crest of sphenoid
ant.inf…septal cartilage Slide 26: Vomer…
Post inf portion of nasal septum
Articulates with… Slide 27: Septal (or quadrangular) cartilage
Is continuous with upper lateral cartilage towards bridge of nose.
Its inferior portion, the columella,is supported by medial crura of alar cart.
This Columella is connected by membrane to lower border of septal cartilage(mobile or membranous septum).
Is small bar of cartilage on either side of inf border of septal cartilage. Slide 28: Nerve supply of septum
Anterior ethmoidal nerve.(ant sup)
Ant sup alveolar(ant inf)
Nasal branch of ant palatine nerve Slide 29: Blood supply of septum
Ant & post ethmoidal artery
Superior labial artery
branch(coronary art) Slide 30: Muscles of the Nose
Are arranged in two overlapping layers.
All innervated by facial nerve.
depressor septi Slide 31: Procerus: (Pyramidalis nasi)
Is continuation of frontal
muscle onto the nose
Is attached to nasal bones
& upper lat.cartilage
or elevates nose
(Levator labii superioris)
upper lip Slide 32: Depressor septi:
Inserted into septum
& back part of ala
Arise from incisive
fossa of maxilla
Action… draws ala of
constricts nares Slide 33: The Nasalis (Compressor naris)
alar part Blood supply of external nose : Blood supply of external nose origin.. lateral nasal branch
(upper part of facial or
dorsal nasal artery
external nasal artery Nerve supply of external nose : Nerve supply of external nose Supratrochlear & infratrochlear branches of the ophthalmic nerve supply the skin of root,bridge,upper portion of side of nose
Infraorbital branch of the
maxillary nerve supply
the skin on side of
nearly the lower half
Ext.nasal branch of
Ant. Ethmoidal nerve
skin over dorsum to
tip Lymphatic drainage : Lymphatic drainage Main Submandibular/Submental nodes
Bilateral drainage & flow to the parotid nodes Nasal cavity : Nasal cavity Paired cavities separated by nasal septum
Ant .nares or nostrils are oval shaped
Post nares or choanae is oval shaped nasopharyngeal opening of the cavity.
Walls of nasal cavity:
Lateral …cartilaginous,membranous,bony structure.
Floor…ant 3/4th palatal process of maxillary bone.
post 1/4th horizontal process of the palatine bone Slide 38: Roof…ant. Nasal bone, nasal spine of frontal bone, floor of frontal sinus
midportion cribrifoms plate of ethmoid
post..ant wall of sphenoid sinus and bone Subdivision of nasal cavity : Subdivision of nasal cavity Olfactory region
olfactory region:-comprises superior nasal concha & corresponding opp.septum
less vascular (yellow in colour)
nerve cell bodies that give rise to olfactory nerve fiber(nonmylinated)
Serous glands( of bowman) Slide 40: Respiratory region
Remainder of nasal cavity
Covered by mucous membrane(exp.vestibule)
Highly vascular with mucous & serous glands
Covered by pseudo stratified columnar ciliated epithelium Lateral nasal wall : Lateral nasal wall Formed by 3 or 4 conchae(or turbinates)
Named from below inferior,middle,superior,supreme conchae.
Meatus refers to air spaces located beneath conchae
Remaining nasal cavity posterior to turbinates is nasopharyngeal meatus.
Separate bone covered by thick mucous membrane
Nasolacrimal opening in anterior portion of lateral wall of inferior meatus
Slit like opening is protected by fold of mucous membrane, the plica lacrimalis or valve of Hasner Slide 44: Middle turbinate/meatus
Portion of ethmoid bone
Consists of two parts
Lateral lamina/lamina basilaris
Medial lamina/lamina ta
Post part of middle turbinate
Ant ethmoidal roof to a small
crest of Palatine bone. Slide 45: Medial lamina :
ant part of middle turbinate
Ascends upwards lining ethmoid air cells
Attached to roof of ethmoid at junction of fovea with cribrifom.
Most superior portion of middle meatus is inferior to genu known as frontal recess..Ostia of frontal sinus and some ant ethmoidal cells are located here.
Rest of middle meatus posteroinferiorly contains
semilunar hiatus Slide 46: Uncinate process:
Crescent shaped bone curved downward/backwards
Variation of attachment
Aerated middle turbinate/unilateral or bilateral
May obstruct middle meatus osteomeatal complex(sinusitis)
May get infected form mucocele Slide 47: Paradoxical middle turbinate:
Greater curvature of middle turbinate is concave to middle meatus
Double middle turbinate:
Anteriorly bent UP may come in contact with middle turbinate
Narrows middle meatus & appear as additional turbinate Slide 48: Superior turbinate/meatus
Is appx. ½ length of middle turbinate
Starts about midde of lower turbinate & becomes continous with tham
Sphenoethmoidal recess lies between superior & supreme turbinate
Unilaterally or bilaterally in 60% of individuals
Ostia of pos. ethmoidal cells open into supreme meatus(75%) Paranasal sinuses : Paranasal sinuses Paranasal sinuses are air filled spaces in skull bones lined by mucosa and drain into nasal cavity. Frontal sinus : Frontal sinus Seen in frontal bone
Two sinuses are rarely symmetrical
May have septa which partially
subdivide the cavity & interfere with
drainage. Slide 51: Bent and Kuhn classification of frontal cells.
Type1…single frontal recess cell above the agger nasi cell, but below the frontal sinus
Type11…tier of more than one cell in frontal recess above the agger nasi cell, but below the frontal sinus
Type111…large single cell pneumatizing cephaloid into frontal sinus
Type1V…single isolated cell within the frontal sinus Slide 52: Opening of the frontal sinus
Drainage into frontal recess anterior to the infundibulum(55%)
Drainage above but not into the infundibulum(30%)
Drainage into infundibulum(15%)
Drainage above the bulla(1%) Slide 53: Blood supply of frontal sinus
Small vein that unites the Supraorbital and Superior ophthalmic veins.
Supraorbital nerve(ophthalmic nerve)
Supratrochlear nerve(ophthalmic nerve)
Submandibular nodes Ethmoidal sinuses : Ethmoidal sinuses Ethmoid means sieve like
Ethmoid is trapezoid box
wide posteriorly(4-5cm AP
2-3cm high width 0.5cm ant/1.5cm p)
Multiple air containing cells situated
in ethmoidal labyrinth(3-18)
Boundaries of ethmoidal sinus Classification of ant ethmoidal cells : Classification of ant ethmoidal cells Anterior group-(drains –middle meatus)
Middle group(drains-middle meatus)
Posterior group(drains-superior meatus) Slide 56: Bagatella et al classification of ant. group of cells
pre infundibular group(0-1)agger nasi cells
Lateral infundibular group(0-2)
Post infundibular group(0-2)
Posterior ethmoidal cells
Onadi cells… posterior ethmoidal cells seen just in front of sphenoid
Haller cell..ant ethmoidal cells seen anteriorly & below the orbit. Blood supply of ethmoid sinus : Blood supply of ethmoid sinus Anterior ethmoidal artery(ophthalmic artery)
Post. Ethmoidal artery
Sphenoidal artery(maxillary artery)
Ant. Ethmoidal vein
Post. Ethmoidal vein Nerve supply : Nerve supply Ant ethmoidal nerve
Post etmoidal nerve
Maxillary branch of trigeminal nerve
ant.& middle ethmoidal cells-submandibular group
Post ethmoidal –retropharyngeal nodes Sphenoidal sinus : Sphenoidal sinus Sphenoid means wedged(frotal,temporal,occipital)
Right & left are rarely symmetrical in shape
Pneumatization may extend
into body of sphenoid bone
basilar portion of occipital bone
nasal septum/perpendicular plate of ethmoid
Dimensions … (L..4-44mm)( w..25-34mm)(h.. 5-33mm)
volume (7.5ml) Slide 60: Boundries
Lat…ICA/optic nerve/venous cavernosis
Post…brain stem/basilar artery
Floor…vidian nerve Types on basis of pneumatisation : Types on basis of pneumatisation conchal…(3%)
Presellar(11%) Slide 62: Postsellar(86%) Blood supply : Blood supply Posterior ethmoidal artery(roof of sinus)
Sphenopalatine artery(floor of sinus)
Trigeminal (1/11 div)
Retropharyngeal nodes Maxillary sinus : Maxillary sinus Antrum of Highmore
Largest pns/ pyramidal cavity in maxillary bone
volume(15ml) Slide 65: Boundries
Ant..surface of maxilla
Med…lat.wall of nasal cavity
Sup…floor of orbital cavity
Inferior…alveolar & palatine
process of maxilla Maxillary Ostia : Maxillary Ostia 3-4mm in diameter
Post part of medial wall
Drains into middle meatus through ethmoidal infundibulum Slide 67: Accessory ostium:
when present seen post to natural ostia
Almost always circular
Easily seen during endoscope
Myerson1932-31% Blood supply : Blood supply Facial artery
Greater palatine artery
Greater palatine nerve
Post lateral nasal nerves
Superior alveolar (infraorbital nerve) Microscopic anatomy : Microscopic anatomy Histological basis nasal cavity is divided into three:
vestibular region: lined by keratinized stratified sq. epithelium,hair,sebaceous glands. Slide 70: Respiratory region Slide 71: Olfactory region IMAGING OF NOSE & PNS : IMAGING OF NOSE & PNS Plain sinus radiography
Magnetic resonance imaging Slide 73: Radiographic positions to study the paranasal sinuses are standardised around three positions:
1. Two anatomical - namely coronal and sagittal
2. One radiographic - termed as radiographic base line..
The various radiographic positions used to study paranasal sinuses are:
1. Occipito-mental view (Water's view)
2. Occipital-frontal view (Caldwell view)
3. Submento-vertical position (Hirtz position/jug handle)
4. Lateral view
5. Oblique view 39 Degrees oblique (Rhese position) Slide 74: sinus
itomental view FRONTAL SINUS ORBIT ETHMOID SINUS NASAL
SEPTUM MAXILLARY SINUS Infra orbital
margin Slide 75: Sinus Caldwell
view FRONTAL SINUS SPHENOID BONE MAXILLARY
TURBINATE MANDIBLE HARD PALATE MASTOID
AIR CELLS ORBIT Slide 76: Lateral skull FRONTAL
SINUS MASTOID AIR CELLS ANTERIOR CLINOID POSTERIOR CLINOID MAXILLARY
SINUS SPHENOID SINUS FLOOR OF CRANIAL FOSSA ETHMOID SINUS SELLA TURCICA LAMBDOID SUTURE HARD PALATE CORONAL SUTURE Slide 77: Submentovertical ETHMOID
SINUS MAXILLARY SINUS LAT. PTYERGOID PLATE EXT. AUDITORY CANAL MASTOID AIR CELLS Slide 78: CT nose /pns/coronal Slide 79: ct sinus axial view Slide 80: Ct scan
axial view Slide 81: ct scan sinus
axial view MAXILLARY SINUS Slide 82: coronal cuts
sinus INFERIOR TURBINATE ETHMOID SINUS Slide 83: Coronal view
Of sinus Slide 84: coronal cut
CT sinus SPHENOID SINUS Slide 85: MRI nose/pns Slide 87: ..