GIẢI PHẪU MŨI XOANG ppt

D, Sagittal CT image of a cadaver head performed approximately 1.5 cm lateral to the nasal septum shows that the sphenoid sinus S is inferior to the posterior ethmoid sinus PE... Corona

GIẢI PHẪU MŨI XOANG

Dr Đinh Văn Thuyết

CH 17

Axial CT scan shows a mucoid density mass filling the left maxillary sinus It

extended through the infundibulum into the left nasal fossa and nasopharynx This patient had an antrochoanal polyp

Phì đại xương xoăn dưới

Phì đại nm cuốn mũi dưới

ĐMCT lấn trong xoang bướm

Uncinate bulla CT image: an air cell within the right uncinate process

(asterisk) The cell contributes to the narrowing of the right infundibulum and

middle meatus.

Cuốn mũi giữa đảo ngược

NỘI DUNG

 Giải phẫu các xoang cạnh mũi

 Các biến đổi giải phẫu thường gặp

GIẢI PHẪU XOANG

KỸ THUẬT:

 CT th êng:

• C¾t ngang (song song x khÈu c¸i): 3mm

• C¾t däc (vu«ng gãc x khÈu c¸i): 3mm

Tư thế AXIAL

T th CORONAL ư ế

Giải phẫu xoang bình thường

 Các hốc mũi:

• Thông ra trước là lỗ mũi

• Phía sau vào vòm họng.

Cuộn mũi – Khe mũi

 Gồm ba cuộn mũi:

 Cuộn mũi trên: Nguồn gốc từ xương sàng

 Cuộn mũi giữa: Nguồn gốc từ xương sàng

 Cuộn mũi dưới: Vị trí độc lập.

 Khe mũi:

 Khe mũi trên

 Khe mũi giữa

 Khe khe mũi dưới

Diagram of a sagittal view of the lateral nasal fossa wall The midline

nasal septum has been removed.

GIẢI PHẪU MŨI XOANG MÔ TẢ

Xoang sàng

Sàng trước

Sàng trước

Sàng trước

Sàng trước

Sàng trước

Sàng trước

Sàng sau

Sàng sau

Sàng sau

Sàng sau

Sàng sau

Sàng sau

Xoang bướm

Liên quan xoang sàng sau và

xoang bướm

Anatomic relationship of the posterior ethmoid and sphenoid sinuses A and B,

Posterior (A) and anterolateral (B) views from three-dimensional CT images of a

‘‘cast’’ of the aerated nasal cavity, nasopharynx, and paranasal sinuses viewed from behind (A) and from the left side (B) Note that the posterior ethmoid sinus (open

arrows) is wider and positioned more superiorly than the sphenoid sinus (S ) The dotted lines denote the position of the sagittal planes displayed in C and D Frontal sinus (F) and maxillary sinus (M) C, Paraseptal CT image of a cadaver head shows that the sphenoid sinus (S ) is the most posterior and superior air space and that it is accessible from the posterior ethmoid sinus (PE) Frontal sinus (F) D, Sagittal CT image of a cadaver head performed approximately 1.5 cm lateral to the nasal septum shows that the sphenoid sinus (S ) is inferior to the posterior ethmoid sinus (PE)

Frontal sinus (F)

Relationship between the posterior ethmoid sinus and the sphenoid sinus Coronal

CT image through the middle sphenoid sinus reveals a horizontal bony membranous

structure (solid arrow) This structure is not a septation; rather, it represents the

separation from the sphenoid sinus inferiorly and the posterior ethmoid sinus

superiorly.Septations (open arrow) are vertically oriented.

Xoang trán

Anatomy of the frontal sinus Coronal CT images of the frontal sinuses from anterior (A) to posterior (D) show the relationship between the frontal sinus

(F) and the middle meatus (dotted line) Note that there is a bony strut (heavy

black arrow in A and B) separating the frontal sinus and the anterior middle

meatus This separation is lost on the more posterior images (C and D)

revealing the position of the frontal recess (white arrow) Note the position of the frontal cell (A) and its relationship to the frontal recess Nasal septum (S ), ethmoid bulla (B), middle turbinate (T), and concha bullosa (C).

Xoang hàm

Anterior ostiomeatal channels Coronal CT images through the anterior ethmoid sinuses show the air passages communicating with the frontal sinus (F), anterior ethmoid sinus, and maxillary sinus (M) The primary ostium (O) of the maxillary sinus communicates with the infundibulum (INF) The infundibulum is bordered medially by the uncinate

process (U) and laterally by the orbit In turn, the infundibulum communicates with the middle meatus (asterisks) through the hiatus semilunaris (most medial white arrows in

A, small black arrow in B).

The frontal recess (white arrowheads) is patent The ethmoid bulla (B) is usually the

largest air cell in the anterior ethmoid sinus Note the vertical attachment of the middle turbinate (2) to the cribriform plate (CP) and its lateral attachment to the lamina

papyracea, the basal lamella (BL) The air space between the basal lamella and the

ethmoid bulla is the sinus lateralis (sl ) Inferior turbinate (1), nasal septum (NS), vomer (V), and perpendicular plate of the ethmoid bone (P).

ANATOMIC VARIATIONS AND

CONGENITAL ABNORMALITIES

Certain anatomic variations are thought to be predisposing factors for the development of sinus disease or operative complications.Thus, it is necessary for the radiologist and surgeon to be cognizant of these variations, especially if the patient is a candidate for

FESS.

 Variations of the Middle Turbinate

 Nasal Septal Deviation

 Uncinate Process Variations

 Infraorbital Ethmoid Cells (Haller’s Cells)

 Ethmoid Bulla Variations

 Extensive Pneumatization of the Sphenoid Sinus

 Medial Deviation or Dehiscence of the Lamina Papyracea

 Cephalocele

 Posterior Nasal Septal Air Cell

Variations of the Middle Turbinate

 Paradoxic Curvature:

Most authors agree that paradoxic middle turbinates can be a contributing factor to sinusitis

Certain authors have, however, found no significant

relationship between paradoxically curved middle turbinates and recurrent sinusitis

 Concha Bullosa

Most often the middle turbinate, occurring bilaterally more frequently

Found it in 8% and 20% of specimens

The radiographic appearance of concha bullosa on coronal

CT scans ranges from 14% to 53%

 Other Variations

Xoang khí cuốn mũi giữa (concha bullosa)

Concha bullosa in two different patients A, Coronal CT image demonstrates a prominent right

concha bullosa (asterisk) with

communication to the frontal recess

(small arrow) Note the obstruction

of

the right middle meatus (curved

arrow) B, Coronal CT image

demonstrates a left-sided concha

bullosa (asterisk) with

communication to the sinus

lateralis (small arrow) Note the

contralateral Haller (infraorbital

ethmoid) cell (H).

Mucocele within a concha bullosa A, B and C show a prominent soft-tissue

mass (asterisk) well circumscribed by a bony perimeter (the bony

framework of the concha bullosa) The inferior turbinate is compressed

against the medial wall of the maxillary sinus (black arrow)

Paradoxic middle turbinate A, Coronal CT image demonstrates bilateral paradoxic middle

turbinates The right side is

highlighted (Solid arrow) B,

Endoscopic view correlates with

the CT findings (arrow).

Coronal CT scans A to D, The free edge of the middle turbinate may also assume some other shapes Note its prominent lateral curvature in this case

(asterisk) It obstructs the nasal passage (fine white arrows) and contributes

to the position of the uncinate process and, therefore, the prominent

narrowing of the infundibulum (open arrow).

Cuốn mũi giữa đảo ngược

Thiểu sản cuốn mũi giữa và mỏm

móc

Cuốn mũi giữa chia đôi

Nasal Septal Deviation

 Usually congenital but may be posttraumatic in

some patients.

 Asymptomatic septal deviation is observed in 20% to 31% of the population.

Nasal septal deviation with spurring Coronal CT image demonstrates that there is deviation of the nasal septum toward the right side, with a right-

sided cartilaginous nasal ‘‘spur’’ (asterisk) Note the ipsilateral concha bullosa (arrow) Both of these anatomic variants contribute to marked

narrowing of the right nasal cavity and ethmoid passages.

Uncinate Process Variations

 Deviation

 Attachment

 Pneumatization

Medially curved uncinate process A and B: a prominent right-sided deviation of

the nasal septum (straight open arrow) Note the medially curved left uncinate process (curved open arrow), which is medially displacing the left middle

turbinate (+) and obstructs the left middle meatus A left-sided Haller (infraorbital

ethmoid) cell is present (small arrow).

Variations in the superior attachment of the uncinate process A: the right uncinate

process (open arrow) attaches to the superior right middle turbinate B: the left uncinate process (solid arrow) attaches to the roof of the ethmoid sinus On the right side, the uncinate (arrowhead) adheres to the medial agger nasi cell and

frontal cell.

Atelectatic uncinate process CT scan: the right uncinate process is apposed

to the inferomedial aspect of the orbit (arrows) The resultant obstruction of the infundibulum is usually the cause of the prominent inflammatory process in the ipsilateral maxillary sinus (small black M) Note that, in this case, as is often seen, this is associated with hypoplasia of the ipsilateral maxillary sinus

compared with its counterpart (large white M).

Thiểu sản xoang hàm và mỏm móc

Uncinate bulla CT image: an air cell within the right uncinate process

(asterisk) The cell contributes to the narrowing of the right infundibulum and

middle meatus.

Xoang khí mỏm móc

Infraorbital Ethmoid Cells (Haller’s Cells)

 These cells were first identified by Haller in 1765

 Most often, infraorbital ethmoid cells arise from

the anterior ethmoid cells and are closely related

to the infundibulum

 Many authors cite infraorbital ethmoid cells as a factor in recurrent maxillary sinusitis

A, Note the left Haller cell (+) with the ethmoid bulla ostia located medially (b), opening into the infundibula (arrow) B, Bilateral Haller (+) Note their close

proximity to the uncinate process and their influence on the infundibula

(smallarrows).

Bào sàng qúa phát và bào Haller

Extensive Pneumatization of the Sphenoid Sinus

CT image: pneumatization of both anterior clinoid processes

(arrows) and their relationship to the optic nerves (o) and internal carotid arteries (C) The presence of anterior clinoid

pneumatization is an important indicator of optic nerve

vulnerability during FESS.

Medial Deviation or Dehiscence of the

Lamina Papyracea

May be either congenital or the result of prior facial trauma

Medial deviation of the left lamina papyracea CT: the outline of the lamina

papyracea in relation to the anterior ostiomeatal channels Medial deviation (open

arrow), when present, should not be confused with an ethmoid bulla Note that

the medially deviated lamina papyracea lies in close proximity to the lateral

attachment of the middle turbinate, the basal lamella (whitearrow)

 Cephaloceles involving the anterior cranial

fossa floor may be congenital, occur

spontaneously, or be the result of previous ethmoid or sphenoid sinus surgery

 Coronal CT scanning is especially well suited

to display the extent of any such areas of

missing bone

CT and MRI: an encephalocele CT: erosion of the roof of the posterior

ethmoid sinus (open arrow and

asterisk) Axial T1-weighted MR image

(B) shows an isolated soft-tissue mass within the posterior ethmoid sinus

(arrow), which on the coronal

T1-weighted MR image (C) is confirmed to

be an encephalocele Gyrus rectus (r) and gyrus orbitales (o) are noted.

Nasal septal air cell A, Coronal CT image demonstrates an expansile mass in

the anterior sphenoid sinus (asterisk) B, Sagittal T1-weighted MR image

displays the hyperintense inflammatory mass (asterisk), which is well

separated from the intracranial compartment This was proven to be a

mucocele within aposterior nasal septal air cell.

Posterior Nasal Septal Air Cell

Dây thị giác lấn trong xương bướm

Relationship of the optic nerves to the sphenoid sinus.Type 3 optic nerves

(black arrows) course through the sphenoid sinus, with more than 50% of the

nerves surrounded by air Note that there is dehiscence of the bone covering

the right optic nerve (curved white arrow).This increases the risk of optic

nerve damage during FESS.

ĐMCT lấn trong xoang bướm

A and B: show that the carotid canals

(small black arrows) penetrate into the sphenoid sinus (S ) An incomplete sphenoid sinus septum (white arrow)

connects to the bony covering of the carotid canal C, Three-dimensional images display the close relationship

between the internal carotid artery and the

sphenoid sinus septation (small black arrows).

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