Skull I (PNS)

Question 1

What is the four pairs of sinuses

Answer 1

Maxillary
Frotnal
Ethmoidal
And sphenoidal sinuses

Question 2

Ostiomeatal complex

Answer 2

Common channel that links the frontal, anterior and middle ethmoidal, and the maxillary sinuses to the middle meatus that allows air flow and mucocilliary drainage

Question 3

The posterior ethmoidal sinus is emptying to:

Answer 3

Superior meatus

Question 4

Sphenoidal sinus opens to:

Answer 4

Sphenoethmoidal recess

Question 5

Imaging modalities of sinuses

Answer 5

Plain radiography
CT (Gold standard)
MRI (primary investigation)

Question 6

Plain radiography in sinus can:

Answer 6

• Evaluate normal sinuses (tranradiant or translucent bc air)
Show mucosal thickening, air fluid level, bone destruction and fracture.

Question 7

Plain radiography veiws for sinuses:

Answer 7

• Water’s view (occipitomental view) or (nose chin position)
• Lateral view

Question 8

Water’s view is best for

Answer 8

Maxillary sinuses

And can be taken with open mouth to visualize sphenoid sinus

Question 9

Lateral view can visualize:

Answer 9

• Anterior and posterior extent of sphenoid, forntal, and maxillary sinuses.
• Ethmoidal sinuses
• sella turcica

Question 10

Muscoal thickening can be recognized by

Answer 10

Noting the soft tissue interface b/w the air and bony wall

Question 11

Mucosal thickening can be …. or …. (shape)

Answer 11

Smooth in outline
Or polypoid

Question 12

Cuases of mucosal thickening

Answer 12

Allergy
Infection

Question 13

Causes of opaque sinus

Answer 13

Infection
Allergy
Mucocele
Antrochoanal polyp (maxilla…sin)
Truama with hge
Carcinoma of sinus or nasal cavity

Question 14

Sinusitis can occur in any sinuses but most frequently:

Answer 14

Maxillary > ethmoidal > frontal > sphenoidal sinus.

Question 15

Types of sinusitis

Answer 15

Infectiuous (acute, sub.., chronic)
Non-inf(allergic)
Dental infection and sinusitis (20 maxill)

Question 16

Radiographic features of acute sinusitis

Answer 16

Opacified sinus (partial or complete)
Mucosal thickening
Air-fluid levels (diagnostic for acute)

Question 17

Radiographic features of chronic sinusitis

Answer 17

Mucosal thickening
Hyperostosis of bone

Question 18

Talk about Role of CT and MRI in acute sinusitis

Answer 18

It is usually diagnosed and treated clinically, but CT is recommended for symptoms persist.

Both CT and MRI can elegantly demonstrate mucosal thickening and fluid levels as well as displaying the bony walls of the sinuses.

Just for mcq knowledge

Question 19

Radiographic features of fungal sinusitis

Answer 19

Usually with hx of : DM, steroid, and Ab, (immune compromised)

• Bony destruction and rapid extension into adjacent anatomical spaces
• indistinguishable from tumor (req biopsy)
• main role kf CT/MRI is to determine the extent of the disease
• Aspergillosis may appear hyperdense on CT.

Question 20

Sinus Mucocele becomes symptomatic when :

Answer 20

When it extends into surrounding tissue planes secondary to remodeling of the surrounding bone erosion

useless information

Question 21

Most common sinus involvement of mucocele

Answer 21

Frontal (67%) > ethmoidal (20%) > maxillary (10%) > sphenoidal (3%)

Question 22

What is sinus Mucocele

Answer 22

A largely clinically silent mucus-containing expansile lesion of the paranasal sinus with 2ry obstruction of the main ostium of affected sinus.

Lined by cilliated columnar respiratory epithelium.

Question 23

Radiolographic features of sinus mucocele

Answer 23

Diffuse opacification
Remodeling of the bony walls with cortical erosion

High T1 and T2 (on flair) signal
Abnromal contrast enhancement

Question 24

What is sino-nasal polyposis

Answer 24

It is the presence of multiple begin polyps in the nasal cavity and paranasal sinuses

Question 25

Radiographic features of sino-nasal polyposis

Answer 25

• Opacification of PNS
• Thinning of septa
• fluid density lesion
• high T2 signal
• peripheral enhancement on T1+C
• secretion of higher density
•No disruption of adjacent structures

Other signs of chronic sinusitis

Question 26

Signs of antro-choanal polyp

Answer 26

Unilateral opacification of the maxillary antrum and the frontal and anterior ethmoidal sinuses dt obstruction of their drainage pathways

Question 27

Most common type of PNS tumor and most common location

Answer 27

Squamous cell carcinoma (90%)
Maxillary (80%)

Question 28

Both CT and MRI imp in PNS tumor

Answer 28

CT is superior at visualing bone destruction
MRI is preferred for demostrating tumor invasion by showing the extent of any soft tissue mass beyond the sinus cavity.

Question 29

In all opaque sinus, Particularly the antra, special attention should be paid to the bony margins on CT. Why?

Answer 29

Because if these are destroyed; a dx of carcinoma needs exclusion

Question 30

Radiographic features of PNS tumor

Answer 30

• Soft tissue mass with patchy (heterogeneous)postcontrast enhancement
• bony eall destruction
• Aggressive regional spread (invasion)
• low T1 signal
• intermediate (isointense) T2
• patchy orHeterogeneous enhancement

Question 31

Sinus trauma

Answer 31

• Hx of Trauma:
• May comes with fracture of sinus wall + hge (high density) and opacification
• on CT: depressed fracutre may present, mucosal thickening and air-fluid level (blood).