medicine pns orbit and neck

1. PNS
&Orbit
Presented By:
Dr. Seham Adam

2. SINUS ANATOMY:
The para-nasal sinuses consists of usually four
paired air-filled spaces. They have several
functions of which reducing the weight of the head
is the most important. Other functions are air
humidification and aiding in voice resonance.
There are named for the facial bones in which they
are located:
Frontal sinus
Maxillary sinus .
Sphenoid sinus .
Ethmoid sinus .

5. The maxillary ostium opens superioly into the infundibulum, which is
the channel between the inferomedial aspect of the orbit laterally and
uncinated process medially.
The ostium , infundibulum and middle meatus is important clinically
and is known as the ostiomeatal complex .

6. Ostiomeatal complex :
 The ostiomeatal complex (or unit), is a common channel that
links the frontal sinus, anterior and middle ethmoid sinus and
the maxillary sinus to the middle meatus that allows air
flow and mucociliary drainage.
The posterior ethmoidal Sinus empty to the superior meatus.
Sphenoidal Sinus opens to the sphenoethmoidal recess.

8. IMAGING MODALITY OF SINUSES:
• Plain Radiography :
• evaluate normal sinuses (Transradiant Because Contain Air )
• Showing mucosal thickening ,air- fluid level , bone
destruction and fractures.
• Computed Tomography :is the gold standard imaging
investigation in sinus disease.
• Magnetic resonance imaging (MRI):
usually used the primary investigation.

14. Ct sinus scan

15. 1

16. 1
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2

19. Mucosal Thickening
 Thickened mucosa can be recognized providing there is some air in the
sinus by noting the soft tissue interface between the air in the sinus and the
bony wall.
• The mucosal thickening may be smooth in outline or it may be polypoid .
• Allergy and infection both cause mucosal thickening and it is often
impossible to say radiological which condition is responsible.
• Such changes are often seen in asymptomatic people.

20. Opaque Sinus:
The sinus becomes opaque when all the air is replaced.
CAUSES OF AN OPAQUE SINUS:
• Infection.
• Allergy
• Mucocele.
• Antrochoanal polyp.
• Truma with heamorrhage
• Carcinoma of sinus or nasal cavity.

21. Sinusitis
 inflammation of the paranasal sinus mucosa.
 can occur in any of the paranasal sinuses.
 Involvement: maxillary > ethmoidal, frontal >
sphenoidal sinus.

22.  Types:
• Infectious sinusitis( Acute ,Subacute and Chronic).
• Noninfectious (allergic) .
• Dental infection and sinusitis (20% maxillary antra ).

23. Radiographic Features:
• Acute sinusitis is usually diagnosed and treated
clinically, but CT is recommended if symptoms persist.
• Both CT and MRI can elegantly demonstrate mucosal
thickening and fluid levels as well as displaying the
bony walls of the sinuses.
• Opacified sinus may be partial or complete
• Mucosal thickening
• Air-fluid levels( diagnostic for acute sinusitis )
• Chronic sinusitis: mucosal thickening and hyperostosis
of bone.

25. Acute Sinusitis
plain radiography
Normal sinuses Acute sinusitis

26. Acute Sinusitis:
PNS CT
Normal sinuses Acute sinusitis

27. Chronic Sinusitis:
plain radiography
Normal sinuses Chronic sinuses

28. Chronic sinusitis
PNS Ct
Normal sinuses Chronic sinusitis

29. Fungal Sinusitis :
• Predisposing factors: diabetes, prolonged antibiotic or steroid therapy,
immune-compromised patient
Radiographic Features :
• Bony destruction and rapid extension into adjacent anatomic spaces
• Indistinguishable from tumor: biopsy required
• Main role of CT/MRI is to determine extent of disease
• Aspergillosis may appear hyperdense on CT .

31. Mucocele:
• A largely clinically silent mucus-containing expansil lesion of the
paranasal sinuses with secondary obstruction of the main ostium of the
affected paranasal sinus.
•The lesion is lined by ciliated columnar respiratory epithelium
•It becomes symptomatic only when it extends into surrounding tissue
planes secondary to remodeling of the surrounding bone and erosion.
•Most common sinus involvement is frontal (67%), followed
by ethmoidal (20%), maxillary (10%), and sphenoidal (3%).

32. CT scan of the head shows
diffuse opacification of the
frontal and ethmoidal sinuses
with remodeling of the bony
walls with cortical erosion
(arrow) of the superior part of
the right lamina papyracea.

33. (a) T1-weighted axial image reveals high T1 signal (arrow) at right frontal
sinus. The left frontal sinus is not pneumatized. (b) FLAIR-weighted axial
image reveals high T2 signal (arrow) at right frontal sinus. (c) Postcontrast
T1-weighted imaging does not reveal any abnormal postcontrast
enhancement (arrow) of the sinus lesion

34. Sino-nasal polyposis:
• Refers to the presence of multiple benign polyps in
the nasal cavity and paransal sinuses , expansion and
opacification of PNS with thinning septa . It causes a
specific pattern of chronic sinusitis

36. Sino-nasal polyp:
Antro- choanal polyp : are solitary sino-nasal polyp that arise within
the maxillary sinus. They pass through and enlarge the sinus
ostium and posterior nasal cavity to the nasopharynx .
 This results in unilateral opacification of the maxillary antrum and the
frontal and anterior ethmoidal sinuses due to obstruction of their
drainage pathways.

38. Polyps are common intranasal mass lesions, resulting
from trapped fluid in the deeper layers of the mucosa of the
nasal cavity. These can occur in any age group and can extend
into the adjacent paranasal sinuses as well asposteriorly into
the pharynx.
Sino-nasal polyp:

39. Coronal plane , sagittal and Axial
reconstructed contrast enhance CT images
there is an extensive fluid-attenuated lesion
filling the right maxillary sinus, nasal cavity ,
and nasopharynx (black arrows), without
disruption of adjacent structures.
On CT, polyps are of low (fluid)
attenuation. However, polyps with
more inspissated secretions can be
of higher density. Such polyps
may be difficult to differentiate
from other lesions by CT alone

40. Sagittal T2-weighted with extensive T2prolongation (white arrow).
and contrast-enhanced axial T1-weighted fat-suppressed
images demonstrate a predominantly peripherally enhancing focus (white arrows)

41. PNS Tumor:
• Types SCC( 90% ), Maxillary sinus( 80%).
• In all opaque sinuses, particularly the antra , special
attention should be paid to the bony margins on CT, because
if these are destroyed a diagnosis of carcinoma needs
exclusion.

42. • CT is superior at visualizing bone destruction, but MRI
is preferred for demonstrating tumour invasion by
showing the extent of any soft tissue mass beyond the
sinus cavity.
• Both CT and MRI have an important role in treatment
planning and in assessing response to treatment.

43. On CT scan, unilateral sinonasal soft tissue mass with patchy
postcontrast enhancement, destruction of the bony wall of sinus,
and aggressive regional spread is seen.
Moderately enhancing aggressive soft
tissue mass at right maxillary sinus with
destruction of medial and posterior wall of
right maxilla extends into masticator space
(arrow), involving the pterygopalatine
fossae (arrow), pterygoid muscles (arrow).

44. (A-C)Low T1 and intermediate T2 signal mass exhibits patchy post-
contrast enhancement. Local infiltration of right temporalis muscle is
more apparent. (D) Invasion of the hard palate (arrow), floor of maxillary
sinus (arrow) with extension into buccal space (arrow), and into the soft
tissue of the cheek (arrow) is seen.

45. Nasopharyngeal Carcinoma

46. Sinus trauma :
A fracture of the sinus wall may
result in hemorrhage (high density)
and opacification of the sinus.

47. Computed tomography
demonstrated a depressed fracture of
the anterior wall of the right
maxillary sinus . Mild mucosal
thickening with air-fluid level in the
maxillary sinus that suggests blood.

50. The Orbit

51. Orbital Anatomy
Anterior view of the orbit
demonstrating
extra ocular muscles, superior
orbital fissure and content of
the intraconal space

52. Orbital Anatomy
Lateral view of the orbit demonstrating:
oculomotor nerve (CN III) with its inferior and
superior division

54. Imaging modalities:
• Computed tomography and MRI clearly demonstrate the
anatomy of the orbits.
• Imaging is indicated in all patients with exophthalmos because
it is important to distinguish between masses arising within the
orbit, masses arising outside the orbit and thyroid eye disease.
• With an intraorbital mass, its relationship to the optic nerve can
be determined.

55. 1.Retr orbital fat
2.Medial rectus
3.Lens
4.Lateral rectus
5.Optic nerve
1
2
3
4 5
Ct Scan Of The Orbit

57. Retinoblastoma:
Malignant tumor that arises from neuro-ectodermal cells of retina.
Clinical:
• leukocoria (white mass behind pupil).
• Age: <3 years
• 30% bilateral, 30% multifocal within one eye
• 10% of patients have a familial history of retinoblastoma
.

58. Retinoblastoma:
In an infant with a soft tissue, partially calcified mass within the optic
globe.
Radiographic Features:
• Intraocular mass
• Calcifications are common (90%);
• Associated with other malignancies most common
(osteosarcoma).

59. On orbital CT, a soft tissue mass is typically
noted. Associated calcifications are present in
70% of cases and strongly suggest the
diagnosis
Contrast-enhanced
orbital CT shows a
partially calcified soft
tissue lesion along the
posterior aspect of the
right optic globe
(arrow
MRI demonstrates slight T1 hyperintensity of
the tumor with low T2 signal and some degree
of contrast enhancement.

60. Optic Nerve Glioma :
Most common cause of diffuse optic nerve enlargement,
especially in childhood.
Clinical findings include loss of vision, proptosis (bulky
tumors).
In neurofibromatosis (NF-1) the disease may be bilateral.
Lesions can involve any portion of the nerve from the orbit to
the optic tract; it can be bilateral

61. Radiographic Features:
•fusiform enlargement of optic nerve.
• Contrast enhancement variable.
• Calcifications rare.
MRI is the imaging modality of choice.

64. Optic Nerve Meningioma
Optic nerve meningiomas are benign tumors arising from the
arachnoid cap cells of the optic nerve sheath.
Age: 4th decade (80% female); younger patients typically
have NF.
Progressive loss of vision interfere with blood supply to the
optic nerve.

65. Radiographic Features:
Mass surrounding the optic nerve,
• Calcification (common)
• Intense contrast enhancement “tram track sign”

68. Orbital infection:
 The orbital septum represents a barrier to infectious spread from
anterior to posterior structures.
Common causes of orbital infection include spread from infected sinus
and trauma.
 Orbital infectious processes divided into preseptal and postseptal
Preseptal “periorbital” cellulitis can be due to several causes including
trauma, dental disease, and adjacent soft tissue inflammatory disease
Postseptal “orbital” cellulitis is almost always seen in the associated
setting of paranasal sinus (ethmoidal or frontal) disease.

69. • Postseptal infection (true orbital cellulitis): Sub periosteal
infiltrate or abscess ,Stranding of retro bulbar fat ,Lateral
displacement of enlarged medial rectus muscle , Proptosis.
• Sub-periosteal abscess is the extreme end of the spectrum of orbital
cellulitis, usually presenting as fluid collection between the lateral
rectus and the lamina papyracea.

70. There is extensive right periorbital and intraorbital soft tissue swelling.
A rim-enhancing fluid collection is present along the right lamina
papyracea (arrow). The adjacent right ethmoid sinuses are extensively
opacified (arrowheads).

71. Thyroid Orbitopathy :
is a thyroid-associated process that results in mucopolysaccharide deposition
within the extraocular muscles resulting in early enlargement of the muscle,
with relative sparing of the tendon.
•Mucopolysaccharide deposition may result in relative low attenuation
centers of the muscles involved.
•Muscular involvement typically follows the temporal pattern of IMSLO,
where the inferior rectus is most frequently affected , followed by the medial,
superior, and lateral recti, and least frequently, the oblique muscles.

72. Thyroid Orbito-pathy:
Radiographic Features:
• Exophthalmos .
• Muscle involvement.
• Inferior (most common) Medial Superior Lateral.
• Spares tendon insertions.
• Often bilateral, symmetrical.
• patient presenting with painless proptosis involving both orbits.

73. Thyroid Ophthalmopathy

74. Ct . scan through the orbits showing enlargement of
the extraocular muscles, particularly the inferior and
medial rectus.

76. Orbital pseudotumor:
• Idiopathic inflammatory condition ,
The exact etiology is not known but an association with many
inflammatory/autoimmune diseases is reported.
• Infiltrating, intraconal, retro-orbital, non-granulomatous mass,
usually unilateral and involving extraocular musculature, including
tendinous portion in patient with painful proptosis.

77. Orbital pseudotumor:
Intense postcontrast enhancement, based on evaluated fat suppressed
postgadolinium T1-weighted MRI.
It is possible to have only muscular involvement; however, the
tendinous portion is always involved. The lacrimal gland, uvea,
sclera, optic nerve sheath, and bony orbits can be variably involved.

79. Coronal noncontrast CT shows an infiltrating
intraconal retrobulbar mass (arrow) involving the
superior and lateral rectus muscle.

80. a) T1-weighted sagittal MRI reveals infiltrating retrobulbar low T1 signal mass
(arrow) involving the superior rectus muscle. (b) T2-weighted coronal MRI
reveals patchily high T2 signal intraconal mass (arrow) involving expanded
superior rectus and lateral rectus muscles. (c) Postcontrast fat-suppressed T1-
weighted image reveals infiltrative intensely enhancing intra-conal retro-orbital
mass(arrow) involving the superior and lateral rectus muscles.

81. Blow out fracture
A direct blow to the eye raises the intraorbital pressure and can
result in a fracture of the orbital floor, which is the weakest part
of the orbit.
The break in the orbital floor allows herniation of orbital
contents into the antrum, which may result in diplopia.
Orbital blowout fractures occur when there is a fracture of one
of the walls of orbit but the orbital rim remains intact. This is
typically caused by a direct blow to the central orbit from a fist
or ball.

82. Imaging is best performed by CT with coronal reconstructions,
which show a crescentic soft tissue mass in the roof of the antrum
this should not be confused with mucosal thickening.
A fracture of the orbital floor may also be visible

83. The arrow refers to the
herniated orbital contents
Frontal Air-fluid level in the right maxillary
antra associated with a "tear drop" arising
from the orbital floor consistent with
prolapsed orbital content

84. Inferior and medial blow out fractures. Note distortion
of inferior rectus and inferior herniation of orbital fat