Fifth Stage
Diagnostic Imaging
Dr. Firas A. – Lecture 7
P a g e
1
Sinuses, Orbits, and Neck imaging
Sinuses:
•
On plain radiographs the normal sinuses are transradiant because they contain
air.
•
Plain films have a role in showing mucosal thickening, fluid levels, bone
destruction and fractures.
•
However, CT is often the preferred technique in sinus disease
•
MRI) also demonstrates the sinuses well, but is rarely needed as the primary
investigation.
•
The causes of an opaque sinus are:
➢
Infection or allergy.
➢
Mucocele.
➢
Carcinoma of the sinus or nasal cavity.
Fifth Stage
Diagnostic Imaging
Dr. Firas A. – Lecture 7
P a g e
2
Mucosal thickening and a fluid level
Nasopharynx
•
Computed tomography and especially
MRI give excellent visualization of the
nasopharynx.
•
Demonstrate the presence of tumour,
the most common being a
nasopharyngeal carcinoma as a mass
disrupting the symmetry of the
nasopharynx.
•
Imaging can detect any spread into
the skull base and lymphadenopathy
in the neck
Fifth Stage
Diagnostic Imaging
Dr. Firas A. – Lecture 7
P a g e
3
Orbits
•
Computed tomography and MRI clearly demonstrate the anatomy of the orbits.
•
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.
•
The main causes of intraorbital masses include various tumours, including
tumours of the optic nerve, vascular malformations and granulomas.
•
The most common orbital masses originating outside the orbit, which often
present with exophthalmos, are tumours or mucoceles of the frontal or ethmoidal
sinuses, and a meningioma arising from the sphenoid ridge.
•
In thyroid eye disease, there is enlargement of the extraocular muscles which is
frequently bilateral and may affect one, several, or all the eye muscles. There is
also infiltration of the fat behind the eye which adds to the exophthalmos.
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,
Fifth Stage
Diagnostic Imaging
Dr. Firas A. – Lecture 7
P a g e
4
Salivary glands
•
Ultrasound is the initial investigation choice
•
Magnetic resonance imaging is the preferred
method for the investigation of masses thought to
be in the salivary glands. The commonest salivary
gland tumour is a benign adenoma.
•
Magnetic resonance imaging is excellent for
demonstrating the presence of a mass and its
relationship to the facial nerve
Sialography
•
Calculi, which occur most commonly in the submandibular duct or gland, normally
contain calcium and can, therefore, be seen on plain films.
•
To show the duct system, a sialogram is performed by injecting contrast into the
ducts of the salivary glands. Stones and strictures in the ducts can be identified.
Dilatation of small ducts, which is known as sialectasis, may occur with
obstruction to the main duct
Neck
•
Ultrasound: is recommended as the first line
investigation, which may demonstrate the extent of
the mass, LNs
•
Doppler studies: will indicate its vascularity
•
CT : for cervical LNs enlargement or cervical mass
(calcification)
Fifth Stage
Diagnostic Imaging
Dr. Firas A. – Lecture 7
P a g e
5
•
MRI: is the best method of imaging the neck because of the superior contrast
between normal soft tissues and tumour
Thyroid imaging
Carcinoma of the thyroid
Tha nk
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