Sinuses, Orbits, and Neck imaging By Dr. Firas Abdullah
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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. • The causes of an opaque sinus are:
Infection or allergy. Mucocele. Carcinoma of the sinus or nasal cavity. •
However, CT is often the preferred technique in sinus disease • MRI) also
demonstrates the sinuses well, but is rarely needed as the primary investigation.
Waters view Occipitomental or Waters view: an angled PA radiograph of the
skull, with the patient gazing slightly upwards. It can be used to assess for facial
fractures, as well as for acute sinusitis.
• Paranasal sinus mucoceles represent complete opacification of one or more
paranasal sinuses by mucus, often associated with bony expansion due to
obstruction of the nasal sinus drainage. The frontal sinus is most common sinus
prone to developing mucocele, then the ethmoidal sinuses are the next most
common, whereas the maxillary and sphenoid sinuses are infrequently involved
• Antrochoanal polyps are solitary sinonasal polyps that arise within the
maxillary sinus. They pass to the nasopharynx through the sinus ostium and
posterior nasal cavity, enlarging the latter two.
• Sinonasal carcinoma is malignant tumor of sinuses, most commonly squamous
cell CA. which appears on CT as soft tissue density mass usually causing bone
destruction.
Frontal mucoceles
1. loss of normal scalloped margin
2. erosin of supra orbital ridge
3. extension to opposite side frontal sinus or posteriory
Nasopharynx
• Computed tomography and especially MRI give excellent visualization of the
nasopharynx.
• Demonstrate the presence of tumour, the most common being a
nasopharyngeal carcinoma (mostly squamous cell carcinoma) as a mass
disrupting the symmetry of the nasopharynx and causing oblitration of
parapharyngeal fat.
• Imaging can detect any spread into the skull base and lymphadenopathy in the
neck
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.
• We should differentiate it from another cause for exophthalmos which is
inflammatory orbital pseudo-tumor …
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ملف
االلكتروني
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,
Salivary glands
• Ultrasound is the initial investigation choice, we can assess shape, size,
vascularity and texture of glands, duct dilatation, stone, or any mass.
• 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 (pleomorphic 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 gland duct, normally
contain calcium and can, therefore, be seen on plain films.
• To show the duct system, a conventional sialogram is performed by injecting
contrast into the ducts of the salivary glands and taking X ray. 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
• Sialogram can be done using CT scan or MRI too.
Neck
• Ultrasound: is recommended as the first line investigation, which may
demonstrate the thyroid gland size and texture, any mass lesion in the neck, and
any enlarged LNs assessing their size and shape and presence or loss of their
hilum • Doppler studies: to assess the vascularity of thyroid gland, assess
vascularity of thyroid or other neck mass, and in carotid Doppler study.
• CT : for cervical LNs enlargement or cervical mass (calcification)
• MRI: is the best method of imaging of neck masses because of the superior
contrast between normal soft tissues and tumour