Articles
Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
1,952 results found
Article
Thyroid cartilage
The thyroid cartilage is the largest of the cartilages of the larynx, with its superior border sitting at the level of the C4 vertebra.
Gross anatomy
The thyroid cartilage consists of bilateral flattened laminae that are fused in the anterior midline to form the laryngeal prominence (Adam's ap...
Article
Subconjunctival fat prolapse
Subconjunctival fat prolapse is an acquired herniation of intraconal fat due to the weakening of the Tenon capsule by normal aging, surgery, or trauma. It presents clinically with a fat-containing epibulbar mass in the lateral canthal area.
Epidemiology
Subconjunctival fat prolapse occurs mai...
Article
Acquired cholesteatoma
Acquired cholesteatomas are far more common than congenital cholesteatomas and are almost always closely related to the tympanic membrane and pneumatized portion of the temporal bone from which most are thought to arise 9.
Cholesteatomas occur far more commonly in the middle ear than in the ext...
Article
Submandibular ganglion
The submandibular ganglion is one of four parasympathetic ganglia of the head and neck. It receives parasympathetic fibers from the facial nerve.
Gross anatomy
small ganglion suspended from the undersurface of the lingual nerve
inferior to submandibular duct sitting on the hyoglossus muscle
...
Article
Otalgia
Otalgia refers to the clinical symptoms of ear pain. It is broadly divided in two categories which are
primary otalgia (~ 50% 3) - ear pain originating from causes within or near to the ear itself
secondary otalgia / referred otalgia (~50% 3)- ear pain due to causes remote from the ear
Pathol...
Article
Pterygopalatine ganglion
The pterygopalatine ganglion (also known as the nasal ganglion, or sphenopalatine ganglion) is one of four parasympathetic ganglia of the head and neck and largest of the peripheral parasympathetic ganglia. It receives parasympathetic fibers from the facial nerve.
Gross anatomy
ganglion locate...
Article
Parietal foramen
The parietal foramina are inconstant foramina on each side of the posterior aspect of the parietal bone near the sagittal suture and represent a normal anatomic variant. They transmit emissary veins, draining to the superior sagittal sinus, and occasionally a branch of the occipital artery. The ...
Article
Xerostomia
Xerostomia is the medical term for a dry mouth, and is most commonly due to hyposalivation.
Epidemiology
Xerostomia is the most frequently observed salivary abnormality in clinical practice 1.
Clinical presentation
dryness of the mouth
uncomfortable swallowing
vocalisation difficulties: to...
Article
Lillie-Crowe sign
The Lillie-Crowe sign is used in the diagnosis of unilateral sinus thrombophlebitis. Digital compression of the internal jugular vein on the opposite side to the thrombus causes dilatation of the retinal veins as venous drainage is now occluded bilaterally 2.
Article
Mandibular lesions
Mandibular lesions are myriad and common. The presence of teeth results in lesions that are specific to the mandible (and maxilla) and a useful classification that defines them as odontogenic or non-odontogenic. While it may often not be possible to make a diagnosis on imaging alone, this classi...
Article
Skull base angle
The skull base angle (of Boogard) allows the diagnosis of platybasia and basilar kyphosis. Several different techniques may be used on sagittal images from MRI or CT.
Traditionally, basal angle measurements were based on plain skull images. With the advent and generalization of MR imaging, it h...
Article
Chronic maxillary atelectasis
Chronic maxillary atelectasis is a descriptive term that is characterized by a persistent decrease in the maxillary sinus volume due to inward bowing of its walls.
Terminology
It is not considered synonymous with - but can include the term silent sinus syndrome, typically when there is also sp...
Article
Bill bar
Bill bar (TA: crista verticalis) also known as the vertical crest, is a bony anatomical landmark that divides the superior compartment of the internal acoustic meatus into an anterior and posterior compartment. Anterior to Bill bar, in the anterior superior quadrant, are the facial nerve (CN VII...
Article
Pyogenic granuloma
A pyogenic granuloma, also known as lobular capillary hemangioma, is a common lesion found arising from the skin and mucous membranes. Sometimes it may be difficult to differentiate them from malignancy, clinically or on imaging.
Terminology
Despite its name, a pyogenic granuloma is not a tru...
Article
Otosyphilis
Otosyphilis, otic syphilis or syphilitic labyrinthitis is a manifestation of neurosyphilis affecting the inner ear.
For a general discussion, and for links to other system-specific manifestations, please refer to the article on syphilis.
Pathology
The pathological features of syphilitic laby...
Article
Laryngocele
A laryngocele is the dilatation of the saccule of the laryngeal ventricle and is unilateral in the vast majority of cases 8.
On imaging, these lesions are generally characterized as well-defined, thin-walled, fluid or air-filled cystic lesions in the paraglottic space. Communication with the la...
Article
Prussak space
Prussak space is a subcomponent of the lateral epitympanic space and extends from the level of the scutum to the umbo. This space is best demonstrated on the oblique coronal image.
Gross anatomy
Boundaries
lateral: pars flaccida of the tympanic membrane and the scutum
medial: neck of the ma...
Article
Eyelid
The eyelids cover the eyes, with an upper and lower eyelid on each side, and are covered in front with loose skin and behind with adherent conjunctiva. The lower lids possess very little mobility; the upper eyelid is elevated by levator palpebrae superioris muscle fibers and the lids are closed ...
Article
Pseudodacryocystitis
Pseudodacryocystitis refers to anterior ethmoidal sinus inflammation, usually with superimposed infection, extending into the adjacent lacrimal sac region and consequently giving a clinical presentation similar to dacryocystitis.
Unlike dacryocystitis, clinical irrigation typically shows patenc...
Article
Sensorineural hearing loss
Sensorineural hearing loss (SNHL) refers to deafness secondary to conditions affecting the inner ear, internal acoustic canal, cerebellopontine angle, or vestibulocochlear nerve.
It an be classified audiometrically into two types
sensory (cochlear)
neural (retrocochlear)
Pathology
Conditio...
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