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 edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

38 results found
Article

Facial angiofibroma

Facial angiofibroma, also known as fibrous papule, is a fairly common skin lesion seen in males and females after puberty. Pathology They represents a focal vascular and collagen growth. This lesion is usually solitary and located on the nose skin, measuring 1-5 mm.  There is no hereditary p...
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Facial artery

The facial artery is one of the branches of the external carotid artery and supplies blood to the structures of the face. Summary origin - branch of the external carotid artery a little above the level of the lingual course - ascends anteriorly through the cheek with a tortuous route towards ...
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Facial bones

The facial bones comprise a set of bones that make up the face: midline single sphenoid bone ethmoid bone vomer mandible ​paired bilateral palatine bone nasal bone lacrimal bone inferior nasal concha zygoma (zygomatic bone) maxilla Where these bones join each other, sutures occur.
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Facial clefts

Facial clefts comprise of a wide spectrum of pathologies which result from failure of fusion in the facial region during the embryonic - early fetal period. This results is gap in the fetal face. These clefts can affect the lip, philtrum, alveolus and hard and soft palate to varying degrees.  E...
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Facial fractures

Facial fractures are commonly caused by blunt or penetrating trauma sustained during motor vehicle accidents, assaults, and falls. The facial bones are thin and light making them susceptible to injury. Epidemiology Males are affected more commonly than females and facial fractures are most com...
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Facial nerve

The facial nerve is one of the key cranial nerves  with a complex range of functions. Although at first glance it is a motor nerve to facial expression, which begins as a trunk and emerges from the parotid gland as five branches (see facial nerve branches mnemonic here), it has taste and parasy...
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Facial nerve branches (mnemonic)

There are many mnemonics to recall the branches of the facial nerve (superior to inferior) as they exit the anterior border of the parotid gland. Examples include: Tall Zulus Bear Many Children Two Zulus Bit My Cat Two Zebras Bit My Coccyx Ten Zebras Buggered My Car To Zanzibar By Motor Car...
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Facial palsy

Facial palsy refers to the neurological syndrome of facial paralysis. It can result from a broad range of of physiological insult to the facial nerve or its central nervous system origins. The most common causes of this is Bell palsy.  Terminology While facial palsy refers to the clinical pres...
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Factitious hyperthyroidism

Factitious hyperthyroidism or thyrotoxicosis factitia refers to precipitation of thyrotoxicosis due to exogenous ingestion of thyroid hormone (e.g. levothyroxine). It has been rarely associated with myocardial ischaemia 2. Radiographic features Ultrasound The hypervascularity which is seen wi...
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Falciform crescent

The falciform crescent is a horizontal ridge that divides the internal acoustic meatus into superior and inferior portions. Superior The facial nerve and superior vestibular nerve (SVN) travel in the superior portion of the IAM with the facial nerve anterior to the SVN and separated from ...
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Fallopian canal

The Fallopian canal refers to a bony canal through which the facial nerve traverses the petrous temporal bone, from the internal acoustic meatus to the stylomastoid foramen. It is, for those of you fond of trivia, the longest bony canal through which a nerve passes. It is also responsible for th...
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Fatty nodal metaplasia

Fatty nodal metaplasia in the neck occurs as a result of chronic inflammation or radiotherapy 3. The normal fatty nodal hilum enlarges, such that the lymph node appears cystic. However, its center is of fatty density. There is no surrounding stranding, and the node otherwise looks normal. Diffe...
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Fetal goitre

A fetal goitre is an enlargement of the thyroid gland in utero. It can occur with either hyper or hypothyroidism (and in isolated cases of euthyroidism 8). Pathology The mechanism is different dependent on whether the underlying cause is hyper or hypothyroidism.  Associations maternal Graves...
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First branchial cleft cyst

First branchial cleft cysts are a type of branchial cleft anomaly. They are uncommon and only represent ~7% of all branchial cleft cysts. Epidemiology They usually manifest early in first decade of life. Pathology First branchial cleft cysts develop as a result of incomplete fusion of the cl...
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Fissula ante fenestram

The fissula ante fenestram is a small connective tissue-filled cleft located where the tendon of tensor tympani turns laterally toward the malleus. It is situated immediately anterior to the oval window, and posterior to the cochleariform process 1.  The fissula ante fenestrum is the most commo...
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Fistula test

The fistula test is used when examining patient with recurrent vertigo. A finger is abruptly applied to the external meatus which causes a pulse of air-transmitted pressure. If nystagmus is induced in association with vertigo, it indicates bony destruction within the inner ear e...
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Floating teeth

Floating teeth is the description given to the appearances on imaging of teeth 'hanging in the wind' as a result of alveolar bone destruction around the root of the teeth.  Differential diagnosis They are uncommonly encountered, with a wide differential diagnosis - albeit that the underlying c...
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Floor of mouth

The floor of mouth is an oral cavity subsite, and is a common location of oral cavity squamous cell carcinoma.  Gross anatomy The floor of mouth is a U-shaped space extends (and includes) from the oral cavity mucosa superiorly, and the mylohyoid muscle sling 2,3.  Boundaries superiorly: oral...
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Focal calvarial thinning

Focal calvarial thinning can result from a number of causes. They include: bilateral thinning of the parietal bones (normal variant) most common arachnoid cyst mega cisterna magna peripherally located tumors (e.g. oligodendroglioma) See also calvarial thinning calvarial thickening
Article

Follicular thyroid adenoma

Follicular thyroid adenoma is a commonly found benign neoplasm of the thyroid consisting of differentiated follicular cells. It can not be differentiated from follicular carcinoma on cytologic, sonographic or clinical features alone 1. Epidemiology Follicular thyroid adenoma is more commonly f...
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Follicular thyroid cancer

Follicular thyroid carcinoma (FTC) is the second most frequent malignancy of the thyroid gland after papillary cancer and accounts for ≈10-20% of all thyroid neoplasms.  Epidemiology It typically occurs in women and in an older age group than papillary (i.e. 40-60 years of age). Pathology Un...
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Foramen caecum

The foramen caecum is located in the anterior cranial fossa, anterior to cribriform plate of ethmoid bone and posterior to the frontal bone, within the frontoethmoidal suture. It lies at a variable distance from the crista galli. The foramen caecum is frequently found in infant, uncommonly in c...
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Foramen caecum (disambiguation)

Foramen caecum can refer to a number of different anatomical structures: foramen caecum (tongue) foramen caecum (anterior cranial fossa)
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Foramen ovale (head)

Foramen ovale is an oval shaped opening in the middle cranial fossa located at the posterior base of the greater wing of the sphenoid bone, lateral to the lingula. It transmits the mandibular nerve branch (V3) of the trigeminal nerve, accessory meningeal artery, emissary veins between the cavern...
Article

Foramen ovale contents (mnemonic)

A mnemonic to remember foramen ovale contents is: OVALE Mnemonic O: otic ganglion (inferior) V: V3 cranial nerve (mandibular division of trigeminal nerve) A: accessory meningeal artery L: lesser petrosal nerve E: emissary veins
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Foramen rotundum

The foramen rotundum is located in the middle cranial fossa, inferomedial to the superior orbital fissure at the base of greater wing of sphenoid. Its medial border is formed by lateral wall of sphenoid sinus. It runs downwards and laterally in an oblique path and joins the middle cranial fossa ...
Article

Foramen tympanicum

The foramen tympanicum (also known as foramen of Huschke) is an anatomical variation in the external acoustic canal (EAC), where a bony defect connects the EAC to the temporomandibular joint (TMJ). Epidemiology Various studies have reported on the occurrence of a foramen tympanicum in the asym...
Article

Fourth branchial cleft cyst

Fourth branchial cleft cysts are very rare, and parallel the course of the recurrent laryngeal nerve. They are most commonly on the left side (80%) and usually form a sinus which extends from the apex of the piriform sinus, as do third branchial cleft sinuses, but passes inferiorly rather than s...
Article

Frontal bone

The frontal bone is a skull bone that contributes to the cranial vault. It contributes to form part of the anterior cranial fossa. Gross anatomy The frontal bone has two portions vertical portion (squama): has external/internal surfaces horizontal portion (orbital): has superior/inferior sur...
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Frontal bossing

Frontal bossing is a calvarial radiographic feature where the front of the skull appears protruding anteriorly. It is best appreciated on a sagittal or lateral image. Pathology This feature can be seen in many conditions (in alphabetical order): 18q syndrome acromegaly achondroplasia ß-tha...
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Frontal sinus

The frontal sinus develops from anterosuperior pneumatisation of the frontal recess into the frontal bone. Development begins late in intrauterine life or may start after birth (from one to twenty years and starts in the vertical segment). Pneumatisation develops from one to twelve years-old. G...
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Frontoethmoidal suture

Frontoethmoidal suture is a short cranial suture located in the anterior cranial fossa, between the orbital process of frontal and orbital plate of ethmoid bones. It forms part of the medial wall of the orbit. The anterior and posterior ethmoidal foramina are seen just superior to it, through w...
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Frontolacrimal suture

The frontolacimal suture is the cranial suture between the frontal and lacrimal bones.
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Frontomaxillary-suture

The frontomaxillary suture is the site where nasal process of frontal bone meets the frontal process of maxilla.
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Frontonasal dysplasia

Frontonasal dysplasia is a rare disorder involving the face and often the central nervous system: Clinical spectrum face hypertelorism median cleft lip absence of the nasal tip central nervous system  cranium bifidum occultum ethmoidal cephalocele agenesis of the corpus callos...
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Frontonasal suture

The frontonasal suture is the cranial suture between the frontal bone and the two nasal bones. This suture meets the internasal suture at the nasion.
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Frontozygomatic suture

The frontozygomatic suture (or zygomaticofrontal suture) exists between the zygomatic process of the frontal bone and the frontal process of the zygomatic bone.
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Fungal sinusitis

Fungal sinusitis is a collective term referring to a number of entities, which can be divided into two groups, depending on the presence of fungal hyphae within or beyond the mucosa 1: non-invasive: hyphae do not invade mucosa allergic fungal sinusitis sinus fungal mycetoma invasive: hyphae ...

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