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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.

1,736 results found
Article

Harvard scoring system for rhinosinusitis

The Harvard scoring system for rhinosinusitis is, as the name implies, a scoring system based on CT-scan assessment for grading of rhinosinusitis. Scoring 0: normal (< 2 mm mucosal thickening on any sinus wall) 1: all unilateral disease or anatomic abnormality 2: bilateral disease limited to...
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Hashimoto thyroiditis

Hashimoto thyroiditis, also known as lymphocytic thyroiditis or chronic autoimmune thyroiditis, is a subtype of autoimmune thyroiditis. It is one of the most common thyroid disorders.  Epidemiology Typically affects middle-aged females (30-50 year age group with an F:M ratio of 10-15:1).  Cli...
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Head and neck anatomy

Head and neck anatomy is important when considering pathology affecting the same area. In radiology, the 'head and neck' refers to all the anatomical structures in this region excluding the central nervous system, that is, the brain and spinal cord and their associated vascular structures and en...
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Head and neck cancer therapy response interpretation (Hopkins criteria)

The head and neck cancer therapy response interpretation (Hopkins criteria) is a qualitative system of interpretation for therapy response assessment using PET-CT. Background Widely used options for therapy response assessment are clinical examination, histopathology, CT and MR imaging, howeve...
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Head and neck squamous cell carcinoma (overview)

Head and neck squamous cell carcinomas (SCC) are common, being the sixth most common cancer. They can have a cutaneous or mucosal origin. As such there is a wide array of clinical and radiographic manifestations, and are separated into: squamous cell carcinoma of the skin of the head and neck ...
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Head and neck squamous cell carcinomas

Head and neck squamous cell carcinomas (HNSCC) are the most common histologic type of head and neck cancer. While the term may include any squamous cell carcinoma of the head and neck, common usage focuses on those of mucosal origin, i.e., squamous cell carcinoma of the upper aerodigestive tract...
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Heerfordt syndrome

Heerfordt syndrome, also known as Heerfordt-Waldenström syndrome or uveoparotid fever, is a variant of sarcoidosis, comprising of: fever parotid enlargement facial palsy ocular involvement (anterior uveitis) Epidemiology The exact prevalence is unknown, as only isolated case reports exist....
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Helicotrema

The helicotrema (plural: helicotremas or helicotremata) is a part of the cochlear apex where the scala tympani and scala vestibuli meet. It is located at the termination of the spiral lamina. See also cochlear anatomy
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Hemifacial hypertrophy

Hemifacial hyperplasia or hemifacial hypertrophy is a rare developmental anomaly characterized by asymmetric growth of hard and soft tissues of the face 1. Epidemiology These asymmetries are often noted at birth and are usually accentuated with increasing age, especially around puberty 2. The...
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Hemifacial microsomia

Hemifacial microsomia (HFM) is the second most common congenital facial anomaly after cleft lip/palate. The condition may vary from mild to severe. Goldenhar syndrome has been described as a variant of HFM, in which vertebral anomalies and epibulbar dermoids were present. Terminology HFM is al...
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Hemifacial spasm

Hemifacial spasm is characterized by episodic facial spasms due to irritation of the facial nerve (CN VII). Clinical presentation Often the condition begins insidiously with painless spasm of the orbicularis oculi gradually spreading in extent and severity to involve the majority of the face, ...
Article

Hennebert sign (inner ear)

The Hennebert sign describes a positive fistula test without clinical evidence of middle ear or mastoid disease. It is associated with congenital syphilis and may also be present in Ménière disease. It has been postulated that the vestibular stimulation is mediated by fibrous bands between foot...
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Hernia (general)

Hernias (or herniae) are a common pathological entity, in which an anatomical structure passes into an abnormal location via an opening. The opening may be a normal physiological aperture (e.g. hiatus hernia: stomach passes through the diaphragmatic esophageal hiatus) or pathological. Iatrogeni...
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Heterogeneous thyroid echotexture

Heterogeneous echogenicity of the thyroid gland is a non-specific finding and is associated with conditions diffusely affecting the thyroid gland. These include: Hashimoto thyroiditis Graves disease
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Hiatus semilunaris

The hiatus semilunaris is a semicircular shaped opening located on the lateral wall of the nasal cavity. It is a component of the ostiomeatal complex and serves as the opening for the frontal and maxillary sinuses and the anterior ethmoid air cells. It is inferior to the ethmoid bulla and the un...
Article

Hiccups

Hiccups (or hiccoughs), medical term singultus (rarely used), are an unpleasant phenomenon, experienced by everyone on occasion, and usually self-limiting. However the much rarer intractable chronic form can be extremely debilitating. Epidemiology Hiccups are a symptom that has probably been e...
Article

High arched palate

High arched palates are a facial feature of many syndromes, although the classic association is Marfan syndrome. There are hundreds of conditions associated with high arched palates, with some of the radiologically-more important including: Down syndrome Apert syndrome Rubinstein-Taybi syndro...
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High-riding brachiocephalic artery

A high-riding brachiocephalic artery (now preferred to innominate artery) is a rare anomaly of the neck vessels in which the brachiocephalic artery passes much more superiorly than normally. It is a clinically important variant, as mistaking it for a neck lump and sampling it or neck surgery in ...
Article

High riding jugular bulb

A high riding jugular bulb indicates the dome (roof) of the jugular bulb extends more superiorly in the petrous temporal bone than is typical. The transverse level above which a jugular bulb is considered high riding has been variably defined as the following 1,6,8: floor of the internal acoust...
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High-velocity penetrating brain injury

High-velocity penetrating brain injuries, in practical terms most often due to cranial gunshot injuries, are a form of penetrating traumatic brain injuries, which are much less common than blunt traumatic brain injuries and distinguished from low-velocity penetrating brain injuries (such as stab...
Article

HIV-associated salivary gland disease

HIV-associated salivary gland disease is a condition characterized by lymphatic infiltration of the salivary glands, especially the parotids. This condition of HIV patients can be part of the diffuse infiltrative lymphocytosis syndrome. The condition is one of the most important AIDS-associated ...
Article

Hockey stick sign (disambiguation)

The hockey stick sign can refer to a variety of different signs and appearances: hockey stick sign (thyroid hemiagenesis) hockey stick sign (Creutzfeldt-Jakob disease) hockey stick sign (ureters)
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Hockey stick sign (thyroid hemiagenesis)

Hockey stick sign has been used to describe the appearance of the thyroid gland in cases of thyroid hemiagenesis when investigated with thyroid scan (Tc-99m)​ 1. The unilateral lobe and isthmus make a shape reminiscent of a hockey stick.  See also hockey stick sign (Creutzfeldt-Jakob disease)
Article

Hollenhorst plaque

Hollenhorst plaques are seen on clinical examination of the retina and are the result of cholesterol emboli at the retinal arteriole bifrication 1. They most commonly originate from the carotid or aortic atheroscleroritc plaque 2. Hollenhorst plaques are a a risk factor for ischemic stroke and a...
Article

Holman-Miller sign (maxillary sinus)

The Holman-Miller sign (also called the antral sign) is seen in juvenile nasopharyngeal angiofibroma; it refers to the anterior bowing of the posterior wall of the maxillary antrum as seen on a lateral skull radiograph or cross-sectional imaging 1,2. This is a non-specific sign that can be prod...
Article

HPV-mediated (p16-positive) oropharyngeal cancer (staging)

Human papillomavirus (HPV)-mediated oropharyngeal (p16+) cancer staging refers to TNM staging of squamous cell carcinomas of the oropharynx that test positive for p16, an immunohistochemical proxy for HPV infection. Nodal metastases of p16+ squamous cell carcinoma without an identified primary t...
Article

Hurthle cell

Hurthle cells are a type of oncocyte arising from thyroid follicular epithelial cells. Pathology Under microscopy, Hurthle cells are larger than typical follicular cells, with abundant mitochondria. Cancers of Hurthle cell origin can be benign adenomas or malignant carcinomas and consist of a...
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Hutchinson sign (disambiguation)

The Hutchinson sign can refer to two clinical signs.  Hutchinson sign (ophthalmology) Relates to involvement of the tip of the nose from facial herpes zoster. It implies involvement of the external nasal branch of the nasociliary nerve (branch of the ophthalmic division of the trigeminal nerve...
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Hutchinson teeth

Hutchinson teeth are smaller and more widely spaced than normal and are notched on their biting surfaces. It is a sign of congenital syphilis and should not be confused with: Hutchinson triad Hutchinson pupil Hutchinson freckle Hutchinson sign Hutchinson syndrome History and etymology Na...
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Hyoglossus muscle

The hyoglossus muscle is a thin, quadrilaterally shaped muscle in the upper neck and the floor of the mouth. It is one of the extrinsic muscles of the tongue. The submandibular ganglion suspended from the lingual nerve sits on it. Summary origin: hyoid bone: from the entire length of the great...
Article

Hyoid bone

The hyoid is a "horseshoe-shaped" bone that serves as a structural anchor in the mid-neck. It is the only bone in the human body that does not directly articulate with another bone (other than sesamoids). It is a place of convergence of multiple small neck muscles that permit the pharyngeal phas...
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Hyoid bone fracture

Hyoid bone fractures are rare and are most commonly associated with victims of strangulation and hanging. Occasionally it has been reported in trauma other than manual strangulation. It can sometimes be serious due to complications with asphyxia 2. Classification One described method is as in...
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Hyoid elevation

Hyoid elevation on a modified barium swallow study indicates that the pharyngeal muscles are contracting appropriately. Radiographic features Modified barium swallow With real time fluoroscopy (or videofluoroscopy) during the act of swallowing, the larynx moves upward and forward when there i...
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Hyperattenuating paranasal sinus opacification

Hyperattenuating paranasal sinus opacification can arise in a number of situations: fungal sinus disease inspissated secretions acute hemorrhage into sinus (hemosinus) Differential diagnosis In some situations can consider early calcification within the sinus - intrasinus calcification.
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Hyperostosis of the skull (differential)

Hyperostosis of the skull has many causes, broadly divided into focal or diffuse. Diffuse Paget disease of bone metastatic disease, especially prostate carcinoma chronic, severe anemia hyperparathyroidism acromegaly osteopetrosis hyperostosis frontalis interna long-term phenytoin use g...
Article

Hyperparathyroidism

Hyperparathyroidism is the effect of excess parathyroid hormone in the body. It can be primary, secondary, or tertiary. There are many characteristic imaging features, predominantly involving the skeletal system. Clinical presentation Hyperparathyroidism is supported biochemically by either an...
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Hyperparathyroidism-jaw tumor syndrome

Hyperparathyroidism-jaw tumor syndrome is an extremely rare condition where a gene mutation results in hyperparathyroidism in association with both benign and malignant tumors, most notably, tumors in the mandible or maxilla 2. Epidemiology Approximately 200 cases have been reported in the med...
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Hypertelorism

Hypertelorism refers to an abnormal increase in distance between any two organs although some authors use the term synonymously with orbital hypertelorism meaning an abnormal increase in distance between the two eyes. The article mainly focuses on the latter. The abnormality is similar to teleca...
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Hyperthyroidism

Hyperthyroidism refers to increased production and secretion of thyroid hormone from the thyroid gland. Terminology Hyperthyroidism is not synonymous with thyrotoxicosis, the latter referring to a clinical syndrome of excess thyroid hormone.   Clinical presentation Hyperthyroidism may be acc...
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Hypodontia

Hypodontia refers to the congenital absence of one or more teeth. Epidemiology Hypodontia is common, affecting ~15% of the population with a recognized variations in ethnicities, e.g. prevalence of 1% in indigenous Australians through to 30% in Japanese populations. There is a female preponder...
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Hypoglobus

Hypoglobus refers to the inferior displacement of the globe in the orbit. It may or may not be associated with enophthalmos. Causes include: fracture of the orbital floor (most common) silent sinus syndrome orbital masses orbital foreign bodies thyroid ophthalmopathy
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Hypoglossal canal

The hypoglossal canal is located between the occipital condyle and jugular tubercle and runs obliquely forwards (posteromedial to anterolateral) allowing the hypoglossal nerve to exit the posterior cranial fossa.  Its proximal portion is often divided by a fibrous (sometimes ossified) septum, w...
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Hypoparathyroidism

Hypoparathyroidism results from reduced secretion of parathyroid hormone by the parathyroid glands. It results in hypocalcemia. Epidemiology Hypoparathyroidism has an estimated prevalance 37 per 100,000 person-years and incidence of 0.8 per 100 000 person-years. It carries no increased risk of...
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Hypopharyngeal carcinoma (staging)

Hypopharyngeal carcinoma staging refers to TNM staging of carcinomas originating in the hypopharynx. This system most commonly applies to squamous cell carcinomas but can also apply to rarer epithelial malignancies in the region. The following article reflects the 8th edition published by the Am...
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Hypopharyngeal squamous cell carcinoma

Squamous cell carcinoma (SCC) of the hypopharynx is relatively uncommon, carries the worst prognosis of any head and neck squamous cell carcinoma (HNSCC), and is a challenge to diagnose and treat.  Hypopharyngeal carcinoma is relatively uncommon representing only 10% of all proximal aerodigesti...
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Hypopharynx

The hypopharynx or laryngopharynx forms the most inferior portion of the pharynx, being the continuation of the oropharynx superiorly and both the larynx and esophagus inferiorly. It also forms part of the upper respiratory tract. Gross anatomy The hypopharynx begins as the continuation of the...
Article

Hypotelorism

Hypotelorism refers to an abnormal decrease in distance between any two organs although some authors use the term synonymously with orbital hypotelorism meaning an abnormal decrease in the distance between the two eyes (the eyes appear too close together). The article mainly focuses on the latte...
Article

Hypothyroidism

The clinical syndrome of hypothyroidism is marked by inadequate thyroid hormone production, resulting in a decreased rate of cellular metabolism. It may be primary, in which the dysfunction pertains to the thyroid gland itself, or secondary, due to hypothalamic or pituitary dysfunction 1. Epide...
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Hypotympanum

The hypotympanum refers to the portion of the tympanic cavity lying inferior to the level of the inferior margin of the external acoustic canal (EAC). Gross anatomy The hypotympanum is the smallest of the three compartments that make up the tympanic cavity and is a shallow depression in the fl...
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Hyrtl fissure

Hyrtl fissure (also known as tympanomeningeal fissure) is a congenital infralabyrinthic fissure through the petrous temporal bone. It is a very rare cause of spontaneous CSF otorrhea and meningitis. Development This fissure is present in the developing fetal petrous temporal bone and is typica...
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Iannetti classification of orbital invasion

The Iannetti classification grades orbital invasion by ethmoido-orbital tumors, such as adenocarcinoma, squamous cell carcinoma, adenoid cystic carcinoma, undifferentiated carcinoma, sarcoma, or olfactory neuroblastoma. Classification grade I: erosion or destruction of the orbital medial wall ...
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Ice cream cone sign (disambiguation)

The ice cream cone sign may refer to: ice cream cone sign (middle ear ossicles) ice cream cone sign (vestibular schwannoma)
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Ice cream cone sign (middle ear ossicles)

The ice cream cone sign describes the normal appearance of the middle ear ossicles on axial CT scan. The ball of the ice cream is formed by the head of the malleus and cone is formed by the body of the incus, with the tapering conical point formed by the short process pointing towards the aditus...
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Ice cream cone sign (vestibular schwannoma)

The ice cream cone sign refers to the appearance of a medium-sized (1.5 to 3.0 cm) vestibular schwannoma. The intracanalicular component represents the cone and the cerebellopontine angle (CPA) (cisternal) component representing the ice cream ball. See also ice cream cone sign (middle ear ossi...
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Idiopathic orbital inflammation

Idiopathic orbital inflammation (IOI), also known as orbital pseudotumor and non-specific orbital inflammation, is an idiopathic inflammatory condition that most commonly involves the extraocular muscles. Less commonly there is inflammatory change involving the uvea, sclera, lacrimal gland, and ...
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Idiopathic osteosclerosis

Idiopathic osteosclerosis is a common incidental finding on dental imaging. Terminology Idiopathic sclerosis is also known as dense bone islands, enostoses, bone scar or focal periapical osteopetrosis 2,3. Epidemiology Idiopathic sclerosis is detected on ~5% (range 4-31%) of dental imaging 2...
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IgG4-related disease

IgG4-related disease (IgG4-RD) is a systemic disease that is characterized by fibroinflammatory infiltration of various organs, including by plasma cells that express IgG4 (immunoglobulin G subclass 4). Terminology This condition has been known by many other names in the past, such as IgG4-rel...
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IgG4-related orbital disease

IgG4-related orbital or ophthalmic disease is a manifestation of systemic IgG4-related disease that accounts for a substantial minority of what was previously considered idiopathic orbital inflammation (orbital pseudotumor). Clinical presentation Patients usually present with either painless p...
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Incidental thyroid nodules

Incidental thyroid nodules, sometimes called thyroid incidentalomas, are discrete lesions in the thyroid gland found on cross-sectional imaging performed for indications other than thyroid evaluation. They are common but occasionally represent thyroid cancer 1. This article discusses the epidemi...
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Incisive canal

The maxillary incisive canal runs through the maxilla in the midline. It connects the inferior nasal cavity with the superior oral cavity, opening at the incisive foramen posterior to the central maxillary incisor teeth. It contains the descending palatine artery and the nasopalatine nerve.  Re...
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Incisive canal cyst

Incisive canal cysts, also known as nasopalatine duct cysts (NPDC), are developmental, non-neoplastic cysts arising from degeneration of nasopalatine ducts. These ducts usually regress in fetal life. The persistence of ductal epithelium leads to formation of cyst. It is considered the most comm...
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Incisive foramen

The incisive foramen (also known as nasopalatine foramen or anterior palatine foramen) is the oral opening of the nasopalatine canal. It is located in the maxilla in the incisive fossa, midline in the palate posterior to the central incisors, at the junction of the medial palatine and incisive s...
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Incisive nerve

The incisive nerve is one of the two terminal branches of the inferior alveolar nerve, a branch of the posterior division of the mandibular division of the trigeminal nerve. It continues running anteriorly in the mandibular incisive canal (a continuation of the mandibular canal) after the mental...
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Incudomalleolar joint

The incudomalleolar joint, also known as the incudomallear joint, is the joint between the incus and the malleus. The joint is part of the chain of ossicles sending vibrations from the tympanic membrane to the oval window. Related pathology dislocations of the joint result in conductive hearin...
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Incudostapedial joint

The incudostapedial joint is the articulation between the incus and stapes bones in the middle ear. It is one of the three joints in the ossicular chain.
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Incus

The incus (plural: incudes) is the middle of the three ossicles articulating with the head of the malleus anteromedially, forming the incudomalleolar joint, and the stapes inferomedially, forming the incudostapedial joint. Named parts include: a body which articulates with the head of the mall...
Article

Infantile cervical ligament edema

Infantile cervical ligament edema can typically be seen when infants have suffered accidental or abusive head and neck trauma. The finding is best seen on sagittal STIR images. Terminology The posterior ligamentous complex refers to the ligamentum flavum and interspinous ligaments. The anterio...
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Infantile hemangioma

Infantile hemangiomas are benign vascular neoplasms that are the most common head and neck tumors of infancy. They can occur virtually anywhere, but the majority are found in the head and neck regions. This article aims to be a generic discussion of the condition, for detailed and more specific...
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Inferior alveolar artery

The inferior alveolar artery is a branch of the maxillary artery. It runs with the inferior alveolar nerve as it descends through the infratemporal fossa and enters the mandibular canal and supplies mandibular teeth. In the region of the first premolar it bifurcates into the incisive and mental ...
Article

Inferior alveolar nerve

The inferior alveolar nerve or inferior dental nerve is a mixed sensory and motor branch of the posterior division of the mandibular division of the trigeminal nerve, located in the pteryogomandibular space of the oral cavity/masticator space. Gross anatomy The inferior alveolar nerve divides ...
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Inferior alveolar nerve injury

Inferior alveolar nerve injuries are most common iatrogenic post third mandibular molar extraction although they can occur post dental implant or in mandibular fractures. This article is focused on iatrogenic injuries.  Epidemiology The incidence of inferior alveolar nerve injuries after third...
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Inferior labial artery

Inferior labial artery (old name: inferior coronary artery) is one of the facial branches of the facial artery. It is smaller than the superior labial artery. It supplies the lower lip, including its labial glands, mucous membranes and muscles. Summary origin: facial branch of the facial arter...
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Inferior laryngeal artery

The inferior laryngeal artery accompanies the recurrent laryngeal nerve into the larynx, where it anastomoses with the superior laryngeal artery to supply the muscles and mucous membranes of the larynx 1.  Summary origin: branch of the inferior thyroid artery course: ascends the trachea to en...
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Inferior longitudinal muscle of the tongue

The inferior longitudinal muscle of the tongue is one of the four intrinsic muscles of the tongue, which alter the shape of the tongue mass, being entirely confined to the tongue without any extraglossal attachment (cf. extrinsic muscles of the tongue). Gross anatomy The muscles fibers attach ...
Article

Inferior meatus

The inferior meatus (plural: meatus) is an air passage of the lateral nasal cavity located between the inferior nasal concha and lateral nasal wall. The nasolacrimal duct drains into the inferior meatus, and Woodruff plexus is located posteriorly. 
Article

Inferior nasal concha

The inferior nasal conchae or turbinates are one of the pairs of conchae in the nose. Gross anatomy It extends horizontally along the lateral wall of the nasal cavity and consists of a lamina of spongy bone, curled upon itself like a scroll. The inferior nasal conchae are considered a pair of ...
Article

Inferior oblique muscle

The inferior oblique muscle is one of six extraocular muscles that control eye movements. Summary innervation: inferior branch of the oculomotor nerve (CN III) origin: orbital surface of the maxilla insertion: globe (posterior, inferolateral surface) primary function: one of two ocular exte...
Article

Inferior ophthalmic vein

The inferior ophthalmic vein (IOV) is a vein of the inferior orbit and is smaller than the more well-known superior ophthalmic vein (SOV). Gross anatomy Origin The vein forms from a plexus of several veins within the anteroinferior orbit along the infraorbital margin from facial vein tributar...
Article

Inferior orbital fissure contents (mnemonic)

Mnemonic for the contents of the inferior orbital fissure (from medial to lateral) is: Inferior Orbit Gets Infra-Orbital Nerves and VeinZ Mnemonic Inferior Orbit Gets Infra-Orbital Nerves and VeinZ IO: inferior ophthalmic vein (tributary to both pterygoid venous plexus and cavernous sinus) ...
Article

Inferior pharyngeal constrictor muscle

The inferior pharyngeal constrictor muscle is one of the pharyngeal constrictor muscles. The muscle is described as having two main parts, thyropharyngeus and cricopharyngeus, which originate from the oblique line of the thyroid lamina and lateral aspect of the cricoid cartilage respectively. G...
Article

Inferior rectus muscle

The inferior rectus muscle is one of the six extraocular muscles that control eye movements. Summary innervation: inferior branch of the oculomotor nerve (CN III) origin: annulus of Zinn (tendinous ring) insertion: globe (anterior, inferior surface) primary function: one of two ocular depre...
Article

Inferior salivatory nucleus

The inferior salivatory (or salivary) nucleus is the nucleus associated with the visceral efferent innervation of the parotid gland. It is one of the four nuclei of the glossopharyngeal nerve. Gross anatomy The inferior salivatory nucleus is located within the dorsal aspect of the pons just su...
Article

Inferior thyroid artery

The inferior thyroid artery is a branch of the thyrocervical trunk (85%) or subclavian artery (15%) and ascends to enter the thyroid gland on its posterior surface, as well as supplying both the superior and inferior parathyroid glands 1. If the artery arises from the subclavian artery, it may ...
Article

Inferior thyroid vein

The inferior thyroid vein, along with the superior and middle thyroid veins contribute to the drainage of the thyroid venous plexus on the anterior surface of the thyroid 1. Gross anatomy After arising from the venous plexus, the left inferior thyroid vein passes downwards to join the left bra...
Article

Inferior turbinate hypertrophy

Inferior turbinate hypertrophy is one of many causes of nasal obstruction and can be a contributing factor to obstructive sleep apnea.  Pathology Etiology allergic rhinitis (most common) vasomotor rhinitis drug-induced rhinitis Treatment and prognosis Pharmacological treatment (e.g. topic...
Article

Inferior tympanic canaliculus

The inferior tympanic canaliculus is a small bony passageway that lies within the petrous portion of the temporal bone, between the carotid canal and jugular foramen. Gross anatomy The inferior tympanic canaliculus is a bony canal that separates the opening of the carotid canal anteromedially ...
Article

Infrahyoid muscles

The infrahyoid muscles or strap muscles are a group of four paired muscles in the anterior neck below the hyoid bone, within the muscular triangle. They are responsible for depressing the hyoid during swallowing. Gross anatomy There are four strap muscles: sternohyoid: superficial and medial ...
Article

Infraorbital artery

The infraorbital artery is a branch of the third part of the maxillary artery. It runs through the inferior orbital fissure, orbit, infraorbital canal then the infraorbital foramen. Here it gives off the anterior superior alveolar artery which supplies the anterior teeth and the anterior part of...
Article

Infraorbital canal

The infraorbital canal is a bony canal within the maxillary bone located at the anterior aspect of the orbital floor. It transmits the infraorbital nerve, which is a branch of the maxillary division of the trigeminal nerve (CN Vb), as well as the infraorbital artery and vein. The canal commences...
Article

Infraorbital foramen

The infraorbital foramen is located in the maxillary bone. It is the anterior opening of the infraorbital canal, which is the anterior continuation of the infraorbital groove, which course through the floor of the orbit. The canal may reside entirely in the maxillary sinus, suspended from the si...
Article

Infraorbital nerve

The infraorbital nerve is a branch of the maxillary division of the trigeminal nerve.   Gross anatomy The infraorbital nerve divides off the maxillary division just after emerging from the foramen rotundum to enter the pterygopalatine fossa. It courses laterally over the palatine bone and maxi...
Article

Infratemporal fossa

The infratemporal fossa is a complex space of the face that lies posterolateral to the maxillary sinus and many important nerves and vessels traverse it. It lies below the skull base, between the pharyngeal sidewall and ramus of the mandible. Gross anatomy The infratemporal fossa is the space ...
Article

Infratrochlear nerve

The infratrochlear nerve is an extraconal branch of the nasociliary nerve, a branch of ophthalmic division of the trigeminal nerve. Some authors describe it as the terminal branch of the nasociliary nerve. It courses through the medial aspect of the extraconal space of the orbit inferior to the ...

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