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.

Create new article

1,924 results found

Basilar fractures of the skull

Basilar fractures of the skull, also known as base of skull fractures, are a common form of skull fracture, particularly in the setting of severe traumatic head injury, and involve the base of the skull. They may occur in isolation or often in continuity with skull vault (calvarial) fractures or...

Multiple endocrine neoplasia type IV

Multiple endocrine neoplasia type IV (MEN4), previously known as MENX, is a rare type of MEN with clinical overlap with MEN1 but is due to a CKDN1B mutation. It is characterized by 1,2: parathyroid adenoma primary hyperparathyroidism in 80% anterior pituitary adenoma neuroendocrine tumors (...

Battle sign (base of skull fracture)

Battle sign is an eponymous term given to mastoid ecchymosis (bruising of the scalp overlying the mastoid process) and is strongly suggestive of a base of skull fracture, most commonly a petrous temporal bone fracture. History and etymology Mr William Henry Battle (1855-1936) was an English s...

Otorrhagia

Otorrhagia denotes hemorrhage from the external acoustic meatus and is commonly seen in the setting of petrous temporal bone fractures or soft tissue injuries to the external or middle ear. Rarely an internal carotid artery aneurysm with dehiscence into the middle ear can present with spontaneou...

Deep petrosal nerve

The deep petrosal nerve transmits post-ganglionic sympathetic fibers from the internal carotid plexus to the Vidian nerve on its way to the pterygopalatine ganglion. Gross anatomy The nerve begins at the internal carotid plexus and runs alongside the lateral aspect of the internal carotid arte...

Posterior superior alveolar artery

The posterior superior alveolar artery is a branch of the third (peterygopalatine) part of the maxillary artery. It branches off within the pterygopalatine fossa and exits via the pterygomaxillary fissure on its way to the maxillary tuberosity. It supplies the upper premolar and molar teeth as...

Accessory meningeal artery

The accessory meningeal artery is a branch of the maxillary artery but can also branch from the middle meningeal artery. The artery passes upwards through the foramen ovale to supply the trigeminal ganglion and the dura mater of Meckel cave and the middle cranial fossa. It also usually supplies...

Proliferating trichilemmal cyst

Proliferating trichilemmal cysts, sometimes known as proliferating trichilemmal tumors, are dermal or subcutaneous tumors with squamoid cytologic features and trichilemmal-type keratinization, which usually arise in the scalp. Terminology A variety of names have been used for this pathology, i...

Skull fractures

Skull fractures are common in the setting of both closed traumatic brain injury and penetrating brain injury. Their importance is both as a marker of the severity of trauma and because they are, depending on location, associated with a variety of soft tissue injuries. This article will focus o...

Sistrunk procedure

The Sistrunk procedure consists of removing a thyroglossal duct cyst and surrounding tissues. The rationale for this procedure is that cure of the thyroglossal duct cysts will be unsuccessful unless the epithelium-lined tract (extending from the cyst to the foramen cecum of the tongue) is comp...

Posterior perforated substance

The posterior perforated substance or substantia perforata posterior, is an area of grey matter in the brain situated in the interpeduncular fossa between the cerebral crura. Gross anatomy The posterior perforated substance is a triangular area of grey matter located within the interpeduncular...

Myofascial cone

The myofascial cone is a structure within the orbit involved in the movement and support of the globe, or more simply the eye. It also serves as the physical division between the intraconal and extraconal compartments, but the cone itself is included in the contents of the intraconal space 1. ...

Orbital apex

The orbital apex refers to the posterior confluence of the orbit at the craniofacial junction, where nerves and vessels are transmitted from the intracranial compartment into the orbit via several bony apertures. It is also the point where the extraocular muscles derive their origins. Contents ...

Foramen Vesalii

The foramen Vesalii (plural: foramina Vesalii), also known as the foramen of Vesalius, sphenoidal emissary foramen, foramen venosus or canaliculus sphenoidal, is a tiny variably present foramen in the greater wing of the sphenoid bone. It transmits a sphenoidal emissary vein linking the pterygoi...

Lesser wing of sphenoid

The lesser wing of the sphenoid bone, or orbito-sphenoid, is a sharp, pointed triangular plate arising laterally from the upper anterior portion of the sphenoid body. Gross anatomy The lesser wing features both superior and inferior surfaces: the superior surface is flattened and is in conta...

Internal auditory canal diverticulum

An internal auditory canal (IAC) diverticulum or notch, also known as cupping of the internal auditory canal, is a small focal outpouching arising from the anterolateral wall of the internal acoustic canal (IAC). This is a benign normal variant and distinct from, although may occur in conjunctio...

Naso-orbitoethmoid region

The naso-orbitoethmoid (NOE) region or interorbital region simply refers to the space between the orbits. Gross anatomy Boundaries anterior: frontal process of the maxilla, nasal process of frontal bone, nasal bone posterior: sphenoid sinus lateral: medial orbital wall superior: cribrifor...

Greater wing of sphenoid

The greater wing or ali-sphenoid of the sphenoid bone is a process which projects from either side of the lower part of the sphenoid body, at a common junction with the pterygoid process 1. It is a paired structure, which curves upward, backward and laterally from each side of the sphenoid body,...

Olfactory system

The olfactory system transmits smell from detection of odorants at the olfactory epithelium in the nasal cavity to the primary olfactory cortex. It is phylogenetically the most ancient sensory tract and terminates on primitive cortical areas. Gross anatomy Primary olfactory neurons are bipola...

Ocular globe

The ocular globes or simply, the eyes are paired spherical sensory organs, located anteriorly on the face within the orbits, which house the visual apparatus. Gross anatomy Location The globe is suspended by the bulbar sheath in the anterior third of the bony orbit. Size Each globe is an a...

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

Olfactory fossa

The olfactory fossae or grooves of the cribriform plate are shallow depressions located within the ethmoid bone in the anterior cranial fossa that contains the olfactory bulb of the olfactory nerve 1. The floor is formed by the medial lamella of the cribriform plate, bordered laterally by the la...

COL4A1-related disorders

COL4A1-related disorders are a group of autosomal dominant disorders caused by a mutation in the COL4A1 gene. Epidemiology The exact prevalence is unknown, but the group of disorders is considered to be under-recognized, especially asymptomatic variants 1. Clinical presentation The clinical ...

Iodine

Iodine (chemical symbol I) is one of the trace elements. Its biological importance is its central place in the physiology of the thyroid gland and, in radiology, as the key chemical constituent of most of the radiographic, fluoroscopic, and CT contrast media. Chemistry Basic chemistry Iodine ...

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...

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...

RASopathy

RASopathies are a class of developmental disorders caused by germline mutations in genes that encode for components or regulators of the Ras/mitogen-activated protein kinase (MAPK) pathway. Epidemiology As a group, RASopathies represent one of the most common malformation syndromes, with an in...

Cochlear incomplete partition

Cochlear incomplete partition is a group of cochlear malformations associated with variable other inner ear architecture defects. These malformations have in common that the cochlea is clearly separated from the vestibule and the external contour of the cochlea is nearly normal in size, but ther...

Interscalar septum

The interscalar septum is a thin bony plate that separates each turn of the cochlea 1. It radiates from the modiolus laterally to the spiral ligament 2. Vessels (venules, arterioles and capillaries) run within the septum through bony canals 2. Related pathology Partial absence of the intersca...

Cochlear incomplete partition type II

Cochlear incomplete partition type II (IP-II) is a type of inner ear malformation, specifically a cochlear incomplete partition, associated with sensorineural hearing loss. It is characterized by a cystic cochlear apex and should not be confused with Mondini anomaly, which is a historic term for...

Asymmetric pneumatization of the petrous apex

Asymmetric pneumatization of the petrous apex is a frequent normal anatomic variant resulting in an appearance that can be mistaken for pathology within the petrous apex; see petrous apex lesions (differential). Clinical presentation As this is an anatomical variant it is entirely asymptomatic...

Wolff-Chaikoff effect

Wolff-Chaikoff effect is an autoregulatory phenomenon, whereby a large amount of ingested iodine acutely inhibits thyroid hormone synthesis within the follicular cells, irrespective of the serum level of thyroid-stimulating hormone (TSH) 1. Pathology The Wolff-Chaikoff effect is thought to be...

Perilymph

Perilymph is one of the two types of fluid in the inner ear, the other being endolymph. It surrounds the membranous labyrinth within the bony labyrinth. The portion within the cochlea is located in the scala vestibuli and scala tympani. It is a clear fluid with an ionic composition very similar...

Endolymph

Endolymph is one of the two types of cochlear fluids, the other being perilymph. It is located in the scala media of the cochlea. It is secreted by the stria vascularis (also colloquially called the 'battery of the cochlea') on the outer wall of the scala media. It has a high level of potassium...

Scala vestibuli

The scala vestibuli, also known as vestibular duct, is the superior most duct of the cochlea duct. It is filled with perilymph and communicates directly with the subarachnoid space via the perilymphatic duct. It is separated from the scala media by Reissner's membrane (vestibular membrane) and ...

Scala tympani

The scala tympani, also known as the tympanic duct, is the inferior most duct of the cochlea. It is filled with perilymph and communicates directly with the subarachnoid space via the perilymphatic duct. It is separated from the scala media and scala vestibuli by the spiral lamina. See also c...

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

Round window

The round window (or fenestra cochleae) is one of two openings in the middle ear at the level of the cochlea allowing communication between the mesotympanum of the middle ear and the inner ear. It vibrates with opposite phase to vibrations from the inner ear, producing movement of perilymph in t...

Organ of Corti

The organ of Corti, also known as the spiral organ, is the receptor organ for hearing, located in the cochlea (housed inside the scala media). It is a strip of sensory epithelium made of hair cells which act as the sensory receptors of the inner ear. Function This is a gross oversimplification...

Spiral ganglion

The spiral ganglion is a group of nerve cells located in the modiolus that enables the sense of hearing by sending a representation of sound from the cochlea to the brain. The body of these nerve cells emits a peripheral process that contacts acoustic receptors in the organ of Corti and a centr...

Spiral lamina

The cochlear spiral lamina is a thin bone structure that projects from the modiolus, separating the cochlear canal in two main components or scala, the scala tympani (lower portion) and the scala vestibuli (upper portion). At the cochlear apex, the spiral lamina ends in a hook-shaped process ca...

Modiolus (cochlea)

The modiolus (plural: modioli) is part of the cochlea and is a conical-shaped structure that consists of spongy (porous) bone located in the center of the cochlea and contains the spiral ganglion. The spiral lamina projects from the modiolus. Abnormality of the modiolus results in sensorineura...

Nasal vestibule

The nasal vestibule forms the small mildly dilated area of the most anterior portion of the nasal cavity, just inside the anterior naris. It is formed by the columella medially, the nasal ala laterally and anteriorly and the nasal sill posteriorly.

Anterior naris

The anterior (or external) nares (singular: naris) (a.k.a. nostrils) are openings that form the entrance to the nose. Each naris is formed by a ring of structures: medially the columella (soft tissue anteroinferior portion of the nasal septum) laterally and superiorly the nasal ala inferiorly...

Endophthalmitis

Endophthalmitis (plural: endophthalmitides) is a potentially sight-threatening condition that involves intraocular inflammation of any cause. It is distinguished from panophthalmitis in that it does not extend beyond the sclera. It is either infectious or non-infectious in etiology, but in clini...

Columella

The columella is the most anteroinferior portion of the nasal septum and forms the central fleshy portion between the two nostrils when looking at someone's nose. It is a single midline structure composed of cartilage and overlying skin, extending posteriorly from the tip of the nose. The latera...

Nasal sill

The nasal sill is the soft tissue ridge forming the posterior margin of the anterior naris. It also forms the caudal margin of the nasal vestibule. The nasal sill forms part of the nasal base, which is defined as the inferior third of the nose when viewing the nose from below with the neck exte...

Ritscher-Schinzel syndrome

Ritscher-Schinzel syndrome (RTSC), also known as 3C (cranio-cerebello-cardiac) syndrome, is a rare entity with a variable spectrum of CNS (primarily cerebellar), craniofacial, and congenital heart defects. Clinical presentation craniofacial cleft palate ocular coloboma prominent occiput lo...

Depressor anguli oris muscle

The depressor anguli oris muscle (also known as the triangularis muscle) is one of the facial muscles. Summary origin: oblique line of the mandible insertion: modiolus at the angle of the mouth superficial fibers from both sides merge to form the transversus menti innervation: facial ner...

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...

Superior labial artery

Superior labial artery (old name: superior coronary artery) is one of the facial branches of the facial artery. It is bigger and more serpiginous than the inferior labial artery. It supplies the upper lip, including its labial glands, mucous membranes and muscles. Summary origin: facial branch...

Nasal septum

The nasal septum (Latin: septum nasi) separates the left and right nasal cavities. It extends from the nares anteriorly to the choanae posteriorly and is covered by squamous epithelium. Gross anatomy The vertical midline nasal septum is comprised primarily of a single nasal cartilage from the ...

Dacryocystography

Dacryocystography (DCG) is a fluoroscopic contrast examination of the nasolacrimal apparatus. The nasolacrimal duct is cannulated enabling iodinated contrast to be instilled into the nasolacrimal system. Indications The most frequent indication is epiphora: excessive tearing or watering of the...

Adenocarcinoma of the lacrimal glands

Adenocarcinoma of the lacrimal glands is rare, with few cases reported in the literature since it was first described in 1996 1. Primary adenocarcinoma of the lacrimal gland is extremely rare; only 9 cases have been reported in the literature 1,2. It can be classified into high- and low-grade ma...

Palatine bone

The palatine bones are paired L-shaped bones joined at the midline. They form the hard palate with the maxillary bones. They also form part of the floor of the nasal cavity (the hard palate separates the oral cavity from the nasal cavity). Gross anatomy The palatine bones are located at the b...

Syphilis

Syphilis is the result of infection with the gram-negative spirochete Treponema pallidum, subspecies pallidum. It results in a heterogeneous spectrum of disease with many systems that can potentially be involved, which are discussed separately. Epidemiology Despite the discovery of penicillin...

Neurosyphilis

Neurosyphilis results from infection of the central nervous system by the spirochete Treponema pallidum, subspecies pallidum. The disease has a heterogeneous spectrum of early and late manifestations. For a general discussion, and for links to other system-specific manifestations, please refer ...

Superficial temporal vein

The superficial temporal vein arises in a plexus on the side and vertex of the skull and, in the substance of the parotid gland, joins with the maxillary vein to form the retromandibular vein. Gross anatomy The superficial temporal vein originates from a venous plexus on the side and vertex of...

Facial vein

The facial vein (previously known as the anterior facial vein) is the continuation of the angular vein and joins the anterior branch of the retromandibular vein to form the common facial vein 1-3. Gross anatomy At the level of the lower margin of the orbit, the angular vein becomes the facial ...

Angular vein

The angular vein drains the anterior region of the scalp 1. It is formed by the union of the supratrochlear and supraorbital veins and becomes the facial vein 1,2,3. Gross anatomy The angular vein forms at the medial canthus as the supratrochlear and supraorbital veins unite 1,2. The angular v...

Rhinal sulcus

The rhinal sulcus is located on the anteromedial surface of the temporal lobe. It curves in an anteroposterior direction and separates the uncus from the temporal pole. Some sources consider it to be an extension of the collateral sulcus 1-4. The grey matter overlying the rhinal sulcus has been ...

Stellate ganglion

The stellate ganglion (plural: ganglia), also known as the cervicothoracic ganglion, is formed by the inferior cervical and first thoracic ganglia and is located just anterior to the head of the first rib. It receives input from the paravertebral sympathetic chain and provides sympathetic effere...

Common facial vein

The common facial vein is formed by the joining of the facial vein and the anterior branch of the retromandibular vein. It is part of the venous drainage system of the face. Summary origin and termination: the facial vein (along with the facial artery) pierces the deep investing fascia of the ...

Waardenburg syndrome

Waardenburg syndrome is a rare neurocristopathy, with congenital pigmentary disorder secondary to an abnormal distribution of neural crest-derived melanocytes during embryogenesis resulting in patchy areas of depigmentation. It is considered in the investigation of congenital sensorineural deafn...

Koerner septum

The Koerner septum, also known as the petrosquamous lamina or septum, is a thin bridge of bone which divides the petrous and squamous portion of the mastoid air cells at the level of the mastoid antrum. It represents the continuation and persistence of the petrosquamous suture 2. It is commonly...

CDKN2A/p16

CDKN2A (cyclin-dependent kinase inhibitor 2A) is a tumor suppressor gene that encodes for the p16 protein, involved in the CDK4/6–RB1 cell-cycle pathway 5. p16 is a widely used immunohistochemical marker indicating expression of the cell cycle protein, which is upregulated by human papillomavi...

Lingual tonsils

The lingual tonsils are aggregations of lymphoid follicles that mediate B- and T-cell lymphocytes, which serve a role in formulating the immune system. They are covered by stratified squamous nonkeratinized epithelium and contain deep crypts and mucosal glands. They form a part of the Waldeyer r...

Vitreous hemorrhage

Vitreous hemorrhage refers to bleeding into the vitreous humor. Epidemiology Vitreous hemorrhage has an incidence of approximately 7 in 100,000 1,2. Clinical presentation The most common clinical presentation is with sudden, painless visual loss to varying degrees of severity 2. Associated...

Supraclavicular triangle

The supraclavicular triangle is one of the paired triangles in the posterior triangle of the neck. The triangles of the neck are surgically focussed, first described from early dissection-based anatomical studies which predated cross-sectional anatomical description based on imaging (see deep sp...

Occipital triangle

The occipital triangle is one of the paired triangles in the posterior triangle of the neck. The triangles of the neck are surgically focussed, first described from early dissection-based anatomical studies which predated cross-sectional anatomical description based on imaging (see deep spaces o...

Submental triangle

The submental triangle is the single midline triangle, part of the anterior triangle of the neck. The triangles of the neck are surgically focussed, first described from early dissection-based anatomical studies which predated cross-sectional anatomical description based on imaging (see deep spa...

Muscular triangle

The muscular triangle is one of the paired triangles in the anterior triangle of the neck. The triangles of the neck are surgically focussed, first described from early dissection-based anatomical studies which predated cross-sectional anatomical description based on imaging (see deep spaces of ...

Carotid triangle

The carotid triangle is one of the paired triangles in the anterior triangle of the neck. The triangles of the neck are surgically focussed, first described from early dissection-based anatomical studies which predated cross-sectional anatomical description based on imaging (see deep spaces of t...

Triangles of the neck

The triangles of the neck are surgically focussed divisions of the neck, first described from early dissection-based anatomical studies which predated cross-sectional anatomical description based on cross-sectional imaging (see deep spaces of the neck). The neck can be divided into anterior and...

Digastric triangle

The digastric triangle is one of the paired triangles in the anterior triangle of the neck. The triangles of the neck are surgically focussed, first described from early dissection-based anatomical studies which predated cross-sectional anatomical description based on imaging (see deep spaces of...

Posterior triangle of the neck

The posterior triangle of the neck forms the posterior compartment of the neck and is separated from the anterior triangle by the sternocleidomastoid muscle. The triangles of the neck are surgically focused, first described from early dissection-based anatomical studies which predated cross-sect...

Anterior triangle

The anterior triangle forms the anterior compartment of the neck and is separated from the posterior triangle by the sternocleidomastoid muscle. The triangles of the neck are surgically focused, first described from early dissection-based anatomical studies which predated cross-sectional anatomi...

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...

Canadian C-spine rules

Canadian C-spine rules are a set of guidelines that help a clinician decide if cervical spine imaging is not appropriate for a trauma patient in the emergency department. The patient must be alert and stable. There are three rules: is there any high-risk factor present that requires cervical s...

NEXUS criteria

NEXUS (National Emergency X-Radiography Utilization Study) is a set of validated criteria used to decide which trauma patients do not require cervical spine imaging. Trauma patients who do not require cervical spine imaging require all of the following: alert and stable no focal neurologic de...

Shock thyroid

Shock thyroid is an uncommon part of the hypovolemic shock complex. It was initially described in 2006 as heterogeneous thyroid contrast enhancement and fluid surrounding the thyroid on trauma CT of shocked patients without evidence for direct thyroid injury 2. Only eight cases have been descr...

Sphenoid sinus mucocele

A sphenoid sinus mucocele is a location-specific subtype of a paranasal sinus mucocele. Epidemiology Sphenoid sinus mucoceles are uncommon and only account for around 1-2 % of all paranasal sinus mucoceles 1-7. Clinical presentation Can be variable and range from deep-seated headaches to cr...

Bolger classification of maxillary sinus hypoplasia

The Bolger classification of maxillary sinus hypoplasia proposed by Bolger et al. in 1990 1 takes into account associated anomalies of the uncinate process, which are of utmost importance for planning functional endoscopic sinus surgery (FESS). Maxillary sinus hypoplasia in itself is asymptomat...

Squamomastoid suture

The squamomastoid suture is the cranial suture at the outer surface between the squamous and (petro)mastoid portion of the temporal bone. It is also called the external petrosquamous suture 2 or external posterior petrosquamosal suture 3 as it actually represents the posterior and external aspec...

Calcification of the external ear (differential)

Calcification of the external ear (auricular cartilage) may arise from a number of causes, including: hyperparathyroidism gout pseudogout relapsing polychondritis frostbite trauma cauliflower ear ochronosis sarcoidosis diabetes mellitus adrenal insufficiency osteoprotegerin (OPG)-def...

Coccidioidomycosis

Coccidioidomycosis refers to an infection caused by the dimorphic fungus Coccidioides spp., usually localized to the lungs. This disease is not to be confused with the similarly named paracoccidioidomycosis. Epidemiology The most common species of Coccidioides are Coccidioides immitis and Cocc...

Odontohypophosphatasia

Odontohypophosphatasia is the mildest form of hypophosphatasia that manifests as tooth dysplasia and/or early loss of deciduous or permanent teeth. Pathology As with all forms of hypophosphatasia, the underlying abnormality is a mutation in the ALPL gene that encodes for tissue non-specific al...

Bony orbit

The bony orbit refers to the bones that constitute the margins of the orbits, that is the roof, medial and lateral walls and floor. The orbital margin or rim refers to the anterior circular margin of the orbit. The orbital apex refers to the posterior confluence of the orbit, where the optic can...

Extraconal orbital compartment

The extraconal orbital compartment or extraconal space is the space within the orbit outside the musculofascial cone. The base of which is anterior and is formed by the orbital septum that surrounds the equator of the globe. The external sides are formed by the bones of the orbit and their perio...

Orbital nerve supply

There are numerous nerves of the orbit with have varying functions. There are best described divided into groups based on how they enter the orbit. Optic canal optic nerve (CN II): special sensory nerve of the globe (vision) Superior orbital fissure superior division of the oculomotor nerve ...

Pharynx

The pharynx (plural: pharynges or pharynxes) is the superior dilated part of the alimentary tract that connects the nasal and oral cavities to the esophagus. It also forms part of the upper respiratory tract. Gross anatomy The pharynx is composed of three parts: nasopharynx: posterior to the ...

Sail sign (disambiguation)

There are numerous sail signs in radiology, where a normal structure is displaced or a pathology creates the appearance of a sail: elbow sail sign: the raised anterior fat pad on an elbow radiograph thymic sail sign: normal thymus on a pediatric chest radiograph spinnaker-sail sign (angel win...

Greater occipital nerve

The greater occipital nerve is a cutaneous nerve, the thickest in the body, that innervates the skin from the upper neck, over the occiput, up to the vertex of the scalp 1-3. Terminology The greater occipital nerve has also been known in the past - confusingly - as the nerve of Arnold. But as...

Filtered (1)Done (clear)

+Systems

+Article Sections

+Sort By

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

Unable to process the form. Check for errors and try again.

Thank you for updating your details.