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.

635 results found
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Uncal artery

The uncal artery is a group of small vessels providing arterial supply predominantly to the uncus. It consists of numerous terminal branches (on average 7 branches per uncus) from major intracranial arteries 1, and it is sometimes subdivided into anterior uncal arteries and posterior uncal, or u...
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Supraopticohypophyseal tract

The supraopticohypophyseal tract (TA: tractus supraopticohypophysialis) is one of the two major hypothalamohypophyseal neurosecretory tracts connecting the supraoptic nucleus and the paraventricular nucleus in the hypothalamus with the posterior pituitary (neurohypophysis). Gross anatomy Intra...
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Cerebellomedullary cisterns

Cerebellomedullary cisterns are basal cisterns located laterally and posteriorly around the medulla, between it and the adjacent cerebellum.  They are divided into paired lateral cerebellomedullary cisterns (located on either side of the medulla, directly inferior to the cerebellopontine cister...
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Paraventricular nucleus

The paraventricular nucleus is a group of neurosecretory cells in the hypothalamus that produce the hormones oxytocin and vasopressin (antidiuretic hormone). Gross anatomy The paraventricular nucleus is found in the medial area of the anterior hypothalamus immediately medial to the column of t...
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Persistent dorsal ophthalmic artery

The persistent dorsal ophthalmic artery is a rare anatomical variant of the ophthalmic artery. Instead of arising from the supraclinoid (C6) segment of the internal carotid artery, as is normally the case, the persistent dorsal ophthalmic artery arises from the lateral aspect of the cavernous (C...
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Paracingulate sulcus

The paracingulate sulcus is a secondary sulcus running anteroposteriorly in the medial surface of the frontal lobe above and parallel to the cingulate sulcus 1. It is only found in the great apes and only identified in 70-89% of humans 1.
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Sphincter pupillae muscle

The sphincter pupillae muscle is a circular ring of smooth muscle within the iris responsible for constriction of the pupil (miosis). The structure is stimulated by the parasympathetic nervous system causing the muscle to decrease in diameter as it contracts. Gross anatomy The sphincter pupill...
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Persistent primitive olfactory artery

A persistent primitive olfactory artery (PPOA) is a rare variant of the proximal anterior cerebral artery 1,2. It is proposed to be more prone to aneurysms due to its sharp hairpin-like turn. Embryologically, the persistent primitive olfactory artery is the rostral division of the primitive inte...
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Suboccipital cavernous sinus

The suboccipital cavernous sinuses are paired venous plexuses that surround the horizontal (distal V3) portion of the vertebral arteries at the craniocervical junction. Its name derives from its resemblance to the cavernous sinus as it is a venous cushion surrounding a large arterial loop at the...
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Autonomic nervous system

The autonomic nervous system (ANS) is a subdivision of the peripheral nervous system. The autonomic system provides innervation of the involuntary muscles, i.e. myocardium and smooth muscle, and glands, through which fine control of homeostasis is maintained. The afferent innervation of the aut...
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Peripheral nervous system

The peripheral nervous system (PNS) consists of the nerves (cranial nerves III-XII and spinal) and their related ganglia outside the central nervous system (CNS). The latter comprising the brain and spinal cord. The central nervous system and peripheral nervous system together form the nervous s...
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Carotid cistern

The carotid cistern is one of the basal (subarachnoid) cisterns that surrounds the supraclinoid internal carotid artery. Gross anatomy Relations and/or Boundaries The carotid cistern lies between these brain structures: medially: the optic chiasm and nerve laterally: the mesial temporal lob...
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Central nervous system

The central nervous system (CNS) is the part of the nervous system that includes the brain and spinal cord. Gross anatomy The main components of the CNS are the brain and spinal cord. In addition, the CNS includes the optic nerves (cranial nerve II), retinas, olfactory nerves (cranial nerve I)...
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Commissure (disambiguation)

A commissure (TA: commissura) is a location at which two anatomical structures are united. Though the term most commonly refers to the commissures in the brain, there are a number which exist in the human body:  central nervous system corpus callosum anterior commissure posterior commissure ...
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Trochlea (eye)

The trochlea is a cartilaginous structure acting as a pulley for the superior oblique muscle of the eye.  Gross anatomy The trochlea inserts on the trochlear fovea and spine located on the anteromedial part of the orbital roof. The tendon of superior oblique muscle passes through it 1. Functi...
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Dual stream language processing models

The dual stream language processing models (dorsal and ventral) have replaced the historic model that only included the Broca's and Wernicke's areas and the arcuate fasciculus 1.  Function The dorsal stream is responsible for phonological processing and language production (sound/sign to actio...
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Anococcygeal nerve

The anococcygeal nerve is the terminal branch of the coccygeal plexus and is described as supplying the skin of the post anal region. Gross anatomy Origin The anococcygeal nerve originates from the coccygeal plexus 2.  Course The course of the anococcygeal nerve varies according to source i...
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Coccygeal plexus

The coccygeal plexus is formed by the anterior rami of S4-S5 in combination with the coccygeal nerve and is described as supplying the skin of the post-anal region. Gross anatomy Origin The plexus consists of a minute network of nerve fibers contributed by the anterior rami of S4, S5 and the ...
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Veins of the brainstem

The veins of the brainstem drain the medulla, the pons and the mesencephalon, including the cerebral peduncles, tegmentum and quadrigeminal plate. They are characterized by several variations and feature multiple connections draining into the inferior, medial superior petrosal sinuses or form a ...
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Transverse pontine vein

The transverse pontine veins course in a horizontal fashion along the anterior surface of the pons at different heights above or below the trigeminal nerve. Gross anatomy The transverse pontine veins connect the anterior pontomesencephalic vein to the veins on the lateral pontine surface inclu...
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Peduncular vein

The peduncular veins (PV) or interpeduncular veins are veins of the brainstem and tributaries of the basal vein of Rosenthal, sometimes visible on imaging in the vicinity of the basilar artery tip and the proximal posterior cerebral artery. Gross anatomy The peduncular veins drain the cerebral...
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Anterior medullary vein

The anterior medullary vein (AMV) is a vein of the brain stem that can be seen in several individuals. It connects the anterior spinal vein to the pontomesencephalic venous system and several adjacent dural sinuses via bridging veins. Gross anatomy The anterior medullary vein usually courses i...
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Lateral mesencephalic vein

The lateral mesencephalic veins (LMV) form an important supratentorial-infratentorial anastomosis from the basal veins of Rosenthal to the superior petrosal sinus. Gross anatomy The lateral mesencephalic veins usually course through or near the lateral mesencephalic sinus. They receive venous ...
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Anterior pontomesencephalic vein

The anterior pontomesencephalic vein (APMV) is a longitudinal vein running along the anterior surface of the pons and mesencephalon and in the interpeduncular fossa. Uncommonly it can become large and can potentially lead to confusion on imaging. In a midline position, it is called the median an...
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Superior vermian vein

The superior vermian vein is formed in the midline over the superior aspect of the cerebellar vermis (over the anterior lobe) by multiple tributaries draining not just the subjacent vermis but also the adjacent cerebellar hemispheres. These tributaries most often coalesce into a single trunk ove...
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Ascending auditory pathway

Ascending auditory pathway is the intracranial component of the auditory system. It transmits auditory information collected by the inner ear to the primary auditory cortex in the brain via a number of intermediary pathways and structures.  Summary location: internal auditory canals, brain ste...
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Superior cerebellar vein

The superior cerebellar vein is formed by the union of the precentral cerebellar vein and superior vermian vein in the quadrigeminal cistern and ascends vertically as an unpaired structure to drain into the inferior aspect of the proximal (anterior) great cerebral vein of Galen 1,2.  In some in...
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Precentral cerebellar vein

The precentral cerebellar vein is an unpaired vein that courses superiorly in the quadrigeminal cistern, behind the tectal plate, to eventually drain into the inferior aspect of the proximal (anterior) great cerebral vein of Galen 1,2.  Gross anatomy The precentral cerebellar vein is formed by...
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Sagittal stratum

The sagittal strata are regions of white matter in the posterior brain located around the atria and occipital horns of the lateral ventricles. Gross anatomy The precise anatomical definition has not been agreed upon, but these borders have been proposed 1: medial: tapetum and ventricular epen...
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Marginal artery (disambiguation)

The marginal artery may refer to several different arteries in the body, including two different coronary vessels: callosomarginal artery (CNS) marginal artery (of Drummond) obtuse marginal artery (cardiac) right marginal artery (cardiac)
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Mastoid emissary vein

Mastoid emissary veins (MEV's) are a type of emissary veins representing small venous channels connecting the intracranial and extracranial venous systems. They may have a right sided dominancy and usually run between the sigmoid sinus and posterior auricular or occipital vein by crossing the m...
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Anastamoses between internal and external carotid arteries

Multiple, highly-variable anastomoses exist between the internal and external carotid arteries. These anastomoses may not be evident on non-invasive imaging or even catheter angiography, and may only be demonstrable with elevated intra-arterial pressures or high-flow states. Internal carotid ar...
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Uvula (disambiguation)

The uvula (plural: uvulae or uvulas) may refer to several different anatomical structures. When used as a standalone term it is usually understood to refer to the soft palate uvula. uvula (soft palate) uvula (cerebellum) uvula (male bladder) History and etymology Uvula is Latin for 'little ...
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Cella media

The cella media is another term to denote the body of the lateral ventricle, extending from the foramen of Monro to the ventricular atrium 1. In modern practice, it is seldom if ever used and it is unlikely to be familiar to most clinicians or radiologists. 
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Superior petrosal vein

The superior petrosal vein, also known as Dandy’s vein or simply the petrosal vein, is the largest vein in the posterior cranial fossa, draining the anterior aspect of the cerebellum and brainstem into the superior petrosal sinus.  Gross anatomy Each superior petrosal vein is usually formed by...
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Hypoglossal nucleus

The hypoglossal nuclei, exist as paired nuclei within the medulla oblongata that provide motor innervation to the intrinsic and extrinsic muscles of the tongue (excluding palatoglossus) via the hypoglossal nerve. Gross Anatomy The hypoglossal nuclei are located within the tegmentum of upper me...
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Vestibular nuclei

The vestibular nuclei are a group of four small special sensory nuclei in the lower pons and upper medulla for the vestibular nerve component of the vestibulocochlear nerve. They are part of the extensive cranial nerve nuclei within the brainstem. Gross Anatomy The four nuclei are located adja...
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Cochlear nuclei

The cochlear nuclei are a group of two small special sensory nuclei in the upper medulla for the cochlear nerve component of the vestibulocochlear nerve. They are part of the extensive cranial nerve nuclei within the brainstem. Gross Anatomy The dorsal and ventral nuclei are located in the dor...
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Cranial nerve nuclei

The cranial nerve nuclei are a series of bilateral grey matter motor and sensory nuclei located in the midbrain, pons and medulla that are the collections of afferent and efferent cell bodies for many of the cranial nerves. Some nuclei are small and contribute to a single cranial nerve, such as...
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Facial nucleus

The facial nucleus or facial motor nucleus is the efferent nucleus of the facial nerve. Gross Anatomy The nucleus is located in the caudal lower aspect of the pontine tegmentum at the level of the middle cerebellar peduncles. It lies dorsal to the medial lemniscus and ventral and medial to the...
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Oculomotor nucleus

The oculomotor nucleus is a small somatic motor nucleus in the midbrain and one of the two nuclei for the oculomotor nerve. Gross Anatomy The nucleus is located in the central midbrain at the level of the superior colliculus ventral and medial periaqueductal grey matter. It lies immediately ve...
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Edinger-Westphal nucleus

The Edinger-Westphal nucleus is a small parasympathetic motor nucleus in the midbrain and one of the two nuclei for the oculomotor nerve. It is one of the cranial nerve nuclei. Gross Anatomy The nucleus is located in the central midbrain at the level of the superior colliculus ventral and medi...
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Abducent nucleus

The abducent or abducens nucleus is a small motor nucleus in the pons for the abducens nerve. Gross anatomy The nucleus is located in the paramedian dorsal lower pons in the floor of the fourth ventricle lateral to the medial longitudinal fasciculus. The nucleus forms a longitudinal paramedian...
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Trochlear nucleus

The trochlear nucleus is a small motor nucleus in the midbrain for the trochlear nerve.  Gross Anatomy The nucleus is located in the midbrain at the level of the inferior colliculus ventral and medial periaqueductal grey and dorsal to the medial longitudinal fasciculus. It lies just caudal to ...
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Dorsal vagal nucleus

The dorsal vagal nucleus, also known as the vagal nucleus, dorsal nucleus of the vagus nerve or the dorsal motor nucleus of the vagus nerve, is a elongated nucleus within the medulla oblongata that provides parasympathetic motor innervation to the viscera of the thorax and abdomen. It is the lar...
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Calcar avis

Calcar avis, previously known as hippocampus minor, is a normal variant of the cerebral ventricular system. Gross anatomy It is a medial side indentation of the junction of the trigone and the occipital horn of the lateral ventricles by the calcarine fissure in the brain 1. Radiographic featu...
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Germinal matrix

The germinal matrix is an embryological structure in the fetal brain which is only seen in the fetus and in premature neonates. It is the most vulnerable area of the fetal brain and associated pathology carries significant mortality and morbidity.  Gross anatomy  The germinal matrix is usually...
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Pericallosal cistern

The pericallosal cistern is an unpaired subarachnoid cistern containing the pericallosal artery. It lies between the superior surface of the corpus callosum and the inferior edge of the falx cerebri and extends from the genu to the splenium of the corpus callosum 1-3. 
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Pulvinar (disambiguation)

Pulvinar may refer to: pulvinar thalamic nuclei (classically involved in variant Creutzfeldt-Jakob disease, see pulvinar sign) Haversian fat pad of the hip (which covers the central non-articular part of the acetabulum)
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Fontanelle

Fontanelles are the soft membraneous regions of the fetus and neonate calvarium where the corners of three or four developing flat bones meet and allow for the growth over the skull over the developing brain. There are two main, palpable fontanelles in the midline: anterior fontanelle, the lar...
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Inferior petro-occipital vein

The inferior petro-occipital vein is located immediately inferior to the petro-occipital suture and provides a communication between the internal carotid artery venous plexus of Rektorzik, or less commonly the cavernous sinus, anteromedially and the jugular bulb, or less commonly the inferior pe...
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Anterior condylar confluence

The anterior condylar confluence is an extracranial venous structure at the base of skull that communicates extensively with regional veins and dural venous sinuses.  It is located immediately anterior to the hypoglossal canal and medial to the jugular vein, just inferior to the jugular bulb an...
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Internal carotid artery venous plexus of Rektorzik

Internal carotid artery venous plexus of Rektorzik (also known as the petro-occipital venous plexus) is a plexus of small veins that surrounds the petrous segment internal carotid artery proximal to the cavernous sinus as it passes through the base of skull.  It is believed that the plexus serv...
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Functional neuroanatomy

Functional neuroanatomy is the study of the functional connections in the brain and spinal cord, distinct but interconnected with the structural or "more conventional" anatomic descriptions of the central nervous system. It focuses on the relationship between structure and function and hence it ...
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Marginal sinus (foramen magnum)

The marginal sinus is a dural venous sinus and runs along the inner margin of foramen magnum. It has numerous communications with regional venous structures 1-2:  anteriorly: basilar venous plexus posteriorly: occipital sinus laterally sigmoid sinus veins of the hypoglossal canal inferiorl...
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Clival diploic veins

Clival diploic veins are veins that travel through the body of the clivus connecting intracranial venous structures on the inner surface of the skull (e.g. basilar venous plexus, inferior petrosal sinuses, marginal sinus, internal carotid artery venous plexus of Rektorzik, inferior petro-occipit...
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Porus trigeminus

The porus trigeminus is the dural foramen at the entrance of the Meckel cave. Gross anatomy The porus trigeminus is the dural foramen at the trigeminal depression of the petrous apex through which the trigeminal nerve passes as it extends from the prepontine cistern of the posterior cranial fo...
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Twig-like middle cerebral artery

Twig-like middle cerebral artery or rete mirabile anomaly describes a discontinuity of a single trunk of the middle cerebral artery with several small vessels reconstituting the artery and giving it a twig-like appearance. Distally, normal vascular anatomy of the MCA branches need to be present ...
Article

Motor nucleus of the trigeminal nerve

The motor nucleus of the trigeminal nerve is the only motor nucleus of the four main trigeminal nerve nuclei. Gross anatomy The motor nucleus is a paired structure located within the mid-to-upper pons (tegmentum). It lies anteromedial to the main sensory nucleus and adjacent to the lateral asp...
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Spinal nucleus of the trigeminal nerve

The spinal nucleus of the trigeminal nerve is one of three major nuclei that make up the trigeminal sensory nerve nuclear complex along with the main sensory nucleus and the mesencephalic nucleus 1-2. Gross anatomy The spinal nucleus of the trigeminal nerve is a paired structure and is an infe...
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Mesencephalic nucleus of the trigeminal nerve

The mesencephalic nucleus of the trigeminal nerve is one of three major nuclei that make up the trigeminal sensory nerve nuclear complex along with the main sensory nucleus and the spinal nucleus 1-2. Gross anatomy The mesencephalic nucleus is a paired structure located at the mesopontine junc...
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Main sensory nucleus of the trigeminal nerve

The main or chief sensory nucleus of the trigeminal nerve is one of three major nuclei that make up the trigeminal sensory nerve nuclear complex along with the mesencephalic nucleus and the spinal nucleus 1-2. It also receives fibers from the glossopharyngeal nerve. Some older texts refer to it...
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Petrosphenoidal ligament

The petrosphenoidal ligament, also known as Gruber ligament or petroclival ligament, forms the superior border of Dorello canal, the conduit for the abducens nerve. Terminology The ligament has previously been known as the petroclinoid ligament (ligamentum petroclinoideum) but it actually does...
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Nucleus ambiguus

The nucleus ambiguus is a large longitudinal nucleus within the medulla oblongata that provides motor innervation to muscles of the pharynx, larynx and soft palate in addition to housing preganglionic nuclei involved in parasympathetic nervous system augmentation of heart rate 1,2. Gross anatom...
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Cistern of the lamina terminalis

The cistern of the lamina terminalis is one of the unpaired CSF-filled subarachnoid cisterns. Gross anatomy The cistern of lamina terminalis lies anterior to the anterior wall of the 3rd ventricle in the midline and appears like a high-top tent with a diamond-shaped floor1. It acts as a connec...
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Interpeduncular angle

The interpeduncular angle is defined as the angle formed by the posterior half of the cerebral peduncles on axial images. The interpeduncular angle has been proposed as a sensitive and specific measure of intracranial hypotension (reduced) and progressive supranuclear palsy (PSP) (increased)1,2....
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Lateral tentorial artery

The lateral tentorial artery also known as lateral tentorial arcade, is a branch of the meningohypophyseal trunk (MHT) which arises from the cavernous segment of the internal carotid artery. The lateral tentorial artery runs along the lateral edge of the tentorium cerebelli. Radiographic appear...
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Planum sphenoidale

The planum sphenoidale is a common term for the anterior horizontal part of the superior surface of the body of the sphenoid bone. It is known in the Terminologia Anatomica (2019) as the jugum sphenoideum or sphenoidal yoke 1. Gross anatomy It forms part of the anterior skull base, separating ...
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Crus (disambiguation)

A crus (plural: crura) is an anatomical term used for a structure which resembles a leg. crus (auricle) crus (cerebrum) crus (clitoris) crus (diaphragm) crus (fornix) crus (heart) crus (incus) crus (internal capsule) crus (nose) crus (penis) crus (semicircular duct) crus (stapes) cr...
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Condylar emissary veins

The condylar emissary veins (anterior, lateral, posterior) are major posterior cranial fossa emissary veins: anterior condylar vein connects the internal vertebral venous plexus to the internal jugular vein lateral and posterior condylar veins connect the external vertebral venous system with ...
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Association fibers of the brain

Association fibers of the brain, also known as association tracts of the brain or intrahemispheric tracts (cortex-cortex connections 1) are a type of white matter tract that connects different areas in the same hemisphere. There are two types of association fibers: long-range and U-fibers (short...
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Projection fibers of the brain

Projection fibers of the brain, also known as projection tracts of the brain are a type of white matter tract that connects the cortex with other areas in the CNS, e.g. deep nuclei, brainstem, cerebellum or spine. They may be efferent (motor) or afferent tracts (sensory).  Projection fibers tha...
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Bridging of the sella turcica

Bridging of the sella turcica is the fusion of the anterior and posterior clinoid processes. Epidemiology The prevalence of a sella turcica bridge in a healthy population is estimated to be ~4% (range 1.75-6 %) in anatomical and radiographic studies. Pathology It has been reported to occur i...
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Agenesis (general)

The biological/medical term agenesis (plural: ageneses) refers to failure of an organ to grow or develop during the embryological period. Examples include: appendiceal agenesis cerebellar agenesis corpus callosum agenesis dental agenesis (anodontia) diaphragmatic agenesis dorsal pancreati...
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Angular artery (MCA branch)

The angular artery (branch of the middle cerebral artery (MCA)) is an M4 branch of the middle cerebral artery (it is not the same as the facial artery angular artery branch). The artery arises from the posterior part of the Sylvian fissure and runs posteriorly. On lateral angiogram it forms a d...
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Anterior circulation

The anterior circulation is the blood supply to the anterior portion of the brain, including most of the supratentorial structures excluding the occipital lobes. The anterior circulation is supplied by the internal carotid arteries which each divide into two the large terminal branches, the ant...
Article

Elster's rule (pituitary gland)

Elster's rule provides a guide to the expected approximate pituitary gland height in relation to age 1. The rule follows an even-numbered pattern of 6, 8, 10, and 12 1: 6 mm pituitary gland height in infants and children 8 mm pituitary gland height in men and postmenopausal women 10 mm pituit...
Article

Lateral lemniscus

The lateral lemniscus is a tract of the brainstem, connecting the superior olivary nucleus and the inferior colliculus. It is part of the auditory pathway. 1
Article

Uncinate fasciculus

The uncinate fasciculus is a white matter tract that connects the uncus (Brodmann area 35), the anterior temporal areas (temporal pole; Brodmann area 38), the amygdala and the hippocampal gyrus (Brodmann areas 36 and 30) with areas of the frontal lobe (polar and orbital cortex); runs - forming a...
Article

Choroid (eye)

The choroid is part of the uveal layer of the eye along with the ciliary body and iris 1.   Summary location: posterior aspect of the globe function: vascularization of the outer retina arterial supply: posterior ciliary arteries innervation: short ciliary nerves, long ciliary nerves rela...
Article

Corticobulbar tract

The corticobulbar (or corticonuclear) tract originates primarily in Brodmann area 4 and exits at the brainstem to synapse on the lower motor neurons of the cranial nerves bilaterally. The exception to this bilateral connection is the facial nerve and hypoglossal nerve. Innervation to the lower h...
Article

Petalia

Petalia is an anatomic description of cerebral asymmetry where one of the cerebral hemispheres protrudes towards the other hemisphere and thereby causes an impression on the inner surface of the skull 1,2. Terminology The typical configuration in modern humans is the combination of a right fro...
Article

Transverse fissure

The transverse fissure (of Bichat) is the cerebral fissure that extends laterally from the ambient cistern towards the hippocampus. Gross anatomy The transverse fissure is the lateral extension of the ambient cistern that connects with the choroidal fissure superolaterally and hippocampal fiss...
Article

Hippocampal sulcus

The hippocampal sulcus, or hippocampal fissure, is a sulcus within the hippocampal formation that separates the dentate gyrus from the subiculum. Gross anatomy The hippocampal sulcus is the inferior lateral extension of the transverse fissure (of Bichat), which in turn communicates with the am...
Article

Arterial vasocorona

The arterial vasocorona is part of the spinal cord blood supply and is formed by pial anastomoses between the anterior and posterior spinal arteries on the surface of the spinal cord. It encircles the cord and supplies the peripheral lateral aspect of the spinal cord.  Engorgement of arterial v...
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Medial pontomedullary membrane

The medial pontomedullary membrane is an arachnoid membrane located anterior to the lower brainstem, separating prepontine cistern (above) from the premedullary cistern (below) 1. 
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Lateral pontomesencephalic membrane

The lateral pontomesencephalic membrane is an arachnoid membrane located lateral to the brainstem at the level of the pontomesencephalic junction, separating the ambient cistern (above) form the cerebellopontine cistern (below) 1. 
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Anterior pontine membrane

The anterior pontine membrane is an arachnoid membrane located anteriorly in the posterior fossa to the side of the basilar artery, separating the prepontine cistern (medially) form the cerebellopontine cistern (laterally) 1.  The abducens nerve (CN VI) travels within the membrane as it ascends...
Article

Arachnoid membranes

Arachnoid membranes represent sheet-like connective tissue that crosses the subarachnoid space, from the pia mater to the arachnoid mater, dividing the subarachnoid space into cisterns. A number of these membranes are named 1: Liliequist membrane: separates the chiasmatic cistern and interpedun...
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White grey sign

White grey sign is useful for identifying the central sulcus on MRI images. It reflects that fact that primary motor and sensory cortex has more myelin in it than other cortices. This results in a whitening of the cortex on T1-weighted imaging, especially noticeable at higher field strengths. On...
Article

Circular sulcus

The circular sulcus, or peri-insular sulcus is a deep sulcus that surrounds the lateral surface of the insular cortex and separates it from the operculum of the frontal, temporal and parietal lobes. In this sulcus, the M2 segment of the middle cerebral artery (MCA) completes a downward turn at t...
Article

Venous circle of Trolard

The anastomotic venous circle of the base of the brain 1, also referred to as the venous circle of Trolard 2,3,5, is an inconsistently found venous homologue of the better-known arterial circle of Willis. It should not be confused with other venous structures also described by Trolard such as t...
Article

Trigeminal ganglion

The trigeminal ganglion, also known as the Gasser, Gasserian or semilunar ganglion, is the large crescent-shaped sensory ganglion of the trigeminal nerve located in the trigeminal cave (Meckel cave) surrounded by cerebrospinal fluid. The ganglion contains the cell bodies of the sensory root of ...

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