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Anterior commissure - posterior commissure line

The anterior commissure - posterior commissure line (AC-PC line), also known as the bicommissural line, has been adopted as a convenient standard by the neuroimaging community, and in most instances is the reference plane for axial imaging in everyday scanning. The creation of a standard image p...

Anterior communicating artery

The anterior communicating artery (ACOM) arises from the anterior cerebral artery and acts as an anastomosis between the left and right anterior cerebral circulation. Approximately 4 mm in length, it demarcates the junction between the A1 and A2 segments of the anterior cerebral artery. Branche...

Anterior corticospinal tract

The anterior corticospinal tract is formed at the level of the of the medullary pyramids, where the majority (90%) of descending corticospinal tract fibers decussate to form the lateral corticospinal tract. The majority of the remaining non-decussating 10% of fibers form the much smaller anterio...

Anterior epitympanic recess

The anterior epitympanic recess, also known as the supratubal recess, is a small discrete space in the epitympanum anterior to the malleus. It is separated from the epitympanum proper by the cog.

Anterior ethmoidal foramen

The anterior ethmoid foramen is a small opening in the ethmoid bone. It is the anatomical border of anterior and posterior ethmoid air cells. It transmits the anterior ethmoidal artery, vein and nerve. The anterior ethmoid foramen is situated 25 mm away from the lacrimal crest, 12 mm anterior t...

Anterior ethmoidal nerve

The anterior ethmoidal nerve is an extraconal branch of the nasociliary nerve, a branch of the ophthalmic division of the trigeminal nerve. Some authors describe it as either the terminal branch or a direct continuation of the nasociliary nerve. It branches off distal to the infratrochlear nerv...

Anterior fontanelle

The anterior or frontal fontanelle (or fontanel) is the diamond-shaped soft membranous gap at the junction of the coronal and sagittal sutures. It persists until approximately 18-24 months after birth, after which it is known as the bregma. The precise timing of the anterior fontanelle closure i...

Anterior horn syndrome

Anterior horn syndrome is a fairly generic term used to refer to flaccid paralysis and areflexia due to involvement of the anterior grey matter horns of the spinal cord. Sensation is typically preserved. Causes of anterior horn syndrome include: anterior spinal artery ischemia poliomyeliti...

Anterior inferior cerebellar artery

The anterior inferior cerebellar artery (AICA) is one of three vessels that provides arterial blood supply to the cerebellum. It has a variable origin, course and supply, with up to 40% of specimens not having an identifiable standard AICA. The amount of tissue supplied by the AICA is variable (...

Anterior inferior cerebellar artery (AICA) infarct

Anterior inferior cerebellar artery (AICA) territory infarcts are much less common than posterior inferior cerebellar artery (PICA) infarcts. AICA generally arises from the caudal third of the basilar artery and supplies the lateral pons, inner ear, middle cerebellar peduncle and the anterior in...

Anterior perforated substance

The anterior perforated substance, or substantia perforata anterior, is an area in the basal forebrain that plays an important role with regards to the blood supply of deep grey matter structures of the brain. Gross anatomy Located within the basal forebrain, the anterior perforated substance...

Anterior pituitary

The anterior pituitary (or adenohypophysis) is by far the largest part of the pituitary gland, and is responsible for synthesis and release of most pituitary hormones (with the exception of oxytocin and antidiuretic hormone (ADH) which are released by the posterior pituitary). It consists of 3 ...

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.

Anterior ramus of the lateral sulcus

The anterior ramus of the lateral sulcus, is located at the very anterior end of the lateral sulcus (sylvian fissure), just anterior to the ascending ramus, and passes superiorly into the inferior frontal gyrus separating the pars orbitalis form the pars triangularis of the frontal operculum. ...

Anterior sacral meningocele

Anterior sacral meningocele is a congenital defect seen in the anterior aspect of the spine. It is defined as a meningeal cyst that occurs in the presacral space secondary to agenesis of a portion of the anterior sacrum. Pathology Associations In approximately 50% of cases, associated malform...

Anterior spinal artery

The anterior spinal artery supplies the anterior portion of the spinal cord and arises from the vertebral artery in the region of the medulla oblongata. The two vertebral arteries (one of which is usually bigger than the other) anastamose in the midline to form a single anterior spinal artery at...

Anterior spinal commissure

The anterior spinal commissure connects the left and right sides of the spinal cord anteriorly. It is located between the posterior-most extent of the anterior median fissure anteriorly and the ventral grey matter commissure posteriorly 1. It is composed of anterior and lateral spinothalamic t...

Anterior spinothalamic tract

The anterior spinothalamic tract, also known as the ventral spinothalamic fasciculus, is an ascending pathway located anteriorly within the spinal cord, primarily responsible for transmitting coarse touch and pressure. The lateral spinothalamic tract (discussed separately), in contrast, primar...

Anterior temporal artery

The anterior temporal artery is usually a branch of the M1 segment of the middle cerebral artery (MCA) that curves out of the Sylvian fissure and runs over the temporal lobe to supply the anterior third of the superior, middle and inferior temporal gyri. Variant anatomy The temporopolar arter...

Anterior temporal lobe perivascular spaces

Anterior temporal lobe perivascular spaces are recently recognized special variants of tumefactive perivascular spaces, which can mimic cystic tumors with surrounding edema. Epidemiology A predilection for women has been reported 1. Age range is wide, from 24 to 86 years old reported 1. Clini...

Anthrax

Anthrax is a zoonosis caused by Bacillus Anthracis. There are four types of anthrax: inhalational anthrax (also known as woolsorter's disease and ragsorter's disease ), cutaneous anthrax, injection anthrax and intestinal anthrax. Epidemiology The disease burden of anthrax decreased so dramatic...

Anti-GQ1b IgG antibody syndrome

Anti-GQ1b IgG antibody syndrome refers to a number of conditions which share autoantibodies to the ganglioside complex GQ1b, and have overlapping clinical spectrums. The conditions believed to represent various clinical manifestations of a common immunological disorder include 1: acute ophth...

Anti-MOG associated encephalomyelitis

Anti-MOG associated encephalomyelitis represents a group of inflammatory demyelinating disorders united by the presence of IgG antibodies to myelin oligodendrocyte glycoprotein (MOG) that overlap with acute disseminated encephalomyelitis (ADEM), neuromyelitis optica spectrum disorder (NMOSD) and...

Anti-N-methyl-D-aspartic acid receptor encephalitis

Anti N-methyl-D-aspartic acid (NMDA) receptor encephalitis is an autoimmune encephalitis with antibodies against the NMDA receptors. It is sometimes considered a form of autoimmune limbic encephalitis. It usually affects young patients particularly young females, in about 60% of whom ovarian ter...

Antiphospholipid syndrome

Antiphospholipid syndrome is a systemic autoimmune disorder. It is usually defined as the clinical complex of vascular occlusion and ischemic events occurring in patients who have circulating antiphospholipid antibodies. Clinical presentation Antiphospholipid syndrome is characterized by venou...

Antonio Egas Moniz

Antonio Egas Moniz (1874-1955) 1 was a pioneering Portuguese neurologist that is notable in radiology history for his development of cerebral angiography in 1927. He is also known as the developer of prefrontal leucotomy (now better known as a lobotomy) for which he received a Nobel Prize in 1...

Aphakia

Aphakia (less commonly aphacia) is the absence of the lens from the ocular globe. Pathology Etiology surgical removal of a cataract (commonest cause) trauma congenital Treatment and prognosis Surgical insertion of an intraocular lens implant, in which case the aphakic appearance is calle...

Apraxia

Apraxia is the inability to perform tasks which the patient has previously learned and has no physical impairment which would preclude them from performing them 1. Typically apraxia stems from damage to the parietal lobes.

Aprosencephaly

Aprosencephaly is an extremely rare anomaly fetal cerebral development the derivatives of the telencephalon as well as the diencephalon are absent or dysplastic, while more caudal structures are normal or mildly deformed. It falls under the aprosencephaly / atelencephaly spectrum (AAS). See al...

Aquaporin

Aquaporin is a family of transmembrane water channels found throughout the body of both humans and many other species, facilitating the passage of water, cations and gases 1. At least 13 types of aquaporin have been described, and these are variably expressed. Aquaporin 4 Aquaporin 4 (gene:...

Aqueduct stenosis

Aqueductal stenosis (AS) is the most common cause of congenital obstructive hydrocephalus, but can also be seen in adults as an acquired abnormality. Epidemiology Congenital aqueductal stenosis has an estimated incidence is at ~1:5000 births although the reported range varies greatly (3.7:1,0...

Arachnoid cyst

Arachnoid cysts are relatively common benign and asymptomatic lesions occurring in association with the central nervous system, both within the intracranial compartment (most common) as well as within the spinal canal. They are usually located within the subarachnoid space and contain CSF. On ...

Arachnoid cyst (fetal presentation)

A fetal arachnoid cyst is term given when an arachnoid cyst is diagnosed in utero. For a general discussion of arachnoid cysts refer to the parent article. Pathology They can be classified as being primary or secondary 2. primary (congenital) arachnoid cysts: result from a benign accumulation...

Arachnoid granulation

Arachnoid granulations, also known as Pacchionian granulations, are projections of the arachnoid membrane (villi) into the dural sinuses that allow CSF to pass from the subarachnoid space into the venous system. Epidemiology They increase in size and number with age and are seen in approximate...

Arachnoid hyperplasia

Arachnoid hyperplasia refers to an extensive thickening of meninges surrounding optic glioma often seen in patients with neurofibromatosis. It appears as high signal on T2 sequences surrounding the low signal glioma and resembles perineural CSF space.

Arachnoiditis

Arachnoiditis is a broad term encompassing inflammation of the meninges and subarachnoid space. Terminology Arachnoiditis affecting the cauda equina may be referred to as spinal/lumbar adhesive arachnoiditis. Clinical presentation Lumbar spine arachnoiditis can result in leg pain, sensory c...

Arachnoid mater

The arachnoid mater forms the middle layer of the meninges and together with the pia mater is sometimes referred to as the leptomeninges. Gross anatomy The arachnoid mater is a membrane that comes into direct contact with the dura mater and is separated from the pia mater by a CSF-filled spac...

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...

Arc sign (CARASIL)

The arc sign has been described in late-stage CARASIL and is seen on axial T2 weighted images. It describes high signal extending from one middle cerebellar peduncle, across the pons, to the contralateral middle cerebellar peduncle 1.

Area postrema

The area postrema, also known as the chemoreceptor trigger zone is one of the so-called circumventricular organs located on the dorsal inferior surface of the medulla oblongata at the caudal end of the fourth ventricle. The specialized ependymal cells in the area postrema detect toxins in the b...

Argyll Robertson pupil

Argyll Robertson pupil is usually bilateral and presents as bilaterally miotic and irregular pupils, which constrict briskly with accommodation but do not react to bright light therefore displaying light-near dissociation 1. It is a highly specific sign of late neurosyphilis, however can also ...

Arnold's nerve

Arnold's nerve is the auricular branch, also known as the mastoid branch, of the vagus nerve (CN X). Origin and course Arnold's nerve originates from the superior ganglion of the vagus nerve and also has a small contribution from the inferior ganglion of the glossopharyngeal nerve. It ascends ...

Arterial spin labeling MR perfusion

Arterial spin labeling (ASL) MR perfusion is an MR perfusion technique which does not require intravenous administration of contrast (unlike DSC perfusion and DCE perfusion). Instead it exploits the ability of MRI to magnetically label arterial blood below the imaging slab. The parameter most c...

Arterial supply of the head and neck

The arteries of the head and neck are branches of the common carotid and subclavian arteries. common carotid artery carotid body carotid bifurcation internal carotid artery (segments) caroticotympanic artery persistent stapedial artery ophthalmic artery supraorbital artery lacrimal arte...

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.

Artery of Adamkiewicz

The artery of Adamkiewicz, also known as the great anterior radiculomedullary artery or arteria radicularis anterior magna, is the name given to the dominant thoracolumbar segmental artery that supplies the spinal cord. Gross anatomy Origin The artery of Adamkiewicz has a variable origin but ...

Artery of Bernasconi and Cassinari

The artery of Bernasconi and Cassinari, also known as medial or marginal tentorial artery (of Bernasconi–Cassinari), commonly arises from the cavernous segment of the internal carotid artery. Gross anatomy The artery of Bernasconi and Cassinari is ~2 cm long and is an important branch of the m...

Artery of Percheron

The artery of Percheron is a rare variant of the posterior cerebral circulation characterized by a solitary arterial trunk that supplies blood to the paramedian thalami and the rostral midbrain bilaterally. From the original classification of arterial patterns at the origin of the paramedian art...

Artery of Percheron territory infarct

Artery of Percheron territory infarct is rare, on account of the relative rarity of the artery of Percheron, and presents with a variety of signs and symptoms collectively termed the paramedian thalamic syndrome. It is a type of posterior circulation infarction. On imaging, it is classically ch...

Ascending ramus of the lateral sulcus

Ascending ramus of the lateral sulcus, is located at the anterior end of the lateral sulcus (sylvian fissure), just posterior to the anterior ramus, and passes superiorly into the inferior frontal gyrus separating the pars triangularis from the pars opercularis of the frontal operculum. Termin...

Ascending transtentorial herniation

Ascending transtentorial herniation is a situation where space-occupying lesions in the posterior cranial fossa cause superior displacement of superior parts of the cerebellum through the tentorial notch. Clinical presentation nausea and/or vomiting rapid progression toward a decreased leve...

ASCOD classification (ischemic stroke)

The ASCOD classification system 1, published in 2013, aims to define phenotypes of ischemic strokes for individual patients by assigning a degree of probability to each of the most common causes of this pathology. It serves most strictly as a research tool, but is also useful clinically as a mn...

ASIA impairment scale for spinal injury

The American Spinal Injury Association Impairment Scale was developed by the American Spinal Injury Association (ASIA) in 2006, was revised in 2011, and remains the most widely used neurologic classification of spinal cord injury. Classification The scale divides spinal cord injuries into 5 ca...

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...

Astroblastoma

Astroblastomas are rare glial tumors usually found in the cerebral hemispheres of young adults and children. Epidemiology They occur at all ages range from early childhood to 6th decade but are most commonly seen in children, adolescents, and young adults with a mean age between 10-30 years 2...

Astrocytes

Astrocytes are cells of the central nervous system which act as both physical and physiological support for the neurons that are embedded between them. They are particularly abundant in the grey matter, where they are the most abundant glial cells 1. They are highly branched and contribute to t...

Astrocytic tumors

Astrocytic tumors are primary central nervous system tumors that either arises from astrocytes or appear similar to astrocytes on histology having arisen from precursor cells. They are the most common tumors arising from glial cells. They can be divided into those that are diffuse in growth (th...

Astronomical inspired signs

Many signs in radiology have been inspired by astronomical phenomena: comet tail (disambiguation) comet tail artifact (ultrasound) color comet tail artifact comet tail sign (chest) comet tail sign (phleboliths) earth-heart sign galaxy sign (chest) loss of half-moon overlap sign milky wa...

Asymmetrically large jugular bulb

Asymmetrically large jugular bulbs are entirely normal and asymptomatic; its only significance is to distinguish it from pathology. The size of the jugular bulbs is variable, with the right side being significantly larger than the left in two-thirds of people. A normal but large bulb will have...

Asymmetric fatty bone marrow of the petrous apex

Asymmetric pneumatization of petrous apex is a frequent normal anatomic variant resulting in asymmetric fatty bone marrow within the petrous apex. It is a common incidental finding on brain and skull base MRI. Clinical presentation Asymptomatic. Pathology Asymmetric pneumatization of the pet...

Asymmetric ventriculomegaly, interhemispheric cyst and dysgenesis of the corpus callosum (AVID)

Asymmetric ventriculomegaly, interhemispheric cyst and dysgenesis of the corpus callosum (AVID) is a triad of congenital cerebral anomalies. Radiographic features markedly asymmetric enlargement of the lateral ventricles may be the initial finding on routine fetal morphology ultrasound. inter...

Asymmetry of the lateral ventricles

The lateral ventricles occasionally show small side to side differences in size on CT or MRI of the brain. This asymmetry of the lateral ventricles (ALV) is an anatomic variant in most cases. Epidemiology The prevalence of asymmetry in lateral ventricle size in those without evidence of underl...

Ataxia (clinical sign)

Ataxia denotes the impaired coordination of voluntary muscle function. It is not a specific disease, but a clinical sign that can have diverse etiologies. It is typically caused by either cerebellar damage or impaired vestibular or proprioceptive afferent sensory input to the cerebellum. Clinic...

Ataxia telangiectasia

Ataxia-telangiectasia is a rare multisystem disorder that carries an autosomal recessive inheritance, sometimes classified as a phakomatosis. It is characterized by multiple telangiectasias, cerebellar ataxia, pulmonary infections, and immunodeficiency. On brain imaging, it usually demonstrate...

Atelencephaly

Atelencephaly (also termed atelencephalic microcephaly) is a rare and extreme disorder with only a handful of published cases. In this anomaly, the derivatives of the telencephalon are absent or dysplastic, while more caudal structures are normal or mildly deformed. It falls under the aprosencep...

Atlantodental interval

The atlantodental interval (ADI), as the name suggests, is the horizontal distance between the anterior arch of the atlas and the dens of the axis, used in the diagnosis of atlanto-occipital dissociation injuries and injuries of the atlas and axis. It is the distance (in mm) between the posteri...

Atretic parietal cephalocele

Atretic parietal cephaloceles (APC), also known as atretic cephaloceles, are small subscalp lesions that consist of dura, fibrous tissue, and dysplastic brain tissue. Epidemiology Common presentation in infants and young children. Clinical presentation Palpable midline parietal soft tissue ...

Atypical callosal dysgenesis

Atypical callosal dysgenesis is a term used to denote an unusual pattern of dysgenesis of the corpus callosum. The development of the corpus callosum occurs between the 12th and 16-20th weeks of gestation 2-3. It begins with the genu and then continues posteriorly along the body to the splenium...

Atypical choroid plexus papilloma

Atypical choroid plexus papillomas are WHO grade II tumors derived from choroid plexus epithelium with intermediate clinical and pathological features between the much more common, and more indolent, WHO grade I choroid plexus papilloma and the more aggressive WHO III choroid plexus carcinoma. ...

Atypical meningioma

Atypical meningioma refers to a more aggressive form of meningioma and denotes a WHO grade II tumor (along with two histological variants, clear cell meningioma and chordoid meningioma). Atypical meningiomas account for 20-30% of all meningiomas 1,3. It should be noted that epidemiology, clini...

Atypical teratoid/rhabdoid tumor

Atypical teratoid/rhabdoid tumors (AT/RT) are an uncommon WHO Grade IV tumor, which in the vast majority of cases occurs in young children less than two years of age. It most frequently presents as a posterior fossa mass. AT/RT often resembles medulloblastoma by imaging and even H&E microscopy, ...

Auditory brainstem response tracing (mnemonic)

This mnemonic helps when remembering the ascending order of structures that correspond to each waveform in an auditory brainstem response (ABR) tracing: E COLI Mnemonic E: eighth nerve action potential (wave I) C: cochlear nucleus (wave II) O: olivary complex (superior) (wave III) L: later...

Autoimmune encephalitis

Autoimmune encephalitis, also known as autoimmune limbic encephalitis, is an antibody-mediated brain inflammatory process, typically involving the limbic system, although all parts of the brain can be involved. Autoimmune encephalitis can be divided broadly into two groups, based on whether or...

Autoimmune glial fibrillary acid protein (GFAP) astrocytopathy

Autoimmune glial fibrillary acid protein (GFAP) astrocytopathy, or simply GFAP astrocytopathy, is a rare inflammatory central nervous system (CNS) disorder. Epidemiology Given the rarity of the condition, epidemiological data pertaining to autoimmune GFAP astrocytopathy are not well establishe...

Autophony

Autophony, also known as tympanophony, is the experience of finding that one's own voice sounds much louder than normal or is unpleasantly garbled. Autophony has been described in several clinical entities including superior semicircular canal dehiscence syndrome and patulous Eustachian tube d...

Autosomal recessive spastic ataxia of Charlevoix-Saguenay

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare autosomal recessive spastic ataxia unique to the region of Charlevoix-Saguenay, in the Province of Quebec, Canada. It is due to a mutation on the SACS gene locus q12 of chromosome 13. It has been reported in other regio...

AVAglio criteria for glioblastoma

The AVAglio criteria were developed to assess response to first-line treatment of glioblastoma, treated with radiotherapy and temozolomide with or without bevacizumab 1-2. These were adapted from the older Macdonald criteria, but have since been superseded by they RANO criteria (2010) 1. The A...

Azygos anterior cerebral artery

An azygos anterior cerebral artery is an uncommon to rare variant of the circle of Willis where the two A1 segments of the anterior cerebral artery (ACA) join to form a single trunk. As a result, there is no anterior communicating artery. This organization is similar to that seen in lower primat...

Babinski-Nageotte syndrome

Babinski-Nageotte syndrome is thought to be a brainstem stroke syndrome in between that of the hemimedullary syndrome (Reinhold syndrome) and the lateral medullary syndrome (Wallenberg syndrome) 1,2. Terminology In many texts this eponymous syndrome is incorrectly used synonymously with hemim...

Bálint syndrome

Bálint syndrome is characterized by: simultanagnosia (inability to perceive more than one object at a time) optic ataxia oculomotor apraxia Pathology It typically results from damage to the parieto-occipital regions, and has been associated with 1-3: corticobasal degeneration posterior co...

Baló concentric sclerosis

Baló concentric sclerosis is a rare and severe monophasic demyelinating disease, considered a subtype of multiple sclerosis, appearing as a rounded lesion with alternating layers of high and low signal intensity on MRI, giving it a characteristic 'bullseye' or 'onion bulb' appearance 1,9. Epide...

Band heterotopia

Band heterotopia, also known as double cortex syndrome, is a form of diffuse grey matter heterotopia affecting almost only women. Refractory epilepsy is present in nearly all affected patients, with partial complex and atypical absence epilepsy being the most common syndromes. On imaging, this ...

Band of Giacomini

The band of Giacomini, also known as the tail of the dentate gyrus or limbus Giacomini, is the anteromedial continuation of the dentate gyrus, which in turn is part of the hippocampal formation, along with the hippocampus, subicular complex and entorhinal cortex. It is an important anatomical la...

Bannayan–Riley–Ruvalcaba syndrome

Bannayan–Riley–Ruvalcaba syndrome (BRRS or BRR syndrome) is a very rare autosomal dominant hamartomatous disorder caused by a mutation in the PTEN gene. It is considered in the family of hamartomatous polyposis syndrome. There are no formal diagnostic criteria for this disease, but characterist...

Bannayan-Zonana syndrome

Bannayan-Zonana syndrome, also known as Bannayan-Riley-Ruvalcaba syndrome, is a rare hamartomatous disorder. Epidemiology Male predominance is reported 1. Clinical presentation Bannayan-Zonana syndrome is characterized by: macrocephaly multiple lipomas hemangiomas 1 Other findings that...

Barbell sign (progressive multifocal leukoencephalopathy)

The barbell sign has been described in a short series of patients with progressive multifocal leukoencephalopathy (PML) 1. This describes confluent FLAIR / T2w parieto-occipital abnormalities with a thin continuation of signal abnormality across the splenium. Given the lack of mass effect typi...

Bardet-Biedl syndrome

Bardet-Biedl syndrome (BBS), previously known as the Laurence-Moon-Bardet-Biedl syndrome (LMBBS), is a rare autosomal recessive hereditary condition. Clinical presentation The clinical spectrum includes: retinal anomalies: similar to that of retinitis pigmentosa intellectual disability rena...

Bare orbit sign (sphenoid wing)

The bare orbit sign, is described as a characteristic appearance of the orbit, seen when the innominate line is absent. The innominate line is a projection of the greater wing of the sphenoid, and its absence or destruction is responsible for this appearance. It is the classical frontal radiogr...

Barkovich classification of focal cortical dysplasia

Barkovich classifies focal cortical dysplasias among the his extensive classification system for malformations of cortical development, distributing them as follows: Type I and type IIb (transcortical dysplasia - Taylor type with balloon cells) as non-neoplastic malformations due to abnormal ne...

Barrow classification of caroticocavernous fistulae

Barrow caroticocavernous fistula classification divides caroticocavernous fistulas into direct (type A) or indirect (types B-D). This classification was proposed by Barrow et al. in 1985 1 and at the time of writing (mid 2016) remains the most widely used system for describing caroticocavernous ...

Basal ganglia

The basal ganglia are a group of grey matter nuclei in the deep aspects of the brain that is interconnected with the cerebral cortex, thalami and brainstem. In a strict anatomical sense, it contains three paired nuclei that together comprise the corpus striatum: caudate nucleus lentiform nucl...

Basal ganglia and thalamus signal abnormalities

Basal ganglia and thalamus signal abnormalities occur in a wide variety of conditions. Ischemia/hypoxia, metabolic disorders and toxins, particularly those that affect the respiratory chain, have a predilection for affecting the basal ganglia as they are highly metabolically active. They can b...

Basal ganglia calcification

Basal ganglia calcification is common and is seen in approximately 1% of all CT scans of the brain, depending on the demographics of the scanned population. It is seen more frequently in older patients and is considered a normal incidental and idiopathic finding in an elderly patient but should ...

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