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.

2,183 results found
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Superior temporal sulcus

The superior temporal sulcus runs longitudinally along the lateral surface of the temporal lobe, parallel to the Sylvian fissure above and the inferior temporal sulcus below. It separates the superior temporal gyrus from the middle temporal gyrus.  Posteriorly it is capped by the angular gyrus. 
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Supplementary motor area

The supplementary motor area is involved in preparing for voluntary movements carried out by the primary motor area (precentral gyrus). It is located on the medial surface of the frontal lobe, contained within the medial frontal gyrus, just anterior to the paracentral lobule 1. 
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Supramarginal gyrus

The supramarginal gyrus is a portion of the parietal lobe of the brain. It is one of the two parts of the inferior parietal lobule, the other being the angular gyrus. It plays a role in phonological processing and emotional responses. Gross anatomy Relations The supramarginal gyrus is horsesh...
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Supraoptic nucleus

The supraoptic nucleus (SON) contains neurosecretory cells that produce hormones (oxytocin and vasopressin/antidiuretic hormone).  Gross anatomy The supraoptic nucleus is found in the medial area of the anterior hypothalamus, sitting superior to the optic tract 1. The hormones travel down the...
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Supraoptic recess

The supraoptic recess is a small angular recess or diverticulum that sits at the junction of the floor and anterior wall of the third ventricle, immediately above the optic chiasm. Related pathology When the third ventricle is expanded due to hydrocephalus (e.g. aqueduct stenosis) this recess,...
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Suprasellar arachnoid cyst

Suprasellar arachnoid cysts can be challenging to diagnose and, unlike many other arachnoid cysts, are usually symptomatic.  For a general discussion, please refer to the article on arachnoid cysts. Clinical presentation As can be expected from its location, suprasellar arachnoid cysts manife...
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Suprasellar cistern

The suprasellar cistern (also known as the chiasmatic cistern or pentagon of basal cisterns) is a cerebrospinal fluid-filled cistern located above the sella turcica, under the hypothalamus and between the uncus of the temporal lobes. It contains the proximal part of Sylvian fissure,  the optic c...
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Suprasellar cistern lipoma

Suprasellar cistern lipomas are uncommon, usually incidental findings, with characteristic imaging features and a very limited differential diagnosis.  For a general discussion of intracranial lipomas please refer to the general article: intracranial lipoma.  Epidemiology Suprasellar cistern ...
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Suprasellar cystic lesions

The differential for suprasellar cystic lesions is large and predominantly includes developmental and neoplastic conditions. Differential diagnosis Developmental arachnoid cyst craniopharyngioma Rathke's cleft cyst dermoid cyst epidermoid cyst ependymal cyst enlarged perivascular spaces...
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Supratentorial ependymoma

Supratentorial ependymomas are a type of location-specific ependymoma. They account for 30% of ependymomas, and in most instances are within or abutting the ventricles (third and fourth ventricles). In approximately 40% of cases they are remote from the ventricular surface, located within the pa...
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Supratentorial intracranial mass in an adult (an approach)

The identification of a supratentorial intracranial mass in an adult is a fairly common clinical scenario, the appropriate management of which relies heavily on preoperative imaging. Often important clues will be present in the clinical history (e.g. immunosuppression, systemic malignancy, durat...
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Susac syndrome

Susac syndrome (SS), also known as SICRET syndrome (small infarctions of cochlear, retinal and encephalic tissue), is a rare syndrome typically affecting young to middle-age women that is clinically characterised by the triad of acute or subacute encephalopathy, bilateral sensorineural hearing l...
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Susceptibility weighted imaging

Susceptibility weighted imaging (SWI) is an MRI sequence which is particularly sensitive to compounds which distort the local magnetic field and as such make it useful in detecting blood products, calcium, etc. Physics SWI is a 3D high-spatial resolution fully velocity corrected gradient echo ...
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Sutural diastasis

Sutural diastasis is an abnormal widening of the skull sutures. It may be physiological in a neonate during a growth spurt.  Pathology In non-traumatic scenarios accelerated growth of the sutural connective tissue without concurrent ossification is the underlying pathology.  Aetiology trauma...
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Sutures

There are many sutures of the skull, which are where skull bones meet. In general, sutures don't fuse until brain growth is complete, therefore allowing the skull to increase in size with the developing brain. Gross anatomy Sutures are fibrous joints with the periosteum externally and outer la...
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Suzuki staging system for Moyamoya

The staging system for moyamoya disease first described by Suzuki and Takaku in their seminal 1969 article1 is still in use today. Formally, the staging refers to findings on conventional angiography, although there are efforts to apply similar systems to MR angiography.2 Suzuki stage appears t...
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Swallow tail sign (substantia nigra)

The swallow tail sign describes the normal axial imaging appearance of nigrosome-1 within the substantia nigra on high resolution T2*/SWI weighted MRI. Absence of the sign (absent swallow tail sign) is reported to have a diagnostic accuracy of greater than 90% for Parkinson disease and dementia ...
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Swirl sign (intracranial haemorrhage)

The swirl sign refers to the non-contrast CT appearance of acute extravasation of blood into a haematoma, for example an extradural haematoma or subdural haematoma. It represents unclotted fresh blood which is of lower attenuation than the clotted blood which surrounds it 1. It is the corollary...
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Sylvian cistern

The Sylvian cistern, also known as the insular cistern, is one of the CSF-filled subarachnoid cisterns. Gross anatomy There are two paired cisterns on either side. It is the subarachnoid space extending into the fissure of the frontal and temporal lobes (i.e. the lateral sulcus). It therefore ...
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Sylvian fissure

The Sylvian fissure, also known as the lateral sulcus, separates the frontal and parietal lobes superiorly from the temporal lobe inferiorly. The insular cortex is located immediately deep to the Sylvian fissure.  Anteriorly the fissure courses medially to the 'stem' of the lateral fissure, int...
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Sympathetic chain

The sympathetic chain is a component of the autonomic nervous system and is composed of general visceral afferent and efferent axons that allow for involuntary control of bodily functions via the hypothalamus. The overarching function of the sympathetic system is to control the 'fight, fright o...
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Syntelencephaly

Syntelencephaly, also known as middle interhemispheric variant (MIHV), is a mild subtype of holoprosencephaly that is characterized by an abnormal midline connection of the cerebral hemispheres between the posterior frontal and parietal regions.  Epidemiology Syntelencephaly is a congenital ma...
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Synucleinopathies

Synucleinopathies are a subgroup of neurodegenerative diseases, characterised by impairment of alpha-synuclein metabolism, resulting in abnormal intracellular deposits and can further be divided into those with and those without the formation of Lewy bodies 1-2: diseases with Lewy bodies Parki...
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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...
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Syringobulbia

Syringobulbia is a rare entity and refers to a syrinx that extends into the medulla oblongata 1. Terminology Some authors use syringobulbia to refer to a syrinx present in any portion of the brainstem rather than specifically involving the medulla oblongata, and therefore encompassing syringop...
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Syringocephalus

Syringocephalus , also known as syringoencephalomyelia, is a very rare entity and refers to a syrinx that extends into the cerebrum 1. Clinical presentation Patients with this condition demonstrate a wide variety of focal neurological symptoms depending on where the syrinx is located 1. Patho...
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Syringomesencephaly

Syringomesencephaly is a very rare entity and refers to a syrinx that extends into the midbrain 1. Clinical presentation Patients with this condition demonstrate a wide variety of neurological symptoms localised to the brainstem and spinal cord, depending on where exactly the syrinx is located...
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Syringomyelia

Syringomyelia refers to a cystic collection, or syrinx, that occurs within the spinal cord around the central canal.  Terminology Although syringomyelia is distinct from hydromyelia, in which there is simply dilatation of the central canal, it is very difficult to distinguish the two on imagin...
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Syringopontia

Syringopontia is a rare entity and refers to a syrinx that extends into the pons 1. Clinical presentation Patients with this condition demonstrate a wide variety of neurological symptoms localised to the pons, medulla oblongata, and spinal cord, depending on where exactly the syrinx is located...
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Syrinx

Syrinx is the collective name given to hydromyelia, syringomyelia, syringobulbia, syringopontia, syringomesencephaly, and syringocephalus. Terminology The use of the general term 'syrinx' has grown out of the difficulty in distinguishing between hydromyelia and syringomyelia using current imag...
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Syrinx terminology

There are specific terms used when describing a syrinx or other cystic lesions within the spinal cord 1: hydromyelia: fluid accumulation/dilatation within the central canal, therefore, lined by ependyma syringomyelia: cavitary lesion within cord parenchyma, of any cause (there are many); locat...
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Systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with multisystem involvement. It is also sometimes classified as a vasculitis.  Epidemiology There is an overall increased female predilection. In adults, women are affected 9-13 times more than males. In children, this ratio i...
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Systemic lupus erythematosus (CNS manifestations)

Central nervous system manifestations of systemic lupus erythematosus (CNS lupus) describe a wide variety of neuropsychiatric manifestations that are secondary to systemic lupus erythematosus (SLE) in the central nervous system (CNS). For a general discussion, and for links to other system spec...
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T1 black holes

T1 black holes are hypointense lesions commonly seen on T1WI in patients with multiple sclerosis, and indicates the chronic stage with white matter destruction, axonal loss and irreversible clinical outcome. There is a correlation between the number of black holes and patient positive outcome 3.
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T2 blackout effect

T2 blackout effect is a diffusion weighted imaging phenomenon, representing the reverse of T2 shine through. The 'true' diffusion signal (as determined by ADC values) is reduced on DWI images (e.g. B=1000) by the presence of very low T2 signal (on B=0 images). 
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T2 hyperintense basal ganglia (mnemonic)

A helpful mnemonic to recall the causes of T2 hyperintense basal ganglia is: LINT Mnemonic L: lymphoma I: ischaemia N: neurodegenerative conditions T: toxins See also For a more detailed differential please see T2 hyperintense basal ganglia article. 
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T2 hypointense basal ganglia (mnemonic)

The commonest causes of basal ganglia T2 hypointensity can be recalled using the following mnemonic: ChOMP Mnemonic Ch: childhood hypoxia O: old age M: multiple sclerosis P: Parkinson's disease, more in globus pallidus
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T2 shine through

T2 shine-through refers to high signal on DWI images that is not due to restricted diffusion, but rather to high T2 signal which 'shines through' to the DWI image. T2 shine through occurs because of long T2 decay time in some normal tissue. This is most often seen with subacute infarctions due ...
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T2 washout

T2 washout is a phenomenon encountered on diffusion weighted imaging (DWI) which results in DWI images (e.g. B = 1000) appearing normal despite abnormal ADC maps.  For the phenomenon to occur a particular combination of ADC and T2 signal intensity is required.  increased T2 signal facilitated...
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Tabes dorsalis

Tabes dorsalis is a form of tertiary late neurosyphilis in which there is demyelination of the posterior columns of the spinal cord. For a general discussion, and for links to other system specific manifestations, please refer to the article on syphilis.  Clinical presentation Patients presen...
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Tam o' shanter sign (skull)

The "tam o' shanter" is a Scottish hat, named after the character in Robert Burns' 1 poem of the same name. The appearances of advanced Paget disease of the skull are similar in appearance to the hat.  Paget involvement of the skull, with widening of the diploic space and an overall enlargement...
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Tanycytes

Tanycytes are one of the three types of ependymal cells, themselves a type of glial cell. They are found lining the floor of the third ventricle and the median eminence of the hypothalamus 1.   It is believed that these specialised cells are involved in the feedback mechanisms on the anterior p...
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Tanycytic ependymoma

Tanycytic ependymomas are histological variants of ependymomas, usually found in the spinal cord 1. Their name reflects the morphological similarlity of these tumour cells to the tanycytes. They do not arise from tanycytes which are located primarily in the floor of the third ventricle. 
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Target sign (neurofibromas)

The target sign of neurofibromas is seen on MRI and represents a T2 hyperintense rim surrounding a central area of low signal. It is believed to be due to a dense central area of collagenous stroma. Although this sign is highly suggestive of a neurofibroma, it is occasionally also seen in schwa...
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Target sign (tuberculosis)

The target sign of tuberculosis refers to the bull's eye appearance of some parenchymal tuberculomas involving the brain (see: CNS tuberculosis) and solid abdominal organs (see: hepatic and splenic tuberculosis) on cross-sectional imaging.  Radiographic features Ultrasound hypoechoic nodules ...
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Tarlov cyst

Tarlov cysts, also called perineural cysts, are CSF filled dilatations of the nerve root sheath at the dorsal root ganglion (posterior nerve root sheath). These are type II spinal meningeal cysts that are, by definition, extradural but contain neural tissue. Epidemiology They occur in ~5% of t...
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Tauopathies

Tauopathies are a heterogeneous group of neurodegenerative diseases characterised by abnormal metabolism of tau proteins leading to intracellular accumulation and formation of neurofibrillary tangles (NFT). These neurofibrillary tangles are deposited in the cytosol of neurons and glial cells.  ...
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Tau sign

The tau sign represents the appearance of a persistent trigeminal artery on the sagittal plane of an angiogram or on sagittal MRI images. It resembles the greek letter τ, pronounced 'tau'. Persistent trigeminal artery arises from the junction between the petrous and cavernous ICA and runs poster...
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Taylor dysplasia

Taylor dysplasia is a type of focal cortical dysplasia and a common cause of refractory epilepsy. Under both the Palmini classification and the more recent Blumcke classification of focal cortical dysplasia, Taylor dysplasia is classified as type II.  For further discussion of the radiographic ...
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Tay sachs disease

Tay-Sachs disease is a hereditary neurodegenerative disorder resulting from excess storage of GM2 ganglioside within the lysosomes of cells.  Epidemiology The incidence of the disease is estimated to be 1 in 3600 in Ashkenazi Jews with carrier frequency of 1 in 30 and 1 in 360,000 in other pop...
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Technetium agents

Technetium agents based on the technetium-99m (Tc-99m) radioisotope are frequently used agents in medical imaging. The radioactive technetium radiotracer can be chelated to a number of different compounds to create specific radiopharmaceuticals and optimise the functional imaging of various stru...
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Tectal beaking (midbrain)

Tectal beaking refers to the fusion of the midbrain colliculi into a single beak pointing posteriorly and invaginating into the cerebellum. It is seen with a Chiari type II malformation. Terminology The term bird beak sign is used in a number of other contexts: see bird beak sign (disambiguati...
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Tectal glioma

Tectal gliomas fall under the grouping of childhood brainstem gliomas and unlike the other tumours in that group they are typically low grade astrocytomas with good prognosis.  Epidemiology Tectal plate gliomas are encountered in children and adolescents 4. A male predilection has sometimes be...
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Tegmentovermian angle

The tegmentovermian angle is an important measurable parameter in the assessment of posterior fossa abnormalities in the fetus. The angle is constructed on midsagittal images of the fetal brain, ideally on MRI. The angle is formed by the intersection of the following two lines 1: line 1: along...
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Tegmentum

The tegmentum is one of the areas of the brainstem. It is a phylogenetically old part of the brainstem and, in adults, is the location of the brainstem nuclei.  In the midbrain, it sits between the quadrigeminal plate and cerebral peduncles. In the pons, it is posterior to the basilar part of t...
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Tela choroidea

The tela choroidea is the thin, highly vascularised, loose connective tissue portion of pia mater that gives rise to the choroid plexus. Thus, it is basically the lamina propria of the ependyma and lies directly adherent to it, without any tissue in between the two 6. Gross anatomy Being part ...
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Temporal bone destructive lesions (differential)

Destructive lesions of the temporal bone (petrous pyramid, middle ear and antrum) have a relatively broad differential including 1: lesions affecting petrous pyramid acoustic schwannoma meningioma glioma neuroma of trigeminal and facial nerve chordoma glomus jugulare tumour epidermoid of...
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Temporal bone fracture

Temporal bone fracture is usually a sequela of significant blunt head injury. In addition to potentially damage to hearing and the facial nerve, associated intracranial injuries, such as extra-axial haemorrhage, diffuse axonal injury and cerebral contusions are common. Early identification of te...
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Temporal encephalocele

Temporal encephaloceles are usually small encephaloceles often asymptomatic but increasingly recognised as potential causes of refractory epilepsy and as a sequela of idiopathic intracranial hypertension. Epidemiology Temporal encephaloceles can be congenital or secondary to trauma, idiopathic...
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Temporal lobe

The temporal lobe is one of the four lobes of the brain (along with the frontal lobe, parietal lobe, and occipital lobe), and largely occupies the middle cranial fossa. Gross anatomy The temporal lobe is the second largest lobe, after the larger frontal lobe, accounting 22% of the total neocor...
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Temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is the most common type of partial epilepsy, with often characteristic imaging and clinical findings. It is divided into two broad groups: medial epilepsy most common involves the mesial temporal lobe structures most frequently due to mesial temporal sclerosis l...
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Temporal pole

The temporal pole is an anatomical landmark that corresponds to the anterior end of the temporal lobe, lying in the middle cranial fossa.  It corresponds to Brodmann area 38 and has strong connections with the amygdala and orbital prefrontal cortex, and is sometimes recognised as a component of...
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Temporopolar artery

The temporopolar artery is usually a dorsolateral branch from the M1 segment of the middle cerebral artery (MCA) and supplies the polar and anterolateral portions of the temporal lobe.  This artery may arise as a branch from the anterior temporal artery 1.  
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Tension pneumocephalus

Tension pneumocephalus is a neurosurgical emergency that occurs when subdural air causes a mass-effect over the underlying brain parenchyma, often from a ball-valve mechanism causing one-way entry of air into the subdural space 1. Clinical features Tension pneumocephalus has a varied clinical ...
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Tentorial angle

The tentorial angle is measured between a line connecting the nasion with the tuberculum sellae and the the angle of the straight sinus. Normally it should measure between 27° and 52°. Abnormalities of the posterior fossa / base of skull can alter this. For example this angle is elevated in ach...
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Tentorium cerebelli

The tentorium cerebelli is the second largest dural fold after the falx cerebri. It lies in the axial plane attached perpendicularly to the falx cerebri and divides the cranial cavity into supratentorial and infratentorial compartments 1. It contains free and attached margins 2. Gross anatomy ...
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Terminal myelocystocele

Terminal myelocystoceles are an uncommon form of spinal dysraphism representing marked dilatation of the central canal of the spinal cord, herniating posteriorly through a dorsal spinal defect. The result is a skin-covered mass in the lower lumbar region, consisting of an ependyma-lined sac.  E...
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Terminal zones of myelination

The terminal zones of myelination are located at the posterior aspect of the lateral ventricles (the peritrigonal regions) and are the only part of the cerebral white matter that may exhibit high T2 signal in a normal brain at 2 years of age, when myelination of cerebral white matter normally be...
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Terson syndrome

Terson syndrome refers to vitreous haemorrhage associated with subarachnoid haemorrhage, however some authors include retinal haemorrhage as well. The syndrome is a poor prognostic marker in patients with subarachnoid haemorrhage. Epidemiology Terson syndrome has been reported to occur in 13-5...
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TERT promoter mutations

TERT promoter mutations affect the TERT promoter (located on the short arm of chromosome 5) which encodes for the hTERT component of telomerase, an enzyme which maintains and lengthens telomeres 1. Mutations that result in enhanced activity of telomerase, and therefore longer telomeres, can be i...
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Tethered cord

Tethered spinal cord syndrome, also known as an occult spinal dysraphism sequence, is a neurological disorder caused by tissue attachments that limit the movement of the spinal cord within the spinal column. Clinical presentation The condition is closely linked to spina bifida, and as such pre...
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Thalamencephalon

The thalamencephalon is an anatomic region that includes the thalamus, metathalamus and epithalamus. It is one of the components that form the diencephalon.
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Thalamic haemorrhage

Thalamic haemorrhages or thalamic haemorrhagic strokes are often the result of chronic hypertension. The thalamus transmits or prevents transmission of sensory signals from sensory areas of the cerebral cortex through internal capsule fibres and has a role in memory thus the clinical presentatio...
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Thalamostriate veins

Thalamostriate veins are formed by the joining of anterior caudate vein and the vein of stria terminalis. They join the septal veins and form internal cerebral veins. Related pathology The thalamostriate veins can be compressed in preterm neonates who have had germinal matrix haemorrhage. This...
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Thalamus

The thalamus is the largest of the structures comprising the diencephalon. Role The thalamus acts as a relay centre, receiving and distributing information between the peripheries and higher centres such as the cerebral cortices. It contributes to functions such as: consciousness sleep memo...
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Thallium-201 chloride

Thallium-201 chloride is a radiopharmaceutical used primarily in cardiac imaging. Characteristics photon energy: 80 keV physical half life: 73 hours biological half life rest: 3 minutes exercise: 30 seconds normal distribution: myocardium, skeletal muscle, GI tract, liver, kidneys excret...
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Third ventricle

The third ventricle is one of the four CSF-filled cavities that together comprise the ventricular system. Gross anatomy The third ventricle is a median cleft between the two thalami and is bounded laterally by them and the hypothalamus. Its anterior wall is formed by the lamina terminalis, and...
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Third ventriculostomy

A third ventriculostomy is a type of surgical treatment for obstructive hydrocephalus, especially when obstruction is located at the level of the aqueduct of Sylvius (e.g. aqueduct stenosis). A permanent defect is created in the floor of the third ventricle anterior to the mammillary bodies, thu...
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Thrombolysis in cerebral infarction (TICI) scale

The thrombolysis in cerebral infarction (TICI) grading system was described in 2003 by Higashida et al. 1 as a tool for determining the response of thrombolytic therapy for ischaemic stroke. In neurointerventional radiology it is commonly used for patients post endovascular revascularisation. Li...
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Thumb sign (chordoma)

The thumb sign or thumbing of the pons is described in chordomas as is meant to be relatively specific. It is seen in midline sagittal projection as a projection of the tumour indenting the pons 1,2. See also thumb sign (disambiguation)
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Thyroid-associated orbitopathy

Thyroid-associated orbitopathy (TAO) is the most common cause of proptosis in adults and is most frequently associated with Graves disease. On imaging, it is characterised by enlargement of the extraocular muscles' bellies (frequently: inferior rectus > medial rectus  > superior rectus) sparing...
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Tiger stripe appearance

The tiger stripe appearance refers to the characteristic alternating hypo and hyperintense bands on MRI in Lhermitte-Duclos disease. This rare cerebellar tumour appears like the coat of a tiger. See also tigroid pattern - in brain
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Tight filum terminale syndrome

Tight filum terminale syndrome is caused by incomplete involution of the distal spinal cord during embryogenesis. This leads to development of an abnormally thickened filum terminale, which may be associated with lipomas or cysts within the filum. Tight filum terminale syndrome is always associ...
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Tissue tropism

Tissue tropism is a phenomenon by which certain host tissues preferentially support the growth and proliferation of pathogens. This concept is central to the radiological evaluation of infectious disease.  Pathology As infections that display tissue tropism will thrive in certain tissue locati...
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Toast classification in acute ischemic stroke

The TOAST (trial of ORG 10172 in acute stroke treatment) classification denotes five sub types of ischaemic stroke. large-artery atherosclerosis (embolus / thrombosis)* cardioembolism (high-risk / medium-risk)* small-vessel occlusion (lacune)* stroke of other determined aetiology * stroke o...
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Todd paralysis

Todd paralysis, also known as Todd paresis or postictal paralysis, describes transient focal neurological deficits after an epileptic seizure. It is an important clinical and imaging differential diagnosis of ischaemic stroke presenting with a seizure.   Epidemiology The incidence of Todd para...
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Tolosa-Hunt syndrome

Tolosa-Hunt syndrome (THS) is an idiopathic inflammatory condition that involves the cavernous sinus and orbital apex, and is essentially a clinical diagnosis of exclusion. Clinical presentation Clinically it refers to the presence of a painful ophthalmoplegia secondary to surrounding cavernou...
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Tonsillar herniation

Tonsillar herniation is a type of cerebral herniation characterised by the inferior descent of the cerebellar tonsils below the foramen magnum. The terminology of caudally displaced tonsils is discussed in the article on cerebellar tonsillar ectopia. Pathology It is a secondary sign of signif...
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Top of the basilar syndrome

Top of the basilar syndrome, also known as rostral brainstem infarction, occurs when there is thromboembolic occlusion of the top of the basilar artery. This results in bilateral thalamic ischaemia due to occlusion of perforator vessels. Clinical presentation Clinically, top of the basilar syn...
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Torticollis

Torticollis (wryneck) is a clinical finding of head tilt with or without rotational spinal malalignment. It is not a diagnosis in itself and there are a wide range of underlying conditions. It is most common in the paediatric age group.  Pathology Torticollis can be acute (<1 week) or chronic ...
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Toxic leukoencephalopathy

Toxic leukoencephalopathy is an encephalopathy predominantly affecting white matter as a result of a toxic substance. The presentation can either be chronic or acute. In the acute phase, acute toxic leukoencephalopathy can have a characteristic and profound MR imaging appearance that is potentia...
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Toxoplasmosis

Toxoplasmosis is a common worldwide parasitic disease caused by the protozoan Toxoplasma gondii. It is usually an asymptomatic infection, but it is related with several sequelae when acquired in-utero or related with cerebral abscesses due to its reactivation in immunocompromised patients (e.g. ...
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Toxoplasmosis vs lymphoma

It is common for radiologists to be asked to distinguish between cerebral toxoplasmosis and primary CNS lymphoma (PCNSL) in patients with HIV/AIDS. Treatment is clearly different and thus accurate interpretation of CT and MRI is essential. In many instances, the imaging appearance is classic an...

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