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.

2,503 results found
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Choroid plexus carcinoma

Choroid plexus carcinomas are malignant neoplasms arising from the choroid plexus. They are classified as a WHO grade III tumor and while there is considerable overlap in imaging characteristics it carries significantly poorer prognosis than both WHO grade II atypical choroid plexus papilloma, a...
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Choroid plexus cyst (antenatal)

Antenatal choroid plexus cysts are benign and are often transient typically resulting in utero from an infolding of the neuroepithelium.   They should not be confused with adult choroid plexus cysts (which are very commonly found at autopsy and likely degenerative), large intraventricular simpl...
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Choroid plexus hyperplasia

Choroid plexus hyperplasia (CPH), also known as villous hypertrophy of the choroid plexus, is a rare benign condition that is characterized by bilateral enlargement of the entire choroid plexus in lateral ventricles without any discrete masses. This can result in overproduction of CSF and commun...
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Choroid plexus lipoma

Choroid plexus lipomas are uncommon and like other intracranial lipomas are usually found incidentally at the trigones of the lateral ventricles when imaging is obtained for other indications. Terminology Some of the literature refers to the extension of tubulonodular pericallosal lipoma into ...
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Choroid plexus malignancy

Choroid plexus malignancies can be classified as primary or secondary neoplasms of the choroid plexus: primary choroid plexus papilloma (CPP) 80% WHO Grade I, and WHO Grade II when atypical choroid plexus carcinoma (CPC)  20% WHO Grade III intraventricular meningioma secondary choroid ...
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Choroid plexus metastases

Metastases to the choroid plexus from extracranial tumors are rare, but nonetheless should be included in the differential diagnosis of an intraventricular mass. They are most commonly found within the lateral ventricles, presumably because a large proportion of the choroid plexus is located the...
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Choroid plexus papilloma

Choroid plexus papillomas are an uncommon, benign (WHO grade I) neuroepithelial intraventricular tumor which can occur in both the pediatric (more common) and adult population.  On imaging, these tumors are usually identified in the fourth ventricle in adults and in the lateral ventricles in th...
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Choroid plexus xanthogranuloma

Choroid plexus xanthogranulomata are common, incidental and almost invariably asymptomatic lesions. It is unclear in much of the literature whether they represent a distinct entity from adult choroid plexus cysts, but they share imaging characteristics and are only likely to be distinguishable o...
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Christmas inspired signs

There are many signs in radiology that are related to Christmas: snowcap sign in avascular necrosis snowman sign in total anomalous pulmonary venous return in pituitary macroadenomas snowstorm appearance in complete hydatidiform and testicular microlithiasis holly leaf sign in calcified pl...
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Chronic encephalitides

There are several viral and prion infections which can result in a chronic encephalitis with slow progression into brain atrophy. These have a very poor prognosis with no effective treatment. Some of these include: progressive multifocal leukoencephalitis subacute sclerosing panencephalitis ...
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Chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired demyelinating disease involving peripheral nerves, and is generally considered the chronic counterpart to Guillain-Barré syndrome (GBS).  Clinical presentation Patients typically present with a gradual and protracted (>2 m...
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Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS)

Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) is an uncommon and only recently described disorder characterized by infiltration of the brain by inflammatory cells. It has a predilection for the pons, with fairly characteristic curvilinea...
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Chronic otomastoiditis

Chronic otomastoiditis should be considered a separate entity from acute otomastoiditis, and is defined as persistent or recurrent inflammation of the middle ear and mastoid, lasting usually for a minimum of 12 weeks, and resulting in permanent perforation of the tympanic membrane. Clinical pre...
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Chronic relapsing inflammatory optic neuropathy

Chronic relapsing inflammatory optic neuropathy (CRION) describes a rare, recurrent, corticosteroid-responsive optic neuropathy that should be considered as an important differential diagnosis in patients with multiple episodes of suspected optic neuritis. Epidemiology The exact incidence of C...
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Chronic traumatic encephalopathy

Chronic traumatic encephalopathy is a neurodegenerative tauopathy that is thought to result from mild repetitive head trauma.  Epidemiology The exact incidence and prevalence are unknown. It is most commonly seen in amateur and professional sports players where head contact is common (e.g. box...
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Cingulate gyrus

The cingulate gyrus lies on the medial aspect of the cerebral hemisphere. It forms a major part of the limbic system which has functions in emotion and behavior. The frontal portion is termed the anterior cingulate gyrus (or cortex) 1,2.  Gross anatomy Location The cingulate gyrus extends fro...
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Cingulate island sign

The cingulate island sign is a highly specific radiological sign described in dementia with Lewy bodies. It refers to the pattern of metabolism seen on FDG-PET in patients with dementia with Lewy bodies 1-3. On FDG-PET, there is occipital hypometabolism with relative sparing of the posterior ci...
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Cingulate sulcus

The cingulate sulcus is situated directly superior to the cingulate gyrus, which is formed by the medial surface of the frontal lobes that is directly above the corpus callosum.
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Cingulate sulcus sign

The cingulate sulcus sign has been proposed as being useful as an MRI feature of idiopathic normal pressure hydrocephalus (NPH). It denotes the posterior part of the cingulate sulcus being narrower than the anterior part. The divider between the anterior and posterior parts of the sulcus being a...
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Circle of Willis

The Circle of Willis is an arterial polygon (heptagon) formed as the internal carotid and vertebral systems anastomose around the optic chiasm and infundibulum of the pituitary stalk in the suprasellar cistern. This communicating pathway allows equalization of blood-flow between the two sides of...
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Circular sulcus

The deep circular sulcus surrounds the insular cortex and separates it from the operculum.  The circular sulcus is contiguous with the lateral (Sylvian) sulcus.
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Circumventricular organs (CNS)

The circumventricular organs are neuroendocrine anatomical structures localized around the ventricles of the brain. They are characterized by a rich vasculature and fenestrated (permeable) capillaries. As such, with the exception of the subcomissural organ, they are also characterized by the abs...
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Cisterna magna

The cisterna magna (also known as the cerebellomedullary cistern) is the largest of the CSF-filled subarachnoid cisterns. Gross anatomy The cisterna magna is located between the cerebellum and the dorsal surface of the medulla oblongata at and above the level of the foramen magnum. CSF produce...
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Classification of cerebral vascular malformations

Cerebral vascular malformations encompass a large variety vascular lesions which differ in hemodynamics, structure and prognosis. Some can be life threatening (e.g. vein of Galen aneurysmal malformations, arteriovenous malformations) whilst others are almost always incidental and asymptomatic (e...
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Classification of spinal meningeal cysts

Spinal meningeal cysts can be classified according to a system published by Nabor et al 2: type I: extradural meningeal cyst without neural tissue type Ia: extradural spinal arachnoid cyst type Ib: sacral meningocele type II: extradural meningeal cyst containing neural tissue, e.g. Tarlov cy...
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Classification system for malformations of cortical development

The classification system for malformations of cortical development organizes myriad conditions into one of three major underlying groups according to the main underlying mechanism: group I: abnormal cell proliferation or apoptosis group II: abnormal neuronal migration group III: abnormal cor...
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Classification system for malformations of the cerebellum

Classification systems for malformations of the cerebellum are varied and are constantly being revised as greater understanding of the underlying genetics and embryology of the disorders is uncovered. A classification proposed by Barkovich et al. in 2009 1 divides cerebellar malformations in two...
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Classification system for midline abnormalities of the brain and skull

Classification systems for midline abnormalities of the brain and skull are varied and constantly changing as the underlying embryology and genetics are uncovered. A relatively simple and robust classification system is based on the location of abnormalities, always remembering that midline abno...
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Claude syndrome

Claude syndrome is one of the brainstem stroke syndromes in which there is infarction of the dorsomedial aspect of the midbrain. Clinical presentation Clinical picture is characteristic and includes ipsilateral oculomotor nerve palsy and contralateral upper and lower limb ataxia 1-4. Patholog...
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Claustrum

The claustrum is a vertical curved sheet of subcortical grey matter oriented sagittally between the white matter tracts of the external capsule and extreme capsule. It is lateral to the putamen and medial to the insular cortex. It is not part of the basal ganglia. There are lateral and medial t...
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Claw sign (mass)

The claw sign is useful in determining that a mass arises from a solid structure rather than is located adjacent to it and distorts the outline. It refers to the sharp angles on either side of the mass, which the surrounding normal parenchyma forms when the mass has arisen from the parenchyma. ...
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Clear cell ependymoma

Clear cell ependymomas are a histological variant of ependymoma characterized by prominent perinuclear cytoplasmic clearing, reminiscent of oligodendrogliomas 1.  They are typically encountered in younger patients and usually in the supratentorial compartment 1.  They have a tendency to be qui...
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Clear cell meningioma

Clear cell meningiomas are a histological variant of meningioma with poorer prognosis and a higher rate of recurrence. They are therefore considered WHO grade 2 tumors, regardless of mitotic index, cellular atypia/anaplasia, or presence of brain invasion.  Epidemiology Clear cell meningiomas h...
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Clinically isolated syndrome

Clinically isolated syndrome (CIS) is the first episode suggestive of demyelination 1,2. It can either be monofocal (single lesion) or multifocal 1,2. Not all patients with CIS will go on to develop multiple sclerosis however if at presentation there are changes on MRI suggestive of MS, then the...
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Clinically unclassifiable parkinsonism

Clinically unclassifiable parkinsonism (CUP) is a term applied to patients who have some parkinsonism features, but who do not fulfill clinical criteria for a particular disorder such as:  Parkinson disease  progressive supranuclear palsy (PSP)  multiple system atrophy (MSA-P)   corticobasal...
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Clival masses

The differential of a mass involving or arising from the clivus is a relatively narrow one and can be divided into whether the lesion arises from the skull base itself, the intracranial compartment above or the base of skull below. When evaluating the clivus it is important to compare the marro...
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Cluster headache

Cluster headaches are a particularly painful form of recurrent headache considered the most common trigeminal autonomic cephalalgias 1.  Epidemiology Cluster headaches are fairly uncommon affecting 0.06 to 0.4% of the population 1. Men are more often affected (M:F 3:1) 1.  Clinical presentati...
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CNS aspergillosis

CNS aspergillosis results from angioinvasive infection of the central nervous system by the fungus Aspergillus spp. Along with CNS cryptococcosis, it is one of the most common fungal opportunistic infections of the central nervous system. Epidemiology The disease predominates in immunocompromi...
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CNS capillary telangiectasia

CNS capillary telangiectasiae(s) are small, asymptomatic low flow vascular lesions of the brain.  Epidemiology As these lesions are asymptomatic, diagnosis usually matches the age of first imaging with MRI, and as such are most frequently found in middle-aged and elderly adults. Their inciden...
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CNS cryptococcosis

CNS cryptococcosis results from infection of the central nervous system with the yeast-like fungus Cryptococcus neoformans. It is the most common fungal infection and second most common opportunistic infection of the central nervous system. For a general discussion of infection with this organi...
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CNS infectious diseases

This article aims to be a collection of articles that represent central nervous system infectious (CNS) diseases.  Classification By organsim The organisms involved in CNS infections vary depending on the specific location of infection. Bacteria, viruses, fungi, parasites, and prions can all ...
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CNS lymphoma

CNS lymphoma refers to the involvement of the central nervous system with lymphoma. It can be broadly divided into primary and secondary, with a number of special types of also recognized.  primary CNS lymphoma (PCNSL) intravascular lymphoma MALT lymphoma of the dura 5 secondary CNS lymphoma...
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COACH syndrome

The acronym COACH describes a syndrome associated with: C - cerebellar vermis defect (Joubert syndrome) O - oligophrenia A - ataxia C - coloboma H - hepatic fibrosis Epidemiology There only as little as 11 cases having been reported in the English medical literature. Associations The as...
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Coalescent mastoiditis

Coalescent mastoiditis is simply the term given to acute otomastoiditis when mucoperiosteal disease extends to involve the bone. The septae which normally separate one mastoid air cell from another are resorbed. This change is only easily appreciated on thin section bone-algorithm through the te...
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CoA synthase protein associated neurodegeneration

CoA synthase protein associated neurodegeneration (CoPAN) is a type of neurodegeneration with brain iron accumulation (NBIA). Clinical presentation Patients typically present with a variety of symptoms including spastic-dystonic paraparesis, Parkinsonism, cognitive impairment, obsessive-compul...
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Coccidioidal meningitis

Coccidioidal meningitis refers to central nervous system involvement of the dimorphic fungus Coccidioides spp, mainly Coccidioides immitis and Coccidioides posadasi. For a general discussion, and for links to other system specific manifestations, please refer to the article on coccidioidomycosi...
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Coccidioidomycosis

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

Cochlear implants (CI) are a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing. Unlike conventional hearing aids, the cochlear implant does not amplify sound, but works by directly stimulating any functioning audi...
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Cochlear incomplete partition

Cochlear incomplete partition is a group of cochlear malformations associated with variable degree of inner ear architecture defects. It is classified in three groups: cochlear incomplete partition type I (IP-I) a severe form of IP-I is known as cystic cochleovestibular malformation cochlear...
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Cochlear incomplete partition type I

Cochlear incomplete partition type I  (IP-I) is a type of cochlear anomaly associated with sensorineural hearing loss. Radiographic features CT The main findings on CT are: absent modiolus absent interscalar septum wide (most common) or normal cochlear nerve canal Absence of these structu...
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Cochlear incomplete partition type II

Cochlear incomplete partition type II  (IP-II) is a type of cochlear anomaly associated with sensorineural hearing loss. It should not be confused with Mondini anomaly, which is a historic term for a combination of IP-II and large vestibular aqueduct. Radiographic features CT On CT, the coch...
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Cockayne syndrome

Cockayne syndrome is a rare autosomal recessive dysmyelinating disease. Cockayne syndrome is classified among the childhood leukodystrophies, and brain imaging findings are cardinal features suggesting the diagnosis of Cockayne syndrome. Previously published Cockayne syndrome imaging studies hav...
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Coffin-Siris syndrome

Coffin-Siris syndrome, first described in 1970, is a rare genetic abnormality. Coffin-Siris syndrome should not be confused with Coffin-Lowry syndrome. Epidemiology It occurs more frequently in females (with a M:F of ~4:1). Clinical presentation One of the most typical features is absence o...
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Cognard classification of dural arteriovenous fistulas

The Cognard classification of dural arteriovenous fistulas correlates venous drainage patterns with increasingly aggressive neurological clinical course. It was first described in 1995 1 and at the time of writing (July 2016) is probably the most widely used classification system for dural arter...
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COL4A1 brain small-vessel disease

COL4A1 brain small-vessel disease is an autosomal dominant monogenic COL4A1-related disorder that primarily causes cerebral small vessel disease. Epidemiology The exact prevalence is unknown, but the condition is likely under-diagnosed. Clinical presentation The clinical presentation is vari...
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COL4A1-related disorders

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

COLD syndrome is the acronym for the concurrent diagnosis of Cowden syndrome and Lhermitte-Duclos disease. It has been suggested that COLD syndrome should be considered a phakomatosis 1. 
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Collateral sulcus

The collateral sulcus, also known as the medial occipitotemporal sulcus, runs anteroposteriorly on the inferior surface of the temporal lobe and occipital lobe. Anteriorly it is sometimes continuous with the rhinal sulcus 1-3.  Anteriorly, it separates the fusiform gyrus laterally, from the par...
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Collateral vessels in acute stroke

During the acute imaging of ischemic stroke, the presence or absence of collateral vessels is an important consideration when deciding if the patient will benefit from endovascular thrombectomy (ECR, endovascular clot retrieval) 1. Studies have shown that in acute stroke, both CTA and MRA are a...
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Colloid cyst of the third ventricle

Colloid cysts of the third ventricle are benign epithelial lined cysts with characteristic imaging features. Although usually asymptomatic, they can rarely present with acute and profound hydrocephalus. Classically these cysts are identified as a well-delineated hyperattenuated mass on unenhanc...
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Coloboma

Coloboma is a collective term encompassing any focal discontinuity in the structure of the eye, and should not be confused with staphylomas, which are due to choroidal thinning.  Pathology Embryologically, colobomas are due to failure of closure of the choroidal fissure. The most common site o...
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Colpocephaly

Colpocephaly is a descriptive term for a disproportionate prominence of the occipital horns of the lateral ventricles. It can result from a wide range of congenital insults. Clinical presentation Patients may present with motor abnormalities, cognitive deficit, visual abnormalities, and seizur...
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Combined cerebral edema

Combined cerebral edema is a type of cerebral edema in which there is a mixed pattern of both cytotoxic and vasogenic cerebral edema. It is usually associated with severe systemic damage, such as with: hypertensive crises severe sepsis / severe inflammatory condition hypoxic-ischemic enc...
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Combined conduit score of sinovenous stenosis

The combined conduit score (CCS) is a grading scheme for the assessment of the degree of transverse-sigmoid sinus stenosis in the setting of idiopathic intracranial hypertension. The score was initially developed for ATECO MR venography 1. Parameters Assessment is performed using maximum inten...
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Commissural fibers of the brain

Commissural fibers of the brain, also known as commissural tracts of the brain or commissures are a type of white matter tract that cross the midline, connecting the same cortical area in opposite hemispheres (right-left hemispheric connections 3). Commissural fibers include: corpus callosum (...
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Communicating hydrocephalus

Communicating hydrocephalus is a type of hydrocephalus where CSF is able to leave the ventricular system.  Terminology Communicating hydrocephalus is commonly used as the opposite of obstructive hydrocephalus which leads to much unnecessary confusion, as most causes of communicating hydrocepha...
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Complications of cranial radiotherapy

Complications of cranial radiation therapy are fairly common, particularly in long-term survivors, and especially in pediatric patients. Cranial radiotherapy is used for a variety of brain tumors, either in isolation or in combination with concurrent chemotherapy. Complications from irradiation...
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Compressive myelopathy

Compressive myelopathy refers to neurological deficits that result from abnormal compression of the spinal cord. It most commonly occurs in the cervical spinal cord.  Pathology Any cause of spinal canal stenosis including disc herniation, osteophytes, extradural mass, and/or paravertebral liga...
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Concentric target sign (cerebral toxoplasmosis)

The concentric target sign is a typical sign for cerebral toxoplasmosis. It is seen on T2 weighted MR imaging as a deep parenchymal lesion showing a series of concentric rings with hyperintense and hypointense/isointense signal alternatingly. Strong perifocal edema is usually visible on T2/FLAIR...
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Concurrent suprasellar and pineal region lesions (differential)

Concurrent suprasellar and pineal region lesions have a relatively short differential to be considered, including:  germinoma other germ cell tumors choriocarcinoma embryonal cell carcinoma yolk sac tumor (endodermal sinus tumor) primary CNS lymphoma cerebral metastasis quadrilateral ret...
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Condylar canal

The condylar canal, or canalis condylaris, is a skull base canal in the posterior cranial fossa, located in the condylar fossa. It is the largest of the emissary foramina of the skull 1. Summary location: in the condylar fossa of the posterior cranial fossa, posterior to the occipital condyles...
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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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Confluence of sinuses

The confluence of sinuses, also known as the torcula or torcular herophili is the site of the confluence of: superior sagittal sinus straight sinus occipital sinus transverse sinuses The anatomy is highly variable and three types can be distinguished: type 1: superior sagittal sinus drains...
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Congenital absence of the internal carotid artery

Congenital absence of the internal carotid artery (ICA) is a rare anomaly that occurs in less than 0.01% of the population. It encompasses agenesis, aplasia, and hypoplasia 1. The most common type of collateral flow is through the circle of Willis, through the anterior communicating artery (ACO...
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Congenital anomalies of the posterior atlas arch

Congenital anomalies of the posterior arch of the atlas (C1) are relatively common anomalies. They may range from partial defects presenting as clefts to complete absence of the posterior arch (aplasia). These anomalies are classified according to Currarino (see below). It should not be confuse...
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Congenital calvarial defects

Congenital calvarial defects are a group of disorders characterized by congenital calvarial bone defects that vary in severity. Radiographic features CT with 3D shaded surface reformats is the best imaging tool as it demonstrates calvarial defects and bone margins: parietal foramina parietal...
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Congenital cataract

Congenital cataracts are a major cause of blindness with early detection the most important factor in reducing impact on future vision.  Epidemiology Incidence is ~3 per 100,000 in the United Kingdom 1. Although the incidence tends to be higher in areas with increased rates of congenital infec...
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Congenital cerebral toxoplasmosis

Congenital cerebral toxoplasmosis is a manifestation of congenital toxoplasmosis and refers to development of cerebral toxoplasmosis in the fetus through maternal transmission. Please refer on congenital toxoplasmosis to a broad discussion on epidemiology and pathology.  Radiographic features ...
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Congenital cholesteatoma

Congenital cholesteatomas are identical to epidermoid cysts, differing only in name and location.  Pathology They are intraosseous inclusions of ectoderm, and are therefore comprised of keratin debris and cholesterol. Characteristically, they are located at the petrous apex. In contrast middle...
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Congenital cytomegalovirus infection

Congenital cytomegalovirus infections result from intrauterine fetal infection by cytomegalovirus (CMV). Epidemiology Cytomegalovirus is the most common cause of intrauterine infection and the most common cause of congenital infective and brain damage, occurring in 0.2-2.4% of live births. An...
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Congenital facial nerve aplasia

Congenital facial nerve aplasia is a rare condition where the patient presents with signs of facial nerve paralysis. Clinical presentation Patients present with unilateral or bilateral facial weakness characterized by facial asymmetry, incomplete closure of eyelid, deviation of angle of mouth ...
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Congenital facial palsy

A congenital facial palsy is an uncommon cause of neonatal asymmetric crying facies, which are more frequently due to absence or hypoplasia of the depressor anguli oris muscle, often associated with other congenital anomalies.  Epidemiology Congenital facial palsy is reported with an incidence...
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Congenital muscular dystrophies (central nervous system manifestations)

Congenital muscular dystrophies are a heterogeneous group of autosomal recessive myopathies presenting at birth with hypotonia, delayed motor development, and early onset of progressive muscle weakness, confirmed with a dystrophic pattern on muscle biopsy.  Clinical presentation There is a wid...
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Congenital ossicular anomalies

Congenital anomalies of the ossicles are most frequently associated with external ear abnormalities also, although they can occur in isolation.  Clinical presentation These anomalies result in conductive hearing loss. Pathology When bilateral, they are most frequently genetic with autosomal ...
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Congenital spinal meningocele

Congenital spinal meningoceles are developmental anomalies of meningothelial elements displaced into the skin and subcutaneous tissues. Please refer to the meningocele article for a broad overview of all types of this condition.  Pathology It is a defect of the neural tube, an embryonic struc...
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Congenital syndromes associated with enlarged ventricles

Congenital ventriculomegaly can have a large number of syndromic associations. Common acrocephalosyndactylies Apert syndrome Pfeiffer syndrome acrocephalopolysyndactylies Crouzon syndrome  achondroplasia fetal alcohol syndrome lissencephaly osteopetrosis Sotos syndrome  X-linked hyd...
Article

Conjoined nerve root

A conjoined root is a type of developmental anomaly involving a nerve root. It is the most common nerve root developmental anomaly of the cauda equina being twice as common as two roots in the same foramen, the next most common anomaly. Epidemiology The incidence in cadaveric studies is ~10 (r...
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Connatal cyst

Connatal cysts, also known as coarctation of the lateral ventricles or frontal horn cysts, are cystic areas adjacent to the superolateral margins of the body and frontal horns of the lateral ventricles and are believed to represent a normal variant. Epidemiology The incidence is 0.7% in low bi...
Article

Contrast-induced neurotoxicity

Contrast-induced neurotoxicity, also known as iodinated contrast-induced encephalopathy, is a rare complication of iodinated intravascular contrast resulting in a usually temporary neurological deficit. CT imaging findings can be dramatic, demonstrating contrast staining and edema, but spontaneo...
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Conus medullaris

The conus medullaris is the terminal end of the spinal cord. Gross anatomy After the cord terminates, the nerve roots descend within the spinal canal as individual rootlets, collectively termed the cauda equina. The conus medullaris most commonly terminates at the L1/2 intervertebral disc leve...
Article

Conus medullaris syndrome

Conus medullaris syndrome is caused by an injury or insult to the conus medullaris and lumbar nerve roots. It is a clinical subset of spinal cord injury syndromes. Injuries at the level of T12 to L2 vertebrae are most likely to result in conus medullaris syndrome. Clinical presentation Patient...
Article

Convexal subarachnoid hemorrhage

Convexal subarachnoid hemorrhages (cSAH) are non-traumatic intracranial hemorrhages that occur within the surface sulci of the brain (cf. basal cisternal distribution of aneurysmal SAH). Pathology There are various causes of convexal subarachnoid hemorrhage, some of which include: dural venou...
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Convolutional markings

Convolutional markings are normal impressions of the gyri on the inner table of the skull, seen predominantly posteriorly. If they are pronounced and over the more anterior parts of the skull, then this is referred to as a copper beaten skull and suggests the presence of raised intracranial pres...

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