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 continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
More than 200 results
Article
Hypovitaminosis A
Hypovitaminosis A results from inadequate intake of vitamin A, fat malabsorption, or liver disorders and produces a variety of epithelial alterations.
Epidemiology
The World Health Organizatiοn estimates that 45-122 countries have a vitamin A deficiency of public health significance based on t...
Article
Deep cerebral vein thrombosis
Deep cerebral vein thrombosis is a subset of cerebral venous thrombosis involving the internal cerebral veins, often coexisting with cortical vein thrombosis or dural venous sinus thrombosis, and with different clinical presentations relying on which segment is involved.
As such please refer to...
Article
Trochlear nerve
The trochlear nerve is the fourth (CN IV) and thinnest cranial nerve. It exits the midbrain posteriorly, eventually passes into the cavernous sinus and into the orbit where it supplies superior oblique muscle with motor fibers (TA: nervus trochlearis or nervus cranialis IV).
Gross anatomy
Nuc...
Article
Cognard classification of dural arteriovenous fistulas
The Cognard classification of dural arteriovenous fistulas (dAVF) correlates venous drainage patterns with increasingly aggressive neurological clinical course and stratifies the risk of intracerebral hemorrhage. It was first described in 1995 1 and at the time of writing (July 2016) is probably...
Article
Spinal cord stimulator
Spinal cord stimulators, also known as dorsal column stimulators, are surgically placed devices intended to provide symptom relief in individuals with chronic neurological pain (e.g. failed back syndrome, brachial plexopathy, complex regional pain syndrome).
However, their use remains controver...
Article
Occipital condyle syndrome
Occipital condyle syndrome describes the concurrence of unilateral occipital pain and ipsilateral hypoglossal nerve palsy, which localizes to pathology affecting an occipital condyle. While occipital condyle syndrome can have many potential causes, it nearly always represents a manifestation of ...
Article
Osteolipoma
Osteolipomas, also known as ossified lipomas, are rare intracranial masses, typically located in the suprasellar cistern, composed of mature adipocytes surrounded by calcified ossification 1. They are a variant of intracranial lipomas which rarely have calcification/ossification elsewhere, with ...
Article
Langerhans cell histiocytosis
Langerhans cell histiocytosis (LCH) is a rare multisystem disease with a wide and heterogeneous clinical spectrum and variable extent of involvement.
Terminology
Langerhans cell histiocytosis was previously known as histiocytosis X. The newer term is preferred as it is more descriptive of its...
Article
Sphincter pupillae muscle
The sphincter pupillae muscle is a circular ring of smooth muscle within the iris responsible for constriction of the pupil (miosis). The structure is stimulated by the parasympathetic nervous system causing the muscle to decrease in diameter as it contracts.
Gross anatomy
The sphincter pupill...
Article
Intramedullary spinal metastasis
Intramedullary spinal metastases are rare, occurring in ~1% of autopsied cancer patients, and are less common than leptomeningeal metastases.
Intramedullary lesions may result from:
growth along the Virchow-Robin spaces
hematogenous dissemination
direct extension from the leptomeninges
Epid...
Article
Cerebral hyperperfusion syndrome
Cerebral hyperperfusion syndrome is a rare complication seen after treatment of long-standing severe carotid stenosis by carotid endarterectomy or carotid artery stenting. It is believed to be the result of failure of normal cerebral blood flow autoregulation.
Terminology
Cerebral hyperperfus...
Article
Kissing carotids
The term kissing carotids refers to tortuous and elongated carotid arteries which touch in the midline. They can be found in:
retropharynx 2
intrasphenoid 1
within the pituitary fossa
within sphenoid sinuses
within sphenoid bones
The significance of kissing carotids is two-fold:
may mimi...
Article
Transforaminal epidural steroid injection
Transforaminal epidural steroid injections (TFESI), also known as transforaminal nerve root injections or nerve root blocks, are performed for the treatment and diagnosis of radicular pain. They differ from selective nerve root blocks (SNRB), as the aim is to get an "epidural spill" and get the ...
Article
CSF alpha-fetoprotein
Alpha-fetoprotein (AFP) in the cerebrospinal spinal fluid (CSF) has been reported as a tumor marker for some intracranial tumors with yolk sac elements, and teratoma 1.
Interpretation
Elevation
intracranial yolk sac tumor
intracranial embryonal carcinoma
congenital CNS tumors with yolk sac ...
Article
Gyrus rectus
The gyrus rectus, or straight gyrus, is located at the most medial margin of the inferior surface of the frontal lobe 1,2. Its function is unclear but it may be involved in higher cognitive function (e.g. personality) 3.
Gross anatomy
The gyrus rectus is bounded medially by the interhemispheri...
Article
Intracranial dermoid cyst
Intracranial dermoid cysts are uncommon lesions with characteristic imaging appearances. Dermoid cysts can be thought of as along the spectrum: from epidermoid cysts at one end (containing only desquamated squamous epithelium) and teratomas at the other (containing essentially any kind of tissue...
Article
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 1.
The specialized ependymal cells in the area postrema detect toxins in the...
Article
Shagreen patch
A shagreen patch is a subepidermal collagenous connective tissue nevus, also known as a collagenoma, associated with tuberous sclerosis. The overlying skin may be discoloured with obvious pores, giving the appearance of orange peel. These lesions are most commonly found in the lumbosacral region...
Article
Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL)
Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a systemic genetic disorder affecting the cerebral small vessels, spine and hair follicles.
CARASIL is an HTRA1-related cerebral small vessel disease, and thus is closely related to, but dis...
Article
Cerebrovascular malformations
Cerebrovascular malformations are vascular malformations related to the vessels that supply the brain and other cranial structures.
Classification
Over the years, cerebral vascular malformations have been classified in a variety of ways by many authors, often on the basis of the presence or ab...
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