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
Interthalamic adhesion
The interthalamic adhesion, or massa intermedia, is a small variably present non-neural connection between the medial apposing surfaces of the two thalami that passes through the third ventricle7. It is not a commissure as once thought, as it does not contain neurons; instead, it is composed of ...
Article
Diffuse axonal injury (grading)
Grading of diffuse axonal injury due to trauma is described according to the anatomic distribution of injury. Contrary to the implication of the word "diffuse," diffuse axonal injury has a topological predilection for focal involvement of certain sites in the brain. These sites, in turn, vary in...
Article
Tolosa-Hunt syndrome
Tolosa-Hunt syndrome is an idiopathic inflammatory condition that involves the cavernous sinus and orbital apex and is essentially a clinical diagnosis of exclusion.
Epidemiology
The estimated incidence of Tolosa-Hunt syndrome is 1 per 1,000,000 person-years with an average age of onset at 41 ...
Article
Circle of Willis
The circle of Willis (COW) or circulus arteriosus 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-...
Article
Histoplasmoma
Histoplasmoma is the name for a specific kind of nodule secondary to granulomatous reaction to histoplasmosis infection. It is often described as having a pathognomonic target lesion appearance, describing a well-defined nodule with a central core of calcification 5.
Histoplasmomas can appear ...
Article
Flame sign (carotid)
The flame sign refers to a gradual tapering of contrast opacification in the mid-cervical internal carotid artery, sparing the carotid bulb. The sign can be observed on angiography (digital subtraction angiography 1, CT angiography 1, or contrast-enhanced MR angiography 2) in either of two scena...
Article
Perivascular spaces
Perivascular spaces, also known as Virchow-Robin spaces, are fluid-filled spaces that surround small arterioles, capillaries and venules in the brain. Those that surround perforating vessels are frequently seen on routine MRI imaging.
Despite having been described well over a century ago and se...
Article
Spinal meningioma
Meningiomas arising from the coverings of the spinal cord are one of the two most common intradural extramedullary spinal tumors, representing 25-30% of all such tumors 2.
This article specifically relates to spinal meningiomas. For a discussion on intracranial meningiomas and a general discus...
Article
Combined cerebral edema
Combined cerebral edema is a type of cerebral edema in which there is a mixed pattern of different types of cerebral edema (cytotoxic, vasogenic or osmotic).
It is usually associated with severe systemic damage, such as:
hypertensive crises
severe sepsis / severe inflammatory condition
hypox...
Article
Neurodegeneration with brain iron accumulation
Neurodegeneration with brain iron accumulation (NBIA), is a heterogeneous group of rare genetic disorders characterized by accumulation of iron in the basal ganglia, which results in variable neurological disorders including extrapyramidal symptoms, neuropsychiatric and visual symptoms.
Numerou...
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Charcot-Marie-Tooth disease
Charcot-Marie-Tooth (CMT) disease, also known as hereditary motor and sensory neuropathy (HMSN), refers to a heterogeneous group of inherited peripheral neuropathies rather than a single clinical entity 9.
Epidemiology
The prevalence of CMT has been reported at ~45 cases (range 10-82) per 100,...
Article
Neuroblastoma
Neuroblastomas are tumors of neuroblastic origin. Although they may occur anywhere along the sympathetic chain, the vast majority arise from the adrenal gland.
They represent the most common extracranial solid childhood malignancy and are the third most common childhood tumor after leukemia and...
Article
Chordoma
Chordomas are uncommon malignant tumors of the axial skeleton that account for 1% of intracranial tumors and 4% of all primary bone tumors.
They originate from embryonic remnants of the primitive notochord (earliest fetal axial skeleton, extending from the Rathke's pouch to the tip of the cocc...
Article
Diffuse pediatric-type high-grade gliomas, H3-wildtype and IDH-wildtype
Diffuse pediatric-type high-grade gliomas, H3-wildtype and IDH-wildtype are high-grade pediatric tumors included in the 5th Edition (2021) of the WHO brain tumor classification.
Terminology
Diffuse pediatric-type high-grade gliomas H3-wildtype and IDH-wildtype are classified among the "pediatr...
Article
External auditory canal atresia
External auditory canal atresia, also known as congenital aural atresia, is characterized by complete or incomplete bony atresia of the external auditory canal (EAC), often in association with a dysplastic auricle and an abnormal middle ear cavity or ossicles.
Epidemiology
The incidence is 1 i...
Article
Hemimegalencephaly
Hemimegalencephaly is a rare congenital disorder of cortical formation characterized by hamartomatous overgrowth of all or part of a cerebral hemisphere. This overgrowth results from either increased proliferation or decreased apoptosis (or both) of developing neurons 2.
Epidemiology
Hemimegal...
Article
Superior vermian vein
The superior vermian vein is formed in the midline over the superior aspect of the cerebellar vermis (over the anterior lobe) by multiple tributaries draining not just the subjacent vermis but also the adjacent cerebellar hemispheres. These tributaries most often coalesce into a single trunk ove...
Article
Subdural hygroma
Subdural hygromas (alternative plural: hygromata 9), or subdural effusions, refer to the accumulation of fluid in the subdural space. Where it is associated with head injury it can also be termed a traumatic subdural hygroma.
Epidemiology
Subdural hygromas are encountered in all age-groups bu...
Article
Ciliopathies
Ciliopathies refer to diseases due to malfunctioning cilia (singular: cilium). Cilia are organelles that are external extensions of the cell membrane. Cilia fall into two main types: primary (or immotile) cilia and motile cilia.
Clinical presentation
Primary cilia are found in virtually every...
Article
Facial nerve
The facial nerve is the seventh (CN VII) cranial nerve and comprises two roots, a motor root and a smaller mixed sensory, taste and parasympathetic root, known as nervus intermedius, which join together within the temporal bone (TA: nervus facialis or nervus cranialis VII).
The facial nerve has...
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