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.
2,954 results found
Article
Parasellar dark T2 signal sign
The parasellar dark T2 signal sign is a MRI feature where there is parasellar low T2 signal. Some authors describe it as a specific finding in differentiating lymphocytic hypophysitis from a pituitary adenoma.
Article
Dragonfly sign
Dragonfly sign describes the appearance of the cerebellum on coronal images, which is seen secondary to cerebellar atrophy in pontocerebellar hypoplasia 1.
The sign is so called as the whole cerebellum resembles the shape of a dragonfly if one imagines the vermis is the body of the insect and t...
Article
Double panda sign
The double panda sign refers to the combination of the face of the giant panda and face of the miniature panda (cub of the giant panda) seen on T2 weighted images of midbrain and pons respectively, most commonly seen in Wilson disease.
The midbrain face of the giant panda sign consists of norma...
Article
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...
Article
AIDS-related diffuse large B-cell lymphoma
AIDS-related diffuse large B-cell lymphomas are one of the immunodeficiency-associated CNS lymphomas, and in Western countries represented a dramatic increase in primary CNS lymphoma during the HIV/AIDS epidemic of the 1980s, although the incidence is likely lower in patients treated with antire...
Article
Osmotic demyelination syndrome
Osmotic demyelination syndrome refers to acute demyelination seen in the setting of osmotic changes, typically with the rapid correction of hyponatremia. It is the preferred term replacing central pontine myelinolysis, recognizing that extrapontine structures can also be affected, previously kno...
Article
Bilateral thalamic glioma
Bilateral thalamic gliomas are rare but characteristic low-grade astrocytomas that occur in both children and young adults.
Clinical presentation
Presentation may vary with age. Young children with bilateral thalamic glioma often have signs of increased intracranial pressure and movement disor...
Article
Cacosmia
Cacosmia refers to a form of olfactory dysfunction where the patient has an inability to "recognize" smells. It can arise from a number of pathologies and can include peripheral sinonasal and central sensorineural components. In this situation, the patient knows there is a smell but cannot disti...
Article
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 tumor indenting the pons 1,2.
See also
thumb sign (disambiguation)
Article
Ageusia
Ageusia refers to a complete loss of taste. In instances where it is partial it is then falls under the spectrum of the conditions such as
hypogeusia (decreased sensitivity to all tastants)
hyperguesia (enhanced gustatory sensitivity)
dysgeusia (unpleasant perception of a tastant) and
phanto...
Article
Cryptococcoma
Cryptococcomas are a rare complication of infection by the Cryptococcus genus of invasive fungi, where a discrete, encapsulated lesion of immune infiltrates and pathogen forms. Cryptococcus gattii is most often isolated but Cryptococcus neoformans may also form cryptococcomas.
Epidemiology
In ...
Article
PHASES risk prediction score
The PHASES risk prediction score is a method of calculating the absolute 5-year risk of intracranial aneurysm rupture based on the data pooled from prospective cohort studies in the USA, Canada, Netherlands, Finland and Japan1. PHASES stands for: Population, Hypertension, Age, Size, Earlier suba...
Article
Chondrosarcoma
Chondrosarcomas are a heterogeneous group of malignant cartilaginous tumors most commonly found in older patients. They can arise de novo or secondary from an existing benign cartilaginous neoplasm. On imaging, these tumors have ring-and-arc chondroid matrix mineralization with aggressive featur...
Article
Posterior choroidal artery stroke
Posterior choroidal artery occlusion uncommonly presents as an isolated stroke syndrome. It usually coexists with posterior cerebral artery and often superior cerebellar artery involvement.
When seen in isolation damage is characteristically limited to the:
lateral geniculate body
pulvinar
...
Article
Ganglion
A ganglion (plural: ganglia) is a group of neuronal cell bodies and processes located in the peripheral nervous system 1.
Ganglia can be categorized into two groups - sensory ganglia and autonomic ganglia. Sensory ganglia primarily contain the cell bodies of neurons as well as their central an...
Article
CNS neuroblastoma, FOXR2-activated
Central nervous system neuroblastoma, FOXR2-activated is a novel brain tumor entity included in the WHO brain tumor classification 1.
Terminology
Central nervous system neuroblastoma with FOXR2 activation was identified in 2016 as a molecular entity, distinguished from primitive neuroectoderma...
Article
Medulloepithelioma of the optic disc and optic nerve
Medulloepitheliomas of the optic disc and optic nerve are extremely rare primary intraocular embryonal tumors arising from the optic disc and optic nerve.
Terminology
A medulloepithelioma of the optic disc and optic nerve may also be referred to as a diktyoma or teratoneuroma, although the use...
Article
Melioidosis
Melioidosis is an infectious disease caused by the bacterium Burkholderia pseudomallei (previously known as Pseudomonas pseudomallei) and is a multisystem disorder which may affect the lungs, brain, visceral organs, or musculoskeletal system.
Epidemiology
Melioidosis is a disease of the monsoo...
Article
Clival fracture
Clival fractures are uncommon skull base fractures resulting from high-energy cranial trauma and are usually associated with other skull vault fractures and brain injuries.
For a general discussion, please refer to the article on basilar fractures of the skull.
Epidemiology
Most fractures of ...
Article
Multiple sclerosis
Multiple sclerosis (MS) is a relatively common acquired chronic demyelinating disease involving the central nervous system, and is the second most common cause of neurological impairment in young adults, after trauma 19. Characteristically, and by definition, multiple sclerosis is disseminated i...
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