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.

2,942 results found
Article

14-3-3 protein

14-3-3 proteins are found in the cerebrospinal fluid (CSF) and are currently used to help identify patients with sporadic Creutzfeldt-Jakob disease (sCJD).  Seven distinct 14-3-3 proteins have been found in humans. In diagnosing sCJD, the sensitivity of 14-3-3 protein is 92%, and its specifici...
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18q deletion syndrome

18q deletion syndrome is a rare chromosomal anomaly where there is a deletion of part of the long arm of chromosome 18. Associated symptoms and findings vary widely, as do their severity. Characteristic clinical features include short stature, intellectual disability, hypotonia, facial, and dist...
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1p19q codeletion

1p19q codeletion stands for the combined loss of the short arm chromosome 1 (i.e. 1p) and the long arm of chromosome 19 (i.e. 19q) and is recognized as a genetic marker predictive of therapeutic response to both chemotherapy and combined chemoradiotherapy and overall longer survival in patients ...
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2-hydroxyglutarate

2-hydroxyglutarate (2HG) is a metabolite that accumulates in the brains of patients with IDH1 mutated (IDH1 positive) brain tumors, particularly diffuse low-grade gliomas. Although not in widespread clinical use, it is likely that 2-hydroxyglutarate, which resonates at 2.25 ppm, will be able to ...
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5-ALA fluorescence-guided surgery

5-ALA fluorescence-guided surgery is an intraoperative technique that takes advantage of tumor cells accumulating a fluorescent compound to make the location of the tumor more readily apparent. It is primarily used in the resection of high-grade gliomas (e.g. glioblastoma, grade 3 or 4 astrocyto...
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ABC/2

ABC/2, also confusingly written as 1/2ABC in some literature, is a fast and simple method for estimating the volume of intracerebral hemorrhage (or any other ellipsoid lesion for that matter) which does not require volumetric 3D analysis or software. Intracerebral hemorrhage volume is an import...
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Abducens nerve

The abducens nerve is the sixth cranial nerve (CN VI). It is a motor nerve responsible for abduction of the eye (TA: nervus abducens or nervus cranialis VI). It courses from the abducens nucleus, located in the dorsal pons, up to the cavernous sinus, via a long cisternal segment that is prone to...
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Abducens nerve palsy

Abducens nerve palsy, or sixth nerve palsy, results in weakness of the ipsilateral lateral rectus muscle. Clinical presentation Patients present with horizontal diplopia with an inability to abduct the ipsilateral eye, thereby resulting in an esotropia (nasal deviation of the eye). Pathology ...
Article

Abducens nucleus

The abducens nucleus is a small motor nucleus in the pons for the abducens nerve. Gross anatomy The nucleus is located in the paramedian dorsal lower pons in the floor of the fourth ventricle lateral to the medial longitudinal fasciculus. The nucleus forms a longitudinal paramedian column of s...
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Aberrant arachnoid granulations

Aberrant arachnoid granulations, also known as arachnoid pits, are arachnoid granulations that penetrated the dura but failed to migrate normally in the venous sinus. They are most often located in the greater wing of the sphenoid bone and may be seen in idiopathic intracranial hypertension. Occ...
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Aberrant internal carotid artery

Aberrant internal carotid artery is a variant of the internal carotid artery and represents a collateral pathway resulting from involution of the normal cervical portion (first embryonic segment) of the internal carotid artery 5. Gross anatomy There is consequent enlargement of the usually sma...
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Abscess

Abscesses are focal confined collections of suppurative inflammatory material and can be thought of as having three components 1: a central core consisting of necrotic inflammatory cells and local tissue peripheral halo of viable neutrophils surrounded by a 'capsule' with dilated blood vessel...
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Absent posterior limb sign

The absent posterior limb sign is one of the main MRI findings of prognostic significance in term neonates with suspected hypoxic-ischemic brain injury. An absent posterior limb sign is defined as loss of the normally distinct hyperintensity on T1-weighted images in the posterior part of the pos...
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Absent septum pellucidum

An absent septum pellucidum may rarely be an isolated finding, or more commonly be seen in association with a variety of conditions. Epidemiology The septum pellucidum is partly or entirely absent in 2 or 3 individuals per 100,000 in the general population.  Pathology An absent septum pelluc...
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Abusive head trauma

Abusive head trauma is a term that is used for inflicted head injury that has occurred by either shaking, impact head trauma, or both, as part of the spectrum of non-accidental injury (NAI). Pathology Intracranial injuries Subdural hemorrhage in a child should be viewed with suspicion. Most o...
Article

Aceruloplasminemia

Aceruloplasminemia is an autosomal recessive type of neurodegeneration with brain iron accumulation and disorder of iron metabolism caused by a mutation in the ceruloplasmin (CP) gene resulting in the production of dysfunctional ceruloplasmin. Epidemiology Aceruloplasminemia is a very rare dis...
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Acalculia

Acalculia (or acquired dyscalculia) represents the acquired loss of the ability to perform simple arithmetic tasks secondary to CNS pathology. It is not to be confused with developmental dyscalculia, which is a different entity and represents developmental disturbance of computational ability.  ...
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Accessory middle cerebral artery

The accessory middle cerebral artery is a variant of the middle cerebral artery (MCA) that arises from the anterior cerebral artery (ACA). It is different from a duplicated middle cerebral artery, in which the duplicated vessel originates also from the distal end of the internal carotid artery (...
Article

Accessory nerve

The accessory nerve, also called the spinal accessory nerve, or historically, the nerve of Willis, is the eleventh cranial nerve (CN XI) and is composed of two parts, the cranial part and the spinal part (TA: nervus accessorius or nervus cranialis XI). Connections and course The cranial part (...
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Achondroplasia

Achondroplasia is a congenital genetic disorder resulting in rhizomelic dwarfism and is the most common skeletal dysplasia. It has numerous distinctive radiographic features.  Epidemiology It occurs due to sporadic mutations in the majority of cases but can be inherited as an autosomal dominan...

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