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.

16,793 results found
Article

Hemorrhagic transformation of ischemic stroke

Hemorrhagic transformation is a complication of cerebral ischemic stroke and can significantly worsen prognosis. Terminology The term hemorrhagic transformation is somewhat variably used and collectively refers to two different processes, which have different incidence, appearance and prognost...
Article

Automatic exposure control

Automatic exposure control (AEC) is incorporated into radiographic and mammographic imaging systems. Its function automatically terminates exposure when a preset amount of radiation has been detected. Automatic exposure control systems help to provide a consistent optical density/signal-to-nois...
Article

Denver criteria for blunt cerebrovascular injury

The Denver criteria are a set of screening criteria used to determine when CT angiography of the neck is indicated to detect blunt cerebrovascular injury (BCVI) in patients presenting after trauma.  Screening criteria The Denver criteria were initially developed in 1996 1, modified in 2005 to ...
Article

Anal sphincter injury

Anal sphincter injury is a form of perineal trauma that can involve internal or external anal sphincters and may extend to the anorectal mucosa in severe cases. This article is focusing on the most common type of anal sphincter injury that is associated with vaginal delivery and represents thir...
Article

Occipital lobe

The occipital lobe is the smallest of the four lobes of the brain. It sits posterior to the temporal lobe and parietal lobes, underlying the occipital bone and overlying the tentorium cerebelli. Its most notable functional component is the primary and secondary visual cortex. Gross anatomy The...
Article

Primary visual cortex

The primary visual cortex (Brodmann area 17 ) is also known as the calcarine cortex, striate cortex, or V1. It is the main site of input of signals coming from the retina. It is located on the medial aspect of the occipital lobe, in the gyrus superior and inferior to the calcarine sulcus. Most o...
Article

Corpora quadrigemina

The corpora quadrigemina (Latin for "quadruplet bodies", singular: corpus quadrigeminum) are the four colliculi, two inferior and two superior, that sit on the quadrigeminal plate on the posterior surface of the midbrain. The corpora quadrigemina are reflex centers involving vision and hearing:...
Article

Lateral geniculate nucleus

The lateral geniculate nucleus, also known as the lateral geniculate body, is one of the thalamic nuclei. It acts as the principal relay nucleus for the visual system and, as such, it is conveniently located at the termination of the optic tract. Together with the medial geniculate body, it for...
Article

Optic tract

The optic tracts are the posterior continuation of the optic nerves after the medial (temporal field) fibers decussate at the optic chiasma. Gross anatomy The optic nerves, optic chiasm, and optic tracts pass through the Circle of Willis in the way that it courses below the anterior cerebral a...
Article

Optic chiasm

The optic chiasm or chiasma is the midline structure where the nasal (medial) fibers of the optic nerves decussate to continue posteriorly as the optic tracts. It lies in the chiasmatic cistern and along with the pituitary stalk, is completely encircled by the circle of Willis. Gross anatomy R...
Article

Optic nerve

The optic nerve is the second (CN II) cranial nerve (TA: nervus opticus or nervus cranialis II). It is a purely sensory nerve that conveys visual information from the eye to the brain.  The nerve arises from the back of the globe exiting the orbit via the optic canal. It joins the contralateral...
Article

Ankle fractures

Ankle fractures account for ~10% of fractures encountered in trauma, preceded only in incidence by proximal femoral fractures in the lower limb. They have a bimodal presentation, involving young males and older females. Ankle injuries play a major part in functional impairment after multi or pol...
Article

Acrocephalosyndactyly

Acrocephalosyndactyly syndromes (ACS) are a rare group of disorders collectively characterized by: calvarial anomalies, e.g. craniosynostoses digital anomalies, e.g. syndactyly Pathology While there can be some overlap in features, they can be primarily classified into the following major su...
Article

Watershed cerebral infarction

Watershed cerebral infarctions, also known as border zone infarcts, occur at the border between cerebral vascular territories where the tissue is furthest from arterial supply and thus most vulnerable to reductions in perfusion.  Epidemiology Watershed cerebral infarction accounts for 5-10% of...
Article

Accessory renal artery

Accessory renal arteries are a common variant of the renal arteries. They are present in ~25% (range 20-30%) of the population and bilateral in ~10% 1. Accurate identification is of utmost importance for surgical planning prior to live donor transplantation 2,3 and renal artery embolization for ...
Article

Neural tube defects

Neural tube defect (NTD) refers to the incomplete closure of the neural tube in very early pregnancy, resulting in cranial defects or spinal dysraphism. The neural tube comprises a bundle of nerve sheath which closes to form brain caudally and spinal cord rostrally. The closure should occur at ...
Article

Fetal hydantoin syndrome

The fetal hydantoin syndrome refers to a spectrum of features that can develop in a small proportion (~ 10% 5) of women taking the antiseizure medication phenytoin (DilantinTM) during pregnancy. Clinical presentation CNS anomalies microcephaly increased risk of intracranial bleeding intra-u...
Article

Eastern equine encephalitis

Eastern equine encephalitis (EEE) is one of many viral encephalitides and results from infection with the eastern equine encephalitis virus. Clinical presentation Most patients have non-specific viral prodromal symptoms for approximately one week, including fevers, headache, nausea and vomitin...
Article

Neurocysticercosis

Neurocysticercosis is caused by the CNS infection with the pork tapeworm Taenia solium, which is endemic in most low-income countries where pigs are raised. This form of cysticercosis is a relevant cause of seizures in endemic areas. Epidemiology The disease is endemic in Central and South Ame...
Article

Mesial temporal sclerosis

Mesial temporal sclerosis, also commonly referred to as hippocampal sclerosis, is the most common association with intractable temporal lobe epilepsy 2,3,5. It is seen in up to 65% of autopsy studies, although significantly less in imaging. Clinical presentation Most patients present with temp...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.