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.
16,937 results
Article
Round pneumonia
Round pneumonia is a type of pneumonia usually only seen in pediatric patients. They are well defined, rounded opacities that represent regions of infected consolidation.
Epidemiology
The mean age of patients with round pneumonia is 5 years and 90% of patients who present with round pneumonia ...
Article
Left atrial appendage closure devices
Left atrial appendage (LAA) closure devices are implantable cardiac devices which are placed in the left atrial appendage for stroke prevention in patients with atrial fibrillation who have contraindications to pharmacological anticoagulation. Depending on the device they may be inserted percuta...
Article
Hypothalamic hamartoma
Hypothalamic hamartomas, also known as tuber cinereum hamartomas, are benign non-neoplastic heterotopias in the brain that typically occur in the region of the hypothalamus, arising from the tuber cinereum, a part of the hypothalamus located between the mammillary bodies and the optic chiasm.
E...
Article
Delta phalanx
Delta phalanx, also known as the delta bone, Δ bone, or longitudinal epiphyseal bracket (LEB), is a rare condition occurring in the hand or the foot. The affected bone may be the phalanges, metacarpal or metatarsal bones with both unilateral and bilateral distributions.
Epidemiology
The delta...
Article
Lambl excrescence
Lambl excrescences, also known as valvular strands, are small, filiform, fibrous strands located on cardiac valves.
Epidemiology
Thought to be present in 70-80% of adults according to pathological studies, but only ~40% on echocardiograph studies 1. When present, multiple Lambl excrescences ar...
Article
HACEK organisms
The HACEK organisms, or HACEK group, is an acronym for Haemophilus spp., Aggregatibacter spp., Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae, a group of Gram-negative common oral commensal bacteria which are associated with infective endocarditis.
Epidemiology
Infective end...
Article
Trident sign (neurosarcoidosis)
The trident sign is a radiological (MRI) sign described in spinal cord neurosarcoidosis.
The sign is formed by the axial appearance of a longitudinally extensive transverse myelitis due to spinal cord neurosarcoidosis, whereby on a T1-weighted post-contrast (gadolinium) MRI sequence, there is c...
Article
Transposition of the great arteries
Transposition of the great arteries (TGA), also known as transposition of the great vessels (TGV), is the most common cyanotic congenital cardiac anomaly presenting during the newborn period, with cyanosis in the first 24 hours of life.
It occurs as a result of ventriculoarterial discordance, w...
Article
Dural arteriovenous fistula
Dural arteriovenous fistulas (dAVF) are a heterogeneous collection of conditions that share arteriovenous shunts from dural vessels. They present variably with hemorrhage or venous hypertension and can be challenging to treat.
Epidemiology
Most dural arteriovenous fistulas present in adulthood...
Article
Retinal detachment
Retinal detachment is a detachment of the neurosensory retina from the underlying pigmented choroid. Apposition of the retinal pigmented epithelium to the overlying retina is essential for normal retinal function.
Terminology
There are numerous subtypes of retinal detachment 5:
rhegmatogenous...
Article
Ovary
The ovaries (TA: ovarium 9) are paired female gonads of the reproductive and endocrine systems. They lie within the ovarian fossa on the posterior wall of the true pelvis and form part of the adnexa.
Gross anatomy
The ovaries are firm and ovoid in shape and measure approximately 1.5-3.0 cm × ...
Article
Rheumatic fever
Rheumatic fever is an illness caused by an immunological reaction following group A streptococcal infection.
Epidemiology
Risk factors include:
children and adolescents aged 5 to 15 years
developing nations where antibiotic prescription is low 1
poverty, overcrowding
Clinical presentation...
Article
Sydenham chorea
Sydenham chorea, also referred to as chorea minor or historically as St. Vitus dance, is a manifestation of rheumatic fever.
Clinical presentation
hyperkinetic movement disorder
neuropsychiatric manifestations with or without the presence of carditis or arthritis
cognitive and behavioral sym...
Article
Ovarian teratoma
Ovarian teratomas are the most common group of ovarian germ cell tumors.
They can be divided into 3 main sub types
mature ovarian teratoma
immature ovarian teratoma
specialized teratoma
struma ovarii tumor
See also
ovarian tumors
Article
Regenerative liver nodule
Regenerative liver nodules are a form of non-neoplastic nodules that arise in a cirrhotic liver.
Terminology
This may be slightly different from the term nodular regenerative hyperplasia, which are described histopathologically as regenerative nodules with little or no hepatic fibrosis and lar...
Article
Air trapping
Air trapping is the retention of excess gas in lung distal to one or more obstructed airways. Subnormal reduction in volume and subnormal increase in attenuation on end-expiratory CT are diagnostic findings and the affected areas are typically sharply demarcated. Reactive vasoconstriction is oft...
Article
Spinal hemangioblastoma
Spinal hemangioblastomas are the third most common intramedullary spinal neoplasm, representing 2-6% of all intramedullary tumors 1,4,7.
This article specifically relates to spinal hemangioblastomas. For a discussion on intracranial hemangioblastomas and a general discussion of the pathology re...
Article
Theodore Keats
Theodore Keats (1924-2010) was an eminent American radiologist whose unwavering dedication to education and authorship left an indelible mark on radiology. He is best remembered as the author of the Atlas of Normal Roentgen Variants That May Simulate Disease.
Early life
Theodore Eliot Keats wa...
Article
Cerebral cavernous venous malformation
Cerebral cavernous venous malformations, also commonly known as cavernous hemangiomas or cavernomas, are common cerebral vascular malformations, usually with characteristic appearances on MRI. It is the third most common cerebral vascular malformation after developmental venous anomaly and capil...
Article
Susceptibility weighted imaging
Susceptibility weighted imaging (SWI) is an MRI sequence that is particularly sensitive to compounds which distort the local magnetic field and as such make it useful in detecting blood products, calcium, etc.
Physics
SWI is a 3D high-spatial-resolution fully velocity corrected gradient-echo M...
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