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
Transitional cell carcinoma (urinary tract)
Transitional cell carcinoma (TCC), also called urothelial cell carcinoma (UCC), is the most common primary malignancy of the urinary tract and may be found along its entire length, from the renal pelvis to the bladder.
As imaging findings and treatment vary according to where along the urinary...
Article
Synostosis
The term synostosis (plural: synostoses) refers to the fusion of bones usually at cartilaginous or fibro-osseous connections. Synostoses occur physiologically, as asymptomatic anatomical variants or might be abnormal and cause clinical symptoms as a functional loss. The latter is clinically sign...
Article
Progressive supranuclear palsy
Progressive supranuclear palsy (PSP), also known as the Steele-Richardson-Olszewski syndrome, comprises a group of related tauopathies and is considered a neurodegenerative disease with no efficacious treatment.
Epidemiology
Progressive supranuclear palsy typically becomes clinically apparent...
Article
Brachytherapy
Brachytherapy, also known as sealed source radiation therapy or endocurietherapy, is a form of radiation therapy where a radioactive source is placed, under the guidance of imaging, within or next to the area requiring treatment. This provides localized targeted internal radiation.
Brachytherap...
Article
Acquisition time
The time of acquisition for a conventional spin echo or gradient echo sequence is the product of the repetition time, phase encoding steps, and number of averages (TR x phase steps x NEX).
For example, with a one-second TR, 128 phase steps, and two averages, we would get an acquisition time of ...
Article
Exudative retinitis
Exudative retinitis, also known as retinal telangiectasis or Coats disease, is a rare congenital disease affecting the eyes and a cause of leukocoria.
Epidemiology
It occurs predominantly in young males, with the onset of symptoms generally appearing in the first decade of life with a peak age...
Article
CT stair-step artifact
The CT stair-step artifact is found in straight structures which are oriented obliquely with respect to movement of the table and appear around the edges of sagittal and coronal reformatted images when wide collimations and non-overlapping reconstruction intervals are used.
It is also seen in c...
Article
Impending testicular infarction
Impending testicular infarction is a rare complication of epididymo-orchitis which can be diagnosed by absence or reversal of diastolic flow in intra-testicular arteries 1,2.
Clinical presentation
Patients may present with worsening of symptoms of epididymo-orchitis despite proper treatment.
...
Article
Ground-glass opacification
Ground-glass opacification/opacity (GGO) is a descriptive term referring to an area of increased attenuation in the lung on computed tomography (CT) with preserved bronchial and vascular markings. It is a non-specific sign with a wide etiology including infection, chronic interstitial disease an...
Article
Halo sign (chest)
The halo sign in chest imaging is a feature seen on lung window settings consisting of ground glass opacity surrounding a pulmonary nodule, mass, or consolidation. It is typically seen in angioinvasive aspergillosis.
Pathology
It is a non-specific finding which can represent partial alveolar f...
Article
Idiopathic inflammatory myopathy
Idiopathic inflammatory myopathy is applied to a group of autoimmune inflammatory muscle disorders (myositis). Which specific disorders are included in this group has evolved, particularly with advances in the discovery of myositis-specific antibodies 1,2.
Diagnosis
The diagnosis of idiopathic...
Article
Cannonball metastases (lungs)
Cannonball metastases refer to multiple large, well-circumscribed, round pulmonary metastases that appear not unsurprisingly like cannonballs. The French terms "envolée de ballons" and "lâcher de ballons", which translate to "balloons release", are also used to describe this same appearance.
M...
Article
Kuwada classification of Achilles tendon tear
The Kuwada classification of Achilles tendon tear was proposed in 1990 4 and remains the most widely used system for describing Achilles tendon rupture ref.
Classification
Achilles tendon tears may be grouped (according to the severity of the tear and degree of retraction) into four types:
ty...
Article
Meandering main pancreatic duct
Meandering main pancreatic duct denotes a main pancreatic duct that drains normally into the major papilla but performs a hairpin turn (reverse Z-type) or loop (loop-type) in the pancreatic head, in contradistinction to the smooth curvature seen in most cases.
Epidemiology
Their exact incidenc...
Article
Brand name
Brand names should generally not be used unless there is something specific about a particular brand that is important. An example of when a brand name is acceptable is an article or case that describes a specific implantable medical device with particular imaging features (see medical device ar...
Article
Content review
Radiopaedia's content review process for cases and articles is open and transparent 1. Contributors' and reviewers' names and disclosures are available, and all changes to content are stored in perpetuity as a publically accessible revision history.
Interaction between contributors and reviewer...
Article
Cesarean scar ectopic pregnancy
Cesarean scar ectopic pregnancy is a rare type of abnormal implantation. It is often considered the rarest type of ectopic pregnancy, although some do not include it in this category as implantation occurs within the uterus, instead preferring the term "cesarean scar pregnancy" 6.
Epidemiology
...
Article
Shoulder radiograph (an approach)
Shoulder radiographs are common films to see in the Emergency Department, especially during the weekend after sporting events.
Systematic review
Choosing a search strategy and utilizing it consistently is a helpful method to overcome common errors seen in diagnostic radiology. The order in whi...
Article
Bethesda system for reporting thyroid cytopathology
The Bethesda system for reporting thyroid cytopathology comprises six categories of pathological reporting of thyroid FNA, with each category linked to a malignancy risk.
Usage
The Bethesda system was first published in 2010 and subsequently revised with the third edition published in 2023 to ...
Article
Placenta previa
Placenta previa is an abnormally low-lying placenta covering the internal cervical os. As a common cause of antepartum hemorrhage, placenta previa is a potentially life-threatening condition for both mother and infant. As such, antenatal diagnosis is essential to prepare for childbirth adequatel...
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