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.

16,886 results found
Article

Acoustic shadowing

Acoustic shadowing (sometimes referred to as posterior acoustic shadowing) is a form of ultrasound artifact. It is characterized by the apparent lack of signal deep to an imaged tissue interface, due to all (or nearly all) of the transmitted sound wave being being reflected back to the transduce...
Article

Fothergill sign

The Fothergill sign describes an examination finding that is used to help distinguish an abdominal wall mass from an intra-abdominal mass. The sign is said to be present if a mass remains palpable and fixed even when the rectus muscles are contracted, such as when the patient lifts their head f...
Article

Non-pulsatile tinnitus

Non-pulsatile tinnitus is a form of tinnitus where there is a continuous ringing sensation of the ears. It is thought to have a considerable subjective component in many individuals. Pathology Many factors have been postulated, inclusive of 1-5: cerumen impaction middle ear infection medica...
Article

Biliary atresia

Biliary atresia is a congenital biliary disorder that is characterized by an absence or severe deficiency of the extrahepatic biliary tree. It is one of the most common causes of neonatal cholestasis, often causing cirrhosis immediately and leading to death and accounts for over half of children...
Article

Carnett sign

The Carnett sign describes an examination finding used to distinguish pain arising from the abdominal wall from pain arising from within the abdomen itself. Testing for Carnett sign is performed as a two-stage procedure; The examiner locates the point of maximal tenderness through palpation of...
Article

Lymphomas of the central nervous system

Lymphomas of the central nervous system, the most common of which is primary diffuse large B-cell lymphoma of the CNS, are the second most common primary brain tumor after gliomas 17. By definition, there is no co-existing systemic disease at the time of diagnosis, distinguishing it from CNS inv...
Article

Pituitary carcinoma

Pituitary carcinomas or metastatic PitNET are rare tumors that are histologically indistinguishable from pituitary adenomas (PitNET) on imaging, defined only by the presence of central nervous system or systemic metastases. Terminology In the 5th edition of the WHO classification of CNS tumors...
Article

Jones fracture

A Jones fracture is a fracture of the proximal metadiaphyseal junction of the fifth metatarsal bone that involves the 4th-5th metatarsal articulation. Pathology It is a transverse fracture at the base of the fifth metatarsal, 1.5 to 3 cm distal to the proximal tuberosity at the metadiaphyseal ...
Article

Trimalleolar fracture

Trimalleolar fractures refer to a three-part fracture of the ankle. The fractures involve the medial malleolus, the posterior aspect of the tibial plafond (referred to as the posterior malleolus) and the lateral malleolus. Having three parts, this is a more unstable fracture and may be associate...
Article

Distal radial fracture

Distal radial fractures are a heterogeneous group of fractures that occur at the distal radius and are the dominant fracture type at the wrist. These common fractures, representing ~15% of all fractures 7, usually occur when significant force is applied to the distal radial metaphysis.  Epidemi...
Article

Dinner fork deformity (wrist)

A dinner fork deformity, also known as a bayonet deformity, occurs as the result of a malunited distal radial fracture, usually a Colles fracture. The distal fragment is dorsally angulated, displaced and often also impacted. The term is descriptive, as the lateral view of the wrist is similar to...
Article

Navicular fracture

Navicular fractures, along with cuboid fractures, form the most common isolated mid-foot fractures.  Epidemiology Navicular fractures are responsible for approximately 5% of all foot fractures and 35% of all midfoot fractures 7. Clinical presentation May present with pain, swelling or hemato...
Article

Radiographic evaluation of anterior cruciate ligament reconstruction

Radiographic evaluation of anterior cruciate ligament (ACL) reconstruction involves: femoral component a line is drawn along the posterior cortex of the femur a second line is drawn along the roof of the intercondylar notch of the femur (Blumensaat line) the point of intersection of these tw...
Article

Renal agenesis

Renal agenesis refers to a congenital absence of one or both kidneys. If bilateral (traditionally known as the classic Potter syndrome) the condition is fatal, whereas if unilateral, patients can have a normal life expectancy.  Epidemiology Unilateral renal agenesis affects approximately 1 in ...
Article

Fetal tricuspid regurgitation

Tricuspid regurgitation (TR) (also known as tricuspid insufficiency) is a common finding in imaging of the fetus. Tricuspid regurgitation represents the abnormal backflow of blood into the right atrium during right ventricular contraction due to valvular leakage (i.e. it is a valvulopathy).  Ep...
Article

Lying down adrenal sign

The lying down adrenal sign is a cross-sectional imaging sign of renal agenesis or ectopia in which the ipsilateral adrenal gland appears to be 'lying down' on the psoas muscle posteriorly. Due to the linear as opposed to Y-shaped configuration of the gland in such situations, it is also describ...
Article

Chiari III malformation

Chiari III malformation is an extremely rare anomaly characterized by a low occipital and high cervical encephalocele with herniation of posterior fossa contents, that is, the cerebellum and/or the brainstem, occipital lobe, and fourth ventricle.  Pathology Associations agenesis of the corpus...
Article

Medical abbreviations and acronyms (D)

This article contains a list of commonly used medical abbreviations and acronyms that start with the letter D and may be encountered in medicine and radiology (please keep both the main list and any sublists in alphabetic order). A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q...
Article

Non-ischemic cerebral enhancing (NICE) lesions

Non-ischemic cerebral enhancing (NICE) lesions are an uncommon delayed complication of cerebrovascular procedures, including aneurysm coiling, thrombectomy and placement flow-diverter stent placement 1,2,4,5. Epidemiology As NICE lesions are seen following endovascular procedures most commonly...
Article

Delayed intraparenchymal hemorrhage

Delayed intraparenchymal hemorrhage (DIPH), or delayed ipsilateral parenchymal hemorrhage, is a rare and serious complication following successful and otherwise uncomplicated endovascular treatment of intracranial aneurysms, usually with flow-diverter stents. Terminology Although delayed ipsil...

Updating… Please wait.

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

 Thank you for updating your details.