Articles

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16,887 results found
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Focal hepatic hot spot sign

The focal hepatic hot spot sign, also known as the hot quadrate sign can be seen on technetium 99m sulfur colloid scans of the liver and spleen, as well as CT studies. Radiographic features It occurs as a focal area of increased radiopharmaceutical uptake, or iodinated contrast accumulation, i...
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Autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD), also sometimes referred to as "adult polycystic kidney disease", is an inherited form of adult cystic renal disease.  Epidemiology Autosomal dominant polycystic kidney disease is one of the most common serious hereditary diseases, found in ...
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Cauda equina

The cauda equina is the collective term given to nerve roots distal to the conus medullaris, which occupy the lumbar cistern.  Its name comes from the Latin for "horse's tail". The cauda equina is contained within the thecal sac and suspended in cerebrospinal fluid (CSF). The lower sacral (S2-...
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Superior mesenteric artery syndrome

Superior mesenteric artery (SMA) syndrome, also known as Wilkie syndrome, cast syndrome or aortomesenteric duodenal compression syndrome, is a rare acquired vascular compression disorder in which acute angulation of the superior mesenteric artery (SMA) results in compression of the third part of...
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Foramen Vesalii

The foramen Vesalii (plural: foramina Vesalii), also known as the foramen of Vesalius, sphenoidal emissary foramen, foramen venosus or canaliculus sphenoidal, is a tiny variably present foramen in the greater wing of the sphenoid bone. Its incidence varies markedly. A study of 100 cadaveric sk...
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Cor triatriatum dexter

Cor triatriatum dexter is a rare congenital anomaly wherein the right atrium of the heart is divided into two pseudo chambers by a membranous fold 1. Epidemiology It accounts for significantly less than 0.1% of all congenital heart defects 2. The more common cor triatriatum sinister has a high...
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Methotrexate-related leukoencephalopathy

Methotrexate-related leukoencephalopathy, resulting from the administration of methotrexate, is an uncommon yet important type of toxic encephalopathy. Methotrexate is administered via oral, intravenous, or intrathecal routes for many clinical indications, but its use as a chemotherapy agent for...
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Bifurcate ligament

The bifurcate ligament, also known as the Chopart ligament 5,8, is a key stabilizer of the subtalar and midtarsal joints 5,7. It originates from the anterior process of the calcaneus before dividing into two bands that insert into the navicular and cuboid 5-7. Gross anatomy The bifurcate ligam...
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Malignant peripheral nerve sheath tumor

Malignant peripheral nerve sheath tumors (MPNSTs) are forms of peripheral nerve sheath tumors occurring either de novo or arising from pre-existing tumors (e.g. neurofibromas, schwannomas etc.). Approximately half of such tumors are seen in individuals with neurofibromatosis type I (NF1), in suc...
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Gardner syndrome

Gardner syndrome is one of the polyposis syndromes. It is characterized by: familial adenopolyposis multiple osteomas: especially of the mandible, skull, and long bones epidermal cysts fibromatoses desmoid tumors of mesentery and anterior abdominal wall Other abnormalities include: supern...
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Little league shoulder

Little league shoulder is thought to occur due to overuse damage of the proximal humeral epiphysis/metaphysis, seen typically in young baseball players, especially pitchers. Epidemiology Although it is most commonly seen in baseball players particularly in pitchers, it also presents in adolesc...
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Osteolipoma

Osteolipomas, also known as ossified lipomas, are rare intracranial masses, typically located in the suprasellar cistern, composed of mature adipocytes surrounded by calcified ossification 1. They are a variant of intracranial lipomas which rarely have calcification/ossification elsewhere, with ...
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Medical abbreviations and acronyms (P)

This article contains a list of commonly used medical abbreviations and acronyms that start with the letter P and may be encountered in medicine and radiology (please keep 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 - R ...
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Hydatid disease

Hydatid cysts result from infection by the Echinococcus tapeworm species and can result in cyst formation anywhere in the body. Epidemiology Cystic echinococcosis has a worldwide geographical distribution. The Mediterranean basin is an important endemic area 6,7. Pathology Two main species o...
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Calcific axillary lymphadenopathy (differential)

Calcific axillary lymphadenopathy is in general, more concerning than axillary lymphadenopathy alone and is particularly so if it contains microcalcifications. While this is concerning for malignancy, it can also occur from occasional nonmalignant causes. Pathology Etiology metastatic axillar...
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Water lily sign (hydatid cyst)

The water lily sign, also known as the camalote sign, is seen in hydatid infections when the inner endocyst detaches from the outer pericyst, resulting in a free-floating membrane within the cyst. It is classically described on plain radiographs (mainly chest X-ray) when the collapsed membranes...
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Polymorphous low grade neuroepithelial tumor of the young

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is an epileptogenic tumor of children and young adults. They are often considered part of the heterogeneous group of tumors known as long-term epilepsy-associated tumors (LEATs). Terminology First described in 2016 1, polymorpho...
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Shoulder protocol (MRI)

The MRI shoulder protocol encompasses a set of different MRI sequences for the routine assessment of the shoulder joint. Note: This article aims to frame a general concept of an MRI protocol for the assessment of the shoulder joint. Protocol specifics will vary depending on MRI scanner type, sp...
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Hepatolithiasis

Hepatolithiasis is the presence of bile duct stones within the intrahepatic bile ducts, specifically proximal to the confluence of the right and left hepatic ducts.  Epidemiology Hepatolithiasis is common in Asia and the Pacific, with a prevalence of ~40%. It is rare in the West with a prevale...
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Bile duct stricture

Bile duct strictures are problematic in terms of management and distinction between benign and malignant. Pathology Etiology There are numerous causes of biliary duct strictures, including 1,2: malignant cholangiocarcinoma involvement by pancreatic head adenocarcinoma involvement by ampul...

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