Articles

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16,858 results found
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Osteoid

Osteoid is a protein mixture secreted by osteoblasts that forms the organic matrix of bone. Bone is formed when osteoid mineralizes. Osteoid is important in several disease processes: failure of osteoid to mineralize leads to osteomalacia in adults and rickets in children. focal accumulations...
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Osteosarcoma

Osteosarcomas are malignant bone-forming tumors. They are the second most common primary bone tumor after multiple myeloma, accounting for ~20% of all primary bone tumors. In children, they are considered the most common primary bone tumor 12. They can be classified into primary and secondary fo...
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Congenital cerebral toxoplasmosis

Congenital cerebral toxoplasmosis is a manifestation of congenital toxoplasmosis and refers to development of cerebral toxoplasmosis in the fetus through maternal transmission. Please refer to congenital toxoplasmosis for a broad discussion on epidemiology and pathology.  Radiographic features...
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Cerebral paragonimiasis

Cerebral paragonimiasis is a serious manifestation of paragonimiasis, and refers to a parasitic brain infection caused by a the Paragonimus genus of trematodes (flukes). Epidemiology Paragonimiasis is endemic in Asia, West Africa, and Latin America. Infections can occur after ingesting underco...
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Fecal calprotectin

Fecal calprotectin (FCAL) is a protein marker of gut inflammation. It is used as a diagnostic tool and marker of disease activity for Crohn disease and ulcerative colitis. Biochemistry Calprotectin is a protein complex from the S-100 family, which is formed of three polypeptide chains, two hea...
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Lobar consolidation

Lobar consolidation is the term used to describe consolidation in one of the lobes of the lung. It implies an alveolar spread of disease and is most commonly due to pneumonia. Pathology Consolidation refers to the alveolar airspaces being filled with fluid (exudate/transudate/blood), cells (in...
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Portal vein

The portal vein (PV) (sometimes referred to as the main or hepatic portal vein) is the main vessel in the portal venous system and drains blood from the gastrointestinal tract and spleen to the liver. Terminology A portal venous system connects two capillary beds, meaning one organ / organ sys...
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High riding jugular bulb

A high riding jugular bulb indicates the dome (roof) of the jugular bulb extends more superiorly in the petrous temporal bone than is conventional. The transverse level above which a jugular bulb is considered high riding has been variably defined as the following 1,6,8: floor of the internal a...
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Transient intussusception

Transient or uncomplicated intussusception is known to occur in adults and children and can be considered physiological. Given the condition's transient nature, it is probably underdiagnosed. The main factors distinguishing transient from intussusceptions requiring surgical intervention are abse...
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Imperforate hymen

Imperforate hymen is a congenital condition in which the hymen lacks a normal opening. Epidemiology It happens in 0.1% of the female population, usually an isolated finding.  Clinical presentation Primary amenorrhea with cyclic lower abdominal pain during menarche age. An imperforate hymen c...
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Mastoid emissary vein

Mastoid emissary veins (MEV) are a type of emissary veins representing small venous channels connecting the intracranial and extracranial venous systems. They may have a right sided dominancy and usually run between the sigmoid sinus and posterior auricular or occipital vein by crossing the mas...
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Acute disseminated encephalomyelitis (ADEM)

Acute disseminated encephalomyelitis (ADEM), as the name would suggest, is featured by a monophasic acute inflammation and demyelination of white matter typically following a recent (1-2 weeks prior) viral infection or vaccination 4,6. Grey matter, especially that of the basal ganglia, is also o...
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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...
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Target sign (disambiguation)

There are many bull's eye signs, many also called target signs: Gastrointestinal intussusception: see target sign of intussusception barium studies 2 aphthoid ulcers: earliest lesion seen in Crohn disease  gastric lymphoma with central ulceration 4 gastric adenocarcinoma with central ulcer...
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Androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS), also known as testicular feminization syndrome, results from end-organ resistance to androgens, particularly testosterone. AIS may be complete or incomplete with variable imaging findings.  Epidemiology The incidence may vary depending on whether it is co...
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Alport syndrome

Alport syndrome is a hereditary disease characterized by progressive sensorineural hearing loss, renal disease and, at times, ocular lesions. Clinical presentation hematuria sensorineural hearing loss: typically high frequency 2 ocular abnormalities anterior lenticonus which may result in c...
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Pineal parenchymal tumor of intermediate differentiation

Pineal parenchymal tumors of intermediate differentiation (PPTID) are, as the name suggests, tumors that fall between pineocytoma (well-differentiated, WHO grade 1) and pineoblastomas (poorly differentiated, WHO grade 4). They are considered WHO grade 2 or 3 tumors 4. Their radiographic appearan...
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Post-hydrocephalus corpus callosum damage

Post-hydrocephalus corpus callosum damage is seen both in the setting of, and following treatment for, long-standing hydrocephalus. The exact pathophysiology remains to be fully elucidated but both compression and rapid decompression with resultant changes in morphology have been implicated. Tw...
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Institutional member (institutions)

Institutional members are Radiopaedia users who are affiliated with one or more verified institutions and who have themselves been verified by their institution's admin as belonging to that institution.  Thus to become a verified institutional member and attain the institutional member achievem...
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Teratoma

Teratomas are germ cell tumors that arise from ectopic pluripotent stem cells that fail to migrate from the yolk sac endoderm to the urogenital ridge during embryogenesis. By definition, they contain elements from all three embryological layers: endoderm, mesoderm and ectoderm although frequentl...

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