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
DNA
DNA (deoxyribonucleic acid) is a nucleic acid that encodes the genetic information (genome) necessary for RNA (ribonucleic acid) transcription (transcriptome) and protein synthesis (proteome) 1. It is contained in the nucleus of eukaryotic cells in the form of chromatin or chromosomes 7,8. Human...
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Infraction
Infractions are incomplete fragmented fractures without displacement. The most well-known is Freiberg infraction.
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Supermicrosurgery
Supermicrosurgery is the specialized surgical technique employed to anastomose blood vessels and nerves measuring 0.3 to 0.8 mm in caliber (so-called microneurovascular anastomosis) 1. The instruments developed for these demanding procedures are very fine microsurgical devices. Microsurgery as a...
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Enchondroma
Enchondromas, also known as chondromas 7, are relatively common intramedullary hyaline cartilage neoplasms with benign imaging features. They share histologic features with low-grade chondrosarcoma and are sometimes classified under the umbrella term low-grade chondral series tumors.
Enchondrom...
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Schenck classification of knee dislocation
The Schenck classification is categorizing knee dislocation based on the pattern of ligament tears. The four major ligamentous stabilizers are the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) and the lateral collateral ligament (LCL) compl...
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Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST)
Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) are guidelines to asses tumors that makes use of positron emission tomography (PET) to provide functional information to help determine tumor viability.
The criteria consist of four categories: complete metabolic response ...
Article
Mirizzi syndrome
Mirizzi syndrome refers to an uncommon phenomenon that results from extrinsic compression of an extrahepatic biliary duct from one or more calculi within the cystic duct or gallbladder. It is a functional hepatic syndrome but can often present with biliary duct dilatation and can mimic other hep...
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Faceless kidney
A faceless kidney refers to one in which the normal appearance of the renal sinus on cross-sectional imaging is absent. It was initially described as a sign of duplication of the collecting system 1 (a slice obtained between the two collecting systems will not demonstrate the normal components o...
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Progressive muscular atrophy
Progressive muscular atrophy is one of the motor neuron diseases, sometimes considered a variant of amyotrophic lateral sclerosis, confined to the lower motor neurons.
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Meyers and McKeever classification of ACL avulsion fractures
Meyers and McKeever classification is used to categorize ACL avulsion fractures.
Usage
The Meyers and McKeever classification is the most frequently used system (c. 2024) to describe ACL avulsion fractures 2.
Classification
Under the Meyers and McKeever system (with modifications by Zariczny...
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Periportal halo (CT/US)
Periportal halo or periportal collar sign refers to a zone of low attenuation seen around the intrahepatic portal veins on contrast-enhanced CT or hypoechogenicity on liver ultrasound. It likely represents periportal edema, which is often used as a synonymous term. Periportal haloes may occur ar...
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Skeletal survey (overview)
The skeletal survey is a radiographic series performed to survey the entire skeleton (axial skeleton, upper and lower limbs) for pathology or injury. Specific projections vary depending on the clinical indication and the institution's protocol.
There are various clinical indications that may wa...
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Bowl of grapes sign
The bowl of grapes sign has been described in synovial sarcoma. It refers to the characteristic multilobulated lesion subdivided by multiple septa, forming large cystic foci with regions of hemorrhage.
Article
Psoriasis
Psoriasis is an inflammatory dermatological disease with several variants. The most common variant is plaque psoriasis, other variants of the disease are guttate, erythrodermic and pustular psoriasis 1.
Epidemiology
There is a geographic variation in the prevalence of psoriasis such that popul...
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Right lower lobe collapse
Right lower lobe (RLL) collapse forms a triangular opacity extending from the hilum to the diaphragm. There is less overlap with the heart shadow compared to left lower lobe collapse.
Findings of lower lobe collapse can be grouped together as they are almost identical on both sides.
For a gen...
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Anderson and Montesano classification of occipital condyle fractures
The Anderson and Montesano classification is a widely used system for describing occipital condyle fractures. It divides injuries into three types based on morphology and mechanism of injury 1-5.
Classification
type I: impacted type occipital condyle fracture
morphology: comminution of the co...
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Os odontoideum
Os odontoideum (plural: ossa odontoidea) is an anatomic variant of the odontoid process of C2 and needs to be differentiated from persistent ossiculum terminale and from a type 2 odontoid fracture. It can be associated with atlantoaxial instability.
Although it was originally thought to be a c...
Article
Chordoma
Chordomas are uncommon malignant tumors of the axial skeleton that account for 1% of intracranial tumors and 4% of all primary bone tumors.
They originate from embryonic remnants of the primitive notochord (earliest fetal axial skeleton, extending from the Rathke's pouch to the tip of the cocc...
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Orthopantomography
The orthopantomogram (also known as an orthopantomograph, pantomogram, OPG or OPT) is a panoramic single image radiograph of the mandible, maxilla and teeth. It is often encountered in dental practice and occasionally in the emergency department; providing a convenient, inexpensive and rapid way...
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Germ cell tumors of the ovary
Germ cell tumors of the ovary account for approximately 15-20% of all ovarian tumors. In children and adolescents, up to 60% of ovarian tumors can be of germ cell origin.
They include:
ovarian teratoma(s): commonest primary benign tumor of ovary and commonest germ cell tumor:
mature (cystic) ...