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 edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

15,922 results found
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Parasellar dark T2 signal sign

The parasellar dark T2 signal sign is a MRI feature where there is parasellar low T2 signal. Some authors describe is as a specific finding in differentiating lymphocytic hypophysitis from a pituitary adenoma.
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Retroaortic anomalous coronary sign (echocardiography)

The retroaortic anomalous coronary (RAC) sign describes the sonographic appearance of an anomalous left coronary artery traveling posteriorly to the aortic root. It is most commonly observed with anomalous origin of the left circumflex artery from the right sinus of Valsalva, but is also describ...
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Contrast agent pooling sign

The contrast agent pooling sign is a CT sign characterized by dense intravenous contrast agent pooling in veins, and may signal imminent cardiac arrest. Radiographic features The contrast agent pooling sign is characterized by dense intravenous iodinated contrast media pooling and layering in ...
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Clade

A clade is a taxonomic term which is used to describe organisms which form a distinct group with shared characteristics that distinguish them from other groups of organisms. For example, organisms making up genetic variants within a particular species. See also monkeypox
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Monkeypox

Monkeypox is a rare zoonosis caused by an orthopoxvirus and in general, produces a mild flu-like illness and rash in humans. Virologically and clinically the condition is similar to smallpox, the first viral disease to be eradicated by humans. In 2022, a new outbreak of monkeypox was identified ...
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Secundum atrial septal defect

A secundum atrial septal defect (ASD) is the most common congenital abnormality of the interatrial septum. It describes a defect in the center of the interatrial septum in the region of the fossa ovalis and is most commonly due to a discontinuity in the portion of the septum derived from the emb...
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Cervical cerclage

Cervical cerclage is a treatment that is undertaken during pregnancy to reduce the chances of preterm labor. It involves the placement of a suture around the neck of the cervix. It aims to reduce the risk of preterm birth and provides mechanical support to keep the cervix closed 1,2. Cervical c...
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Wilbrand knee (optic radiation)

The Wilbrand knee refers to a small anterior loop of axons from the medial retina passing a short distance into the contralateral prechiasmatic optic nerve after decussating in the optic chiasm. It is said to account for the occurrence of the junctional scotoma caused by lesions at the junction ...
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Right gastric vein

The right gastric vein, also known as pyloric vein, forms part of the venous drainage network of the stomach and proximal duodenum. It is a tributary of the portal vein. Gross anatomy Location The right gastric vein courses parallel to the right gastric artery adjacent to the lesser curvature...
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Symphyseal fundal height

Symphyseal fundal height (SFH) is commonly used measurement practiced primarily used to detect fetal intrauterine growth restriction (IUGR). For fetuses after 24 weeks' gestation, it is measured using a tape as the distance from - the pubic symphysis (by identifying the upper border of the sy...
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Speed test (shoulder)

A speed test is a clinical tests in assessing the shoulder.  In this test examiner places the patient's arm in shoulder flexion, external rotation, full elbow extension, and forearm supination. Manual resistance is then applied by the examiner in a downward direction or the patient is asked to ...
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Aortic valve prolapse

Aortic valve prolapse refers to the improper closure of aortic valve leaflets. Aortic valve prolapse can result in aortic regurgitation, aortic root dilatation, and eccentric remodeling of the left ventricle.  Pathology  Etiology  pulmonary atresia rheumatic aortic valve disease bicuspid ao...
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Gain of function

Gain of function represents the set of laboratory techniques thanks to which it is possible to genetically modify a pathogen (for example a virus) in order to provide it with new capabilities.The field of application of the gain-of-function, in fact, is virology, in order to improve the understa...
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Cyanosis

Cyanosis (plural: cyanoses) is a physical sign represented by bluish discolouration of the skin. It indicates there is reduced oxygen bound to red blood cells in the bloodstream. Diagnosis of the underlying cause of cyanosis is based on a thorough history and physical examination. Pathology Et...
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Holstein-Lewis fracture

Holstein-Lewis fractures represent a special type of humeral shaft fracture. It is a simple spiral fracture of the distal humerus with a radial displacement of the distal fragment 1,3,4. These fractures are reported to have a higher rate of radial nerve palsy when compared to other humeral shaft...
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Pulmonary mycobacterium parascrofulaceum infection

Pulmonary mycobacterium parascrofulaceum infection results from infection by the species Mycobacterium parascrofulaceum, which is a relatively new species of non-tuberculous mycobacterium (NTM) belonging to group 2. Infection by this species is rare and infrequently reported and the lung is cons...
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Optic disc edema

Optic disc edema refers to unilateral or bilateral swelling of the optic disc.  Terminology  Optic disc edema describes the swelling of nerve fiber layer at the optic nerve head, and it is the consequence of many different pathological processes. Optic disc edema is sometimes mistaken for papi...
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Obsolete imaging techniques

It is almost axiomatic that as time passes, the imaging techniques by which patients are evaluated, eventually become obsolete, due to continued scientific and technological innovations.  Although the reality of new-fangled technology coming along and supplanting established methodology is of c...
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Renal large cell neuroendocrine carcinoma

Renal large cell neuroendocrine carcinomas are an extremely rare renal tumor, with only six cases reported in the literature (c. 2022) 1.  Epidemiology  Renal large cell neuroendocrine carcinoma represents <1% of the total reported cases of primary renal cancers. The most affected population i...
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Aortic root to right ventricle fistula

An aortic root to right ventricle fistula refers to abnormal fistulous communication between the aortic root and the right ventricle. It results from a defect of the aortic wall usually in the area above the right coronary cusp, where it separates aorta and right ventricular outflow tract. It ca...
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Metanephric adenofibroma

Metanephric adenofibroma, originally referred to as 'nephrogenic adenofibroma', is a rare, biphasic, and benign metanephric tumor.  Epidemiology Metanephric adenofibroma typically occurs in children and young adults with a mean age of 13 years 1,3. Clinical presentation Patients present with...
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Asbestos related diffuse pleural thickening

Asbestos related diffuse pleural thickening is a form of asbestos-related benign pleural disease and may occur with or without asbestos related fibrosis.  Pathology They may co-exist with pleural plaques but if thought to occur from a different pathology. Generation of reactive oxygen and nit...
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Complications of radiation therapy

Radiation therapy has the potential to cause complications in many organ systems, many of which, especially in the thorax, are important for radiologists to be aware of.  acute radiation syndrome complications of cranial radiation therapy radiation-induced cerebral vasculopathy radiation-ind...
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Paracingulate sulcus

The paracingulate sulcus is a secondary sulcus running anteroposteriorly in the medial surface of the frontal lobe above and parallel to the cingulate sulcus 1. It is only found in the great apes and only identified in 70-89% of humans 1.
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Salivary duct carcinoma

Salivary duct carcinomas are a subtype of primary salivary gland tumor. Salivary duct carcinomas show high rates of metastasis and recurrence.  Epidemiology Salivary duct carcinomas represent 5-10% of salivary gland malignancies and can arise de novo or out of a pleomorphic adenoma 1,2. They t...
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Canadian Association of Radiologists

The Canadian Association of Radiologists (CAR) is the national society for radiologists in Canada. Its current president is Gilles Soulez. It publishes the Canadian Association of Radiologists Journal. History The Canadian Association of Radiologists was founded in 1937 by Canadian radiologist...
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Gastrointestinal stents

Gastrointestinal (GI) stents are increasingly used to treat obstruction of the GI tract, most commonly due to malignancy. Types of stent esophageal stent gastric stent duodenal stent enteric stent colorectal stent History and etymology Somewhat surprisingly the word 'stent' is actually a...
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Glasgow-Blatchford score

The Glasgow-Blatchford score (GBS) is a widely-used and well-validated scoring system for upper GI bleeding and the need for intervention. Score The scoring system relies upon knowing the patient's urea, hemoglobin, systolic blood pressure, and several other criteria. Each criterion is scored,...
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Pediatric clavicle (AP view)

The anteroposterior clavicle view for pediatrics is part of a two view series examining the entirety of the clavicle and the sternoclavicular and acromioclavicular joints. This view is ideally performed erect, but supine may be necessary depending on the patient's level of distress and severity ...
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Colorectal cancer (TNM staging 7th edition)

The 7th edition of the TNM classification of colorectal carcinomas was proposed in 2010, and has now been updated and replaced by the 8th edition, published in 2016. Primary tumor staging (T) Tx: primary tumor cannot be assessed T0: no evidence of primary tumor Tis: carcinoma in situ T1: in...
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Feeding artery sign (endometrial polyp)

Feeding artery sign (a.k.a. pedicle artery sign) refers to the presence of a single feeding artery to endometrial lesion using color/power Doppler on ultrasonography. It is often seen in endometrial polyps 1. The feeding vessel indicates the stalk attachment of the polyp to the uterus. Endometr...
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Impacted teeth

Impacted teeth are common with the third molars most common. Other impacted teeth (e.g. maxillary canines, maxillary second molar, mandibular second premolar, and mandibular second molar) are less common 1,2.  Radiographics features CBCT Cone beam CT (CBCT) allows for 1,3: impacted tooth loc...
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Tetanus

Tetanus is a rare vaccine-preventable disease caused by Clostridium tetani, a ubiquitous soil bacterium which contaminates open wounds. It secretes a powerful neurotoxin which degrades neuromuscular junction function, producing muscle spasms and, despite intensive intervention, is often fatal. ...
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Notch sign (primary CNS lymphoma)

The notch sign refers to abnormally deep depression at the tumor margin in contrast-enhanced MRI in primary CNS lymphoma 1. It is not an uncommon sign in primary CNS lymphoma and can be seen in both immunocompetent and immunocompromised patients. It suggests an irregular growth pattern as well a...
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Metanephric stromal tumor

Metanephric stromal tumor (MST) is a very rare, benign renal neoplasm that predominantly affect children.  Epidemiology  Metanephric stromal tumor is characterized by pure stromal morphology, hyper-differentiation, and no metastasis. The median age of diagnosis was 2 years. Less than fifty cas...
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Pseudoendoleak

Pseudoendoleak is a recently described color Doppler ultrasound phenomenon caused by spurious color signal in the aneurysm sac following endovascular aneurysm repair (EVAR).  Radiographic features Pseudoendoleak is defined as flow signal on color Doppler in the aneurysm sac following EVAR. The...
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Tronzo classification of trochanteric fractures

The Tronzo classification of trochanteric fractures is a classification system used when assessing intertrochanteric fractures. The Tronzo classification is proposed to provide a guide to the management of these fractures. Due to its simplicity, the Tronzo classification has become the preferr...
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Vinyl chloride toxicity

Vinyl chloride toxicity (and polyvinyl chloride) may rarely result from occupational exposure, most notably manifesting as chronic liver disease and rare hepatic malignancies. However due to strict regulation of the industrial manufacturing and processing of vinyl chloride since the 1970s, signi...
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Heart failure with reduced ejection fraction

Heart failure with reduced ejection fraction (HFrEF) is a type of heart failure due to left ventricular dysfunction (left heart failure) classified by a left ventricular ejection fraction of 40% or less. Heart failure with reduced ejection fraction occurs when the left ventricle is unable to con...
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Effman Classification of urethral duplication

The Effman classification is a widely adopted system to classify the several distinct types of urethral duplication. It's considered to be the most complete classification from a clinical and functional point of view, but it's only based on male forms and does not distinguish sagittal from coron...
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Desmoplastic small round cell tumor of the pleura

Desmoplastic small round cell tumor (DSRCT) of the pleura is a rare primary pleural malignancy comprising of mesenchymal cells. Epidemiology Tend to occur in younger patients (mean ~ 25.5 years) and with a slightly greater male predilection.  Treatment and prognosis DSRCT tend to be aggressi...
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Herbert classification of scaphoid fractures

The Herbert classification of scaphoid fractures, also known as the Herbert and Fisher classification, is one of the most frequently used classification systems when assessing scaphoid fractures. The Herbert classification is proposed to provide a guide to the management of these fractures. Cl...
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Ventricular tachycardia

Ventricular tachycardia is a type of ventricular arrhythmia with at least three consecutive ventricular beats occurring at greater than 100 beats per minute. If left untreated, ventricular tachycardia can lead to ventricular fibrillation and cardiac arrest. Epidemiology  Ventricular tachycardi...
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Branch retinal artery occlusion

Branch retinal artery occlusion (BRAO) refers to the acute obstruction of an arteriolar branch of the central retinal artery, which can lead to retinal ischemia and transient or permanent visual loss. The distribution affecting a branch distinguishes this disease from central retinal artery occl...
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Ground glass (disambiguation)

The term ground glass may be used to refer to: ground glass opacity (lungs) ground glass matrix of fibrous dysplasia
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Matrix (bone)

The matrix (plural: matrices) of the bone is used in a general pathological context to refer to the extracellular material in which the cellular components of the bone lie. Indeed the term extracellular matrix, often shortened to matrix, is used for the secreted extracellular components of any t...
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Traction esophageal diverticulum

A traction esophageal diverticulum is a true esophageal diverticulum (i.e. includes all layers of the esophageal wall) which occurs secondary to pulling forces (traction) on the esophageal wall. Causes pulmonary or mediastinal scarring, fibrosis inflammatory processes in the mediastinum (for ...
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Trigeminal radiofrequency ablation

Trigeminal radiofrequency ablation, also known as trigeminal radiofrequency rhizotomy, is a percutaneous interventional procedure used to treat trigeminal neuralgia. It is the most popular technique for trigeminal ablation. Indications trigeminal neuralgia resistant to traditional medical trea...
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Mickey Mouse sign (anencephaly)

The Mickey Mouse sign in obstetric ultrasound denotes the characteristic "floating appearance" of the fetal cerebral lobes due to the absence of the cranium due to anencephaly.  Radiographic features The sign is best seen in the coronal plane (in relation to the fetal head), where the cerebral...
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Frog eye sign

The frog eye sign is seen when the orbital structures show a characteristic protrusion due to fetal anencephaly. The term is particularly used in point of care ultrasound (POCUS) 1.  Radiographic features On obstetric ultrasound the frog eye sign is best appreciated in the coronal plane (in re...
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Non-arteritic anterior ischemic optic neuropathy

Non-arteritic anterior ischemic optic neuropathy (NAION) is a form of ischemic optic neuropathy. Epidemiology It is considered the most common acute optic neuropathy in patients over 50 years of age (especially in those with vasculopathy risk factors (e.g. diabetes mellitus, hypertension, and ...
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Bone Reporting and Data System (Bone-RADS)

The Bone Reporting and Data System (Bone-RADS) is an algorithm developed and proposed by the Practice Guidelines and Technical Standards Committee of the Society of Skeletal Radiology for the diagnostic workup of incidentally encountered solitary bone lesions in adults on MRI and/or CT 1. Class...
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Subperiosteal hematoma

A subperiosteal hematoma occurs between the periosteum and the cortex of a bone and is therefore geographically limited to the affected bone. Clinical presentation Clinical presentation varies with location. Subperiosteal hematomas have been described in the calvarium, iliac bone, humerus, fem...
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Chiari-Frommel syndrome

Chiari-Frommel syndrome is a rare disease of young females that is exhibited by a lack of ovulation, lactation, and amenorrhea in post-partum patients for a period of greater than six months. Additional symptomatology comprises headache, abdominal pain, vision impairment, obesity, and emotional ...
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Human metapneumovirus pulmonary infection

Human metapneumovirus (hMPV) pulmonary infection is a recently detected condition reported to cause mild to severe respiratory tract infection, particularly in children, immunocompromised patients, and the elderly 6. Pathology Human metapneumovirus (HMPV), is an RNA virus and was first describ...
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Pudendal nerve entrapment syndrome

Pudendal nerve entrapment (PNE) syndrome is a rare and under-diagnosed condition associated with chronic pain, sexual dysfunction and impaired sphincter control due to compression of the pudendal nerve.   Anatomy The pudendal nerve arises from S2-S4 roots of the sacral plexus, carrying both s...
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Practical classification of forearm fractures

The practical classification of forearm fractures is a simple descriptive classification system commonly used when assessing forearm fractures, especially in the pediatric population. Although simple, the classification provides a good guide to the management. These characteristics allow for a ...
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Depressor labii inferioris muscle

The depressor labii inferioris muscle, also known as quadratus labii inferioris muscle, is one of the facial muscles. Summary origin: oblique line of the mandible, medial to the mental foramen insertion:  ​modiolus at the angle of the mouth ascends to medially insert into lower lip innerva...
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Miliary lung nodules (mnemonic)

The list of differential diagnoses for miliary lung nodules can be recalled with the mnemonic: TEMPEST Mnemonic TEMPEST T: tuberculosis E: eosinophilic granuloma M: metastases (especially thyroid) P: pneumoconiosis E: extrinsic allergic alveolitis (now known as hypersensitivity pneumonit...
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Carotid artery tortuosity

Carotid artery tortuosity is the elongation of the extracranial carotid arteries with redundancy and/or altered course, which may present on imaging as kinking, coiling, and/or looping 1,2. Clinical presentation Carotid artery tortuosity is mostly (~80%) asymptomatic. When symptomatic (~12.5%,...
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Harris ring

A Harris ring is a ring-like shadow observed at the base of the odontoid process on a lateral radiograph of the cervical spine. It is formed by the superimposition of the lateral masses of the C2 vertebra (axis) on its body. Disruption of the Harris ring is seen in type III, and less commonly, ...
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Superior triangle sign (right lower lobe collapse)

The superior triangle sign is seen with complete right lower lobe (RLL) collapse alone or combined with right middle lobe collapse on PA chest x-rays. This sign can be a useful indirect sign of right lower lobe collapse where typical features are absent. Radiographic features Plain radiograph ...
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Free standing bronchiectasis

Free-standing bronchiectasis or non-traction bronchiectasis is a descriptive term for bronchiectasis that is not related to regional fibrotic effects (e.g. traction bronchiectasis). Amongst other causes, this form may occur in recurrent chronic infective-inflammatory states such as in those with...
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Ankle extensor compartment injury

Ankle extensor compartment injuries are infrequently reported in the medical literature in contrast to the other ankle pathology.  Epidemiology The incidence of ankle extensor tendon abnormalities is unclear ref. Pathology The ankle extensor compartment contains (from medial to lateral) ref:...
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V sign of interphalangeal joint dislocation

The V sign is characterized on a lateral radiograph of the digit by the separation of the dorsal base of the dislocated phalanx and the head of the phalanx proximal to the incongruent joint 1,2. Before reduction, the V sign might be assessed to identify more subtle dorsal subluxations 1. If th...
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Lateral collateral ligament calcification

Lateral collateral ligament calcification is rare that can cause acute knee pain. Clinical presentation Most patients with lateral collateral calcification are asymptomatic while a small proportion will have lateral knee pain. Radiographic features Plain radiograph Calcification is adjacen...
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Virtual grid

Virtual grid softwares are a relatively new innovation utilizing no physical grid at all. Instead, the original purpose of a grid is replicated by an algorithm 1 based on fundamental mathematics (i.e. Laplace transformation, wavelet transformation and Gaussian decomposition) which iteratively re...
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Scaphoid abdomen

Scaphoid abdomen is the term given to an inward concavity of the anterior abdominal wall. It is used both for the clinical appearance and its radiological equivalent.  In children it maybe a sign of congenital diaphragmatic hernia. In both adult and pediatric patients, it raises the possibility...
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Area postrema syndrome

Area postrema syndrome is a disorder of the chemoreceptor trigger zone (area postrema) which is located on the medial posteroinferior surface of the medulla oblongata. It is usually a demyelinating disorder, as one of the core clinical characteristics of neuromyelitis optica spectrum disorder 1,...
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Arhinencephaly

Arhinencephaly, sometimes spelled arrhinencephaly, refers to congenital absence of the olfactory bulbs and tracts. It causes congenital anosmia and can be found in: isolated arhinencephaly Kallmann syndrome holoprosencephaly septo-optic dysplasia CHARGE syndrome Waardenburg-Shah syndrome
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Karnofsky performance status

The Karnofsky performance status (KPS) is a standardized measure of a patient’s ability to perform a variety of ordinary tasks. It is a score that ranges from 0 to 100 with a higher score indicating higher (less impaired) function. It is widely used in trials and allows for patient groups to be ...
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Scapulothoracic bursa

Scapulothoracic bursae refer to a number of bursae that allow for the gliding movement of the scapulothoracic joint. Two major bursae have been reliably described 1,3: infraserratus (scapulothoracic) bursa: between the serratus anterior muscle and the chest wall supraserratus (subscapularis) ...
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Green and O'Brien classification of thumb metacarpal fractures

The Green and O'Brien classification of thumb metacarpal fractures is a commonly used classification system when assessing thumb metacarpal fractures. However, since most types of fractures coincide with famous eponymous fractures, the system itself isn't usually used properly, giving preferenc...
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Superior cervical ganglion

The superior cervical ganglion (plural: ganglia) is the largest ganglion of the cervical sympathetic trunk, providing innervation to the head and neck region 1. Gross anatomy The superior cervical ganglion is formed by embryologically fused C1 to C4 sympathetic ganglia. It is elongated, cylind...
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CT angiography of the circle of Willis (protocol)

CT angiography of the circle of Willis (CTA COW) is a technique that allows visualization of the intracranial arteries; specifically the circle of Willis. While digital subtraction angiography (DSA) remains the gold standard for the diagnosis of intracranial aneurysms especially, CTA is a less i...
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Supraclavicular brachial plexus block (ultrasound)

A Supraclavicular brachial plexus block is indicated for establishing sensory and motor blockade of the upper extremity, including the humerus, elbow, forearm, wrist and hand.  Indications necessity to provide analgesia of the upper extremity for: abscess incision and drainage elbow dislocat...
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Subperiosteal abscess

Subperiosteal abscesses refer to the subperiosteal spread of infection characterized by purulent encapsulated fluid collections within the subperiosteal space. Epidemiology Subperiosteal abscesses are more often seen in children than in adults 1,2. Associations Subperiosteal abscesses have b...
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Orbital apex syndrome

Orbital apex syndrome, also known as Jacod syndrome, is a constellation of clinical findings, presenting as a result of several potential pathologies that compress or otherwise affect structures passing through the orbital apex. Clinical presentation Presentation is according to the structures...
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Spinnbarkeit

Spinnbarkeit is a property of viscoelastic fluids that describes their capacity to be drawn out into an unbroken strand 1. Synonymous terms include spinnability and fibrosity. Human bodily fluids that can exhibit a degree of spinnbarkeit include mucus (especially cervical mucus), saliva and syno...
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Hypoglossal nerve palsy

Hypoglossal nerve palsies, or twelfth nerve palsies, result in weakness of the muscles supplied by the hypoglossal nerve, namely the intrinsic and extrinsic tongue muscles, except for palatoglossus. Clinical presentation The hypoglossal nucleus receives a major component of contralateral corti...
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N-butyl-2-cyanoacrylate pulmonary embolism

N-butyl-2-cyanoacrylate pulmonary embolism is a potentially life-threatening complication that can arise following the use of the tissue glue, butyl-cyanoacrylate, for endoscopic sclerotherapy to treat variceal bleeding. Epidemiology Sclerosis with biological glue (butyl cyanoacrylate) is curr...
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Striated testis

The striated testis is an imaging finding that is seen in symptomatic and asymptomatic individuals. In geriatric people, the most common cause is interstitial fibrosis. In adolescent individuals, a few of the causes include trauma, neoplasm including non Hodgkin lymphoma, infection and testicula...
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Pulmonary hypertension associated with chronic obstructive pulmonary disease

Pulmonary hypertension associated with chronic obstructive pulmonary disease (PH-COPD) can be a common complication of chronic obstructive pulmonary disease and usually manifests as mild to moderate pulmonary hypertension in those with advanced COPD. Pulmonary arterial pressures in this situatio...
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Ciliary muscle

The ciliary muscle (TA: musculus ciliaris) is located within the ciliary body of the eye. It acts to facilitate lens accommodation for near vision, and receives parasympathetic innervation from short ciliary nerves, arising from the oculomotor nerve via the ciliary ganglion. Gross anatomy The ...
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Dilator pupillae muscle

The dilator pupillae muscle is a ring of contractile cells within the iris. These cells are arranged radially, such that their contraction facilitates pupillary dilation (mydriasis). The dilator pupillae muscle receives innervation from the sympathetic nervous system. Gross anatomy The dilator...
Article

Ulcer (soft tissue)

An ulcer refers to the break in the skin, epithelium, or mucous membrane resulting in the discontinuity in the surface tissue, necrosis, and often pus formation 1. Risk factors immunocompromised (e.g. diabetics) 1 immobile patients 1,2 advanced age 2 poor nutrition 2 increased moisture 2 ...
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Coandă effect (physics)

The Coanda effect refers to the phenomenon by which a narrow jet of liquid (or air) passing through an orifice directly in sequence with a solid (especially convex) surface will deviate from its path and adhere to this curved surface, following its shape in parallel. The mechanism is thought to...
Article

Fascia iliaca compartment block (ultrasound)

The fascia iliaca compartment block is a nerve block used to provide anesthesia to the lower extremity commonly in the perioperative period. It is most commonly used for analgesia of the hip, thigh, and knee. It involves the deposition of a local anesthetic beneath the fascia iliaca, targeting t...
Article

Clitoral ultrasound

Clitoral ultrasound is a modality for imaging clitoral pathology, which can be the etiology of female sexual dysfunction. It can also be performed before and after gynecologic surgery to assess clitoral anatomy and blood flow. The exam involves a transperineal component. Normal ultrasound anato...
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Sphincter pupillae muscle

The sphincter pupillae muscle is a circular ring of smooth muscle within the iris responsible for constriction of the pupil (miosis). The structure is stimulated by the parasympathetic nervous system causing the muscle to decrease in diameter as it contracts. Gross anatomy The sphincter pupill...
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Birbeck granules

Birbeck granules refer to unusual rod-shaped structures specific to Langerhans cells. Their origin and function remain undetermined. Langerin is a crucial component within Birbeck granules. History and etymology Birbeck granules were first described by Michael S Birbeck in 1961 3. Related pat...
Article

Water-soluble contrast challenge

A water-soluble contrast challenge (more widely known as a Gastrografin challenge) is a combined diagnostic study and therapeutic intervention utilized in the evaluation and management of small bowel obstruction. It is used when clinical or imaging features determine there to be small bowel obst...
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Bronchocentricity

Bronchocentricity (or bronchocentric distribution) describes a process in the lungs that is centered around bronchi (or bronchioles). The term centrilobular is commonly used for peribronchiolar disease. Because of the parallel relationship of bronchi and pulmonary arteries these processes are al...

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