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15,962 results found

Hebbian learning

Hebbian learning describes a type of activity-dependent modification of the strength of synaptic transmission at pre-existing synapses which plays a central role in the capacity of the brain to convert transient experiences into memory. According to Hebb et al 1, two cells or systems of cells th...

Lower limb radiography (pediatric)

Lower limb radiography involves plain film imaging of the pelvis, hip, knee and ankle bones in pediatric patients. Depending on the patients' age, the difficulty of the examination will vary, often requiring a specialist trained radiographer familiar with a variety of distraction and immobilizat...

Pediatric scaphoid (axial view)

The scaphoid view in pediatrics examines the scaphoid bone in its true anatomical position. Since minimizing radiation dose is essential in pediatric imaging, one posteroanterior angled view of the scaphoid is usually sufficient. The scaphoid bone begins ossification at age 5 and completes aroun...

Cholinergic crisis (mnemonic)

Mnemonics for clinical findings relating to cholinergic crisis comprise: MDS' BEDBUG LBS FW HRCT CDS' CASA Mnemonics MDS' BEDBUG LB Relying on an ampersand as a placeholder, this mnemonic corresponds to the clinical features of acute cholinergic toxicity, relating to the stimulation of mu...

Sugaya classification

The Sugaya classification is a 5-point system used to evaluate rotator cuff repair. Usage The Sugaya classification is the most common system used to evaulate rotator cuff repair 2 although intra- and inter-observer reproducibility is variable 3,4. Classification The Sugaya classification a...

Cervical foraminal stenosis

Cervical foraminal stenosis is a common condition that is mostly asymptomatic but in some results in cervical radiculopathy. Clinical presentation Cervical foraminal stenosis is most commonly asymptomatic but can result in cervical nerve root compression, which in turn results in cervical radi...

Stener-like lesion of the medial collateral ligament of the knee

Stener-like lesions of the medial collateral ligament (MCL) occur when a tear involves the distal fibers of the superficial medial collateral ligament (sMCL) are displaced superﬁcially to the pes anserinus, which can result in compromised healing. Pathology Usually, the sMCL runs deep to the p...

Chudley-McCullough syndrome

Chudley-McCullough syndrome is an extremely rare autosomal recessive disorder characterized by early-onset sensorineural hearing loss and a distinctive combination of structural brain abnormalities, with relative preservation of psychomotor development. Epidemiology Chudley-McCullough syndrome...

Florid

Florid is a descriptive term often used in imaging reports to describe a process/appearance which is severe in degree, often following a subjective assessment. History and etymology The term florid derives from the Latin term "floridus" meaning flowery, itself from "flos", a flower 2. From me...

Reynolds pentad

Reynolds pentad is a combination of clinical signs found in acute cholangitis. It consists of Charcot triad 2-4: fever and/or chills RUQ pain jaundice as well as: delirium or lethargy, and shock Usefulness Sensitivity of Reynolds pentad from a large systematic review of nine studies was ...

Oral tori

Oral tori (singular torus) are benign bony outgrowths from the maxilla and mandible: maxillary tori a.k.a. torus palatinus mandibular tori a.k.a. torus mandibularis Oral tori are subcategorised according to their shape 1: flat spindle nodular lobular Although not usually called tori, fur...

Enlarged hilar periportal space sign

The enlarged hilar periportal space sign refers to the widening of the periportal space seen on MRI in early liver cirrhosis. Usage Enlarged hilar periportal space sign is one of the early signs of cirrhosis and may be used to detect fibrotic changes in the liver in patients who do not yet hav...

Triceps tendon rupture

A triceps tendon rupture represents the extreme end of the spectrum of triceps tendon tears where there is complete detachment of the triceps tendon. It most often occurs at the distal end. Pathology If can either occur in an acute setting with trauma (e.g. as a result of a sudden forceful elb...

Tracheostomy tube

Tracheostomy tubes, a.k.a. tracheotomy tubes, are inserted through a stoma post-tracheostomy to help patients unable to breathe normally. It may be temporary or permanent depending on the patient's condition, with its insertion where clinically indicated showing a lowered in-hospital mortality r...

Intracranial translucency

Intracranial translucency (IT) is the ultrasound appearance of the fourth ventricle in mid-sagittal plane as seen on 11-13 week antenatal scan. It is used as a marker for neural tube defects. Its absence is reported in open spina bifida 1. Radiographic features Technique the fetus must be in ...

Black hole sign (intracerebral hemorrhage)

The black hole sign refers to the non-contrast CT appearance of acute extravasation of blood into a hematoma, for example, an intracerebral hemorrhage. It represents a well-defined hypodense region (black hole) within hyperdense hematoma and is not connected to the nearby brain parenchyma. The h...

Voriconazole-induced periostitis

Voriconazole-included periostitis is a type of drug-induced periostitis and is a rare cause of diffuse bone pain in those on high dose or prolonged voriconazole therapy. Epidemiology Voriconazole-induced periostitis primarily occurs in the immunocompromised and transplant patient populations,...

Yolk sac tumor

A yolk sac tumor (YST) (or an endodermal sinus tumor) is a type of malignant germ cell tumor. Epidemiology They usually develop in infants, young children, and young women 1 Pathology They are non-epithelial tumors of germ-cell origin. Location They occur variable sites with the ovary bein...

Zebra sign (disambiguation)

The evocative appearance of the coat of a zebra has been used for several distinctive signs in radiology: zebra sign: cerebellar hemorrhage 1 zebra sign: amyotrophic lateral sclerosis 2 zebra spleen: arterial phase appearance of normal spleen 4,5 zebra stripe sign: treated osteogenesis imper...

Liposuction

Liposuction is a cosmetic procedure to reduce the volume of adipose tissue in the neck, arms, legs and/or abdomen. Areolar fat, a deeper layer of adipose tissue, is the main target and shows a good response to vacuum-assisted liposuction. There are three types of this procedure 1,2: power-ass...

Thoracic spine protocol (MRI)

The MRI thoracic spine protocol encompasses a set of MRI sequences for the routine assessment of the thoracic spine. Note: This article aims to frame a general concept of an MRI protocol for the assessment of the thoracic spine. An MR thoracic spine protocol might be combined with a cervical sp...

Acute flaccid myelitis

Acute flaccid myelitis is an uncommon cause of acute flaccid paralysis similar to poliomyelitis, primarily affecting children and usually seen following a respiratory viral illness. Epidemiology Acute flaccid myelitis primarily affects children. Cases appear to be temporally related to respi...

Acute flaccid paralysis

Acute flaccid paralysis is a syndrome resulting from a wide array of underlying conditions. The features are of a fairly rapidly progressing lower motor neuron pattern weakness with potential involvement not only of the limbs but also of muscles of the pharynx, trunk and diaphragm 1. Historica...

Cervical spine protocol (MRI)

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

Lumbar spine protocol (MRI)

The MRI lumbar spine protocol encompasses a set of MRI sequences for the routine assessment of the lumbar spine. Note: This article aims to frame a general concept of an MRI protocol for the assessment of the lumbar spine. Protocol specifics will vary depending on MRI scanner type, specific har...

Bone marrow reconversion

Bone marrow reconversion generates a red bone marrow pattern that is in reverse to the normal yellow-to-red distribution. Pathology Bone marrow reconversion occurs when there is increased hematopoietic demand, which may be 1,2: physiological cigarette smoking obesity high endurance athlet...

Encysted spermatic cord hydrocele

Encysted spermatic cord hydroceles are one of the subtypes of spermatic cord hydrocoele where the fluid collection does not communicate with the peritoneum above or the tunica vaginalis below. Pathology In this encysted type, a loculated hydrocoele occurs along the spermatic cord due to oblit...

Focal nodular marrow hyperplasia

Focal nodular marrow hyperplasia is a rare, benign condition where there is a localized conversion of red/hematopoietic from yellow/fatty bone marrow. Its main relevance is of having a pseudotumor appearance mimicking skeletal metastases on MRI 1. Pathology Location Most commonly located in t...

Low T1 bone lesion

Low T1 bone lesions or T1 hypointense bone lesions are radiological terms to categorize bone lesions according to their visually perceived low signal on T1 weighted images. Apart from the usual description of a bone lesion seen on MRI they are used to categorize incidentally found solitary bone ...

Persistent dorsal ophthalmic artery

The persistent dorsal ophthalmic artery is a rare anatomical variant of the ophthalmic artery. Instead of arising from the supraclinoid (C6) segment of the internal carotid artery, as is normally the case, the persistent dorsal ophthalmic artery arises from the lateral aspect of the cavernous (C...

Subcutaneous implantable defibrillator

A subcutaneous implantable defibrillator (SICD) is a medical device implanted, typically in the chest wall, It delivers an electric impulse to the heart like a standard cardiac defibrillator (AICD) without leads being inserted into the myocardium.

Hook-like osteophytes

Hook-like osteophytes describe overhanging bone spurs seen at the metacarpal heads, usually at the radial aspect, and characteristically seen with hemochromatosis, although may be seen in other conditions 1. Differential diagnosis Hook-like osteophytes are seen in: hemochromatosis: characteri...

High T1 bone lesion

High T1 bone lesions or T1 hyperintense bone lesions are radiological terms to categorize bone lesions with a high signal on T1 weighted images. Apart from the usual description of a bone lesion seen on MRI they are used to categorize incidentally found solitary bone lesions in the Bone Reportin...

Curtain sign (lung ultrasound)

The curtain sign refers to the normal ultrasound characteristics of lung bases where the lungs are fully aerated. This is because the air in the costophrenic recess will cast a hyperechoic "air curtain" over the recess, obscuring the outline of the lateral diaphragm. The "air curtain" will also ...

Cauldwell Classification

Cauldwell classification is a commonly used classification in assessing bronchial artery branching pattern. Classification The bronchial artery branching pattern is classified into four types based on the number of intercostobronchial trunks (ICBT) - that gives rise to right bronchial artery a...

Chemical ablation

Introduction Chemical ablation is a technique in which chemical ablative substances are used to cause cell death in neoplastic tissue. It is used as a standalone procedure or in combination with other techniques like TACE and radiofrequency ablation. Agents Absolute ethanol (most commonly use...

Ossification of the interosseous membrane of the leg

Ossification of the interosseous membrane of the leg is considered a form of heterotopic ossification. It is typically seen as bridging ossification between the tibia and fibula. Three types have been described. type I: usually occurs after a syndesmosis ankle sprain type II: usually from a t...

Internal auditory canal exostosis

Internal auditory canal (IAC) exostoses are bony growths that can narrow the IAC lumen, sometimes causing neurological symptoms due to nerve compression. Epidemiology Unlike their counterpart in the external auditory canal, IAC exostoses are uncommon and can be difficult to detect 1. Clinical...

Bone remodeling

Bone remodeling is the continuous lifelong coupled process of bone resorption and bone formation 1-4. It is the prerequisite for repairing bony microdamage during daily physical activities, the adaption of bone architecture to meet different mechanical demands and the prevention of aging effects...

Pediatric clavicle (AP cephalic view)

The cephalad angulation 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 sever...

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 it as a specific finding in differentiating lymphocytic hypophysitis from a pituitary adenoma.

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...

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 ...

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

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 ...

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...

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...

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 ...

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...

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...

Speed test (shoulder)

The Speed test is used to clinically assess for biceps tendon pathology. Procedure In this test, the 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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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.

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...

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...

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...

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,...

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 ...

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...

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...

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...

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. ...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

Ground glass (disambiguation)

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

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...

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 ...

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...

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...

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...

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 ...

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...

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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