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.

908 results found
Article

Echogenic renal pyramids (differential)

Echogenic renal pyramids in children can be due to many different causes.  Differential diagnosis Nephrocalcinosis Iatrogenic (most common cause) furosemide (frusemide) vitamin D steroids Non-iatrogenic idiopathic hypercalcemia Williams syndrome hyperparathyroidism milk-alkali syndrom...
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Ectopia lentis

Ectopia lentis refers to subluxation or dislocation of the lens of the eye secondary to dysfunction or disruption of zonular fibers.  Pathology Etiology trauma systemic and syndromic disorders Marfan syndrome typically upwards and out most common spontaneous cause 2 homocystinuria -  typ...
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Elbow arthroplasty

Elbow arthroplasties are an increasingly common joint replacement, most often used for treatment of late stage rheumatoid arthritis, but which may also be used as a treatment for late stage osteoarthritis or complex fractures of the proximal radius, proximal ulna, or distal humerus. total elbow...
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Elevated diaphragm

Elevated diaphragm refers to the symmetrical elevation of both domes of the diaphragm. Pathology Etiology There is some overlap with causes of an elevated hemidiaphragm.  Technical  supine position poor inspiratory effort Patient factors obesity pregnancy Diaphragmatic pathology paral...
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Elevated hemidiaphragm

An elevated hemidiaphragm may result from direct and indirect causes which include: above the diaphragm 1 decreased lung volume atelectasis/collapse prior lobectomy or pneumonectomy pulmonary hypoplasia diaphragm 3-7 phrenic nerve palsy diaphragmatic eventration contralateral stroke: ...
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Elevated prolactin (differential)

Elevated prolactin can be due to a number of causes, including elevated production/secretion as well as reduced inhibition.  Prolactin is controlled by numerous homeostatic mechanisms, with tonic secretion of prolactin inhibitory hormone (dopamine) by the hypothalamus having a dominant effect 1...
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Empty gestational sac

Empty gestational sacs can be due to a number of causes: anembryonic pregnancy (also known as "blighted ovum") early pregnancy (intrauterine): by 5.5 weeks gestational age, a yolk sac should be identifiable by transvaginal ultrasound pseudogestational sac with an ectopic pregnancy gestationa...
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Empyema

Empyemas are purulent inflammatory collections within a body cavity. Contrast this with abscesses, which arise within parenchymal tissue, rather than occupying a pre-existing anatomical space. Terminology Colloquially, the standalone term empyema is used to refer to thoracic empyemas but there...
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Encephalitis due to herpesvirus family

Although sporadic viral encephalitis is most commonly due to herpes simplex virus 1 (HSV-1) the extended herpesvirus family consists of many other viruses many of which can also infect the central nervous system. Encephalitis due to herpesvirus family include 1:   herpes simplex virus 1 (HSV-1)...
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Endobronchial metastases

Endobronchial metastases are an uncommon form of intrathoracic metastases. They are much less common than intrapulmonary metastases. Clinical presentation The clinical presentation varies and includes: hemoptysis cough post-obstructive pneumonitis from distal obstruction Pathology Frequen...
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Endoleak

Endoleaks are characterized by persistent blood flow within the aneurysm sac following endovascular aneurysm repair (EVAR). Normally the aortic stent-graft used for EVAR excludes the aneurysm from the circulation by providing a conduit for blood to bypass the sac. Epidemiology An endoleak is a...
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Endometrial fluid

Fluid in the endometrial cavity can result from a number of causes if excessive and associated with distension.  Pathology There are essentially three types of fluid:  hydrometra: simple fluid hematometra: hemorrhagic content / clot pyometra: pus Premenopausal normal (i.e. physiological) ...
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Endometrial microcalcifications

Endometrial microcalcifications can arise from a vast range pathologies but are usually of benign in etiology. Epidemiology They have an increased incidence with older age, postmenopausal state, atrophic endometrium, and endometrial polyps.  Associations In some cases they are associated wit...
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Endosteal scalloping

Endosteal scalloping refers to the focal resorption of the inner layer of the cortex (i.e. the endosteum) of bones, most typically long bones, due to slow-growing medullary lesions. It is important to note that although it is evidence of a slow non-infiltrative lesion, it does not equate to ben...
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Enlarged azygos vein

An enlarged/dilated azygos vein may result from a number of physiological as well as pathological causes. The enlarged azygos vein may be seen as a widened right paratracheal/paraspinal stripe on a frontal chest radiograph. Terminology Spelling it "azygous" when referring to the vein is incorr...
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Enlarged echogenic fetal kidneys

Enlarged echogenic fetal kidneys can be associated with a number of pathologies that include: autosomal recessive polycystic kidney disease (ARPKD) 1 autosomal dominant polycystic kidney disease (ADPKD) 3: the large cysts may not form in utero and the kidneys may initially appear as enlarged a...
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Enlarged extraocular muscles (differential)

There is a short list of causes for enlarged extraocular muscles: thyroid associated orbitopathy lymphoma orbital pseudotumor sarcoidosis metastases amyloidosis (very rare) 2
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Enlarged posterior fossa 'CSF' space

An enlarged posterior fossa 'CSF' space posterior to the cerebellum has a number of differentials that include: mega cisterna magna epidermoid cyst arachnoid cyst Careful attention to the cerebellum needs to paid as also to be considered are: cerebellar atrophy Dandy-Walker malformations ...
Article

Enlarged pulmonary trunk on chest radiography (differential)

The differential of an enlarged pulmonary trunk/main pulmonary artery on chest radiography includes:  normal may appear prominent in young patients especially women projectional rotation lordotic view rotation of the heart pectus excavatum left lower lobe collapse pulmonary arterial hyp...
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Enlarged sella turcica (differential)

Enlargement of sella turcica can be seen in situations including the following: empty sella syndrome slight globular enlargement of the sella with no erosion, destruction or posterior displacement of dorsum sellae intracranial hypertension enlargement with erosion of anterior cortex of dorsu...
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Enlargement of the cardiac silhouette

Enlargement of the cardiac silhouette on a frontal (or PA) chest x-ray can be due to a number of causes 1: cardiomegaly (most common cause by far) pericardial effusion anterior mediastinal mass prominent epicardial fat pad expiratory radiograph AP projection (from supine radiographs taken ...
Article

Enteritis

Enteritis (plural: enteritides) refers to inflammation of the small bowel. When associated with inflammation of the stomach, the term gastroenteritis is used which is usually caused by infection. Pathology Etiology infection infective enteritis eosinophilic enteritis ischemia inflammatory...
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Epididymal calcification

Epididymal calcification can be seen on ultrasound as hyperechoic foci within the epididymal head. If the calcifications are large enough, then they may demonstrate acoustic shadowing. Differential diagnosis chronic epididymitis: e.g. bacterial, granulomatous (TB) or genital filariasis  traum...
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Epididymal masses

Epididymal masses are most commonly encountered on ultrasonography. Most epididymal masses are benign; malignant lesions are rare. Differential diagnosis Benign solid adenomatoid tumor of the scrotum (most common epididymal mass 4) epididymal leiomyoma sperm granulomas / post vasectomy gran...
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Epilepsy

Epilepsy is a common neurological disorder that has a varied presentation and requires two or more unprovoked seizures at least 24 hours apart for diagnosis. MRI is the modality of choice for epilepsy, most often investigating for an underlying cause, especially in adults.  Epidemiology Epilep...
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Epiphora

Epiphora (plural: epiphoras) represents excessive tearing of the eye and is a common clinical presentation to ophthalmological practice. It is most frequently due to an obstruction of the nasolacrimal drainage apparatus. Less commonly, overproduction of tears may be responsible.  Epidemiology ...
Article

Epiphyseal lesions (differential)

Epiphyseal lesions comprise tumors and other pathologies that occur around the epiphysis and any epiphyseal equivalent bone. Differential diagnosis Common differential diagnoses include 2-4: chondroblastoma: rare epiphyseal tumor found in young adults; it usually does not extend into the meta...
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Epithelial ovarian tumors

Ovarian epithelial tumors account for the majority of all ovarian tumors (60-70%) and their malignant forms represent >90% of ovarian cancers 1. They can range from being benign to highly malignant. Epidemiology There is a difference in frequency of ovarian tumor subtypes depending on menopaus...
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Eponymous fractures

There are numerous eponymous fractures which are named after the people who first described their existence (but see Stigler's law of eponymy) 1: Bankart fracture: glenoid Barton fracture: wrist Bennett fracture: thumb Bosworth fracture: ankle Chance fracture: vertebral Charcot joint: foot...
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Erlenmeyer flask deformity

Erlenmeyer flask deformity (EFD) (also known as metaphyseal flaring) refers to a radiographic appearance typically on a femoral radiograph demonstrating relative constriction of the diaphysis and flaring of the metaphysis. It has been classically used with reference to the distal ends of the fe...
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Erosion of superior aspects of ribs (differential)

Differential diagnosis of erosion of the superior aspects of the ribs include:  hyperparathyroidism rheumatoid arthritis scleroderma neurofibromatosis poliomyelitis progeria
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Erosion of the odontoid process (differential)

Erosion of the odontoid peg can result from a number of pathological entities: inflammatory arthropathy rheumatoid arthritis: classic 1,2 systemic lupus erythematosus crystal arthropathy calcium pyrophosphate arthropathy (CPPD): relatively common gout non-inflammatory arthropathy: osteoar...
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Erosive arthritis (differential)

Erosive arthritis has a broad differential: erosive osteoarthritis clinically an acute inflammatory attacks (swelling, erythema, pain) in postmenopausal woman typically includes the distal interphalangeal joints, proximal interphalangeal joints, 1st carpometacarpal joint 6, but not the metaca...
Article

Erythrocytosis

Erythrocytosis (or polycythemia) is the presence of an excessive number of red blood cells in the circulation. It can be primary or arise secondarily to another pathology. Definition Absolute erythrocytosis is defined as a red cell mass which is >125% predicted for sex and age 2. Although the...
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Exophytic hepatic mass

Exophytic hepatic mass or tumor is a lesion which predominantly lies outside the margins of liver but originates from within the liver. Pathology Causes include 1: benign  hepatic hemangioma hepatic adenoma hepatic cyst hepatic angiomyolipoma focal nodular hyperplasia malignant  hepati...
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Exostosis

Exostoses are defined as benign growths of bone extending outwards from the surface of a bone. It can occur in any bone and be triggered by a number of factors. There are a number of examples of exostoses that occur due to local irritant stimuli: ivory exostosis exostosis of the external audit...
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Expansile lytic lesions without cortical destruction of bone (differential)

Expansile lytic bone lesions without cortical destruction can result from various benign and malignant neoplastic pathologies, causes include 1: unicameral bone cyst aneurysmal bone cyst (eccentric) enchondroma chondromyxoid fibroma (eccentric) non-ossifying fibroma (eccentric) desmoplasti...
Article

Extensor mechanism of the knee injuries

Extensor mechanism of the knee injuries include: quadriceps muscle tears quadriceps tendon rupture patellar tendon rupture patella fracture patellar dislocation often with medial retinaculum tears patellar sleeve fractures Chronic injuries Osgood-Schlatter disease Sinding-Larsen-Johans...
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Extra-axial

Extra-axial is a descriptive term to denote lesions that are external to the brain parenchyma, in contrast to intra-axial which describes lesions within the brain substance.  Radiographic features Often it is trivially easy to distinguish an intra-axial from an extra-axial mass. In many cases,...
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Extra-axial masses (differential)

Extra-axial masses of the intracranial compartment have a wide range of differentials, ranging from benign developmental cysts to malignant tumors.  Differential diagnosis neoplasms chordoma choroid plexus papilloma/carcinoma cranial nerve schwannoma meninges meningioma solitary fibrous ...
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Extraconal orbital lesions

Extraconal orbital lesions include lesions which arise from structures within the extraconal orbital space and those extending from adjacent structures into the orbits. Differential diagnosis Intraorbital lesions dermoid cyst: most common lesion in pediatrics  lacrimial gland lesions dacryo...
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Extraneural spread of intracranial neoplasm

Extraneural spread of primary intracranial neoplasm is distinctly uncommon, occurring far less frequently than CSF spread.  The most frequent neoplasms to do so, in decreasing order of frequency, are: glioblastoma (GBM) meningioma medulloblastoma
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Extraskeletal musculoskeletal lesions by compartment

Knowing extraskeletal musculoskeletal lesions by compartment is useful to help generate a meaningful differential diagnosis: Intermuscular extraskeletal myxoid chondrosarcoma fibromatosis ganglion leiomyosarcoma nodular fasciitis neurogenic tumors synovial cyst Intra-articular lipoma a...
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Extratesticular cystic lesions (differential)

The differential diagnosis for extratesticular cystic lesions includes: hydrocele epididymal cyst spermatocele hematoma haematocele loop of bowel from an inguinal hernia abscess pyocele post-vasectomy varicocele Very rarely, a scrotal mesothelioma may present as a cystic mass.
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Extratesticular scrotal mass (differential)

Extratesticular scrotal masses (non-testicle and non-epididymis) are mostly mesenchymal in origin and benign 1.  Benign lesions lipoma (most common) leiomyoma of the scrotum neurofibroma granular cell tumor angiomyofibroblastoma-like tumor fibrous pseudotumor fibrous hamartoma of infancy...
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Facial fractures

Facial fractures are commonly caused by blunt or penetrating trauma at moderate or high levels of force. Such injuries may be sustained during a fall, physical assault, motor vehicle collision, or gunshot wound. The facial bones are thin and relatively fragile making them susceptible to injury. ...
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Facial palsy

Facial palsy refers to the neurological syndrome of facial paralysis. It can result from a broad range of physiological insults to the facial nerve or its central nervous system origins. The most common causes of this is Bell palsy.  Terminology While facial palsy refers to the clinical presen...
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Failed early pregnancy

Failed early pregnancy refers to the death of the embryo and therefore, miscarriage. The most common cause of embryonic death is a chromosomal abnormality. Radiographic features Ultrasound Findings diagnostic of pregnancy failure crown-rump length (CRL) of ≥7 mm and no heartbeat on a transva...
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Fall onto an outstretched hand

Fall onto an outstretched hand (FOOSH) is a common mechanism for wrist-forearm fractures, in certain cases with involvement of elbow structures, particularly in children. Some injuries that result from such a fall include: Colles fracture Scaphoid fracture Monteggia fracture-dislocation Gal...
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Fat containing breast lesions

Fat containing breast lesions generally have some radiolucent component on mammography. Pathology They are generally classified at BIRADS II lesions. Common breast lipoma breast hamartoma fat necrosis within the breast/oil cyst intramammary lymph node: classically has a central fatty hilu...
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Fat containing cardiac lesions

Fat containing cardiac lesions have a limited differential diagnosis. These include 1-4: normal aging/physiologic: mostly subepicardial, more in the right ventricle (especially right ventricular outflow tract) than left ventricle lipomatous hypertrophy of the interatrial septum chronic myocar...
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Fat containing liver lesions

A variety of benign and malignant liver lesions may contain macroscopic and/or intracytoplasmic fat in sufficient quantities enabling characterization on imaging studies. Most fat containing liver lesions (80%) in patients with cirrhosis are malignant, most of which are hepatocellular carcinoma ...
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Fat containing renal lesions

There are numerous fat-containing renal lesions, including: renal angiomyolipoma renal cell carcinoma Wilms tumor renal oncocytoma renal or perirenal lipoma/liposarcoma Non-mass lesions may also occasionally contain fat: renal junction line fat in a renal scar renal sinus lipomatosis x...
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Fat containing solitary pulmonary nodule

The differential of a fat containing solitary pulmonary nodule is very narrow. In a well circumscribed smooth or lobulated mass (especially if it has been largely stable in size over time) presence of fat is essentially pathognomonic of a pulmonary hamartoma, and usually not further assessment ...
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Fat containing thoracic lesions

There is a long list of fat containing thoracic lesions. They may involve the mediastinum, lung, pleura or chest wall. Differential diagnosis includes:  intrapulmonary: fat containing pulmonary lesions pulmonary hamartoma endobronchial lipoma intrapulmonary lipoma lipoid pneumonia myeloli...
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Fatty mediastinal masses (differential)

Fatty mediastinal masses are relatively uncommon, and the differential diagnosis is brief, including 1-4: lipoma liposarcoma thymolipoma benign mature teratoma lipoblastoma extravasation of lipid-rich hyperalimentation fluid 3 fibrofatty replacement of the central portion of mediastinal l...
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Female infertility

Female infertility is common and can be due to a number of factors. Radiology often plays a key part in the work-up.  Pathology Etiology Often more than one factor (including male infertility) is the cause of infertility, some of the common causes are listed below 1-3: age > 35 years immuno...
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Fetal anterior abdominal wall defects

Fetal anterior abdominal wall defects can occur with a number of pathologies. Individual entities omphalocele gastroschisis cloacal exstrophy bladder exstrophy Syndromes/complexes limb body wall complex OEIS complex omphalocele-radial ray (ORR) complex Pentalogy of Cantrell amniotic ...
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Fetal ascites

Fetal ascites refers to the accumulation of free fluid in the fetal abdomen. It is often considered under the same spectrum of hydrops fetalis. Pathology Etiology any condition that results in hydrops fetalis additional causes include idiopathic bowel perforation (e.g. meconium peritonitis...
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Fetal bowel dilatation

Fetal bowel dilatation can occur from many causes, which include: intestinal atresias: mainly distal anal atresia apple-peel intestinal atresia ileal atresia jejunal atresia jejuno-ileal atresia Hirschsprung disease megacystis microcolon hyperperistalsis syndrome 4 congenital chloride d...
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Fetal brain tumors

Fetal brain tumors are uncommon and tends to have very different pathological spectrum than that observed in adults; in order of decreasing frequency: fetal intracranial teratoma: most common tumor by far astrocytoma/glioblastoma: next most common craniopharyngioma: papillary type primitive ...
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Fetal cardiac tumors

Fetal cardiac tumors refer to primary cardiac tumors that can present in the in utero population.  Epidemiology Fetal cardiac tumors are rare; the prevalence, reported from autopsy studies of patients of all ages, varies from 0.0017-0.28 % 2. Pathology Known cardiac tumor types that present ...
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Fetal chylothorax

Fetal chylothorax is defined as the presence of lymphatic fluid within the pleural cavity of the fetus. Pathology Associations pulmonary hypoplasia hydrops fetalis premature delivery Radiographic features Antenatal ultrasound may show echogenic fluid in the pleural cavities Treatment S...
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Fetal clenched hands

Fetal clenched hands are an antenatal ultrasound observation where the fetal hands are in a constant (permanently) clenched position as if being unable to extend. Pathology Some authors 3 suggest  that the abnormal posture results in part from: muscle variations along the radial margin of the...
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Fetal death in utero

Fetal death in utero (FDIU), also known as intrauterine death (IUD), is the term used when the death of a fetus occurs after the 20th week of pregnancy. Prior to this, it is considered a miscarriage. Epidemiology 1% of normal, uncomplicated pregnancies end in fetal death. In ~15% of FDIU, no c...
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Fetal intra-abdominal cysts (differential)

Fetal intra-abdominal cystic lesions can arise from a number of physiological and pathological causes. Physiological fetal gastric dilatation / fetal gastric bubble (can be pathological if there is a gastric outlet obstruction normal fetal gallbladder Pathological No color flow fetal chole...
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Fetal intracranial calcification

Fetal intracranial calcification refers to intracranial calcification detected in utero. This can arise from a number of pathologies which include: in utero infections fetal toxoplasmosis infection: calcification tends to be randomly distributed fetal cytomegalovirus infection1: calcificatio...
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Fetal intracranial cystic lesions

Fetal intracranial cystic lesions can arise from a number of pathologies, including: Non-tumourous fetal arachnoid cyst  fetal choroid plexus cyst fetal connatal cyst fetal porencephalic cyst fetal interhemispheric cyst fetal subependymal cyst dorsal cyst of holoprosencephaly Blake pouc...
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Fetal intracranial hemorrhage

Fetal intracranial hemorrhage may occur either within the cerebral ventricles, subdural space or infratentorial fossa. Pathology Hemorrhages can occur in a number of situations: mechanical trauma, e.g. maternal abdominal blunt or birth trauma severe fetal hypoxia background fetal thrombocyt...
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Fetal intrahepatic calcification

Fetal intrahepatic calcification can be a relatively common finding. Calcifications in the liver can be single or multiple and in most cases in which isolated hepatic calcific deposits are detected, there is usually no underlying abnormality. The presence of isolated intrahepatic calcification ...
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Fetal limb bowing

Fetal limb bowing may be a feature of skeletal dysplasia, particularly if it is severe. A mild degree of lateral bowing of the femur can occur as part of normal variation. Conditions associated with fetal limb bowing include: campomelic dysplasia 1 thanatophoric dysplasia 2: particularly type...
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Fetal pleural effusion

Fetal pleural effusions (FPE) refer to an accumulation of pleural fluid in utero. It can refer to either a fetal chylothorax or a fetal hydrothorax. Pathology A fetal pleural effusion can occur as part of hydrops fetalis, in association with other anomalies without hydrops or in isolation - pr...
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Fetal pyelectasis

Fetal pyelectasis refers to a prominence of the renal pelvis in utero that is a relatively common finding, which in the majority of cases resolves spontaneously.  Please refer to the article on fetal hydronephrosis for a continued discussion on this matter.  Terminology  Although there is an ...
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Fetal rib fractures

Fetal rib fractures can be caused by certain skeletal dysplasias. These include: osteogenesis imperfecta: type II - one of the classical causes of fetal rib fractures achondrogenesis: type Ia - Houston-Harris sub type
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Fetal tumors

Although rare, a number to tumors may be diagnosed antenatally. These fetal tumors are a diverse and a unique group of conditions, and include: neuroblastoma: most common tumor overall teratomas sacrococcygeal teratoma head and neck teratoma/epignathus mediastinal teratoma intrapericardial...
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Fetal ventriculomegaly (differential)

Fetal ventriculomegaly (ventricle width >10 mm) is an important finding in itself and it is also associated with other central nervous system abnormalities. For more information, see the main article fetal ventriculomegaly. Differential diagnosis Fetal ventriculomegaly can be thought of in ter...
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Fibromatosis

Fibromatosis refers to a wide range of soft tissue lesions that share an underlying histopathologic pattern of fibrous tissue proliferation. They can occur in a variety of anatomic sites (e.g. musculoskeletal, abdominopelvic, breast, etc.) and also vary in their behavior, ranging from indolent/b...
Article

Fibropolycystic liver disease

Fibropolycystic liver disease is a collective term for a group of congenital liver and biliary abnormalities resulting from abnormal development of the ductal plates.  Disease in this group include: congenital hepatic fibrosis biliary hamartomas autosomal dominant polycystic disease Caroli d...
Article

Fibrous lesions

The differential for fibrous lesions is wide and includes: non-ossifying fibroma fibrous dysplasia osteofibrous dysplasia / adamantinoma desmoplastic fibroma fibromatoses, e.g.  plantar fibromatosis palmar fibromatosis malignant fibrous histiocytoma / fibrosarcoma dermatofibrosarcoma p...
Article

Floating meniscus

Floating meniscus (also known as meniscal avulsion) occurs in acute traumatic settings when the meniscotibial coronary ligaments get disrupted leading to avulsion of the meniscus from the tibial plateau. Radiographic features MRI Displacement of the meniscus for 5 mm or more from the tibial p...
Article

Flowing ossifications

Flowing ossifications are seen in diffuse idiopathic skeletal hyperostosis (DISH).They are defined as heterotopic ossifications involving the anterior longitudinal ligament, paraspinal connective tissues and annulus fibrosus of at least four contiguous vertebral bodies and are originally describ...
Article

Fluid-fluid level containing bone lesions

Fluid-fluid level containing bone lesions are best seen on MRI, although with narrow window width they can also be appreciated on CT. Epidemiology Their prevalence is estimated at ~3% of bone and soft tissue tumors 1. Differential diagnosis Their presence is non-specific, as they are seen in...
Article

Focal calvarial thinning

Focal calvarial thinning can result from a number of causes. They include: bilateral thinning of the parietal bones (normal variant) most common arachnoid cyst mega cisterna magna peripherally located tumors (e.g. oligodendroglioma) See also calvarial thinning calvarial thickening
Article

Focal gallbladder wall thickening (differential)

Focal gallbladder wall thickening is an imaging finding that includes both benign and malignant etiologies. cholecystoses cholesterolosis adenomyomatosis masses gallbladder polyps gallbladder carcinoma: look for infiltration into adjacent organs, metastases, lymphadenopathy, bile duct dil...
Article

Focal gas collection in right upper quadrant (differential)

Focal gas collection in right upper quadrant on plain radiographs can occur from a number of pathologies. Things to consider are: enterobiliary fistula: common types include cholecystoduodenal fistula and cholecystocolic fistula. It may occur with: gallstone ileus (being most common) 3 perfor...
Article

Focal hypodense hepatic lesions on non-enhanced CT (differential)

Focal hypodense hepatic lesions on a non-contrast CT scan can result from a number of pathological entities, including: neoplasms benign hepatic hemangioma adenoma biliary hamartoma: von Meyenberg complexes 2 malignant hepatoma/hepatocellular carcinoma (HCC) hepatic lymphoma hepatic ha...
Article

Foregut duplication cyst

Foregut duplication cysts are a type of congenital duplication cyst. They are sometimes classified under bronchopulmonary foregut malformations. Entities classified as foregut duplication cysts include: bronchogenic cysts neurenteric cysts other enteric cysts esophageal duplication cysts l...
Article

Fracture-dislocations of the radius and ulna

Fracture-dislocations of the radius and ulna illustrate the importance of including the joint above and below the site of injury on radiographic assessment. Most forearm fractures (60%) include fracture of the distal radius as well as an ulnar fracture. In some cases, there is associated disloc...
Article

Fractures of the thumb

Fractures of the thumb are important due to huge impact the thumb has on the overall function of the hand, an understanding of the types of fractures that occur is important, as treatment varies with fracture type. Pathology Types Metacarpal fractures include: intra-articular fractures Benn...
Article

Frontal bossing

Frontal bossing is a calvarial radiographic feature where the front of the skull appears protruding anteriorly. It is best appreciated on a sagittal or lateral image. Pathology This feature can be seen in many conditions (in alphabetical order): 18q syndrome acromegaly achondroplasia ß-tha...
Article

Gallbladder cholesterol polyps

Gallbladder cholesterol polyps are the most common subtype of gallbladder polyps, representing more than 50% of all polyps. They are frequently seen in middle-aged women and are benign lesions, with no malignant potential.  For further details, please refer to the parental article on gallbladde...
Article

Gallbladder ghost triad

Gallbladder ghost triad is a term used on ultrasound studies when there is a combination of three gallbladder features on biliary atresia: atretic gallbladder, length less than 19 mm irregular or lobular contour  lack of smooth/complete echogenic mucosal lining with an indistinct wall The te...
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Gamut

Gamuts in radiology refer to the complete list of differential diagnoses for any radiological finding. We include gamut as a section for articles on Radiopaedia.org. History and etymology According to Maurice Reeder, writing in the preface of his own eponymous text on gamuts, it was the trailb...

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