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.

1,140 results found
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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 of 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 immun...
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Femoral anteversion

Femoral anteversion refers to the orientation of the femoral neck in relation to the femoral condyles at the level of the knee. In most cases, the femoral neck is oriented anteriorly as compared to the femoral condyles. In the case of posterior orientation, the term femoral retroversion is also ...
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Fetal anterior abdominal wall defects

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

Fetal biophysical profile score (BPS or BPP) refers to assessment of four discrete biophysical variables by ultrasound. It is a standard tool in antepartum fetal assessment. It is usually assessed after 28 weeks of gestation. Radiographic features Antenatal ultrasound The ultrasound variables...
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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 to femur can occur as part of normal variation. Conditions associated with fetal limb bowing include: camptomelic dysplasia 1 thanatophoric dysplasia 2: particularly type I ...
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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...
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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...
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Fibrous hamartoma of infancy

Fibrous hamartoma of infancy is a rare benign tumor of the subcutaneous tissues seen in children. More than 90% of cases present in the first year of life with up to 25% being congenital 1. Epidemiology There is a reported male:female ratio of 2:1 but the exact incidence is unknown 2. Clinica...
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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...
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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...
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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...
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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...
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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
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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...
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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...
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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...
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Fracture-a-la-signature (skull fracture)

Fracture-a-la-signature (or signature fracture) is another term used to described a depressed skull fracture.  Fracture-a-la-signature derives its name from forensic medicine because the size and shape of a depressed skull fracture may give information on the type of weapon used. It can be a si...
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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...
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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...
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Fragility fracture

Fragility fractures are the result of forces that would not fracture a normal bone. They can occur in the context of very low energy (i.e. minimal) trauma such as falling from standing height, or they may be no identifiable preceding trauma. There is overlap between fragility fractures and insuf...
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Free silicone breast injections

Free silicone breast injections (silicone mastopathy) are an alternative form of breast augmentation to breast implants, although they have serious adverse effects and are banned in many countries.  Radiographic features There are similar features to that of free silicone from breast implant r...
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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...
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Gallbladder adenoma

Gallbladder adenomas are uncommon gallbladder polyps that, although benign, have a premalignant behavior.  Terminology As the distinction of adenomas and intracholecystic papillary-tubular neoplasms (ICPN) is not entirely clear, with important overlap between both entities, some authors have p...
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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...
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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
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Gallbladder inflammatory polyps

Gallbladder inflammatory polyps are a benign subtype of gallbladder polyps, representing ~10% of all polyps. They appear as a result of chronic inflammation (chronic cholecystitis).  For further details, please refer to the parental article on gallbladder polyps.  Pathology Thought to develop...
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Gallbladder sludge

Gallbladder sludge, also known as biliary sand, biliary sediment, or thick bile, is a mixture of particulate matter and bile, normally seen as a liquid-liquid level in the gallbladder on ultrasound, corresponding to the precipitate of bile solutes.  Pathology These precipitates consist of chol...
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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 category for articles on Radiopaedia.org to cover sections which cover multiple diagnoses, findings or systems. History and etymology According to Maurice Reeder, writi...
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Gas in the urinary bladder

There numerous causes of gas in the bladder. In the hospital setting by far the most common is the recent placement of an indwelling urinary catheter. Other causes include 1: iatrogenic indwelling urinary catheter is by far the most common cause cystoscopy, etc. emphysematous cystitis intra...
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Gasless abdomen

A gasless abdomen refers to a paucity of gas on abdominal radiography, and the specific cause can usually be identified when the patient's history is known. Common causes include: small bowel obstruction bowel ischemia congenital atresia ascites pancreatitis gastroenteritis large abdomina...
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Gastric band

A gastric band is a surgically placed device, used to assist in weight loss. It is now the most popular form of bariatric surgery, largely replacing gastric bypass procedures 1. Performed laparoscopically, a silicone band device is placed around the stomach to reduce its volume. The band is adj...
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Gastric band malposition

Gastric band malposition is an early complication from laparoscopic gastric band procedures which are performed for obesity. It can occur as in isolation or with other gastric band complications. As surgical experience of lap gastric banding has accumulated, it has become a relatively rare comp...
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Gastric band erosion

Gastric band erosion or penetration is a potentially serious complication following laparoscopic gastric band surgery for obesity.  Epidemiology Gastric band erosion is a delayed complication observed in between 0.3-14% of patients 1,2. Clinical presentation Patients often present non-specif...
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Gastric diverticulum

Gastric diverticula are sac-like projections that usually originate from the gastric fundus, most commonly on the posterior surface. They are the least common gastrointestinal diverticulum.  Epidemiology Gastric diverticula are rare and commonly detected incidentally. The incidence varies from...
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Gastric outlet obstruction

Gastric outlet obstruction is a syndrome resulting from mechanical obstruction of stomach emptying. Pathology Etiology Gastric outlet obstruction can be due to malignant or benign causes. Malignant adenocarcinoma (second most common 4) GIST lymphoma (less commonly than other malignancies ...
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Gastrinoma triangle

The gastrinoma triangle, also known as Passaro's triangle, is an anatomical area in the abdomen, from where the majority (90%) of gastrinomas are thought to arise.  Gross anatomy Boundaries The triangle is formed by joining the following three points: superiorly: confluence of the cystic and...
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Generalized increased bone density in adults

The causes of generalized increase in bone density in adult patients can be divided according to broad categories:  myeloproliferative disorders: myelosclerosis marrow cavity is narrowed by endosteal new bone patchy lucencies due to persistence of fibrous tissue (generalized osteopenia in the...
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Generalized increased bone density in children

The causes of generalized increased bone density in pediatric patients can be divided accodring to broad categories of cause : skeletal dysplasias osteopetrosis pyknodysostosis metabolic renal osteodystrophy poisoning lead dense metaphyseal bands cortex and flat bones may also be slight...
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Generalized increase in hepatic echogenicity

Causes of generalized increased liver echogenicity include: diffuse fatty infiltration cirrhosis: can be coarsened as well chronic hepatitis 3: can be coarsened as well diffuse infiltration or deposition malignant process granulomata  tuberculosis brucellosis sarcoidosis glycogen stora...
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Generalized osteopenia

Generalized osteopenia refers to osteopenia diffusely affecting the bones. Differential diagnosis The differential diagnosis is wide and includes: osteoporosis: decreased osteoid production osteomalacia: undermineralisation of osteoid hyperparathyroidism multiple myeloma diffuse metastase...
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Generalized periosteal reaction

The list of causes of a generalized periosteal reaction overlaps that of symmetrical periosteal reaction, and includes 1,2: vascular stasis (common) congenital syphilis fluorosis Gaucher disease hypertrophic osteoarthropathy pachydermoperiostosis hypervitaminosis A infantile cortical hyp...
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Generalized reduced hepatic echogenicity

Causes of generalized reduction of liver echogenicity on ultrasound include: acute hepatitis diffuse malignant infiltration See also generalized increase in liver echogenicity hepatic attenuation on CT
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Gibbus deformity

Gibbus deformity is a short-segment structural thoracolumbar kyphosis resulting in sharp angulation. Pathology There are a number of causes which can be divided into congenital and acquired. Congenital achondroplasia cretinism (congenital hypothyroidism) Apert syndrome Coffin-Lowry syndro...
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Glass foreign bodies

Glass foreign bodies may be present if they are ingested, inserted or as a result of an injury.  Epidemiology The prevalence of glass foreign bodies in wounds from injury has been recorded at a rate of 1.5% in superficial (subcutaneous) wounds and 7.5% of deeper wounds 1.  Radiographic featur...
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Glycogen storage disease

Glycogen storage disease (GSD) refers to a number of syndromes which are characterized by a defect in synthesis, metabolism or storage of glycogen. Pathology There are many types of GSD: type I: von Gierke disease type II: Pompe disease type III: Cori or Forbes disease type IV: Andersen di...
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Gonadal dysgenesis

Gonadal dysgenesis refers to a spectrum of anomalies with abnormal development of the gonads. It falls under the even broader group of disorders of gender development. Pathology In many cases the gonads are replaced by fibrous tissue. Subtypes complete gonadal dysgenesis (CGD) / Swyer syndro...
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Gracile bones

Gracile bones refer to changes in the skeleton in which the bones are more slender than usual (over-tubulated) and occasionally deformed in other ways such as being abnormally curved. This may occur in a number of disorders and can occur with or without fractures. Pathology Etiology neurofibr...
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Granular mucosal pattern of the esophagus (differential)

Granular mucosal pattern of the esophagus represents very fine nodularity of the esophageal mucosal surface. This finding is nonspecific and may represent: reflux esophagitis (most common) Candida esophagitis glycogenic acanthosis Barrett esophagus superficial spreading esophageal carcinoma...
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Granulomatous lung disease

Granulomatous lung disease refers to a broad group of infectious and non-infections conditions characterized by the formation of granulomas. The spectrum includes infectious mycobacterial pulmonary tuberculosis pulmonary non-tuberculous mycobacterial infection fungal pulmonary coccidioido...
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Gravity dependent atelectasis

Gravity dependent atelectasis refers to a form of lung atelectasis which occurs in the dependent portions of the lungs due to a combination of reduced alveolar volume and increased perfusion. Being due to gravity, it usually has a dependent and subpleural distribution. It is very commonly seen i...
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Grey-white differentiation

Grey-white differentiation refers to the appearance of the interface between cerebral and cerebellar white matter and grey matter on brain CT and MRI. The term is most often used when trying to differentiate cytotoxic from vasogenic edema.  cytotoxic edema (see ionic edema), where there is a l...
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Ground-glass opacification

Ground-glass opacification/opacity (GGO) is a descriptive term referring to an area of increased attenuation in the lung on computed tomography (CT) with preserved bronchial and vascular markings. It is a non-specific sign with a wide etiology including infection, chronic interstitial disease an...
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Gynecological ultrasound set-pieces

The clinical history will nearly always lead to a short differential or the answer. Show off to the examiner that you have a structured approach to reporting and managing the patient. Structured approach uterus: size, version and shape (normal or variant which you should elaborate on and say w...
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Gynecomastia

Gynecomastia refers to a benign excess of the male breast tissue, that is usually reversible. It is not a risk factor per se for developing male breast cancer. Epidemiology While it can occur at any age, it tends to have greater prevalence in two groups: adolescent boys and older men (some pub...
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Hematospermia

Hematospermia (less commonly hemospermia) refers to the presence of blood in semen or ejaculatory fluid. It is a symptom that can cause great anxiety in patients despite usually being of benign etiology. Pathology Etiology Benign urogenital infections including sexually transmitted disease, ...
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Hemobilia

Hemobilia refers to the presence of blood in the biliary tree. Clinical presentation The classical clinical triad, only seen in ~50% of cases, consists of: melena (i.e. upper gastrointestinal bleeding) jaundice abdominal pain Pathology Etiology iatrogenic: surgical or percutaneous proced...
Article

Hemolytic anemia

Hemolytic anemia is a form of anemia where red blood cells (RBCs) are destroyed either intravascularly or extravascularly. Clinical presentation The patient presents with anemia and jaundice. Diagnosis is based on several laboratory parameters 1: reticulocytosis increased unconjugated biliru...
Article

Hemopericardium

Hemopericardium refers to the presence of blood within the pericardial cavity, i.e. a sanguineous pericardial effusion. If enough blood enters the pericardial cavity, then a potentially fatal cardiac tamponade can occur.  Pathology Etiology There is a very long list of causes 1,4 but some of ...
Article

Hemoperitoneum

Hemoperitoneum is the presence of blood within the peritoneal cavity. Pathology Etiology penetrating or non-penetrating abdominal trauma (often with associated organ injury) 1 ruptured ectopic pregnancy ovarian cyst rupture aneurysm or pseudoaneurysm rupture neoplasm rupture acute hemorr...
Article

Hemopneumothorax

Hemopneumothorax (or, less commonly, pneumohemothorax) is a term given when there is concurrent presence of a hemothorax and well as a pneumothorax. It is a variant of a hydropneumothorax.  Epidemiology Approximately 5% of patients with pneumothorax will have concomitant hemothorax 6 . Pathol...
Article

Hemoptysis

Hemoptysis refers to coughing out blood. Generally, it appears bright red in color as opposed to blood from the gastrointestinal tract which appears dark red. It is considered an alarming sign of a serious underlying etiology. Terminology Massive hemoptysis is referred to as expectoration of >...
Article

Hemosiderosis

Hemosiderosis is a general term referring to the accumulation of hemosiderin, which particularly occurs in the reticuloendothelial system (RES) and does not cause organ damage. Pathology Some causes include: frequent transfusion  mainly depositional siderosis in RES if >40 units transfused:...
Article

Hemothorax

Hemothorax (plural hemothoraces), or rarely hematothorax, literally means blood within the chest, is a term usually used to describe a pleural effusion due to accumulation of blood. If a hemothorax occurs concurrently with a pneumothorax it is then termed a hemopneumothorax.  A tension hemothor...
Article

Hangman fracture

Hangman fracture, also known as traumatic spondylolisthesis of the axis, is a fracture which involves the pars interarticularis of C2 on both sides, and is a result of hyperextension and distraction. Clinical presentation Post-traumatic neck pain after a high-velocity hyperextension injury is ...
Article

Haustral markings

Haustral markings are the radiological appearance of the haustral folds within the colon. Disappearance of the haustral folds results in the lead pipe appearance of ulcerative colitis.
Article

Hematopoietic stem cell transplantation (thoracic complications)

There are many thoracic complications that can occur following hematopoietic stem cell transplantation. These can precipitate during various stages following transplantation and can be either infectious or noninfectious. Complications Early pulmonary edema engraftment syndrome diffuse alveo...
Article

Hemithorax white-out (differential)

Complete white-out of a hemithorax on the chest x-ray has a limited number of causes. The differential diagnosis can be shortened further with one simple observation: the position of the trachea. Is it central, pulled or pushed from the side of opacification? Is there pulmonary volume loss or vo...
Article

Hepatic attenuation on CT

Hepatic attenuation on CT, reflected by Hounsfield values, depends on a combination of factors including the presence or absence, as well as the phase, of IV contrast administration. Allowing for all these factors, the mean unenhanced attenuation value is around 55 HU 4. Pathology Several int...
Article

Hepatic lymphangioma

A hepatic lymphangioma is a rare benign condition that corresponds to focally dilated lymphatic channels in the liver.  Clinical presentation Most cases are asymptomatic. Pathology A lymphangioma is a benign lesion that can occur at almost any location in the body. Hepatic involvement is les...
Article

Hepatic osteodystrophy

Hepatic osteodystrophy is an often forgotten metabolic bone disease seen in patients with chronic liver disease, in particular cirrhosis, primary biliary cirrhosis, and primary sclerosing cholangitis. These patients have increased risk factors for developing osteoporosis such as hypogonadism, al...
Article

Hepatisation of the gallbladder

Hepatisation of the gallbladder is a sonographic entity in which the gallbladder lumen is entirely filled with tumefactive sludge giving the gallbladder a similar appearance to liver parenchyma. It is one of the causes of non-visualization of the gallbladder on sonography. Pathology In the set...
Article

Hepatolithiasis

Hepatolithiasis is the presence of bile duct stones within the intrahepatic bile ducts, specifically before the confluence of the right and left hepatic ducts.  Epidemiology Hepatolithiasis is common Asia and the Pacific, with a prevalence of ~40%. It is rare in the West with a prevalence of ~...

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