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.

Create new article

Filtered (1)Done (clear)

+Systems

×Article Sections

+Sort By

Support Radiopaedia and see fewer ads

1,144 results found

≤11 ribs (differential)

≤11 ribs is associated with a number of congenital abnormalities and skeletal dysplasias, including: Down syndrome, Trisomy 21 campomelic dysplasia kyphomelic dysplasias asphyxiating thoracic dysplasia (Jeune syndrome) short rib polydactyly syndromes trisomy 18 chromosome 1q21.1 deletion ...

Abdominal hernia

Abdominal hernias (herniae also used) may be congenital or acquired and come with varying eponyms. They are distinguished primarily based on location and content. 75-80% of all hernias are inguinal. Content of the hernia is variable, and may include: small bowel loops mobile colon segments (s...

Abdominal opacities

An opacity projecting over the abdomen has a broad differential. Possibilities to consider include: foreign bodies ingested, e.g. coins, batteries, bones, etc artifacts, e.g. object attached to the cloth of the patient like a safety pin or button iatrogenic, e.g. hemostatic clips, gastric ba...

Abdominal trauma

Abdominal trauma is usually divided into blunt and penetrating trauma. Findings of abdominal trauma haemoperitoneum splenic trauma: most common hepatic trauma renal trauma pancreatic trauma gastrointestinal tract (bowel) trauma: proximal jejunum is most commonly affected by blunt trauma,...

Abdominoschisis

Abdominoschisis refers to a split or in the abdominal wall. Some authors use the term synonymously with a gastroschisis. When the defect continues into the thoracic region it is termed a thoraco-abdominoschisis. A large abdominoschisis is considered part of the limb body wall complex 2. See als...

Abnormal bowel wall attenuation patterns

Abnormal bowel wall attenuation patterns on CT scan can be grouped under five categories: white enhancement gray enhancement water halo sign fat halo sign black attenuation The first three patterns are seen on contrast studies. White enhancement It is defined as uniform enhancement of th...

Abnormally thickened endometrium (differential)

Abnormally thickened endometrium on imaging may occur for a number of reasons which may be categorized based on whether or not they are related to pregnancy. Etiologies may also be classified based on whether the patient is premenopausal or postmenopausal. Differential diagnosis Pregnancy-rela...

Abscess

Abscesses are focal confined collections of suppurative inflammatory material and can be thought of as having three components 1: a central core consisting of necrotic inflammatory cells and local tissue peripheral halo of viable neutrophils surrounded by a 'capsule' with dilated blood vessel...

Absent fetal stomach on ultrasound (differential)

Non-visualization of the fetal stomach on ultrasound can occur with various physiological as well as pathological processes. It becomes a significant sonographic observation >14 weeks of gestation (about the time the fetus begins to swallow). Causes include: physiological emptying: transient ...

Absent septum pellucidum

An absent septum pellucidum may rarely be an isolated finding, or more commonly be seen in association with a variety of conditions. Epidemiology The septum pellucidum is partly or entirely absent in 2 or 3 individuals per 100,000 in the general population. Pathology An absent septum pelluc...

Achilles tendon thickening

Achilles tendon thickening can occur for a number of reasons. The Achilles tendon has an average AP diameter of 6 mm 1. Thickening of the tendon is when it exceeds 8 mm in AP diameter and can result from: Achilles tendinosis/tear post-surgical thickening retrocalcaneal bursitis degeneration...

Acute abdominal pain

Acute abdominal pain is a common acute presentation in clinical practice. It encompasses a very broad range of possible etiologies and diagnoses, and imaging is routinely employed as the primary investigative tool in its modern management. Terminology A subgroup of patients with acute abdomina...

Acute airspace opacification with lymphadenopathy (differential)

Acute airspace opacification with lymphadenopathy is a subset of the differential diagnosis for generalized airspace opacification and includes: post-obstructive causes (usually chronic, but 'new' changes can occur) primary lung cancer pulmonary metastases lymphoma/leukemia infection prim...

Acute aortic syndrome

Acute aortic syndrome (AAS) describes the presentation of patients with one of a number of life threatening aortic pathologies that give rise to aortic symptoms. The spectrum of these aortic emergencies include: aortic dissection aortic intramural hematoma penetrating atherosclerotic ulcer ...

Acute basilar artery occlusion

Acute occlusion of the basilar artery may cause brainstem or thalamic ischemia or infarction. It is a true neuro-interventional emergency and, if not treated early, brainstem infarction results in rapid deterioration in the level of consciousness and ultimately death. Epidemiology Occlusions o...

Acute bilateral airspace opacification (differential)

Acute bilateral airspace opacification is a subset of the larger differential diagnosis for airspace opacification. An exhaustive list of all possible causes of acute bilateral airspace opacities is long, but a useful way to consider the huge list is via the material within the airways: infecti...

Acute gastritis

Acute gastritis is a broad term that encompasses a myriad of causes of gastric mucosal inflammation. Epidemiology Depends on the etiology (see below). Clinical presentation asymptomatic epigastric pain/tenderness nausea and vomiting loss of appetite Pathology Etiology infection: H. py...

Acute hepatitis

Acute hepatitis occurs when the liver suffers an injury with a resulting inflammatory reaction. The cause of the injury can happen in multiple different ways, and imaging findings are often non-specific. Acute hepatitis is a clinical diagnosis and normal imaging appearance of the liver does not ...

Acute myeloid leukemia

Acute myeloid leukemia (AML), also referred to as acute myelogenous leukemia, is a hematological malignancy characterized by the abnormal clonal proliferation of immature myeloid precursors (myeloblasts) or poorly differentiated cells of the hematopoietic system. It primary infiltrates the bone ...

Acute unilateral airspace opacification (differential)

Acute unilateral airspace opacification is a subset of the differential diagnosis for airspace opacification. Differential diagnosis The exhaustive list of all possible causes would be huge, but a useful framework includes: pus, i.e. infection bacterial pneumonia fungal pneumonia viral p...

Acute vs chronic ischemic stroke

Differentiating between acute and chronic infarction on a CT brain is an important skill for many health professionals particularly in the emergency setting: pathology acute: cytotoxic edema chronic: encephalomalacia; Wallerian degeneration hypoattenuation acute: more dense than CSF chroni...

Adenosis of the breast

Adenosis of the breast is a benign lobulocentric proliferative process in which lobules are enlarged and increased in number in addition to an increased number of glands within each lobule. Pathologically subclassified into three main subtypes which include: sclerosing adenosis of the breast ...

Adhesive atelectasis

Adhesive atelectasis refers to the specific form of lung atelectasis that occurs due to the decrease or absence of pulmonary surfactant produced by type II pneumocytes. Without sufficient surfactant the alveoli collapse due to increased surface tension. It is most commonly seen in the neonate wi...

Adrenal calcification

Adrenal calcification is not a rare finding in healthy asymptomatic people and is usually the result of previous hemorrhage or tuberculosis. Addison disease patients only occasionally develop calcification. Pathology Etiology Hemorrhage sepsis: Waterhouse-Friderichsen syndrome blunt abdomi...

Adrenal cyst

Adrenal cysts are rare lesions and are commonly incidental findings. Epidemiology Adrenal cysts are reported to be rare with an incidence of <1% 1. Clinical presentation Patients can present with pain or swelling, although a significant portion (~40%) are incidental findings 1,3. Patholo...

Adrenal gland tumors

Despite its small size, the adrenal gland is affected by a relatively large number of neoplastic entities: adrenal adenoma adrenal myelolipoma adrenal cortical carcinoma adrenal pheochromocytoma adrenal neuroblastoma adrenal metastases See also adrenal lesions: for a more general list of...

Adrenal hemorrhage

Adrenal hemorrhage can result from a variety of traumatic and non-traumatic causes. When unilateral, it is often clinically silent. In contrast, bilateral adrenal hemorrhage can lead to catastrophic adrenal insufficiency. Clinical presentation The large majority of patients with unilateral adr...

Adrenal lesions (differential)

Adrenal lesions cover a broad spectrum from benign to neoplastic entities. Due to increased use of cross-sectional imaging they are frequently detected as incidental lesions (incidentalomas). If found incidentally, please refer to the Management of Incidental Adrenal Masses: American College of ...

Adrenal tuberculosis

Tuberculous adrenalitis is the result of adrenal mycobacterium tuberculosis (TB) infection. Its incidence has decreased in the western world with the declining incidence of tuberculosis. Pathology As the tuberculous infection causes destruction of the adrenal cortex, primary adrenal insufficie...

Adult cervical lymphadenopathy (differential)

Cervical lymphadenopathy in an adult can result from a vast number of conditions. They include: malignancy metastases from head and neck tumors lymphoma other neoplastic lesions Castleman disease Kaposi sarcoma infection bacterial infection viral infection Epstein-Barr virus herpes ...

AIDS-defining illness

AIDS-defining illnesses are conditions that in the setting of a HIV infection confirm the diagnosis of AIDS, and do not commonly occur in immunocompetent individuals 2. According to the CDC surveillance case definition 1, they are: Infectious bacterial infections: multiple or recurrent candid...

Air crescent sign (lung)

An air crescent sign describes the crescent of air that can be seen in invasive aspergillosis, semi-invasive aspergillosis or other processes that cause pulmonary necrosis. It usually heralds recovery and is the result of increased granulocyte activity. In angioinvasive fungal infection, the no...

Air space opacification

Air space opacification is a descriptive term that refers to filling of the pulmonary tree with material that attenuates x-rays more than the surrounding lung parenchyma. It is one of the many patterns of lung opacification and is equivalent to the pathological diagnosis of pulmonary consolidati...

Air space opacities

The differential for air space opacities is extensive, and needs to be interpreted in context of chronicity (previous imaging) and clinical context. It is therefore useful to divide airspace opacities as follows: acute airspace opacities with lymph node enlargement acute airspace opacities: un...

Airway foreign bodies in children

Airway foreign bodies in children are potentially fatal, which is why immediate recognition is important. Unfortunately, delayed diagnosis is common. Epidemiology Children under the age of four years are at increased risk of foreign body (FB) aspiration, with a slight male predominance 1. Cl...

Alpha fetoprotein

Alpha fetoprotein (AFP) is an important plasma protein synthesized by the yolk sac and fetal liver. In adults its main utility is as a tumor marker, primarily for hepatocellular carcinoma or teratoma. Functionally it is the fetal homologue of albumin, i.e. it acts as a major carrier protein in t...

Altered breast density between two mammograms

Mammographic screening detects early breast cancers and thereby reduces potential mortality. However, its sensitivity is inversely related to breast density 1. Altered density between two mammograms can arise in a number of situations: Affecting both breasts: interval commencement/cessation ...

Alternating radiolucent and radiodense metaphyseal lines

Alternating radiolucent and radiodense metaphyseal lines can be seen with a number of conditions and the differential diagnosis is wide: growth arrest lines bisphosphonate therapy rickets: especially those on prolonged treatment, e.g. vitamin D dependent rickets osteopetrosis chemotherapy ...

Amorphous calcification within breast

Amorphous or indistinct calcifications are a morphological descriptive term for breast calcification and are defined as having small, hazy, faint calcifications with no clearly defined shape or form. Radiographic features 80-200 micrometer in diameter small, hazy calcification often magnifi...

Ampullary tumor

The term ampullary tumor generally refers to either benign or malignant neoplasms that arise from the glandular epithelium of the ampulla of Vater, including 1: ampullary adenoma (adenoma of ampulla of Vater) ampullary carcinoma (carcinoma of ampulla of Vater) According to some authors, ampul...

Angiosarcoma (bone)

Angiosarcoma of bone is a malignant vascular tumor of bone. These are rare and account for less than 1% of malignant bone tumors. The majority of these tumors arising in bone are primary; however, a tiny percentage is either radiation-induced or associated with bone infarction Epidemiology Mos...

Ankle impingement syndromes

There are several ankle impingement syndromes. They are characterized by limited range of motion and pain on attempting specific movements about the joint and often in a load-bearing position. They have variable etiology and pathogenesis. They are best classified according to location. The key ...

Anoxic brain injury

Anoxic brain injury, also known as global hypoxic-ischemic injury, is seen in all age groups (from antenatal to the elderly) as a result of numerous etiologies. The pattern of injury depends on a number of factors including: age of the patient (brain maturity) neonatal hypoxic-ischemic encepha...

Anterior inferior cerebellar artery (AICA) infarct

Anterior inferior cerebellar artery (AICA) territory infarcts are much less common than posterior inferior cerebellar artery (PICA) infarcts. AICA generally arises from the caudal third of the basilar artery and supplies the lateral pons, inner ear, middle cerebellar peduncle and the anterior in...

Anterior knee pain

Anterior knee pain is common with a variety of causes which can be divided anatomically using a layered approach1 from superficial to deep: Superficial soft tissues prepatellar bursitis Morel-Lavallée lesion infrapatellar bursitis Extensor mechanism quadriceps tendinosis / partial tear q...

Anterior vertebral body beaking

Anterior vertebral body beaking occurs in a number of conditions and may eminate from the central portion or the lower third of the vertebral body. Middle third Morquio syndrome 1 (middle for Morquio) Lower third Hurler syndrome 2 achondroplasia 3 pseudoachondroplasia 4 cretinism 5 Down ...

Aortic nipple

An aortic nipple is seen in about 10% of PA chest x-rays on the lateral surface of the aortic arch/aortic knob. It represents the left superior intercostal vein. When prominent, superior vena cava obstruction should be considered as the left superior intercostal vein serves as a collateral path...

Aortopulmonary window (radiograph)

The aortopulmonary (aortic-pulmonary or AP) window (also known as APW, but see 'Terminology' below) is a radiological mediastinal space seen on frontal chest radiographs. Terminology The term "aortopulmonary window" (also called an aortopulmonary septal defect) can also refer to a rare form of...

Aphthoid ulceration

Aphthoid ulcers are shallow ulcers of the gastrointestinal mucosa. Pathology Etiology infective inflammatory conditions Yersinia enterocolitis amoebic enterocolitis cytomegalovirus enterocolitis noninfective inflammatory conditions Crohn disease idiopathic granulomatous gastritis vascu...

Apical pleural cap

Apical pleural cap refers to a curved density at the lung apex seen on chest radiograph. Epidemiology The frequency of apical pleural thickening increases with age 3. Pathology It arises from a number of causes: pleural thickening/scarring idiopathic: chronic ischemic etiology is favored f...

Architectural distortion in mammography

Architectural distortion is a mammographic descriptive term in breast imaging. It may be visualized as tethering or indentation of breast tissue. Pathology Architectural distortion per se is not a mass. It is often due to a desmoplastic reaction in which there is focal disruption of the normal...

Areae gastricae

Areae gastricae are a normal finding on double contrast images of the stomach. Radiographic features fine reticular network of barium-coated grooves between 1-5 mm islands/areas of gastric mucosa may be seen in ~70-80% of patients if there is adequate high-density barium coating of the stomac...

Artery of Percheron territory infarct

Artery of Percheron territory infarct is rare, on account of the relative rarity of the artery of Percheron, and presents with a variety of signs and symptoms collectively termed the paramedian thalamic syndrome. It is a type of posterior circulation infarction. On imaging, it is classically ch...

Asbestos related diseases

Asbestos related disease, in particular affecting the lung, comprise of a broad spectrum of entities related to the inhalational exposure to asbestos fibers. They can be divided into benign and malignant changes 1-3. Benign pleural and parenchymal lung disease asbestos related benign pleural d...

Ascending aorta dilatation

Dilatation of the ascending aorta is a common finding in the elderly but unusual in younger patients. Pathology In adults, an ascending aortic diameter greater than 4 cm is considered to indicate dilatation 4. Aneurysmal dilatation is considered when the ascending aortic diameter reaches or ex...

Aseptic loosening of hip joint replacements

Aseptic loosening is considered relatively common complication of hip joint replacements. It is usually considered a long-term complication and is often considered as the most common complication 3. Pathology Aseptic loosening can occur as a result of inadequate initial fixation, mechanical lo...

Aspiration pneumonia

Aspiration pneumonia is caused by a direct chemical insult due to the entry of a foreign substance, solid or liquid, into the respiratory tract. Clinical presentation Aspiration may be clinically silent, or it may present with dyspnea, cough, or fever. The clinical and radiographic features de...

Asplenia syndrome

Asplenia syndrome (also known as right isomerism or Ivemark syndrome) is a type of heterotaxy syndrome. Epidemiology There is an increased male predilection. Asplenia syndrome is usually diagnosed in neonates 4. Clinical manifestation In contrast to polysplenia syndrome, most patients die be...

Asymmetrical density in mammography

Asymmetrical mammographic density is a mammographic morphological descriptor. It is given when there is increased density in one of the breasts, on either one or both standard mammographic views but without evidence of a discrete mass. The criteria for an asymmetry may include borders of the ti...

Asymmetry in breast size

Asymmetry in breast size can arise from a number of factors. Pathology Breasts are rarely absolutely the same size or volume. Normal variation is common. Most females have slight discrepancies in breast size. Asymmetric progressive breast enlargement is unusual but known. The role of the breas...

Athletic pubalgia

Athletic pubalgia refers to pain around the pubic symphysis and can have different causes, including what has become known as sports hernia or sportman's hernia and osteitis pubis. Athletic pubalgia is a clinical syndrome of chronic lower pelvic and groin pain, usually encountered in athletes. ...

Atlantodental interval

The atlantodental interval (ADI), as the name suggests, is the horizontal distance between the anterior arch of the atlas and the dens of the axis, used in the diagnosis of atlanto-occipital dissociation injuries and injuries of the atlas and axis. It is the distance (in mm) between the posteri...

Atraumatic fracture

Atraumatic fractures, as the name suggests, occur with no trauma or minimal trauma that would not normally be expected to result in a fracture 1. They can be: stress fractures fatigue fracture insufficiency fracture atypical fractures, e.g. bisphosphonate-related proximal femoral fractures ...

Atresia

Atresia refers to a situation where there is underdevelopment of a structure with very rudimentary remnant tissues. This contrasts with an agenesis meaning there is no development of the structure as all. The term atresia is often used with hollow structures such as a bronchus or intestine. Fo...

Autoimmune thyroiditis

Autoimmune thyroiditis (plural thyroiditides) (AIT) refers to a group of conditions where there is inflammation of the thyroid gland secondary to thyroid autoantibodies. Epidemiology They are the most common thyroid disease group in the pediatric population 5. Pathology Entities that fall un...

Avulsion fractures of the knee

Avulsion fractures of the knee are numerous due to the many ligaments and tendons inserting around this joint. They include 1: anterior cruciate ligament avulsion fracture posterior cruciate ligament avulsion fracture avulsion of the medial collateral ligament origin of MCL avulsion fracture...

Bands in gestational sacs

Band like structures in the gestational sac is not an uncommon finding in the first trimester or second ultrasounds and can represent a number of varying conditions These include uterine synechiae amniotic bands amniotic shelf circumvallate placenta chorio-amniotic separation velamentous ...

Barium peritonitis

Barium peritonitis is a rare complication of gastrointestinal fluoroscopy, and occurs when there is gastrointestinal tract perforation and spillage of barium into the peritoneal cavity. Pathology Barium in the peritoneal cavity is treated as a foreign body with resultant immune response that ...

Bartholin gland tumors

Bartholin gland tumors represent neoplasms of the Bartholin glands. They include: squamous cell carcinoma of the Bartholin gland: tends to be the most common histological subtype adenocarcinoma of the Bartholin gland adenoid cystic carcinoma of the Bartholin gland

Barton fracture

Barton fractures are fractures of the distal radius. It is also sometimes termed the dorsal type Barton fracture to distinguish it from the volar type or reverse Barton fracture. Barton fractures extend through the dorsal aspect to the articular surface but not to the volar aspect. Therefore, i...

Basal ganglia and thalamus signal abnormalities

Basal ganglia and thalamus signal abnormalities occur in a wide variety of conditions. Ischemia/hypoxia, metabolic disorders and toxins, particularly those that affect the respiratory chain, have a predilection for affecting the basal ganglia as they are highly metabolically active. They can b...

Basal ganglia calcification

Basal ganglia calcification is common and is seen in approximately 1% of all CT scans of the brain, depending on the demographics of the scanned population. It is seen more frequently in older patients and is considered a normal incidental and idiopathic finding in an elderly patient but should ...

Basal ganglia T1 hyperintensity

There are many causes of basal ganglia T1 hyperintensity, but the majority relate to deposition of T1-intense elements within the basal ganglia such as: calcium idiopathic calcification calcium and phosphate abnormalities hepatic failure acquired non-wilsonian hepatocerebral degeneration W...

Basal ganglia T2 hyperintensity

The causes of basal ganglia T2 hyperintensity can be remembered using the mnemonic LINT: lymphoma ischemia hypoxia venous infarction (internal cerebral vein thrombosis) neurodegenerative / metabolic autoimmune encephalitis (e.g. anti-D2 dopamine antibody encephalitis) Creutzfeldt-Jakob di...

Basal ganglia T2 hypointensity

Basal ganglia T2 hypointensities can be caused by any of the following and is commonly remembered using the mnemonic ChOMP. childhood hypoxia old age multiple sclerosis Parkinson disease: more in globus pallidus Parkinson-plus syndrome: more in putamen deoxyhemoglobin of hemorrhage hemosi...

Basilar invagination

Basilar invagination, also called basilar impression, is a congenital or acquired craniocervical junction abnormality where the tip of the odontoid process projects above the foramen magnum. Terminology The terms basilar invagination and basilar impression are often used interchangeably becau...

Basion-axial interval

The basion-axial interval (BAI), as the name suggests, is the horizontal distance between the basion and the posterior cortex of the axis, used in the diagnosis of atlanto-occipital dissociation injuries. It is the distance (in mm) between the basion and the superior extension of the posterior ...

Basion-dens interval

The basion-dens interval (BDI), as the name suggests, is the distance between the basion and the tip of the dens, used in the diagnosis of atlanto-occipital dissociation injuries. It is the distance from the most inferior portion of the basion to the closest point of the superior aspect of the ...

Bathrocephaly

Bathrocephaly, also known as bathrocephalic occiputs is a normal variation in skull shape, caused by an outward convex bulge of mid-portion of the occipital bone, often associated with a modification of the mendosal suture. Epidemiology The true incidence of this disorder is unknown 1. Clinic...

Bat wing opacities (lungs)

Bat's wing or butterfly pulmonary opacities refer to a pattern of bilateral perihilar shadowing. It is classically described on a frontal chest radiograph but can also refer to appearances on chest CT 3-4. Differential diagnosis Bat's wing pulmonary opacities can be caused by: pulmonary edema...

Benign liver tumors (pediatric)

Pediatric benign liver tumors are a relatively rare, but important group of conditions. Importantly, the commonest cause of a benign liver tumor is specific to the pediatric population. The list in descending order of frequency is: infantile hepatic hemangioma (previously hemangioendothelioma) ...

Benign lytic bone lesions

Benign lytic bone lesions encompass a wide variety of entities. A useful starting point is the FEGNOMASHIC mnemonic. This article is a stub, which means it needs more content. You can contribute to Radiopaedia too. Just register and click edit... every little bit helps. See also malignant l...

Benign metastasizing tumors

There are a number of benign metastasizing tumors: benign metastasizing meningioma 1,2 benign metastasizing leiomyoma 3 primary adenoma of thyroid 4 giant cell tumor of bone 5

Benign minor salivary gland pathology

Benign minor salivary gland pathology is a broad term that encompasses a number of relatively uncommon pathologies that affect the minor salivary glands of the head and neck: salivary retention cysts benign neoplasms pleomorphic adenoma

Benign esophageal lesions

Benign esophageal lesions are less symptomatic than malignant esophageal lesions, making up for only 1% of clinically apparent esophageal lesions. Pathology esophageal leiomyoma (>50%) may calcify esophageal fibrovascular polyp (~12.5%) may contain fat esophageal duplication cyst (10%) oe...

Benign tumors and tumor-like lesions of the gallbladder

The gallbladder and extrahepatic bile ducts play host to a surprisingly large number of benign tumors and tumor-like lesions which may be visible on imaging. In the gallbladder, most of them are detected incidentally, whereas in the bile ducts they are usually found in symptomatic patients (obst...

Bentall procedure

Bentall procedure is performed for the repair of ascending aortic root lesions. Typically the native aortic root and aortic valve are replaced with a composite graft that comprises both ascending aortic and aortic valve grafts, to which the coronary arteries are anastomosed. History and etymolo...

Bent bone dysplasias (differential)

Bent bone dysplasias are a class of dysplasia included in a 2010 classification of genetic skeletal disorders 1. campomelic dysplasia Stuve-Weidemann dysplasia kyphomelic dysplasias, a diverse class, including congenital bowing of the long bones cartilage-hair hypoplasia (CHH; metaphyseal d...

Beta-hCG

Beta-hCG (bHCG) is a sex hormone found in the mother's blood serum that can be used to help interpret obstetric ultrasound findings. Beta-hCG levels may be used in three ways in the clinical setting of pregnancy: qualitatively, for presence/absence of fetal tissue more often determined with a...

Bicaudate index

The bicaudate index is the ratio of width of two lateral ventricles at the level of the head of the caudate nucleus to distance between outer tables of skull at the same level. It can be a useful marker of ventricular volume and in the diagnosis of hydrocephalus.

Bilateral adrenal gland enlargement

The differential for bilaterally enlarged adrenal glands is relatively limited: adrenal hyperplasia micronodular adrenal hyperplasia macronodular adrenal hyperplasia adrenocorticotropin (ACTH)-independent macronodular adrenocortical hyperplasia (AIMAH) 2 adrenal metastases adrenal hemorrha...

Bilateral axillary lymphadenopathy (differential)

Bilateral axillary lymphadenopathy can result from a number of causes and generally implies a systemic process. They include: autoimmune diseases, e.g.: rheumatoid arthritis scleroderma dermatomyositis 5 systemic lupus erythematosus (SLE) psoriasis Sjögren syndrome lymphoma leukemia di...

Bilateral middle cerebellar peduncle lesions

Involvement of both middle cerebellar peduncles is uncommon, but has a relatively long list of differential diagnoses, including 1: neurodegenerative diseases multiple systemic atrophy (MSA) olivopontocerebellar atrophy Shy-Drager syndrome spinocerebellar atrophy metabolic diseases adre...

Updating… Please wait.

Unable to process the form. Check for errors and try again.

Thank you for updating your details.