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 continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
16,853 results found
Article
Intervertebral disc disease nomenclature
Intervertebral disc disease nomenclature has changed over the years, and a familiarity with current definitions is essential if clear communication is to be achieved via radiology reports or referrals, especially as lumbar disc disease is a common problem and a source of a great deal of imaging....
Article
Bone marrow
Bone marrow is ubiquitous throughout the skeleton, primarily composed of hematopoietic cells and fat cells between bony trabeculae and fibrous retinacula. It performs numerous physiological functions and dynamically changes during normal aging and in response to stressors and pathology. Although...
Article
Calcaneonavicular coalition
Calcaneonavicular coalition is one of the two most common subtypes of the tarsal coalition, the other being talocalcaneal coalition. As with any coalition, it may be osseous (synostosis), cartilaginous (synchondrosis) or fibrous (syndesmosis).
Radiographic features
This type of coalition is mo...
Article
Anteater nose sign (foot)
The anteater nose sign refers to an anterior tubular elongation of the superior part of the anterior process of the calcaneus, which approaches or overlaps the navicular bone on a lateral radiograph of the foot. This fancifully resembles the nose of an anteater and is indicative of calcaneonavic...
Article
Conditions with upper lobe predominance (mnemonic)
Useful mnemonics to remember conditions with upper lobe predominance in chest radiology are:
STEP
BREASTS
Mnemonics
STEP
S: sarcoidosis, silicosis
T: tuberculosis
E: eosinophilic pneumonia
P: pneumoconiosis
BREASTS
B: berylliosis
R: radiation fibrosis
E: extrinsic allergic alveolitis...
Article
Löffler syndrome
Simple pulmonary eosinophilia (also known as Löffler syndrome) is a type of pulmonary eosinophilia that typically presents with transient radiographic infiltrates, minimal constitutional upset, and an elevated eosinophil count in peripheral blood.
Pathology
Etiology
The cause is not usually i...
Article
Pulmonary interstitial emphysema
Pulmonary interstitial emphysema (PIE) refers to the abnormal location of gas within the pulmonary interstitium and lymphatics usually due to positive pressure ventilation. It typically results from rupture of overdistended alveoli following barotrauma in infants with respiratory distress syndro...
Article
Chest (lateral view)
The lateral chest view examines the lungs, bony thoracic cavity, mediastinum, and great vessels.
Indications
This orthogonal view to a frontal chest radiograph may be performed as an adjunct in cases where there is diagnostic uncertainty. The lateral chest view can be particularly useful in as...
Article
Malignant phyllodes tumor
Malignant phyllodes tumor of the breast accounts for up to a quarter of the phyllodes tumors.
Please, refer to the main article on phyllodes tumors for a general discussion.
Pathology
It is generally thought that it is the stromal component that becomes malignant 4. This may account for thei...
Article
Tarlov cyst
Tarlov cysts, also called perineural cysts, are CSF-filled dilatations of the nerve root sheath at the dorsal root ganglion (posterior nerve root sheath). These are type II spinal meningeal cysts that are, by definition, extradural but contain neural tissue.
Most Tarlov cysts are asymptomatic, ...
Article
Pulmonary arterial ectasia
Pulmonary arterial ectasia refers to more diffuse dilatation of the pulmonary arteries without a focal pulmonary arterial aneurysm. At the time of writing, the upper limit of normal (90th percentile) for the main pulmonary arteries is taken at just under 29 mm for males and just under 27 mm for ...
Article
Long COVID-19
Long COVID-19 also known as post-acute sequelae of SARS-CoV-2 infection (PASC) or post COVID-19 condition, is a post-viral syndrome affecting people who have recovered from COVID-19 infection. Symptoms are similar to those experienced by patients with chronic inflammatory response syndrome (CIRS...
Article
Blake's pouch cyst
Blake's pouch cyst is a cystic appearing structure that represents posterior ballooning of the inferior medullary velum into the cisterna magna, below and posterior to the vermis, that communicates with an open fourth ventricle. It is caused by a failure of the regression of Blake's pouch second...
Article
Malignant peritoneal mesothelioma
Malignant peritoneal mesothelioma is an uncommon primary tumor of the peritoneal lining. It shares epidemiological and pathological features with - but is less common than - its pleural counterpart, which is described in detail in the general article on mesothelioma. Other abdominal subtypes (al...
Article
Focal nodular hyperplasia
Focal nodular hyperplasia (FNH) is a regenerative mass lesion of the liver and the second most common benign liver lesion (the most common is a hemangioma). Many focal nodular hyperplasias have characteristic radiographic features on multimodality imaging, but some lesions may be atypical in app...
Article
Coarctation of the aorta
Coarctation of the aorta (CoA) refers to a narrowing of the aortic lumen.
Epidemiology
Coarctations account for between 5-8% of all congenital heart defects. They are more frequent in males, M:F ratio of ~2-3:1.
Associations
As with many congenital abnormalities, coarctation of the aorta is ...
Article
Interrupted aortic arch
Interrupted aortic arch (IAA) is an uncommon congenital cardiovascular anomaly where there is a separation between the ascending and descending aorta. It can either be complete or connected by a remnant fibrous band. An accompanying large ventricular septal defect (VSD) and/or patent ductus arte...
Article
Photon-counting computed tomography
Photon-counting computed tomography (PCCT) is a new technology in CT that could represent the next major technological milestone in the field. Briefly, photon-counting CT uses energy-resolving detectors, thereby enabling scanning at multiple energies.
Technique
Physical principles
Current cli...
Article
Reflection
Reflection of a sound wave occurs when the wave passes between two tissues of different acoustic impedances and a fraction of the wave 'bounces' back. This forms one of the major principles of ultrasound imaging as the ultrasound probe detects these reflected waves to form the desired image.
An...
Article
Bosniak classification system of renal cystic masses (version 2005)
The Bosniak classification system of renal cystic masses, now known as Bosniak v2005, divides renal cystic masses into five categories based on imaging characteristics on contrast-enhanced CT, and helps predict a risk of malignancy and suggests either follow-up or treatment. An updated classific...
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