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.
More than 200 results
Article
Pulmonary opacification
Pulmonary opacification represents the result of a decrease in the ratio of gas to soft tissue (blood, lung parenchyma and stroma) in the lung. When reviewing an area of increased attenuation (opacification) on a chest radiograph or CT it is vital to determine where the opacification is. The pat...
Article
More black sign
The more black sign is a normal finding in lateral chest x-ray and refers to the gradually increased apparent radiolucency (blackness) of the vertebral bodies when proceeding from the upper to lower chest. This is due to the increased proportion of the chest comprised of air-containing lungs ove...
Article
Peter Kerley
Sir Peter “PK” Kerley (1900-1979) was a globally-renowned cardiothoracic radiologist who is primarily remembered now for his Kerley lines but in his lifetime was famed for his uncanny imaging diagnostic abilities, co-editing the famous 'A Text-book of X-Ray Diagnosis by British Authors', and co-...
Article
Linear atelectasis
Linear atelectasis (plural: atelectases), and also known as discoid, plate or band atelectasis, refers to a focal area of subsegmental atelectasis that has a linear shape. Linear atelectasis may appear to be horizontal, oblique or perpendicular and is very common. It usually occurs as a conseque...
Article
Pulmonary cavity
A pulmonary cavity is a collection of gas and/or fluid enclosed by a thick and often irregular wall which usually occurs when central necrotic tissue is expelled via a bronchial connection. Cavities may be single or multiple and can be isolated or associated with lung disease 12.
Terminology
P...
Article
Calcified pulmonary nodules
Calcified pulmonary nodules are a subset of hyperdense pulmonary nodules and a group of nodules with a relatively narrow differential.
Pathology
Etiology
The most common cause of nodule calcification is granuloma formation, usually in the response to healed infection.
healed infection
cal...
Article
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...
Article
HIV associated neoplasms
HIV-associated neoplasms are numerous and can be broadly divided into two groups:
AIDS-defining malignancies
associated but not AIDS defining malignancies
AIDS-defining malignancies
The development of these malignancies in HIV affected individuals generally implies progression to AIDS 4:
Ka...
Article
High attenuation lymphadenopathy
High attenuation lymphadenopathy or adenopathy variably refers to abnormal lymph nodes with attenuation on CT usually higher compared to muscle, either on a noncontrast exam or following contrast administration (i.e. hyperenhancement) 5.
Differential diagnosis
High attenuation nodes may be due...
Article
Round pneumonia
Round pneumonia is a type of pneumonia usually only seen in pediatric patients. They are well defined, rounded opacities that represent regions of infected consolidation.
Epidemiology
The mean age of patients with round pneumonia is 5 years and 90% of patients who present with round pneumonia ...
Article
Lung abscess
Lung abscesses are circumscribed collections of pus within the lungs. They are often complicated to manage and difficult to treat and, in some cases, maybe life-threatening.
Epidemiology
As a result of the widespread availability of antibiotics, the incidence of lung abscesses has been dramati...
Article
Perisylvian syndrome
Perisylvian syndrome, also known as congenital bilateral perisylvian syndrome (CBPS), bilateral periopercular syndrome or perisylvian polymicrogyria, is a rare neurological disorder characterized by structural malformation of the cortical development 1. This malformation includes the Sylvian fis...
Article
Distal intersection syndrome
The distal intersection syndrome relates to tenosynovitis of the extensor pollicis longus (EPL) tendon (3rd extensor compartment), where it crosses the extensor carpi radialis longus (ECRL) and brevis (ECRB) tendons (2nd extensor compartment) 1. It is distinct from intersection syndrome which oc...
Article
Neuroendocrine neoplasm
Neuroendocrine neoplasms, also commonly known as neuroendocrine tumors (NETs) or carcinoid tumors, comprise a large heterogeneous group of benign and malignant tumors derived from multipotent stem cells found in both endocrine and non-endocrine organs, as well as the diffuse neuroendocrine syste...
Article
Hepatic hemangioma
Hepatic hemangiomas or hepatic venous malformations are the most common benign vascular liver lesions. They are frequently diagnosed as an incidental finding on imaging, and most patients are asymptomatic. From a radiologic perspective, it is important to differentiate hemangiomas from hepatic m...
Article
Nasogastric tube positioning
Assessment of nasogastric (NG) tube positioning is a key competency of all doctors as unidentified malpositioning may have dire consequences, including death.
Radiographic features
Plain radiograph
A correctly placed nasogastric tube should 10:
descend in the midline, following the path of ...
Article
Pseudocoarctation of the aorta
Pseudocoarctation of the aorta is a rare anomaly characterized by elongation of the aortic arch associated with buckling at the level of the ligamentum arteriosum.
Epidemiology
Associations
Reported associations include 3,9:
hypertension
true coarctation of the aorta
congenital heart disea...
Article
Medical abbreviations and acronyms (O)
This article contains a list of commonly used medical abbreviations and acronyms that start with the letter O and may be encountered in medicine and radiology (please keep the main list and any sublists in alphabetic order).
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R...
Article
Cor pulmonale
Cor pulmonale refers to altered structure and function of the right ventricle due to chronic lung disease-related pulmonary hypertension (group 3). The mechanism involves hypoxic vasoconstriction which leads to permanent changes in the pulmonary vascular bed. Cor pulmonale generally progresses s...
Article
Hürthle cell thyroid carcinoma
Hürthle cell carcinoma, also known as oncocytic carcinoma, is a lesser-known subtype of differentiated thyroid carcinoma that was previously regarded as a variant of follicular thyroid cancer. It shares clinical presentation and patterns with follicular cancer 1,2.
Epidemiology
Hürthle cell ca...
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