Articles
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1,985 results found
Article
AAST injury scoring scales
The American Association for the Surgery of Trauma (AAST) injury scoring scales are the most widely accepted and used system of classifying and categorizing traumatic injuries. Injury grade reflects severity, guides management, and aids in prognosis. 32 different injury scores are available (c. ...
Article
Aberrant left pulmonary artery
Aberrant left pulmonary artery, also known as pulmonary sling, represents an anatomical variant characterized by the left pulmonary artery arising from the right pulmonary artery and passing above the right main bronchus and in between the trachea and esophagus to reach the left lung. It may lea...
Article
Aberrant right subclavian artery
Aberrant right subclavian arteries (ARSA), also known as arteria lusoria, are among the commonest aortic arch anomalies.
Epidemiology
The estimated incidence is 0.5-2% 1.
Associations
as can be expected from the embryological development of the artery, the right recurrent laryngeal nerve is...
Article
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...
Article
Absent azygos vein
An absent azygos vein is a very uncommon variant in which the azygos vein fails to develop. In cases of agenesis of the azygos vein, the hemiazygos and accessory hemiazygos veins play an important role in venous drainage, accounting for drainage of both the right and left intercostal veins 1-3.
...
Article
Absent pulmonary valve syndrome
Absent pulmonary valve syndrome (APVS) also known as congenital absence of pulmonary valve or pulmonary valve agenesis is a rare cardiac outflow tract anomaly.
Pathology
It is characterized by a completely absent or rudimentary pulmonary valve. It can be associated with aneurysmal dilatation ...
Article
Accessory fissures of the lung
Accessory fissures of the lung usually occur at the borders of bronchopulmonary segments. They are common normal variants but are less commonly seen on imaging.
Some of the more common accessory fissure include 1:
azygos fissure: most commonly seen accessory fissure
inferior accessory fissur...
Article
Accessory hemiazygos vein
The accessory (or superior) hemiazygos vein forms part of the azygos system and along with the hemiazygos vein, it is partially analogous to the right-sided azygos vein. It drains the left superior hemithorax.
Terminology
Spelling it "hemiazygous" when referring to the vein is incorrect, rega...
Article
Accessory muscles of respiration
Accessory muscles of respiration refer to muscles that provide assistance to the main breathing muscles, mainly when additional power is needed, for example during exercise or those with airway pathologies (e.g. COPD) 1,2.
During normal quiet breathing, inspiration is an active process primaril...
Article
Accessory phrenic nerve
The accessory phrenic nerve is an anatomical variant seen in a little over one third of patients (36%). It most commonly arises from the ansa cervicalis, or slightly less commonly, the subclavian nerve. It is unknown as to how much the accessory phrenic nerve contributes to diaphragmatic functio...
Article
Achalasia
Achalasia (primary achalasia) is a failure of organized esophageal peristalsis that causes impaired relaxation of the lower esophageal sphincter, resulting in food stasis and often marked dilatation of the esophagus.
Obstruction of the distal esophagus from other non-functional etiologies, not...
Article
Acinar-predominant adenocarcinoma of the lung
Acinar-predominant adenocarcinoma of the lung is a histological subtype of non-mucinous invasive adenocarcinoma of the lung.
Terminology
In 2011, the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS) 4 introd...
Article
Acinic cell carcinoma (lung)
Acinic cell carcinoma of the lung (also known as a Fechner tumor) is a type of lung carcinoma of the salivary gland type. It is extremely rare, especially when it presents in the form of primary acinic cell carcinoma.
Pathology
Histologically, they are comprised of clear cells with abundant gr...
Article
Acquired aortic conditions
Acquired aortic conditions include:
aortic dissection
aortic rupture/transection
ascending aortic aneurysm
aortitis
thoracic aortic injury
abdominal aortic aneurysm
inflammatory abdominal aortic aneurysm
Article
Acquired tracheo-esophageal fistula
An acquired tracheo-esophageal fistula refers to a pathological communication between the trachea and esophagus due to a secondary cause.
Pathology
Acquired causes of tracheo-esophageal fistulae can be divided into those that are related to malignancy (common) and those from other causes (unco...
Article
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...
Article
Acute aspiration pneumonitis
Acute aspiration pneumonitis occurs when solid or liquid ingested particles enter the airways and lungs, leading to inflammation.
This article will focus on the acute form of aspiration (cf. chronic aspiration pneumonia), mainly concerning its radiographic features; for a broader discussion, p...
Article
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...
Article
Acute bronchitis
Acute bronchitis (plural: bronchitides) refers to acute-onset, short-term bronchial inflammation. It is usually self-limiting and often the result of a viral infection. Chest radiography is rarely necessary.
Epidemiology
Acute bronchitis can affect people of all ages, but it is commonest in ch...
Article
Acute coronary syndrome
Acute coronary syndrome (ACS) is a group of cardiac diagnoses along a spectrum of severity due to the interruption of coronary blood flow to the myocardium, which in decreasing severity are:
ST elevation myocardial infarction (STEMI)
non-ST elevation myocardial infarction (NSTEMI)
unstable an...
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