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.
798 results found
Article
60/60 sign (echocardiography)
The 60/60 sign in echocardiography refers to the coexistence of a truncated right ventricular outflow tract acceleration time (AT <60 ms) with a pulmonary arterial systolic pressure (PASP) of less than 60 mmHg (but more than 30 mmHg). In the presence of right ventricular failure, it is consisten...
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
ACC/AHA classification of coronary lesions
ACC/AHA classification of coronary lesions is a system used to classify coronary arterial calcific plaque burden. It is classified as
type A
discrete (<10 mm)
concentric
nonangulated segment <45º
smooth contour
little or no calcification
less than totally occlusive
not ostial in locatio...
Article
Accessory left atrial appendage
An accessory left atrial appendage is a frequent fortuitous finding in cardiac imaging, encountered in ~10% of patients. They are more often seen as a small diverticular structure projecting from the right upper side of the left atrial wall.
Differential diagnosis
it must not be confused with ...
Article
Ace-of-spades sign (heart)
Ace-of-spades sign refers to the pathognomonic configuration of the left ventricle as seen in apical hypertrophic cardiomyopathy 1-3.
It consists of marked ventricular wall thickening at the apex resulting in cavity narrowing at the apex with a relatively normal appearance of the mid-ventricula...
Article
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...
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...
Article
Acute right heart syndrome
Acute right heart syndrome (ARHS) is defined as a sudden deterioration in right ventricular (RV) function and failure of the RV to deliver adequate blood flow to the pulmonary circulation. This can result in systemic hypoperfusion.
Pathology
ARHS can occur in several settings 1
in the setting...
Article
Acyanotic congenital heart disease
Acyanotic congenital heart disease comprises numerous etiologies, which can be divided into those with increased pulmonary vascularity (pulmonary plethora) and those with normal vascularity:
increased pulmonary vascularity
ventricular septal defect (VSD)
atrial septal defect (ASD)
atrioventr...
Article
Adenosine
Adenosine is a vasodilating agent, which acts on the vascular smooth muscle surface and leads to vasodilation and a considerable increased vascular flow.
NB: This article aims to give a summarized description of adenosine. For detailed and exact information please refer to the information and d...
Article
Agatston score
Agatston score is a semi-automated tool to calculate a score based on the extent of coronary artery calcification detected by an unenhanced low-dose CT scan, which is routinely performed in patients undergoing cardiac CT. Due to an extensive body of research, it allows for early risk stratificat...
Article
Ammonia (N-13)
13NH3 is a PET tracer used for studies of myocardial perfusion imaging. It is produced in a cyclotron by proton irradiation of the enriched water of the oxygen-16. Ammonia (N-13) is administered intravenously, at a dose of 10-20 mCi (370-740 Mbq) in adults; its physical half-life is 10 minutes.
...
Article
Anaphylaxis
Anaphylaxis (also known as anaphylactic shock or reaction) is an acute severe systemic type I hypersensitivity reaction, commonly presenting with urticaria/angioedema, hypotension and bronchial hyperreactivity. It may be fatal.
Terminology
Anaphylactoid reactions result from non-immune system ...
Article
Anatomy curriculum
The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists.
General anatomy
Neuroanatomy
Head and neck anatomy
Thoracic anatomy
Abdominal and pelvic anatomy
Spinal anat...
Article
Angina
Angina or angina pectoris is cardiac chest pain that occurs as the result of myocardial ischemia.
Clinical presentation
Angina is classically described as substernal chest discomfort that is of a typical quality and duration (heavy, tight, ‘bandlike’ pain that lasts for minutes at a time). Ang...
Article
Angiotensin converting enzyme
Angiotensin converting enzyme (ACE) is a central component of the renin-angiotensin system (RAS) which assists in blood pressure control by regulating the volume of fluids in the body.
Normal individuals may have a small volume of the angiotensin converting enzyme circulating in their blood.
M...
Article
Ankylosing spondylitis (cardiovascular manifestations)
Cardiovascular manifestations of ankylosing spondylitis may affect approximately 2-10% of all patients with ankylosing spondylitis. Cardiac complications had been traditionally classified into 3 main categories which include 2:
aortitis and aortic insufficiency
aortic root dilatation: r...
Article
Anomalous aortic origin of coronary artery
Anomalous aortic origin of coronary artery (AAOCA) refers to a congenital coronary artery anomaly in which a coronary artery arises from a different coronary sinus.
Terminology
Anomalous origin of the coronary artery arising from the opposite sinus (ACAOS) is a narrower definition and refers t...
Article
Anomalous course of coronary arteries
Anomalous course of a coronary artery is a type of congenital coronary artery anomaly. It may represent a benign and incidental finding, but rarely it is a malignant course predisposing patients to life-threatening myocardial ischemia or arrhythmias, depending on where the artery runs.
Clinica...
Article
Anomalous left coronary artery from the pulmonary artery
Anomalous left coronary artery from the pulmonary artery (ALCAPA), also known as Bland-White-Garland syndrome (BWG), is a rare congenital coronary artery anomaly and is considered one of the most severe of such anomalies.
There are two forms, based on the onset of the disease, each of which has...
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