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.

34 results found
Article

Cardiac calcification

Cardiac calcification is a broad term for any calcification affecting the valves, coronary arteries, aortic root, endocardium, myocardium, and/or pericardium. Pathology Causes of cardiac calcification are: coronary artery disease (most common) coronary artery aneurysms, e.g. in Kawasaki dise...
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Cardiomegaly

Cardiomegaly is a catch-all term to refer to enlargement of the heart, and should not be confused with causes of enlargement of the cardiomediastinal outline, or enlargement of the cardiac silhouette.  Pathology Etiology There are many etiologies for cardiomegaly: congestive heart failure i...
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Cardiovascular shunts

Cardiovascular (cardiac) shunts are abnormal connections between the pulmonary and systemic circulations. Most commonly they are the result of congenital heart disease. Pathology Blood can either be shunted from the systemic circulation to pulmonary circulation (i.e. 'left-to-right shunt') or ...
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Carotid pacemaker

Carotid pacemakers, also known as implantable carotid sinus stimulators, are devices that deliver activation energy, via carotid leads, to the carotid baroreceptors. This is sometimes offered for drug-resistant hypertension. The baroreceptors send signals to the brain and the signals are interpr...
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Cyanotic congenital heart disease

A number of entities can present as cyanotic congenital heart disease. These can be divided into those with increased (pulmonary plethora) or decreased pulmonary vascularity : increased pulmonary vascularity total anomalous pulmonary venous return (TAPVR) (types I and II) transposition of the...
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Delayed myocardial enhancement on MRI (differential)

Delayed myocardial enhancement can occur in cardiac MR assessment due to a number of causes. They include: myocardial ischemia: typically subendocardial and follows a vascular territory 1 non-ischemic cardiomyopathies hypertrophic cardiomyopathy non-ischemic dilated cardiomyopathy arrhythm...
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Dextrocardia

Dextrocardia is a congenital cardiac malrotation in which the heart is situated on the right side of the body (dextroversion) with the apex pointing to the right. Terminology Dextrocardia merely refers to the laterality of the heart, it says nothing about the orientation of the patient's other...
Article

Differential diagnosis for a small cardiothoracic ratio

A small cardiothoracic ratio (CTR) is defined as <42%/0.42 when assessed on a PA chest radiograph, and is often called small heart syndrome. A pathologically-small heart is also known as microcardia.It can be due to/associated with a number of entities: adrenal insufficiency, e.g. Addison disea...
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Drug and toxin induced pulmonary hypertension

Drug and toxin induced pulmonary hypertension is one of the causes of pulmonary arterial hypertension. It falls under group 1.3 under the Dana point classification system of pulmonary hypertension.  Pathology A wide range of difference drugs have been associated with developing pulmonary hyper...
Article

Enlarged azygos vein

An enlarged/dilated azygos vein may result from a number of physiological as well as pathological causes. The enlarged azygos vein may be seen as a widened right paratracheal/paraspinal stripe on a frontal chest radiograph. Terminology Spelling it "azygous" when referring to the vein is incorr...
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Enlarged pulmonary trunk on chest radiography (differential)

The differential of an enlarged pulmonary trunk/main pulmonary artery on chest radiography includes:  normal may appear prominent in young patients especially women projectional rotation lordotic view rotation of the heart pectus excavatum left lower lobe collapse pulmonary arterial hyp...
Article

Fat containing cardiac lesions

Fat containing cardiac lesions have a limited differential diagnosis. These include 1-4: normal aging/physiologic: mostly subepicardial, more in the right ventricle (especially right ventricular outflow tract) than left ventricle lipomatous hypertrophy of the interatrial septum chronic myocar...
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Fetal cardiac tumors

Fetal cardiac tumors refer to primary cardiac tumors that can present in the in utero population.  Epidemiology Fetal cardiac tumors are rare; the prevalence, reported from autopsy studies of patients of all ages, varies from 0.0017-0.28 % 2. Pathology Known cardiac tumor types that present ...
Article

Hemopericardium

Hemopericardium refers to the presence of blood within the pericardial cavity, i.e. a sanguineous pericardial effusion. If enough blood enters the pericardial cavity, then a potentially fatal cardiac tamponade can occur.  Pathology Etiology There is a very long list of causes 1,4 but some of ...
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High-output cardiac failure

High output cardiac failure refers to a state of cardiac failure that is associated with a higher than normal cardiac output which is still not sufficient for body tissue demands. Clinical presentation Patients can present with a number of symptoms of varying degrees which include tachycardia,...
Article

HIV/AIDS (cardiovascular manifestations)

Cardiovascular manifestations are seen with increased frequency in the HIV/AIDS adult population, and include: pericardial effusions dilated cardiomyopathy (prevalence 8-30%) endocarditis: either infective or non-bacterial thrombotic (marantic) which is associated with malignancy or HIV wasti...
Article

Medical devices in the thorax

Medical devices in the thorax are regularly observed by radiologists when reviewing radiographs and CTs. Extrathoracic devices tubing, clamps, syringes lying on or under the patient rubber sheets, foam mattresses, clothing, hair braids, nipple piercings etc. may also be visible These devices...
Article

Pericardial fat pads

Pericardial fat pads are normal structures that lie in the cardiophrenic angle. They are adipose tissues surrounding the heart composed of the epicardial fat, which lies between the myocardium and visceral pericardium, and paracardial fat, which is adherent and external to the parietal pericardi...
Article

PET-CT indications

PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET). PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). Fluorine-18 (F-18) is an unstable radioisotope and has a half-...
Article

Porcelain left atrium

Porcelain left atrium, also known as coconut left atrium, is a term used when a large part of or the entire left atrial wall becomes calcified. It can occur as a rare consequence of endocarditis (with underlying rheumatic heart disease). It has also been described in the setting of end-stage ren...
Article

Post-sternotomy complications

Post-sternotomy complications comprise of a varied range problem that can occur at varying durations after a median sternotomy. Imaging playing in detection and aiding management. Epidemiology Complication rates for median sternotomy have been reported to range from 0.5-5%, with mortality rate...
Article

Pott shunt

A Pott shunt is a form of palliative surgery performed in patients with tetralogy of Fallot prior to the ability to repair the defect. It consists of a shunt formed between the descending thoracic aorta and the left pulmonary artery. This does not relieve the right ventricular outflow obstructi...
Article

Primary benign cardiac tumors

Primary benign cardiac tumors are much less common than secondary metastatic deposits. However they are more likely when a cardiac mass is seen outside of the setting of terminal metastatic disease. Tumors include 1-2: cardiac myxoma most common in adults accounts for ~50% of all primary beni...
Article

Primary malignant cardiac tumors

Primary malignant cardiac tumors are rare, and account for only ~25% of primary cardiac tumors, and only a small proportion of all malignant tumors which involve the heart: direct extension of adjacent tumors or metastatic deposits are far more common. Pathology Histologcal types include 1:  ...
Article

Prosthetic heart valve

Prosthetic heart valves are common. The four valves of the heart may all be surgically replaced. However, the aortic and mitral valves are the most commonly replaced. Replacements may be tissue or metallic valves, only the latter being visualized on imaging investigations. Sometimes the annulus...
Article

Pulmonary hypertension (differential)

Pulmonary hypertension has many causes, and these can be divided in many ways. A simple and systematic approach is to proceed along the cardiopulmonary pulmonary circulation, as causes are found at each site (for a more official classification system see 2003 third world symposium on pulmonary a...
Article

RASopathy

RASopathies are a class of developmental disorders caused by germline mutations in genes that encode for components or regulators of the Ras/mitogen-activated protein kinase (MAPK) pathway. Epidemiology As a group, RASopathies represent one of the most common malformation syndromes, with an in...
Article

Restrictive cardiomyopathy

Restrictive cardiomyopathy is the least common subtype of cardiomyopathy and is characterized by a marked decrease in ventricular compliance.  Clinical presentation Patients can present with symptoms and signs of left ventricular failure and/or right ventricular failure 9.  Pathology It is p...
Article

Right atrial enlargement

Right atrial enlargement is less common, and harder to delineate on chest radiograph, than left atrial enlargement. Pathology Causes Enlargement of the right atrium can result from a number of conditions, including: raised right ventricular pressures pulmonary arterial hypertension cor pul...
Article

Right heart strain

Right heart strain (or more precisely right ventricular strain) is a term given to denote the presence of right ventricular dysfunction usually in the absence of an underlying cardiomyopathy. It can manifest as an acute right heart syndrome. Pathology Right heart strain can often occur as a re...
Article

Systemic lupus erythematosus (thoracic manifestations)

Thoracic manifestations of systemic lupus erythematosus can be variable.  For a general discussion, and for links to other system specific manifestations, please refer to the article on systemic lupus erythematosus.  Pathology Pleuropulmonary manifestations pleuritis: considered one of the c...
Article

Troponin

Troponin is a protein of key importance in the functioning of skeletal and cardiac muscle. It forms part of the contractile mechanism, and comprises three main subunits: troponin C, troponin I, and troponin T.  Troponin elevation Elevation of serum troponin can occur from a number of causes an...
Article

Valsalva maneuver

The Valsalva maneuver is the forced expiration of air against a closed airway, resulting in increased intra-abdominal, intrathoracic and pharyngeal pressure. It can be performed against a closed glottis or by one closing the mouth and pinching the nose while forcibly exhaling. It is commonly us...
Article

Valvular heart disease

Valvular heart diseases, or cardiac valvulopathies, describe any acquired or congenital disease affecting one or more of the four cardiac valves. This is a general index article that classifies cardiac valvulopathies depending on which valve(s) is affected 1. See individual articles for in-dept...

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