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.

45 results found
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Bentall procedure

Bentall procedure is performed for the repair of ascending aortic root lesions. Typically the native aortic root and aortic valve are replaced with a composite graft that comprises both ascending aortic and aortic valve grafts, to which the coronary arteries are anastomosed. History and etymolo...
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Blalock-Taussig shunt

Blalock-Taussig shunt, also known as Blalock-Thomas-Taussig shunt, is a palliative procedure performed in patients with tetralogy of Fallot (prior to the ability to repair the defect) to increase the pulmonary blood flow.  Originally the shunt sacrificed the subclavian artery (with a distal lig...
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Cardiac chamber enlargement

Cardiac chamber enlargement can be recognised by cardiac contour changes, new or different interfaces with adjacent lung, and/or displacement of adjacent mediastinal structures. These are discussed separately: right atrial enlargement right ventricular enlargement left atrial enlargement lef...
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Cardiac conduction devices

Implantable cardiac conduction devices are a very common medical device of the thorax, with over one million implanted in the United States of America alone. There are two major types of cardiac conduction devices: pacemakers and automatic implantable cardioverter-defibrillators (AICD/ICD), and...
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Cardiac curriculum

The cardiac curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core cardiac knowledge. Definition Topics pertaining to the heart and pericardium, but excluding the mediastinum (see: chest curriculum) and great vessels (see: vascular curricul...
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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 Aetiology There are many aetiologies for cardiomegaly: congestive heart failure ...
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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 (left-to-right shunt) or between...
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Carotid pacemaker

Carotid pacemaker, also known as implantable carotid sinus stimulators, is a device that delivers activation energy through the carotid leads and the leads conduct activation energy to the carotid baroreceptors. This is sometimes offered for drug-resistant hypertension. The baroreceptors send si...
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COL4A1-related disorders

COL4A1-related disorders are a group of autosomal dominant disorders caused by a mutation in the COL4A1 gene. Epidemiology The exact prevalence is unknown, but the group of disorders is considered to be under-recognised, especially asymptomatic variants 1. Clinical presentation The clinical ...
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Coronary artery bypass graft

A coronary artery bypass graft (CABG or CAG) is placed during a surgical procedure to increase blood flow to the myocardium due to coronary stenoses, usually caused by coronary artery disease. Arteries or veins can be grafted during this procedure. Long term outcome of coronary artery bypass gr...
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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 or decreased pulmonary vascularity (pulmonary plethora): increased pulmonary vascularity total anomalous pulmonary venous return (TAPVR) (types I and II) transposition of the ...
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Deductive echocardiography

Deductive echocardiography is a step-by-step approach in diagnosing and differentiating congenital heart disease. Parameters assessed position of heart  levocardia dextrocardia viscero-atrial situs solitus inversus ambiguus ventricular loop D-loop L-loop conotruncus normal transpos...
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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 ischaemia: typically subendocardial and follows a vascular territory 1 nonischaemic cardiomyopathies hypertrophic cardiomyopathy nonischaemic dilated cardiomyopathy arrhyth...
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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. Epidemiology Dextrocardia is believed to occur in approximately 1 in 12,000 people 2. Pathology There are two main types of dextr...
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Differential diagnosis for a small cardiothoracic ratio

A small cardiothoracic ratio (CTR) as defined as <42%/0.42 when assessed on a PA chest radiograph, and can be due to number of entities: adrenal insufficiency, e.g. Addison disease heart transplant cachexic state  senility malnutrition bulimia nervosa anorexia nervosa asthmatic paroxysm ...
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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...
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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. Causes for dilatation There are a number of physiological causes for e...
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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...
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Epicardial fat pads

Epicardial (pericardial) fat pads are normal structures that lie in the cardiophrenic, more so on the right. Unsurprisingly, they are more prominent in obese patients. Pathology They can be affected by fat necrosis (see: epipericardial fat necrosis).  Radiographic features Plain radiograph ...
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Fetal cardiac tumours

Fetal cardiac tumours refer to primary cardiac tumours that can present in the in utero population.  Epidemiology Fetal cardiac tumours are rare; the prevalence, reported from autopsy studies of patients of all ages, varies from 0.0017-0.28 % 2. Pathology Known cardiac tumour types that pres...
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Haemochromatosis (cardiac manifestations)

Cardiac involvement in haemochromatosis typically occurs with primary haemochromatosis, as the organ is usually spared in the secondary form of the disease. Epidemiology Cardiac involvement occurs in approximately 15-20% of the patients with haemochromatosis.  Clinical presentation Manifesta...
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Haemopericardium

Haemopericardium 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 Aetiology There is a very long list of causes 1,4 but some o...
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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,...
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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

Implantable loop recorder

Implantable loop recorders, also known as insertable cardiac monitors, are small insertable devices that continuously monitor and record cardiac rhythms. They are placed subcutaneously and used for the evaluation of patients with recurrent unexplained episodes of palpitations or syncope. They sh...
Article

Left atrial line

The left atrial (LA) line monitors LA pressure and is indicative of left ventricular function, preload and afterload. The LA line enters from the left superior vein and exits the far side of the chest. The LA line is a single lumen catheter unlike the right atrial line, which is double lumen. N...
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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

Milking effect

Milking effect phenomenon is a pathognomonic angiographic finding in myocardial bridging of coronary arteries. Systolic compression of coronary vessels with partial or complete decompression during diastole is described as milking effect. Its significance lies in:  increased risk of thrombus fo...
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Mitral valve disease

Mitral valve disease (MVD) principally comprise of a two main functional abnormalities, which can occur in isolation or in combination: mitral regurgitation mitral stenosis In addition other pathologies that affect the mitral valve include mitral valve prolapse mitral annular calcification ...
Article

Moguls of the heart

The 'moguls of the heart' refer to the bulges of the cardiomediastinal contour on frontal chest radiographs. The cardiomediastinal bulges are likened to skiing moguls (bumps of packed snow on a mountainside sculptured by turning skis). Awareness of their usual locations and aetiologies is helpfu...
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Myocardial perfusion and viability

Myocardial perfusion and viability assessment is important for many reasons: to diagnose, locate and grade the severity of coronary artery disease to identify candidates who would benefit from re-vascularization to evaluate response of re-vascularization Terminology Stunned myocardium It r...
Article

Partial anomalous pulmonary venous return

Partial anomalous pulmonary venous return (PAPVR), also known as partial anomalous pulmonary venous connection (PAPVC), is a rare congenital cardiovascular condition in which some of the pulmonary veins, but not all, drain into the systemic circulation rather than in the left atrium. Clinical p...
Article

Pericarditis

Pericarditis is defined as inflammation of the pericardium. It is normally found in association with cardiac, thoracic or wider systemic pathology and it is unusual to manifest on its own. Pathology In general, infection is the most common cause of pericarditis. Infection accounts for two-thir...
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

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 tumours

Primary benign cardiac tumours 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. Tumours include 1-2: cardiac myxoma most common in adults accounts for ~50% of all primary be...
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Primary malignant cardiac tumours

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

Prosthetic heart valve

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

RASopathies

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...
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Restrictive cardiomyopathy

Restrictive cardiomyopathy is the least common subtype of cardiomyopathy and is characterised 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...
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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...
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Secondary cardiac neoplasms

Secondary cardiac neoplasms or cardiac metastasis/es refer to a secondary malignant tumour of the heart, arising by lymphatic or haematogenous spread of a primary neoplasm 3,5. Epidemiology Overall cardiac malignancy is an infrequent finding. Metastatic spread is much more common than primary ...
Article

Troponin elevation

Troponin elevation can occur from a number causes although there is no imaging involved, it is useful for the radiologist to have a basic understanding of their causes (especially when interpreting imaging findings associated with troponin elevation). The cardiac troponin complex consists of thr...

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