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.

433 results found
Article

Septal branches of the left anterior descending artery

The septal branches of the left anterior descending artery supply blood flow to the interventricular septum of the heart. Origin These are branches from the left anterior descending artery Supply They provide the main blood supply to the anterior interventricular septum. A smaller posterior ...
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Shepherd's crook right coronary artery

A shepherd’s crook right coronary artery is variant in the terms of the course of the right coronary artery. While the RCA origin is normal it is characterised by a tortuous and high course, usually just after its origin from the aorta. Its prevalence is estimated at approximately 5%. While ofte...
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Shmoo sign

Shmoo sign refers to the appearance of a prominent, rounded left ventricle and dilated aorta on a plain AP chest radiograph giving the appearance of Shmoo, a fictional cartoon character in the comic strip Li'l Abner, which first appeared in 1948. This sign is indicative of left ventricular enlar...
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Single coronary artery

Single coronary arteries are rare (incidence 0.03-0.07%), with a higher incidence in patients with congenital heart disease (in particular truncus arteriosus and pulmonary atresia). They occur when there is a single ostia arising from the aorta with no ectopic ostia. There is a wide variety of c...
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Sinoatrial nodal artery

The sinoatrial (SA) nodal artery is the small artery that supplies the sinoatrial (SA) node of the heart (the pacemaker).  Gross anatomy Origin Right coronary artery in 60% of cases and the left coronary artery in 40% of cases. Course The artery turns posteriorly below the superior vena cav...
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Sinus of Valsalva aneurysm

Sinus of Valsalva aneurysms are a cause of thoracic aortic dilatation. They can be either congenital or acquired (mycotic). Epidemiology There is a male predilection (M:F ratio being around 3-4:1). They are relatively more common in eastern and Asian populations and can occur in any age group ...
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Small cardiac vein

The small cardiac vein is a vein of the heart which accompanies the acute marginal artery from the RCA. It courses in the right posterior atrioventricular groove and drains into the coronary sinus close to it’s termination but may drain directly into the right atrium. It drains the right ventric...
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Snowman sign (total anomalous pulmonary venous return)

Snowman sign refers to the configuration of the heart and the superior mediastinal borders resembling a snowman. This is seen in total anomalous pulmonary venous return (TAPVR) type I (supracardiac type). It is an abnormality of the fetal circulation wherein the entire pulmonary venous flow is ...
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Sonographic approach to dyspnoea (mnemonic)

This mnemonic will help with the sonographic approach to the critically ill patient with dyspnoea: CHEST Mnemonic C: collapsed lung (pneumothorax)  ​absent anterior lung sliding / anterior B lines lung point present 1 H: heart failure (acute pulmonary oedema) diffuse bilateral anterior B ...
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Speckle tracking echocardiography

Speckle tracking echocardiography is a new player in the cardiac arena which is rapidly making its mark in cardiac and radiology circles alike. It is an objective, robust, semiautomatic and reproducible technique with a short post processing time. Traditionally, left ventricular function is mea...
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Stanford classification of aortic dissection

Along with the DeBakey classification, the Stanford classification is used to separate aortic dissections into those that need surgical repair, and those that usually require only medical management. The Stanford classification divides dissections by the most proximal involvement: type A: A aff...
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Stunned myocardium

Stunned myocardium refers to a situation in which an acute transient myocardial ischemic event results in a prolonged wall motion abnormality which eventually resolves. The term is usually distinguished from "hibernating" myocardium, in which a chronic ischaemic process leads to chronic left ve...
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Superior aortic recess

The superior aortic recess is one of the pericardial recesses forming a small space within the pericardium, which arises from the superior margin of the transverse pericardial sinus and surrounds the root of the ascending aorta. Its components are variable and may be further subdivided into: a...
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Surgically-created cardiac shunts (mnemonic)

A mnemonic for surgically-created cardiac shunts for congenital heart disease is: great flow really would be perfect​ The mnemonic is ordered by the position of the shunt antegrade to normal blood flow through the heart, proceeding from the systemic venous system into the right heart, and then...
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Syphilis

Syphilis is the result of infection with the gram negative spirochete Treponema pallidum, subspecies pallidum. It results in a heterogeneous spectrum of disease with many systems that can potentially be involved, which are discussed separately.  Epidemiology Despite the discovery of penicillin...
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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...
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Tachycardia induced cardiomyopathy

Tachycardia induced cardiomyopathy (TIC) (or tachycardiomyopathy) is considered a reversible form of acquired cardiomyopathy where there is impaired left ventricular systolic dysfunction precipitated by a tachycardia or a tachyarrhythmia. Typically there is an impairment left ventricular systol...
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Takeuchi procedure

The Takeuchi procedure refers to a direct anastomosis of the anomalous left coronary artery from the pulmonary artery directly to the aorta was described in the 1970s and currently remains the procedure of choice. An intrapulmonary aortocoronary tunnel or baffle was performed by Takeuchi prior ...
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Takotsubo cardiomyopathy

Takotsubo cardiomyopathy (TC) is a condition which has been described predominantly in postmenopausal women following exposure to sudden, unexpected emotional or physical stress.  Pathology There is a transient left ventricular dysfunction and there is no evidence of obstructive epicardial cor...
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Taussig-Bing anomaly

Taussig-Bing anomaly is a rare congenital heart malformation and is one of the variants of double outlet right ventricle. It consists of transposition of the aorta to the right ventricle and malposition of the pulmonary artery with subpulmonary ventricular septal defect. History and etymology ...
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Technetium agents

Technetium agents based on the technetium-99m (Tc-99m) radioisotope are frequently used agents in medical imaging. The radioactive technetium radiotracer can be chelated to a number of different compounds to create specific radiopharmaceuticals and optimise the functional imaging of various stru...
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Temporary ventricular assist devices

Temporary ventricular assist devices (or temporary VADs) are temporary percutaneous devices used in supporting a failing heart in cardiogenic shock or perioperatively. Principle Temporary VADs consist of an inlet, outlet and impeller pump all housed within a catheter. Temporary VADs are insert...
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Tetralogy of Fallot

Tetralogy of Fallot (TOF) is the overall most common cyanotic congenital heart condition with many cases presenting after the newborn period. It has been classically characterised by the combination of ventricular septal defect (VSD), right ventricular outflow tract obstruction (RVOTO), overridi...
Article

Tetralogy of fallot (mnemonic)

A mnemonic for the underlying anatomic defects in tetralogy of Fallot is: PROVe Mnemonic P: pulmonary stenosis R: right ventricular hypertrophy O: overriding aorta V: ventricular septal defect
Article

Thallium-201 chloride

Thallium-201 chloride is a radiopharmaceutical used primarily in cardiac imaging. Characteristics photon energy: 80 keV physical half life: 73 hours biological half life rest: 3 minutes exercise: 30 seconds normal distribution: myocardium, skeletal muscle, GI tract, liver, kidneys excret...
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Third mogul sign

The third mogul sign can be seen on frontal chest radiograph in the presence of left atrial enlargement. It refers to an extra mogul or bump along the upper left cardiac silhouette just below the left main bronchus. The third mogul sign commonly represents the enlarged left atrial appendage, pa...
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Thoracic aorta

The thoracic aorta is the most superior division of the aorta and is divided into three sections: ascending aorta aortic arch descending aorta The thoracic aorta begins at the aortic valve, located obliquely just to the left of the midline at the level of the the third intercostal space. It ...
Article

Thrombolysis in myocardial infarction (TIMI) risk score

The thrombolysis in myocardial infarction (TIMI) risk score is a prognostic risk stratification system that categorises the risk of death and ischemic events in patients with unstable angina / NSTEMI and provides a basis for therapeutic decision making. It is thought to have potential to improve...
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Total anomalous pulmonary venous return

Total anomalous pulmonary venous return (TAPVR) is a cyanotic congenital heart anomaly with an abnormal drainage anatomy of the entire pulmonary venous system. This contrasts with partial anomalous pulmonary venous return (PAPVR) where only part of the pulmonary venous anatomy is abnormal. In T...
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Total repair of tetralogy of Fallot

Total repair of tetralogy of Fallot is a corrective surgical procedure that involves closure of the ventricular septal defect (VSD) and relief of right ventricular outflow tract (RVOT) obstruction. Procedure Most patients with tetralogy of Fallot (TOF) undergo elective surgical repair between ...
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Transcatheter aortic valve implantation (TAVI)

Transcatheter aortic valve implantation or replacement (TAVI/TAVR) is a technique to replace the aortic valve through a transvascular or transapical approach. Compared to traditional open aortic valve replacement with sternotomy and a heart-lung bypass machine, the TAVI technique is less invasiv...
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Transient ischaemic dilatation

Transient ischaemic dilatation (TID) is a paradoxical phenomenon seen in myocardial perfusion SPECT imaging.   With severe balanced coronary artery disease, myocardial ischaemia may result in apparent enlargement of the left ventricular cavity during stress. The cause of this is not entirely cl...
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Transposition of the great arteries

Transposition of the great arteries (TGA) is the most common cyanotic congenital cardiac anomaly presenting during the newborn period, with cyanosis in the first 24 hours of life. It accounts for up to 7% of all congenital cardiac anomalies 1  and can be assessed with echocardiography, gated car...
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Transverse pericardial sinus

The transverse pericardial sinus is the transverse communication between the left and right parts of the pericardial space proper behind the two outflow arteries of the heart.   Gross anatomy It is superior to the left atrium and posterior to the intrapericardial parts of the pulmonary trunk a...
Article

Traumatic aortic injury in the exam

Getting a film with traumatic aortic injury in the exam is one of the many exam set-pieces that can be prepared for.  This is one of the cases you should look and not speak for 10 seconds as there tends to be a lot of findings on the film of patients with a traumatic aortic injury. Description...
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Tricuspid atresia

Tricuspid atresia is a cyanotic congenital cardiac anomaly which is characterised by agenesis of the tricuspid valve and right ventricular inlet. There is almost always an obligatory intra-atrial connection through either an ASD or patent foramen ovale (PFO) in order for circulation to be comple...
Article

Tricuspid valve

The tricuspid valve is one of the four cardiac valves. It is the atrioventricular valve that allows blood to flow from the right atrium to the right ventricle. It opens during diastole and closes during systole. The valve has anterior, posterior and septal leaflets (cusps), the bases of which at...
Article

Tricuspid valve regurgitation

Tricuspid valve regurgitation, also known as tricuspid valve insufficiency or tricuspid valve incompetence, is a valvulopathy that describes leaking of the tricuspid valve during systole that causes blood to flow in the reverse direction from the right ventricle into the right atrium. Epidemiol...
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Tricuspid valve stenosis

Tricuspid valve stenosis is a valvulopathy that describes narrowing of the opening of the tricuspid valve between the right ventricle and the right atrium. Epidemiology MS is seen more commonly in women and in countries, generally developing nations, where rheumatic fever is common 1,2. Clini...
Article

Triple-rule-out CT

Triple-rule-out CT (TRO CT) angiography may be ordered in the setting of acute chest pain to examine the thoracic aorta and the coronary and pulmonary arteries. The protocol helps exclude life-threatening causes of acute chest pain, especially if atypical, or if alternative causes to acute coron...
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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Truncus arteriosus

Truncus arteriosus is a cyanotic congenital heart anomaly in which a single trunk supplies both the pulmonary and systemic circulation, instead of a separate aorta and a pulmonary trunk. It is usually classified as a conotruncal anomaly. It accounts for up to 2% of congenital cardiac anomalies ...
Article

Tuberous sclerosis

Tuberous sclerosis, also known as tuberous sclerosis complex or Bourneville disease, is a neurocutaneous disorder (phakomatosis) characterised by the development of multiple benign tumours of the embryonic ectoderm (e.g. skin, eyes, and nervous system). Epidemiology Tuberous sclerosis has an i...
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Tuberous sclerosis diagnostic criteria

The tuberous sclerosis diagnostic criteria have been developed to aid the diagnosis of tuberous sclerosis and have been adapted from Roach et al 1998 1: definitive TS complex: either 2 major features or 1 major and 2 minor probable TS complex: 1 major and 1 minor possible TS complex: either 1...
Article

Twiddler syndrome

Twiddler syndrome occurs when a patient manipulates (rotates) a subcutaneous chest device to the point of detaching and retracting the distal portion of the device. It is most commonly seen with implanted cardiac pacemakers or implantable cardiac defibrillators (ICDs). With continued rotation, ...
Article

Uhl anomaly

Uhl anomaly is an unusual cardiac disorder which affects the right ventricle where there is almost complete absence of right ventricular myocardium, normal tricuspid valve, and preserved septal and left ventricular myocardium. History and etymology It is named after Henry S D Uhl, who first de...
Article

Unifocalisation procedure

A unifocalisation procedure is a corrective surgical technique used in patients with complete pulmonary artery atresia with major aortopulmonary collateral arteries (MAPCAs). In this technique, the collateral vessels supplying blood from the aorta directly to the lungs are brought into continuit...
Article

Unilateral pulmonary vein atresia

Unilateral pulmonary vein atresia is a type of pulmonary vein atresia. Clinical presentation The condition usually present in infancy or childhood with recurrent episodes of pneumonia and/or haemoptysis. Presentation in adulthood does occur but is uncommon. Pathology It results from failure ...
Article

Unroofed coronary sinus

An unroofed coronary sinus is a rare variant of atrial septal defect (ASD). The atrial wall between the coronary sinus and left atrium is either partially or completely absent, resulting in a left-to-right shunt. It is associated with persistent left-sided SVC and heterotaxy syndromes. Clinica...
Article

Upper lobe pulmonary venous diversion

Upper lobe pulmonary venous diversion (cephalisation) reflects elevation of left atrial pressure and can occur with pulmonary oedema. It produces stag-antler's sign on a frontal chest x-ray. The normal left atrial pressure is 5-10 mmHg. An elevation of left atrial pressure to 10-15 mmHg will re...
Article

Vagoglossopharyngeal neuralgia

Vagoglossopharyngeal neuralgia is an uncommon presentation of glossopharyngeal neuralgia where the typical symptoms of pain are associated with cardiac symptoms including arrhythmias, asystole, and syncope. It is believed to be due to complex interconnections between the nervus intermedius, the...
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...
Article

Vein of Marshall

The vein of Marshall, oblique vein of Marshall or the oblique vein of the left atrium is a small vein that descends on and drains the posterior wall of the left atrium. It drains directly into the coronary sinus at the same end as the great cardiac vein, marking the origin of the sinus. It repr...
Article

Venae cordis minimae

The venae cordis minimae (smallest cardiac veins or thebesian veins) are a small group of valveless myocardial coronary veins within the walls of each of the 4 cardiac chambers that drain venous blood directly into each of the respective chambers. They are most frequent in the right atrium and t...
Article

Ventricular septal defect

Ventricular septal defects (VSD) represent defects in the interventricular septum that allow a haemodynamic communication between the right and left ventricles. It typically results in a left-to-right shunt. Epidemiology They represent one of the most common congenital cardiac anomalies and ma...
Article

Walking man sign (chest x-ray)

The walking man sign is seen on a lateral chest radiograph and is a sign of left atrial enlargement. It results from posterior displacement of the left main bronchus such that it no longer overlaps the right bronchus. The left and right bronchus thus appear as an inverted 'V', mimicking the legs...
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Watchman device

Watchman device is a permanent left atrial appendage closure device, which is percutaneously implanted to prevent embolisation of thrombus from the appendage into the systemic circulation in cases atrial fibrillation. It is used when there is contraindication to anticoagulation or high risk of l...
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Waterston shunt

A Waterston 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 ascending aorta and the right pulmonary artery. This does not relieve the right ventricular outflow obstruction, ...
Article

Wellens syndrome

Wellens syndrome (also referred to as LAD coronary T-wave syndrome) refers to a specific ECG abnormality in the precordial T-wave segment. It can be associated with a critical stenosis of the proximal left anterior descending artery.
Article

Wells criteria for pulmonary embolism

The Wells criteria for pulmonary embolism is a risk stratification score and clinical decision rule to estimate the probability for acute pulmonary embolism (PE) in patients in which history and examination suggests acute PE is a diagnostic possibility. It provides a pre-test probability which, ...
Article

Williams syndrome

Williams syndrome (WS) is characterised by some or all or the following features: craniofacial dysmorphism (e.g. elfin facies) oral abnormalities short stature (50% of cases) mild to moderate mental retardation supravalvular aortic stenosis 2 pulmonary artery stenosis 3 renal insufficienc...

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