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.

83 results found
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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 ...
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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...
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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 can also be a malignant course predisposing patients to life-threatening myocardial ischaemia or arrhythmias, depending on where the artery runs.  Clinica...
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Anterior cardiac veins

The anterior cardiac veins are a group of parallel coronary veins that course over the anterior surface of the right ventricle, draining it and entering directly into the right atrium. They may occasionally drain into the small cardiac vein. 
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Aortic annulus

The aortic annulus is a fibrous ring at the aortic orifice to the front and right of the atrioventricular aortic valve and is considered the transition point between the left ventricle and aortic root. The annulus is part of the fibrous skeleton of the heart. It is at the level of the sinus of V...
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Aortic isthmus

The aortic isthmus is the part of the aorta just distal to the origin of the left subclavian artery at the site of the ductus arteriosus. This portion of the aorta is partly constricted in the fetus because of the lack of flow within the aortic sac and ascending aorta. It marks the partial sepa...
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Aortic root

The aortic root is the first part of the aorta and connects the heart to the systemic circulation.  Gross anatomy The aortic root lies between the junction of the aortic valve and ascending aorta. It has several subparts 1: three aortic valve leaflets and leaflet attachments three aortic sin...
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Aortic valve

The aortic valve is one of the four cardiac valves. It is the semilunar valve that allows blood to exit the left ventricle. It opens during systole and closes during diastole. The valve has left, right and posterior cusps, the bases of which attach around the valve orifice to a fibrous ring or a...
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Bicuspid aortic valve

Bicuspid aortic valve (BAV) refers to a spectrum of deformed aortic valves with two functional leaflets or cusps which are often unequal in size. They are most often congenital while an acquired bicuspid valve occurs when there is fibrous fusion between the right and left cusps of a pre-existin...
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Cardiac fibrous skeleton

The fibrous skeleton of the heart is a complex set of collagenous rings that connect annuli of all four cardiac valves. Between the four annuli are two trigones (right and left) and the membranous portions of the interatrial, interventricular, and atrioventricular septa. The annuli of the two se...
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Cardiac plexus

The cardiac plexus is a plexus of nerves situated at the base of the heart. It is formed by cardiac branches derived from both the sympathetic and parasympathetic nervous systems. Gross anatomy Sympathetic cardiac nerves are derived from T1 to T4 segments and partly from the T5 segment of the ...
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Cardiac segmentation model

The American Heart Association (AHA) has published the nomenclature and segmentation of the left ventricular myocardium (the cardiac segmentation model), now widely used for the description of disease-affected myocardial territories and wall function. There are 17 segments that have a reasonabl...
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Cardiac valves

The four cardiac valves direct the flow of blood through the heart during the cardiac cycle. Gross anatomy The heart valves are located in the cardiac fibrous skeleton: two are atrioventricular (AV) valves: the right-sided tricuspid valve and left-sided mitral (bicuspid) valve open during di...
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Cavo-atrial junction

The superior cavo-atrial junction, generally referred to as simply the cavo-atrial junction (CAJ), is the junction of the right lateral border of the superior vena cava (SVC) and the superior border of the right atrium. It is an important landmark to recognise because it marks an optimum site f...
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Cervical aortic arch

Cervical aortic arch is a rare aortic arch anomaly characterised by an elongated, high-lying aortic arch extending at or above the level of the medial ends of the clavicles. Clinical presentation Patients with cervical aortic arch are usually asymptomatic. Symptomatic patients may present with...
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Chordae tendineae

The chordae tendineae are thin strong inelastic fibrous chords that extend from the free edge of the cusps of the atrioventricular valves (the tricuspid and mitral valves) to the apices of the papillary muscles within the right and left ventricles respectively.  They transmit the force of the co...
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Circumflex artery

The circumflex artery (Cx) is a major coronary artery that divides off the left main coronary artery (the other branch being the left anterior descending (LAD) artery). Terminology The circumflex artery is referred to by multiple terms: circumflex artery (Cx) ramus circumflex artery (RCx) l...
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Congenital coronary artery anomalies

Congenital coronary artery anomalies (CCAAs) are not common, found only in ~1% (range 0.1-2%) of patients 1,3.The most important finding to look for is the "malignant" course of anomalous coronary artery, namely, does the artery run between big pulsating objects - RVOT and pulmonary artery on on...
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Congenital pulmonary venolobar syndrome

Congenital pulmonary venolobar syndrome is a condition comprised of a rare group of cardiac and pulmonary congenital abnormalities occurring variably in combination. The abnormalities include: anomalous pulmonary venous drainage particularly scimitar syndrome with hypogenic right lung pulmona...
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Conus artery

The conus artery is a small early branch off the right coronary artery (RCA) circulation. Gross anatomy Supply The artery has a variable distribution, but usually supplies a region of the anterior interventricular septum and the conus of the main pulmonary artery (hence its name). Variant an...
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Coronary arterial dominance

Coronary arterial dominance is defined by the vessel which gives rise to the posterior descending artery (PDA), which supplies the myocardium of the inferior 1/3rd of the interventricular septum. Most hearts (80-85%) are right dominant where the PDA is supplied by the RCA. The remaining 15-20% ...
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Coronary arteries

The coronary arteries arise from the coronary sinuses immediately distal (superior) to the aortic valve and supply the myocardium with oxygenated blood. They branch and encircle the heart to cover its surface with a lacy network resembling perhaps a slightly crooked crown. Gross anatomy The ty...
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Coronary sinus

The coronary sinus is the major coronary vein. It returns the majority of the left ventricular blood flow to the right atrium. Gross anatomy The coronary sinus courses along the posterior wall of the left atrium into the left atrioventricular groove. It normally drains into the right atrium. T...
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Coronary veins

The coronary veins return deoxygenated blood from the myocardium back to the right atrium. Most venous blood returns via the coronary sinus. Coronary venous anatomy is highly variable, but is generally comprised of 3 groups of veins: cardiac veins which drain into the coronary sinus: great car...
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Coumadin ridge

A coumadin ridge, also called warfarin ridge or left lateral ridge, is a band-like embryological remnant in the left atrium between the left superior pulmonary vein and the left atrial appendage. It is considered an anatomical variant.  The ridge is formed by the coalition of the left superior ...
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Crista terminalis

The crista terminalis is a smooth muscular ridge in the superior aspect of right atrium. It represents the junction between the sinus venosus and the heart. It divides the pectinate muscle origin and the right atrial appendages in the right atrium. Its identification is significant in the deter...
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Determination of atrial situs

Atrial situs refers to the relative position of cardiac atria in relation to abdominal viscera and the midline. Pathology Identification of atrial situs is an important initial step in the antenatal and postnatal diagnosis of cardiac structural and situs anomalies. Radiographic features Basi...
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Diagonal branches of the left anterior descending artery

Diagonal branches of the left anterior descending coronary artery supply blood flow to the anterior and anterolateral walls of the left ventricle.
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Ductus arteriosus

The ductus arteriosum (or arteriosus) is the thick short conduit for blood to bypass the non-ventilated lungs in the fetus. It is located between and connects the proximal left pulmonary artery and the undersurface of the aortic arch distal to the origin of the last branch of the arch, at the ao...
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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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Eustachian valve

The Eustachian valve (also known as the "valve of the inferior vena cava") is a ridge of variable thickness in the inferior right atrium. It is a remnant of a fetal structure that directed incoming oxygenated blood to the foramen ovale and away from the right atrium.   Incomplete regression of ...
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Foramen ovale (cardiac)

The foramen ovale (or ovalis) is the opening in the interatrial septum in the fetal heart that allows blood to bypass the right ventricle and non-ventilated lungs, shunted from the right atrium to the left atrium. Specifically it represents the opening between the upper and lower portions of the...
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Fossa ovale

The fossa ovale (or ovalis) is the small oval depression in the interatrial septum at the site of the closed foramen ovale, which closes once fetal circulation ceases in the first few minutes of postnatal life. It represents the overlapping primary and secondary septa of the interatrial septum. ...
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Great cardiac vein

The great cardiac vein (GCV) runs in the anterior interventricular groove and drains the anterior aspect of the heart where it is the venous complement of the left anterior descending artery. It is the main tributary of the coronary sinus.  Gross anatomy It begins on the anterior surface of th...
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Heart

The heart is a hollow, muscular organ of the middle mediastinum, designed to pump oxygenated blood around the systemic circulation and de-oxygenated blood around the pulmonary circulation Gross anatomy The heart has a somewhat conical form and is enclosed by pericardium. It is positioned poste...
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Heart chambers

There are four heart chambers, the right atrium, left atrium, right ventricle and left ventricle. These receive blood from the body and lungs, and contract to transmit blood to the lungs for oxygenation and to the body for use in metabolism. It is best to list the four chambers in order of the ...
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Inferior aortic recess

The inferior aortic recess is one of the pericardial recesses forming a small space within the pericardium, which arises from the transverse pericardial sinus between the ascending aorta and the left atrium. It extends inferiorly to the level of the aortic valve. It may mimic mediastinal lympha...
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Inferior interventricular artery

The inferior interventricular artery (also known as the posterior interventricular artery or posterior descending artery, PDA) is an artery that extends along the inferior interventricular sulcus. The artery supplies the posterior third of the interventricular septum through posterior septal per...
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Inferior mediastinum

The inferior mediastinum is the box-shaped space in the mediastinum below the transthoracic plane of Ludwig between the wedge-shaped superior mediastinum above and the diaphragm and inferior thoracic aperture below. There are no physical structures that divide the superior and inferior mediastin...
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Innervation of the heart

The heart has extrinsic and intrinsic innervation, which allows the heart to continue beating if the nerve supply to the heart is disrupted (e.g. in cardiac transplant). The heart receives innervation from both the superficial and deep cardiac plexuses, which have both parasympathetic (from vag...
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Inter-arterial course of the left coronary artery

The inter-arterial course of the left coronary artery, also known as the malignant course of the left coronary artery, is defined as the origin of the left main or left anterior descending coronary artery from the right coronary sinus of Valsalva with a course between the ascending aorta and the...
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Inter-arterial course of the right coronary artery

Inter-arterial course of the right coronary artery (RCA), also known as a malignant variant, may occur if the right coronary artery has an aberrant origin from the the left coronary sinus. It is an uncommon anomaly with potential risk of cardiac ischaemia. When the right coronary artery arises ...
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Intra-atrial course of the right coronary artery

Intra-atrial course of the right coronary artery is an uncommon anatomic variation in the course of the right coronal artery, usually involving the mid and distal segments, where the vessel partially or completely courses through the right atrial chamber. It is usually asymptomatic and clinical...
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Kommerell diverticulum

Kommerell diverticula occur in some anomalies of the aortic arch system. It usually refers to the bulbous configuration of the origin of an aberrant left subclavian artery in the setting of a right-sided aortic arch. However, it was originally described as a diverticular outpouching at the origi...
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LCx and LAD arising separately from the left coronary sinus

One of the anatomical variants of coronary artery origin comprises the left circumflex coronary artery (LCx) and left anterior descending coronary artery (LAD) arising separately from the left coronary sinus. Hence there is no common left main coronary artery (LCA/LMCA). As there is no vascular...
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Left anterior descending artery

The left anterior descending (LAD) artery, also known as the anterior interventricular branch, is a branch of the left coronary artery.  Gross anatomy It can be divided into proximal, mid and distal segments and this helps to differentiate the names of its various small branches 1: origin: le...
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Left atrial appendage

The left atrial appendage (LAA) is a pouch-like projection from the main body of the left atrium lies in the atrioventricular sulcus in close proximity to the left circumflex artery, the left phrenic nerve, and the left pulmonary veins. Gross anatomy Morphological types Four main morphologica...
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Left atrium

The left atrium is one of the four chambers of the heart. It receives oxygenated blood from the pulmonary circulation that is then delivered to the left ventricle and then into the systemic circulation. Gross anatomy The left atrium is grossly cuboidal, and like the right atrium has an appenda...
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Left main coronary artery

The left main coronary artery (LMCA) or left coronary artery (LCA) is one of the two main arteries that supply the heart with oxygenated blood. Gross anatomy Origin It is a branch of the ascending aorta, with its normal origin in the left aortic sinus, just superior to the aortic valve 1-2. ...
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Left pulmonary venous recess

The left pulmonary venous recess is one of the pericardial recesses forming a small space within the pericardium. It arises from the pericardial cavity proper located between the right superior and inferior pulmonary veins, posterior to the left atrium. It invaginates towards the oblique pericar...
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Left pulmonic recess

The left pulmonic recess is one of the pericardial recesses forming a small space within the pericardium, which arises from the transverse pericardial sinus. It is located posterior to the pulmonary trunk and left pulmonary artery.  It may mimic mediastinal lymphadenopathy or a bronchogenic cyst.
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Left ventricle

The left ventricle is one of four heart chambers. It receives oxygenated blood from the left atrium and pumps it into the systemic circulation via the aorta. Gross anatomy The left ventricle is conical in shape with an anteroinferiorly projecting apex and is longer with thicker walls than the ...
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Middle cardiac vein

The middle cardiac vein or posterior interventricular vein is a vein of the heart which accompanies the posterior interventricular artery. It courses in the posterior interventricular groove and drains directly into the coronary sinus close to it’s termination. It drains the posterior wall of bo...
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Mitral valve

The mitral valve (or bicuspid valve) is one of the four cardiac valves. It is the atrioventricular valve that allows blood to flow from the left atrium to the left ventricle. It opens during diastole and closes during systole. The valve has anterior and posterior leaflets (cusps), the bases of w...
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Moderator band

The moderator band, also called the septomarginal trabecula, is a consistent structure in the morphologic right ventricle and can be helpful as a landmark in situations where the ventricles may be ambiguous (i.e. in some forms of congenital heart disease). The term "septomarginal" is descriptiv...
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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 bridging of the coronary arteries

Myocardial bridging is a common congenital anomaly of the coronary arteries where a coronary artery courses through the myocardium.  Epidemiology It is found approximately in 20-30% of the adult population in autopsy studies. Incidence in coronary angiograms is between 2-15%. Pathology Norma...
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Normal contours of the cardiomediastinum on chest radiography

A detailed understanding of the structures that make up the normal contours of the heart and mediastinum (cardiomediastinal contour) on chest radiography is essential if abnormalities are to be detected.  Frontal view (PA/AP) Right cardiomediastinal contour From superior to inferior: right p...
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Oblique pericardial sinus

The oblique pericardial sinus is a blind-ending pericardial cul-de-sac behind the heart which opens into the pericardial space proper inferiorly. Gross anatomy It's boundaries are: right (in ascending order): inferior vena cava, right inferior pulmonary vein and right superior pulmonary vein ...
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Papillary muscles

The papillary muscles are thick bands and ridges of endocardial-lined myocardium that project into the lumen of the cardiac ventricles. They essentially represent dominant ventricular trabeculae which attach to the cusps of the atrioventricular valves via the chordae tendineae. During systole, t...
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Patent foramen ovale

A patent foramen ovale (PFO) is a type of atrial septal defect in which there is channel-like communication between the atria through an unfused fossa ovale. Gross anatomy The foramen ovale in the interatrial septum normally develops into the fossa ovalis when the flaps of the atrial septa pri...
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Pectinate muscles

The pectinate muscles are "teeth of a comb" shaped parallel muscular columns that are present on the inner wall of the right and left atria. The right atrium has thick and coarse pectinate muscles while these are few smooth and thinner in the left atrium. History and etymology The term is der...
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Pericardial ligaments

The pericardial ligaments is a name given to a group of variable fibrous ligaments or adhesions that connect the pericardium to adjacent structures. These ‘ligaments’ tether the fibrous pericardium to it's surrounds, hence movements of the chest wall and diaphragm  influence the position of the ...
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Pericardial recesses

The pericardial recesses are small spaces in the pericardial cavity arising from the transverse pericardial sinus that are formed by the reflections of the pericardium. Pericardial fluid can pool in these recesses, mimicking mediastinal lymph nodes or pathology. There are several pericardial re...
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Pericardial space

The pericardial space or cavity is the fluid-filled space in between the parietal and visceral layers of the serous pericardium. In normal conditions it contains only a small amount of serous pericardial fluid, usually 15-20 mL. Related pathology A pericardial effusion is the pathological accu...
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Pericardium

The pericardium is a conical, flask-like, fibroserous sac which contains the heart and the roots of the great vessels and defines the middle mediastinum.  Gross anatomy The pericardium is made of two sacs in one. The outer sac is the fibrous pericardium and the inner sac is the double-layered ...
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Postcaval recess

The postcaval recess is one of the pericardial recesses forming a small space within the pericardium, which arises from the transverse pericardial sinus. It is located posterior to the superior vena cava and superior to the right superior pulmonary vein. It may mimic mediastinal lymphadenopathy...
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Posterior vein of the left ventricle

The posterior vein of the left ventricle is a vein of the heart which courses over the inferior wall of the left ventricle and drains into the coronary sinus to the left of where the middle cardiac vein drains into the sinus. It drains, not unsurprisingly, the inferior wall of the left ventricle.
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Pulmonary valve

The pulmonary valve is one of the four cardiac valves. It is the semilunar valve that allows blood to exit the right ventricle. It opens during systole and closes during diastole. The valve has anterior, left and right cusps, the bases of which attach around the valve orifice to a fibrous ring o...
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Right atrium

The right atrium (RA) is one of the four chambers of the human heart, and is the first chamber to receive deoxygenated blood returning from the body. It plays an important role in originating and regulating the conduction of the heart. Gross anatomy The right atrium receives deoxygenated from ...
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Right coronary artery

The right coronary artery (RCA) is one of the two main coronary arteries that supply the heart with oxygenated blood. Gross anatomy Origin It is a branch of the ascending aorta, with its normal origin in the right aortic sinus, just superior to the aortic valve Course The RCA courses to th...
Article

Right pulmonary venous recess

The right pulmonary venous recess is one of the pericardial recesses forming a small space within the pericardium. It arises from the pericardial cavity proper located between the right superior and inferior pulmonary veins, posterior to the left atrium. It invaginates towards the oblique perica...
Article

Right pulmonic recess

The right pulmonic recess is one of the pericardial recesses forming a small space within the pericardium, which arises from the transverse pericardial sinus. It is located posterior to the right pulmonary artery and anterior to the oesophagus. It may mimic mediastinal lymphadenopathy or a bron...
Article

Right ventricle

The right ventricle is the most anterior of the 4 heart chambers. It receives deoxygenated blood from the right atrium and pumps it into the pulmonary circulation. Blood enters the right ventricle through the atrioventricular orifice containing the tricuspid valve during diastole and in systole ...
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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...
Article

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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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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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

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

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

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...
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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...

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