Imaging Anatomy of the Heart
and Great Vessels
Reghard du Toit
Imaging modalities
• Chest radiograph: the plain CXR is widely used for the initial
assessment of the heart and great vessels.
• Angiography: Involves injection of contrast directly into the heart
chambers via a pigtail catheter usually introduced the femoral
artery for the left sided chambers and through the femoral vein for
the right sided chambers
• Coronary angiography: Involves selective catheterization of the
coronary arteries
• CT and MRI
• Nuclear medicine; Mainly for functional assessment of the heart (
not discussed)
• Echocardiography; Ultrasound allow both structural and functional
assessment but requires considerable expertise and is not discussed
in this presentation.
Gross anatomy and orientation of the
heart
• Lies obliquely in the chest.
• Left atrium forms the base or posterior part and the
superior and inferior pulmonary veins drain into its four
corners.
• Right atrium forms the right border and the SVC and IVC
drain into its upper and lower parts.
• The apex and left border are formed by the left ventricle
• The right ventricle forms the anterior part.
• The inferior (diaphragmatic) part of the heart is formed by
both the ventricles anteriorly and a small part of the right
atrium posteriorly where the IVC enters this chamber.
The Heart: Gross anatomy and
orientation
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Lies obliquely in the chest
Pyramidal in shape
Left atrium forms the base or posterior part
Right atrium forms the right heart border
Left ventricle forms the apex and left heart
border
• Right ventricle forms the anterior part
• Inferior or diaphragmatic part formed by both
ventricles anteriorly and a small part of the right
atrium posteriorly.
• The oblique orientation of
the heart causes the
ventricles to lie anterior
and inferior to the atria.
• Heart also clockwise
rotated about its axis
which cause the right
atrium and ventricle to be
at a slightly higher level
than the left.
• The interatrial and
interventricular septa lie
in a left anterior oblique
plane.
• The tricuspid and mitral
valves are roughly
vertically oriented.
Anatomy of the heart
Cardiac valves on CXR
• On PA views the valves lie close to a line from
the left atrium to the lowest point of the right
heart border.
• On a lateral view the pulmonary and aortic
valves lie just above and the mitral and tricus
valves just below a line drawn from T5 to the
apex of the heart.
Position of the cardiac valves on plain
radiography
Pericardium
• Closed sac consisting of
parietal and visceral layers that
is draped over the heart and
great vessels and enclose a
potential space which
contains 20-25ml of serous
fluid. ( 1-2 mm in diameter)
• Visceral layer adhered to
myocardium and is known as
the epicardium.
• Parietal layer only bound
inferiorly to central tendon of
diaphragm and superiorly
where it fuses with the
covering of the great vessels.
• Pericardial reflections
(basically the boundaries of
the closed sac) :
• 1. Oblique sinus; space
between the IVC and
pulmonary veins.
• 2. Transvers sinus; space
between the aorta and
pulmonary artery.
• The serous pericardial layers
extend anterosuperiorly over
the SVC and separately over
the aorta and pulmonary
artery.
• The pericardium extends
superiorly for 2-3cm over the
ascending aorta and over the
pulmonary artery almost to its
bifurcation.
• Some fat is present between the epicardium
and myocardium and this normally increases
with age.
• Fat is also present between the pericardium
and the mediastinal pleura and it may be
extensive in the anterior and lateral
cardiophrenic angles where it is know as the
pericardial fat pad.
Pericardial fat pad
Axial CT scan shows a large cardiophrenic fat
pad. Normal variant.
Cardiac chambers and valves
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Right atrium:
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Has a smooth posterior wall into
which the great veins drain.
The coronary sinus drains into the
posterior wall between the orifice of
the IVC and the tricuspid valve.
The interatrial septum bears an oval
depression, known as the fossa ovalis
which represents the closed foramen
ovale.
The right atrial appendage projects
anterosuperiorly and to the left and
is the only part of the right atrium to
contribute to the cardiac outline on
the lateral view.
The inner wall of the atrial
appendage is ridged by musculi
pectinati with a vertical ridge, the
crista terminalis.
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Right ventricle
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Normally in contact with the lower half of
the sternum on the lateral view.
The inner wall is coarsely trabeculated by
thick muscular bundles except for the
smooth muscular conus ( infundibulum) of
the ouflow tract.
The crista supraventricularis demarcates the
smooth conus from the trabeculated wall on
the septal aspect of the conus.
A muscular band, moderator band ,
tranverses the cavity carrying the right
bundle branch fibres. It crosses from the
lower ventricular septum to the anterior wall
joining the anterior papillary muscle.
The entrance to the right ventricle is the
tricuspid valve. This has three leaflets or
cusps each attached to papillary muscles by
the chordae tendineae.
The pulmonary valve has three semilunar
cusps, right and left anterior and posterior.
This is the most anterior and superior of all
the cardiac valves.
Left atrium
• Forms the upper and
posterior part of the
heart on lateral views.
• Receives four pulmonary
veins in its upper part.
• Has a long narrow,
trabeculated appendage
that projects anteriorly on
the left side of the
pulmonary trunk- only
seen on the frontal view
when enlarged.
Left ventricle
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Thick walled and elongated cone
shaped.
Forms the lower half of the posterior
part of the heart on the lateral view.
The mitral valves has two cusps and
separates the left ventricle from the
left atrium.
The free margins of the two cusps,
anterior and posterior, is attached to
the ventricular wall by chordae
tendineae.
Instead of a muscular conus as on the
right, the larger anterior cusp
separates inflow and outflow tracts
and blood flows over both its
surfaces.
The mitral and aortic valves are in
fibrous continuity.
• The aortic valve has
three semilunar cusps,
anterior and left and
right posterior.
• There is a localized
dilatation or sinus
above each cusp known
as the sinuses of
Valsalva.
• Ventricular septum
diameter 5-10mm.
• Myocardial thickness
10-12mm.
Papillary muscles and chordae
tendineae
Three chamber MPR shows left ventricular
papillary muscles and chordae tendineae
Coronal MPR shows LV papillary
muscles
The coronary arteries and veins
• Right coronary artery
arises from the anterior
sinus and is also known as
the right coronary sinus.
• Left coronary artery
arises from the left
posterior sinus and is also
known as the left
coronary sinus.
• No artery arises from the
right posterior sinus, also
know as the non-coronary
sinus.
Overview
Anterior
Right ant
oblique
Lateral
Right coronary artery
• The RCA supplies the right
ventricle and inferior wall of
the left ventricle.
• Arises from the anterior
coronary sinus of Valsalva
and passes between the
pulmonary trunk and right
atrium to decend in the
right atrioventricular groove
as the marginal artery.
• Anastomose with the left
coronary artery in the
region of the posterior
interventricular groove.
Branches
• 1. Conus artery to the pulmonary
outflow tract.
• 2. Atrial and ventricular branches.
• 3. Branch to SA node which
curves anticlockwise around the
SVC .
• 4. Acute marginal branches
supply the right ventricle.
• 5. Branch to AV node
• 6. Posterior interventricular
artery forms the terminal part of
the RCA and supplies the inferior
surface of the left ventricle and
posterior two-thirds of the
interventricular septum.
Left coronary artery
• Arises from the left
posterior sinus of Valsalva
and supplies the remainder
of the left ventricle.
• Bifurcates early into the left
circumflex artery and
anterior decending artery
• Left circumflex continues
laterally in the
atrioventricular groove to
anastomose with the RCA.
• LAD decends in the anterior
interventricular groove.
Branches of LAD
• 1. Septal branches
• 2. Diagonal branches
that run over the
anterolateral wall of the
left ventricle supplying
it.
• 3. Occasionally a branch
to the right ventricle.
Branches of the Left circumflex artery
• 1. Obtuse marginal branches
which supply the lateral wall of
the left ventricle.
• 2. Atrial branches.
• In general the RCA supplies the
right ventricle and the inferior
part of the left ventricle. The LCA
supplies the remainder of the left
ventricle.
• The intervetricular septum is
supplied by the LCA anteriorly
and the RCA posteriorly.
• The SA node is supplied by the
RCA in > 50 % and the AV node
>90% by the RCA.
Coronary dominance
• Is determined by the artery that supplies the PDA
and the posterolateral artery, in effect the artery
supplying the posterior and lateral wall of the left
ventricle.
• Right-dominant: RCA supplies both these arteries
( 60%)
• Left-dominant: Circumflex artery supplies both
these arteries. ( 15%)
• Co-dominant: RCA supplies the PDA and
circumflex artery supplying the posterolateral
artery. ( 25%)
Veins of the heart
• Venous drainage of the
heart mainly ( 60% ) via
veins that accompany the
coronary arteries and
which drains via the
coronary sinus.
• The coronary sinus lies in
the posterior
atrioventricular groove
and drains into the
posterior wall of the right
atrium to the left of the
orifice of the IVC.
Tributaries
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Great cardiac vein: ascends in the
anterior interventricular groove and
then runs to the left in the
atrioventricular groove to become
the coronary sinus.
Middle cardiac vein: ascends in the
posterior interventricular groove.
Small cardiac vein: accompanies the
marginal branches of the RCA, then
posteriorly in the right
atrioventricular groove to enter the
right side of the coronary sinus.
Left posterior ventricular vein:
accompanies the obtuse marginals of
the LCA and drain into the coronary
sinus.
Great vessels
Aorta
• Aortic root ( diameter of 3,7 cm with variation of
0,3 cm in diameter)
• First few centimetres from aorta valve to just
above the coronary sinuses.
• It lies at the level of the right third costal cartilage
anteriorly and T5 posteriorly
• The wall has three focal dilatations corresponding
to the three semilunar cusps of the aortic valve.
MPR Saggital view of thoracic aorta
Ascending aorta
• Continues superiorly, anteriorly and to the
right for approximately 5cm.
• Becomes aortic arch at the level of the
manubrial angle.
• Right ventricle is anterior and to the left,
pulmonary trunk to the left and the right
atrium and SVC to the right.
• Diameter 3,2cm with variation of 0,5 cm at
level of pulmonary trunk bifurcation.
Aortic arch
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Runs superiorly and posteriorly from right to left. ( 1,5 cm with variation of 1,2 cm in diameter)
At first anterior to the trachea and oesophagus and then over the pulmonary trunk and left main
bronchus to a position left of body of T4.
Pulmonary trunk bifurcates beneath the arch and the right pulmonary passes to the right of the
arch.
The left pulmonary artery is attached to the junction of the arch and descending aorta ( i.e.
isthmus) by the ligamentum arteriosum.
In the majority of people (65%) the major vessels arise from the arch in the following order:
1) Brachiocephalic artery
2) Left common carotid artery
3) Left subclavian artery
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The following arteries may also arise from the arch:
-one or both bronchial arteries
-thyroidea ima artery
-inferior thyroid artery
-internal thoracic artery
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Descending aorta
• Passes down the posterior mediastinum to the
aortic hiatus of the diaphragm at the vertebral
body of T12.
• Diameter 2,5cm with variation of 0,4 cm .
• Lies behind the left main stem bronchus,
pulmonary artery and left atrium.
• Right lung and pleura lie laterally.
• Vertebral column lies posteriorly and medially.
• Oesophagus lies antero-medially except in its
upper portion where it lies to the right.
Branches
• 1) Nine pairs of intercostal arteries
• 2) Bronchial arteries, the number and location of which are
variable.
• 3) Oesophageal branches; up to five arteries which form an
anastomotic plexus with branches of the inferior thyroid, inferior
phrenic and left gastric arteries.
• 4) Spinal arteries, up to three branches
• 5) Mediastinal branches
• 6) A pair of superior phrenic arteries
• 7) A pair of subcostal arteries
• The aorta is fixed within the thorax at certain anatomical points, the
aortic isthmus, aortic valve, the main aortic branches, the
intercostal vessels and the diaphragm.
Great Veins
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The SVC is formed by the right and
left brachiocephalic veins behind the
junction of the manubrium and the
first costal cartilage.
The SVC enters the right atrium at the
level of the right third costal
cartilage.
It lies to the right of the aortic arch
and anterior to the right main stem
bronchus.
The azygos vein arches over the right
main stem bronchus to drain into the
posterior aspect of the SVC.
SVC diameter 1,4 cm with variation of
0,4cm at level of aortic arch and 2cm
with variation of 0,4cm at pulmonary
trunk bifurcation.
• The brachiocephalic veins
are formed by the union of
the internal jugular and
subclavian veins behind the
medial end of either
clavicle.
• Both receive the internal
thoracic and inferior thyroid
veins, while the left sided
superior intercostal vein
and thymic vein also drains
into the left brachiocephalic
vein.
• The IVC runs a short course
of only a few centimetres in
the thorax and often makes
up the lowest portion of the
cardiac silhouette on the
right
Pulmonary arteries
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The pulmonary trunk bifurcates
beneath the aortic arch into right and
left main pulmonary arteries.
Pulmonary trunk diameter 2,4cm
with variation of 0,2cm.
The right pulmonary artery passes
under the arch in front of the right
main bronchus and behind the
ascending aorta and SVC.
Proximal right pulmonary artery
diameter 1,9cm with variation of
0,3cm.
It is crossed anteriorly by the right
superior pulmonary vein ( right hilar
point on frontal radiograph)
It divides into an upper and lower
branch before entering the lung
hilum.
• The left main pulmonary artery
passes to the left, initially in front
of the left main bronchus but
then curves superior to the
bronchus.
• Left pulmonary artery diameter
2,1cm with variation of 0,4 cm.
• The ligamentum arteriosum runs
posteriorly from the left
pulmonary artery to its
attachment at the aortic isthmus.
• The left main pulmonary artery is
shorter than the right and lies at
a higher position.
• The left pulmonary vein crosses
anteriorly, thus marking the left
hilar point which is 1cm higher
than the right.
Pulmonary Veins
• The pulmonary veins
enter the left atrium from
the posterolateral margin,
two from each lung.
• They usually converge on
the left atrium beneath
the level of the
pulmonary arteries.
• They may however
become confluent before
entering the left atrium.
References
• 1. Butler P, Mitchell AVM, Ellis H (1999) Applied Radiological Anatomy.
Cambridge University Press.
• 2. Netter FH Atlas of Human Anatomy, Saunders Elsevier.
• 3. Ryan S, McNicholas M, Eustace S (2011) Anatomy for Diagnostic
Radiology 3rd ed, Saunders Elsevier.
• 4. James Obrien, Manvedi B, Serichai E, Hecht D, Jacobs K: Anatomy of the
Heart at Multidetector CT; What the radiologist needs to know.
Radiographics November-December 2007 27: 1569-1582.
• 5. Hym Woo Goo, In-Sock Park, Jae-Kun Ko, Yong Hwue Kim, Dong-Mon
Seo : CT of Congenital Heart disease; Normal Anatomy and Typical
Pathologic Conditions. Radiographics October 2003 23: 147-165.
• 6. www.radiologyassistant.nl : Cardiac Anatomy from left to right by Tineke
Willems and Maricke Hazenwinkel.
• 7. www.radiologyassistant.nl : Coronary Anatomy and anomalies by Robin
Smithuis andTineke Willems.