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Kini et al.
CT Angiography of
Coronary Arterial and
Venous Anatomy
Normal and Variant Coronary
Arterial and Venous Anatomy on
High-Resolution CT Angiography
Sunil Kini1, 2
Kostaki G. Bis2
Leroy Weaver2, 3
OBJECTIVE. This article displays the normal and variant anatomy of the coronary arteries
and subjacent cardiac veins using a high-resolution 64-MDCT scanner.
CONCLUSION. Knowledge of the anatomy of the coronary arteries and subjacent cardiac veins as displayed with maximum intensity and volume-rendered projections is important
for correct image interpretation of coronary CT angiography examinations.
Kini S, Bis KG, Weaver L
ontrast-enhanced CT angiography
(CTA) of the coronary arteries is
becoming feasible as temporal and
spatial resolution improves with
the availability of MDCT. Detection, characterization, and quantification of coronary artery disease and elegant delineation of coronary anatomy are possible using 2D
multiplanar reformation (MPR), 3D maximum-intensity-projection (MIP), and 3D volume-rendered postprocessing techniques. Familiarity with coronary artery and venous
anatomy and anatomic variants is important for
correct image interpretation. This anatomy and
the arterial variants have been well described
using conventional angiographic techniques
[1, 2]. However, the cross-sectional nature of
CT has the benefit of more precisely displaying the spatial relationships of coronary arterial
and venous anatomy with respect to cardiac
structures. This article highlights this anatomy
with a variety of MIP and volume-rendered
techniques (Figs. 1–18).
C
Keywords: anatomy, anomalies, arteriography, cardiac
imaging, coronary arteries, CT angiography, heart, MDCT
DOI:10.2214/AJR.06.1295
Received September 30, 2006; accepted after revision
January 15, 2007.
1Present address: Quantum Medical
Radiology, Atlanta,
GA 30339.
Subjects and Methods
2Department
of Diagnostic Radiology, William Beaumont
Hospital, 3601 W 13 Mile Rd., Royal Oak, MI 48073. Address
correspondence to K. G. Bis ([email protected]).
3Present address: Elkhart
General Healthcare System,
Elkhart, IN 46514.
CME
This article is available for CME credit. See www.arrs.org
for more information.
AJR 2007; 188:1665–1674
0361–803X/07/1886–1665
© American Roentgen Ray Society
AJR:188, June 2007
Coronary CTA protocols usually image the heart
using cranial-to-caudal acquisition [3]. However,
caudal-to-cranial scanning acquisitions are implemented when concomitant imaging of the pulmonary arteries is desired in patients with atypical
chest pain [4]. We describe both of these protocols
because the cardiac venous anatomy may be displayed with variation in enhancement depending on
the type of data acquisition.
The patients who participated in our study were
imaged after the institutional review board had approved the study, which complies with the Health Insurance Portability and Accountability Act, and after
they had provided written informed consent. Patients
were recruited from October 2004 to June 2005.
Imaging was performed on a 64-slice (32-detector) MDCT scanner (Sensation Cardiac 64, Siemens Medical Solutions) after the patient was premedicated with oral atenolol (50–100 mg), IV
metoprolol (5- to 10-mg boluses, up to 50 mg), or
both. An upper extremity 20-gauge IV catheter was
used for venous access. Sublingual nitroglycerin
(0.4 mg) was provided to induce coronary vasodilatation. Bolus timing was measured in the mid ascending aorta with 20 mL of iodixanol (320
mgI/mL [Visipaque, GE Healthcare]) administered
at a rate of 5 mL/s followed by a 50-mL saline flush,
also administered at a rate of 5 mL/s). Alternatively,
bolus tracking can be used to trigger data acquisition by placing a region of interest over the mid ascending aorta and setting the trigger threshold to
160 H above baseline.
Single-sector reconstructions of the coronary arteries were performed at 65% and 35% of the R-R length
and were then modified to a different phase start if
there were motion artifacts. Reconstructions were performed on a workstation (Wizard, Siemens Medical
Solutions) and then transferred to another workstation
(TeraRecon, TeraRecon) for MPRs and MIPs.
Cases were selected to show the normal coronary
arterial and venous anatomy. MIPs were obtained using various thicknesses (5–30 mm) and were displayed using standard orientations (right anterior oblique, left anterior oblique, axial) with or without
caudal or cranial angulation. Volume-rendered images were also obtained using various orientations.
Cranial-to-Caudal Acquisition
Coronary CTA was performed 5 seconds after
aortic peak density; 100 mL of iodixanol (Visipaque) was administered at 5 mL/s and was fol-
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Kini et al.
lowed by a 50-mL saline flush at 5 mL/s [3]. Retrospective ECG-gating was used with the following
parameters: collimation, 0.6 mm; tube rotation
time, 0.33 seconds; tube voltage, 120 mV; effective
mAs, 750–850; pitch, 0.2; and scanning time,
10–12 seconds.
Scanning coverage was from the level of the carina to the bottom of the heart. Reconstruction field of
view, slice thickness and reconstruction increment,
and smooth kernel were as follows: 15–22 cm; 0.6
and 0.3 mm, respectively; and B25f. ECG pulsing is
usually implemented for tube current modulation
and is needed to reduce radiation exposure [5].
Caudal-to-Cranial Acquisition
For the caudal-to-cranial acquisition, a patient
preparation and scanning protocol similar to that
described in the previous section was used. However, contrast injection was performed with a
higher volume of contrast material using a biphasic
protocol: 100 mL of iodixanol was administered at
5 mL/s followed by 30 mL of iodixanol at 3.0 mL/s
and then a 50-mL saline flush at 3 mL/s. The additional volume of contrast material resulted in a prolonged time for contrast injection to ensure adequate enhancement of the pulmonary arteries [4].
As a result, streak artifacts arising from the superior
vena cava and right atrium were present in 37
(88%) of 42 studies; however, these artifacts interfered with the visualization of the right coronary artery (RCA) in only one (2.4%) of the 42 cases [4].
The thorax from the lung bases to just above
(1–2 cm) the aortic arch was scanned with a 12- to
15-second acquisition (no ECG pulsing), but scanning can include the entire thorax when ECG pulsing is applied. As with cranial-to-caudal acquisitions, ECG pulsing is needed to reduce radiation
exposure [5]. Reconstruction field of view, slice
thickness and reconstruction increment, and kernel
for the coronary arteries were similar to those for
the cranial-to-caudal acquisition. However, reconstructions were also obtained with a larger field of
view [4] to display the pulmonary arteries, thoracic
aorta, lungs, and thoracic soft tissues.
Normal Anatomy of the
Coronary Arteries
The right and left coronary arteries originate from the right and left sinuses of Valsalva
of the aortic root, respectively. The posterior
sinus rarely gives rise to a coronary artery and
is referred to as the “noncoronary sinus.” The
locations of the sinuses are anatomic misnomers: The right sinus is actually anterior in location and the left sinus is posterior. The myocardial distribution of the coronary arteries
is somewhat variable, but the right coronary
artery (RCA) almost always supplies the right
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ventricle (RV), and the left coronary artery
(LCA) supplies the anterior portion of the
ventricular septum and anterior wall of the
left ventricle (LV). The vessels that supply the
remainder of the LV vary depending on the
coronary dominance, which we explain later.
RCA Anatomy
The RCA arises from the right coronary sinus somewhat inferior to the origin of the
LCA. After its origin from the aorta, the RCA
passes to the right of and posterior to the pulmonary artery and then emerges from under
the right atrial appendage to travel in the anterior (right) atrioventricular (AV) groove
(Figs. 1 and 2). In about half of the cases, the
conus branch is the first branch of the RCA
(Fig. 3). In the other half, the conus branch has
an origin that is separate from the aorta. The
conus branch always courses anteriorly to supply the pulmonary outflow tract. Occasionally,
the conus branch can be a branch of the LCA
(Fig. 3D), have a common origin with the
RCA, or have dual or multiple branches.
In 55% of cases, the sinoatrial nodal artery
(Figs. 3C, 3D, and 4A) is the next branch of
the RCA, arising within a few millimeters of
the RCA origin. In the remaining 45% of
cases, the sinoatrial nodal artery arises from
the proximal left circumflex (LCx) artery
(Figs. 4B and 11). In either case, the sinoatrial
nodal artery always courses toward the superior vena cava inflow near the cephalad aspect
of the interatrial septum. As the RCA travels
within the anterior AV groove, it courses
downward toward the posterior (inferior) interventricular septum. As it does this, the
RCA gives off branches that supply the RV
myocardium; these branches are called “RV
marginals” or “acute marginals” (Fig. 5).
They supply the RV anterior wall. After it
gives off the RV marginals, the RCA continues around the perimeter of the right heart in
the anterior AV groove and courses toward the
diaphragmatic aspect of the heart.
Coronary Dominance
The artery that supplies the posterior descending artery (PDA) and the posterolateral
branch determines the coronary dominance. If
the PDA and PLB arise from the RCA, then the
system is said to be right dominant (80–85% of
cases) (Figs. 6 and 7). In this instance, the
RCA supplies the inferoseptal and inferior segments of the LV [6]. If the PDA and PLB arise
from the LCx artery, then the system is said to
be left dominant (15–20% of cases) (Figs. 8
and 17). In this instance, the LCA supplies the
inferoseptal and inferior segments of the LV. If
the PDA comes from the RCA and the PLB
comes from the LCx artery, the system is
codominant (about 5% of cases) (Fig. 9).
In left-dominant and codominant systems,
the LCx artery continues in the posterior AV
groove as the left AV groove artery and gives
rise to left PLB. In left dominance, the PDA is
the final branch of the AV groove artery. The
distal RCA divides into the PDA and PLB in
a right-dominant system. The nondominant
system is usually noticeably smaller in caliber
than the dominant system. This difference in
caliber can be used as an additional clue to determine whether the coronary anatomy is
right or left dominant. Usually arising just
distal to the origin of the PDA, the AV nodal
artery (Fig. 6) can be recognized by its direct
vertical course off of the distal RCA. In cases
of left dominance, the AV node branch has a
similar appearance and location, but it arises
just proximal to the (left) PDA.
LCA Anatomy
The LCA normally emerges from the left
coronary sinus as the left main (LM) coronary
artery (Fig. 10). The LM coronary artery is
short (5–10 mm), passes to the left of and posterior to the pulmonary trunk, and bifurcates
into the left anterior descending (LAD) and
LCx arteries (Fig. 11). Occasionally, the LM
coronary artery trifurcates into the LAD artery, the LCx artery, and the ramus intermedius artery (Fig. 12).
Ramus Intermedius Artery
The most common variation in LCA anatomy is the presence of a trifurcation of the LM
coronary artery. In this instance, the LM coronary artery trifurcates into the LAD artery, LCx
arteries, and an artery between them called the
“ramus intermedius” artery (Fig. 12). The ramus intermedius artery itself has variable
branching. The ramus intermedius can be distributed as a diagonal branch or as an obtuse
marginal branch depending on whether it supplies the anterior or the lateral wall, respectively.
LAD Artery
The LAD artery (Fig. 13) runs in the anterior interventricular sulcus along the ventricular septum. Commonly, the LAD artery may be
embedded within the anterior myocardium
forming an overlying myocardial bridge
(Fig. 14). Myocardial bridging is seen more often on CT than described in the coronary angiography literature. Most myocardial bridges
are asymptomatic, although rarely myocardial
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CT Angiography of Coronary Arterial and Venous Anatomy
bridging can be associated with ischemia. The
LAD artery has branches called “septal perforators” (Fig. 14) that supply the anterior ventricular septum. It also has diagonal arteries
(Fig. 15) that course over and supply the anterior wall of the LV. The diagonals and septal
perforators are numbered sequentially from
proximal to distal (i.e., D1, D2, S1, S2).
LCx Artery
The LCx artery (Figs. 16, 17, and 2, 4B, 8,
11, 12, 15) runs in the posterior AV groove analogous to the course of the RCA on the opposite
side. The major branches of the LCx artery consist of obtuse marginals (OMs) (Figs. 16 and
17). OM branches supply the lateral wall of the
LV. They are numbered sequentially from proximal to distal (i.e., OM1, OM2, OM3).
Anomalies of RCA Origin
The RCA can have an anomalous origin. It
is important to be aware of this possibility to
avoid misinterpreting coronary CTA. Typically, the anomalous origin of the RCA is
from the left coronary sinus of Valsalva, with
a subsequent course between the aortic root
and right ventricular outflow tract. Depiction
of these anomalies is beyond the scope of this
article; however, this and other anomalies of
RCA origin are described by Kim et al. [7].
An example of an anomalous origin of the
RCA is shown in Figure 18.
Anomalies of LCA Origin
The LCA and its branches can have an
anomalous origin. It is important to be aware
of this possibility to avoid misinterpreting
coronary CTA. Some of these anomalies are
associated with an increased risk of sudden
death or cardiac arrest (Fig. 18C). Depiction
of these anomalies is beyond the scope of this
article; however, anomalies of LM, LAD, and
LCx origin are reviewed by Kim et al. [7].
Coronary Venous Anatomy
The great cardiac vein (Figs. 4B and
16A) is located in the anterior interventricular sulcus, alongside the LAD artery. It
courses upward from the apex and drains
into the coronary sinus. The middle cardiac
AJR:188, June 2007
vein (Figs. 7A and 7C) also begins at the
apex, but it courses upward in the inferior
interventricular sulcus, alongside the PDA.
Between the two, there is a variable posterolateral vein (Fig. 7C) draining the lateral
wall of the LV. The coronary sinus
(Figs. 7A, 7C, 16A, and 16B) is the wide
vein that courses in the posterior AV groove
accompanying the LCx artery and the AV
groove artery. It drains into the right atrium
and receives the great cardiac vein proximally and the middle cardiac vein distally.
ginal and travels along or close to the posterior AV groove.
Conclusion
Coronary CTA is emerging as an essential
imaging tool for evaluating the coronary arteries. Knowledge of the CT appearance of
the coronary anatomy and various coronary
artery anomalies is essential for accurate diagnosis and proper patient treatment.
References
Reporting System of
Coronary Artery Disease
In an attempt to standardize the reporting
of coronary artery disease, an ad hoc committee of the American Heart Association developed nomenclature and further divided the
main coronary arteries into proximal, middle,
and distal segments [8].
The proximal RCA segment is from the
ostium to one half the distance to the acute
margin of the heart. The middle RCA segment is the RCA from the end of the above
segment to the acute margin of heart. The
distal RCA segment is the RCA running
along the right AV groove from the acute
margin to the origin of the PDA.
The LAD proximal segment is proximal
to and includes the origin of the first major
septal perforator. The middle LAD segment
is the LAD artery immediately distal to the
origin of the first major septal perforator
that extends to the point where the LAD artery forms an angle (right anterior oblique
view). This angle is often, but not always,
close to the origin of the second diagonal. If
this angle or diagonal is not identifiable, this
segment ends one half the distance from the
first major septal perforator to the apex. The
apical LAD segment is the terminal portion
of the LAD artery that begins at the end of
the previous segment and extends to or beyond the apex.
The proximal LCx segment is the mainstem of the LCx artery from its origin off the
LCA to and including the origin of an obtuse
marginal. The distal LCx segment is the LCx
artery distal to the origin of the obtuse mar-
1. Green CE. Coronary cinematography. Philadelphia, PA: Lippincott-Raven, 1996
2. Soto B, Russell RO, Moraski RE. Radiography
anatomy of the coronary arteries: an atlas. Mount
Kisco, NY: Fitura Publishing, 1976
3. Raff GL, Gallagher MJ, O’Neil WW, Goldstein JA.
Diagnostic accuracy of noninvasive coronary angiography using 64-slice computed tomography. J
Am Coll Cardiol 2005; 46:552–557
4. Vrachliotis TG, Bis KG, Hardary A, et al. Enhancement of coronary, aortic and pulmonary vasculature
using biphasic single-injection 64-slice CT: angiography protocol in emergency department patients
with atypical chest pain. Radiology (forthcoming,
May 2007)
5. Jakobs TF, Becker CR, Ohnesorge B, et al. Multislice helical CT of the heart with retrospective
ECG gating: reduction of radiation exposure by
ECG-controlled tube current modulation. Eur
Radiol 2002; 12:1081–1086
6. Cerqueira MD, Weisman NJ, Dilsizian V, et al.
Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart. A
statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical
Cardiology of the American Heart Association.
Circulation 2002; 105:539–547
7. Kim SY, Seo JB, Do KH, et al. Coronary artery
anomalies: classification and ECG-gated multi-detector row CT findings with angiographic correlation. RadioGraphics 2006; 26:317–334
8. Austen WG, Edwards JE, Frye RL, et al. A reporting system on patients evaluated for coronary artery
disease: Report of the Ad Hoc Committee for Grading of Coronary Artery Disease, Council on Cardiovascular Surgery, American Heart Association.
Circulation 1975; 51[suppl 4]:5–40
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Kini et al.
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Fig. 1—Anterior schematic diagram of heart shows course of dominant right
coronary artery and its tributaries. AV = atrioventricular, PDA = posterior
descending artery, RCA = right coronary artery, RV = right ventricular,
SA = sinoatrial.
A
B
Fig. 2—CT images of normal heart in 53-year-old man.
Ao = aortic root, CS = coronary sinus, LA = left atrium,
LAD = left anterior descending artery, LCx = left
circumflex artery, LM = left main coronary artery,
LV = left ventricle, PDA = posterior descending artery,
RA = right atrium, RCA = right coronary artery, RV = right
ventricle, RVOT = right ventricular outflow tract.
A, Axial 5-mm maximum-intensity-projection (MIP)
image shows left main coronary artery as it arises from
left coronary cusp.
B, Axial 5-mm MIP image shows right coronary artery
as it arises from right coronary cusp inferior to level of
beginning of left main coronary artery.
C, Axial 5-mm MIP image shows course of right
coronary artery within anterior atrioventricular groove.
Left anterior descending artery is shown within
anterior interventricular groove, and left circumflex
artery is shown in posterior atrioventricular groove.
D, Axial 5-mm MIP image shows origin of posterior
descending artery from distal right coronary artery.
C
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D
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Fig. 3—Conus branch anatomy variations. Ao = aortic
root, LA = left atrium, LAD = left anterior descending
artery, LM = left main coronary artery, LV = left
ventricle, RA = right atrium, RCA = right coronary
artery, RVOT = right ventricular outflow tract,
SAN = sinoatrial node branch.
A, Left anterior oblique 5-mm maximum-intensityprojection (MIP) image shows conus branch (arrow) in
44-year-old woman as it arises separate from right
coronary artery off of right coronary cusp.
B, Left anterior oblique 15-mm MIP image shows
common origin of conus branch (arrow) and right
coronary artery in 40-year-old man.
C, Axial 10-mm MIP image shows conus branch
(arrow) arising from proximal RCA in 52-year-old man.
It then courses anteriorly toward right ventricular
outflow tract.
D, Axial 10-mm MIP image shows conus branch
(arrow) arising from left anterior descending artery in
46-year-old man.
A
B
C
D
Fig. 4—Sinoatrial node branch variations. Ao = aortic
root, D1 = first diagonal, GCV = great cardiac vein,
LA = left atrium, LAD = left anterior descending artery,
LCx = left circumflex artery, LM = left main coronary
artery, OM1 = first obtuse marginal, RCA = right
coronary artery, RVOT = right ventricular outflow tract,
SVC = superior vena cava.
A, Axial 10-mm maximum-intensity-projection (MIP)
image in 64-year-old man shows large sinoatrial node
branch (arrow) as it arises from proximal right
coronary artery. It then courses posteriorly toward
cephalad aspect of interatrial septum (arrowheads)
posterior to inflow of superior vena cava.
B, Axial 10-mm MIP image shows sinoatrial node
branch (arrow) in 65-year-old woman as it arises from
proximal left circumflex artery: Sinoatrial branch still
courses toward cephalad aspect of interatrial septum.
A
AJR:188, June 2007
B
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Kini et al.
A
B
Fig. 5—Marginal branch anatomy. F = foot, LAD = left anterior descending artery, LV = left ventricle, RCA = right
coronary artery, RV = right ventricle.
A, Right anterior oblique 10-mm maximum-intensity-projection (MIP) image shows large marginal branch (arrow)
arising from right coronary artery (RCA) in 40-year-old woman.
B, Right anterior oblique volume-rendered image shows marginal branch (arrow) of RCA as it courses over right
ventricle in 45-year-old woman.
A
B
Fig. 6—Distal right coronary artery anatomy in 34-yearold man. Left anterior oblique 20-mm maximumintensity-projection image shows course of entire right
coronary artery. Distally, posterior descending artery
and posterior lateral branch are shown, as is
atrioventricular node branch. Ao = aortic root,
AVN = atrioventricular node, IMB = inferior marginal
branch, LCx = left circumflex artery, LV = left ventricle,
PDA = posterior descending artery, PLB = posterior
lateral branch, RCA = right coronary artery,
RVOT = right ventricular outflow tract.
C
Fig. 7—Distal dominant right coronary artery variation on axial projections. CS = coronary sinus, LV = left ventricle, MCV = middle cardiac vein, PDA = posterior descending
artery, PLB = posterior lateral branch, PLV = posterolateral vein, RA = right atrium, RCA = right coronary artery, RV = right ventricle.
A, Axial 10-mm maximum-intensity-projection (MIP) image in 51-year-old man shows typical tortuous course of posterior descending artery as it arises from distal right
coronary artery. Posterior descending artery travels in inferior interventricular groove along side middle cardiac vein. Posterior lateral branch continues along distal coronary
sinus to supply inferior wall.
B, Axial 10-mm MIP image shows dual posterior descending arteries and dual posterior lateral branches in 44-year-old man.
C, Axial 3D volume-rendered projection image shows origin of posterior descending artery, which still courses toward middle cardiac vein, is higher than normal in 49-yearold woman.
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CT Angiography of Coronary Arterial and Venous Anatomy
A
B
C
Fig. 8—Dominant left circumflex artery and posterior descending artery anatomy. Ao = aortic root, AVGA = atrioventricular groove artery, CS = coronary sinus, LA = left
atrium, OM = obtuse marginal, PDA = posterior descending artery, PLB = posterior lateral branch, RA = right atrium, RCA = right coronary artery.
A and B, Left anterior oblique 10-mm maximum-intensity-projection (MIP) images show two examples of dominant left circumflex artery anatomy with typical small nature
of right coronary artery: one in 43-year-old woman (A) and one in 44-year-old man (B). Atrioventricular groove artery descends as larger-caliber artery in posterior
atrioventricular groove subjacent to coronary sinus.
C, Axial 10-mm MIP image shows dual posterior descending arteries as they arise from distal atrioventricular groove artery in 44-year-old man with dominant left circumflex artery.
Fig. 9—Codominance. Axial 10-mm maximumintensity-projection image reveals codominant
anatomy in which posterior descending artery arises
from right coronary artery and posterior lateral branch
arises from distal left circumflex artery in 33-year-old
man. LV = left ventricle, PDA = posterior descending
artery, PLB = posterior lateral branch, RCA = right
coronary artery, RV = right ventricle.
AJR:188, June 2007
Fig. 10—Dominant left
coronary artery anatomy.
Left anterior oblique
schematic diagram of
dominant left coronary
artery anatomy, including
left anterior descending
artery and left circumflex
artery tributaries,
is shown. AVGA =
atrioventricular groove
artery, PDA = posterior
descending artery.
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Kini et al.
Fig. 11—Left main coronary artery bifurcation. Anterior
caudal 10-mm maximum-intensity-projection image
displays typical bifurcation of left main coronary artery
into left anterior descending and left circumflex
arteries in 47-year-old man. AVGA = atrioventricular
groove artery, D1 = first diagonal, LAD = left anterior
descending artery, LCx = left circumflex artery,
LM = left main coronary artery, OM1 = first obtuse
marginal, SAN = sinoatrial node branch.
A
B
C
Fig. 12—Ramus intermedius anatomy. LAD = left anterior descending artery, LCx = left circumflex artery, LM = left main coronary artery, RI = ramus intermedius artery.
A, Right anterior oblique caudal 10-mm maximum-intensity-projection (MIP) image displays trifurcation of left main coronary artery into left anterior descending artery, ramus
intermedius artery, and left circumflex artery in 49-year-old man.
B, Axial 10-mm MIP image shows left main coronary artery dividing into left anterior descending artery, left circumflex artery, and ramus intermedius branches in 42-yearold woman.
C, Left posterior cranial 3D volume-rendered projection image shows branching ramus intermedius artery, which is mostly distributed as obtuse marginal branch to lateral
wall, in 52-year-old man.
Fig. 13—Left anterior descending artery course. Right
anterior oblique 10-mm maximum-intensity-projection
image reveals entire course of left anterior descending
artery within anterior interventricular groove in 44year-old woman. Distally, it is seen wrapping around
left ventricular apex (arrows). LA = left atrium,
LV = left ventricle.
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Fig. 14—Myocardial bridge and septal perforator
branch anatomy in 39-year-old woman. LA = left
atrium, LAA = left atrial appendage, LV = left ventricle,
S1, S2, S3 = first, second, and third septal perforators.
A, Right anterior oblique 10-mm maximum-intensityprojection (MIP) image displays left anterior
descending artery and septal perforator branches.
Myocardial bridge overlies left anterior descending
artery just beyond second septal perforator (arrows).
B, Short-axis (left anterior oblique) 5-mm MIP image at
level of myocardial bridge shows left anterior
descending artery (arrow) deep to right ventricular
myocardium junction with left ventricle.
A
B
Fig. 15—Diagonal branch anatomy. D1 = first diagonal,
D2 = second diagonal, LAD = left anterior descending
artery, LCx = left circumflex artery, LM = left main
coronary artery, LV = left ventricle, RI = ramus
intermedius artery, SP = septal perforator branches.
A, Axial caudal oblique 10-mm maximum-intensityprojection (MIP) image reveals two diagonal branches
(D1 and D2) from left anterior descending artery in 55year-old man. Diagonal branches course laterally, and
small septal perforator branches course medially.
B, Cranial left anterior oblique 10-mm MIP image
shows left anterior descending artery and two
diagonal branches in 47-year-old man.
A
B
Fig. 16—Nondominant left circumflex artery anatomy
in 36-year-old man. AVGA = atrioventricular groove
artery, CS = coronary sinus, D1 = first diagonal,
GCV = great cardiac vein, LAD = left anterior
descending artery, LCx = left circumflex artery,
OM1 = first obtuse marginal.
A, Axial 10-mm maximum-intensity-projection (MIP)
image shows left circumflex artery and left anterior
descending artery with large first obtuse marginal
arising from proximal left circumflex artery. Small left
circumflex artery descends in posterior atrioventricular
groove as atrioventricular groove artery.
B, Left anterior oblique 10-mm MIP image displays left
circumflex artery anatomy with its descent as
atrioventricular groove artery.
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Kini et al.
Fig. 17—Dominant left circumflex artery anatomy in
44-year-old man. AVGA = atrioventricular groove
artery, LCx = left circumflex artery, LM = left main
coronary artery, OM1 = first obtuse marginal,
OM2 = second obtuse marginal, PDA = posterior
descending artery, PLB = posterior lateral branch,
RI = ramus intermedius artery.
A, Left anterior oblique cranial 3D volume-rendered
image shows dominant left circumflex artery anatomy
with two obtuse marginal branches.
B, Axial 3D volume-rendered image reveals dual
posterior descending artery and posterior lateral branch
arising from distal atrioventricular groove artery.
A
B
A
B
C
Fig. 18—Anomalous origin of right coronary artery and left main coronary artery. Ao = aortic root, LAD = left anterior descending artery, LM = left main coronary artery,
RCA = right coronary artery, RVOT = right ventricular outflow tract.
A, Axial 5-mm maximum-intensity-projection (MIP) image shows anomalous origin of right coronary artery in 43-year-old woman from anterior proximal ascending aorta with
subsequent acute rightward course before reaching anterior atrioventricular groove.
B, Three-dimensional volume-rendered projection image shows anomalous right coronary artery in same patient as A above level of right coronary cusp (arrow).
C, Axial 10-mm MIP image reveals anomalous origin of left main coronary artery in 35-year-old man from right cusp near origin of right coronary artery. It then takes intraseptal
course posterior to right ventricular outflow tract near cephalad aspect of interventricular septum.
F O R YO U R I N F O R M AT I O N
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