Download Congenital coronary artery anomalies in adults

The British Journal of Radiology, 82 (2009), 254–261
PICTORIAL REVIEW
Congenital coronary artery anomalies in adults: non-invasive
assessment with multidetector CT
1
A R ZEINA,
MD,
2
J BLINDER,
MD,
3
D SHARIF,
MD,
3
U ROSENSCHEIN,
MD
and 1E BARMEIR,
MD
1
Department of Radiology and MAR Imaging Institute, Bnai Zion Medical Center, Faculty of Medicine, Technion, Haifa,
MAR Imaging Institute, Bikur Holim Hospital, Jerusalem and 3Department of Cardiology, Bnai Zion Medical Center,
Faculty of Medicine, Technion, Haifa, Israel
2
ABSTRACT. Congenital coronary anomalies (CCAs) are uncommon but can cause
sudden cardiac death or other symptoms of myocardial ischaemia, especially in young
healthy subjects. Conventional coronary angiography (CA) is an invasive and expensive
procedure, and cannot provide three-dimensional data on the anomalous vessel.
Electrocardiographic gated multidetector CT (MDCT) has been reported to be useful for
non-invasive evaluation of CCAs. The purpose of this pictorial review is to discuss and
illustrate different CCAs in terms of clinical importance, type and manifestations using
MDCT. Knowledge of the CT appearances and an understanding of the clinical
significance of these anomalies are essential for making the correct diagnosis and
planning patient treatment.
Congenital coronary anomalies (CCAs) are uncommon
and the vast majority are diagnosed incidentally during
coronary angiography (CA) or necropsy. They affect ,1%
of the population, with 87% of affected individuals having
anomalies of origin and distribution and 13% having
coronary artery fistulae (CAF) [1–2]. An isolated single
coronary artery occurs only in ,0.024% of the population
[3]. The incidence does not appear to be related to gender.
CCAs are usually asymptomatic; however, some may
cause sudden cardiac death or other symptoms of
myocardial ischaemia, especially in young adults [4].
To date, the main diagnostic method for the detection
of coronary anomalies has been selective CA. Although
CA is an effective diagnostic tool, it is clearly invasive
and associated with procedural morbidity (1.5%) and
mortality (0.15%) risks [5]. Recognition of important clues
and specific angiographic views are required to delineate
clearly various CCAs. Owing to its two-dimensional
nature, CA cannot show reliably the relationship of
aberrant vessels with the underlying cardiac structures.
These limitations can be overcome by using a noninvasive diagnostic modality that acquires full threedimensional (3D) data from both the heart cavities and
the coronary arteries. Potential techniques that have been
reported to be useful for the evaluation of CCAs are MRI
and mutidetector CT (MDCT) CA. However, the spatial
resolution achievable with cardiac MRI (1.25 6 1.25 6
1.5 mm) is currently inadequate for coronary artery
imaging, particularly for meticulous analysis of the distal
arterial course. In addition, the inherent temporal
Address correspondence to: Abdel-Rauf Zeina, Department of
Radiology and MAR Imaging Institute, Bnai Zion Medical Center,
47, Golomb St, P.O.B. 4940, Haifa 31048, Israel. E-mail:
[email protected]
254
Received 31 August 2006
Revised 8 February 2007
Accepted 6 March 2007
DOI: 10.1259/bjr/80369775
’ 2009 The British Institute of
Radiology
resolution of MRI is unsatisfactory, as the time required
for MRI acquisition is reported to range from 25 min to
50 min per study. In comparison, MDCT allows rapid
acquisition of the entire 3D cardiac volume of data in a
single scan (within 10 s on a 64-row MDCT scanner).
Owing to its high spatial resolution (0.5 6 0.5 6 0.6 mm),
it provides excellent distal coronary artery visualization,
including the small side branches. This resolution is
approaching, but remains inferior to, that of conventional
CA, i.e. 0.2 6 0.2 mm. As mentioned above, the data
using MDCT is acquired as a volume, and retrospective
electrocardiographic (ECG) gating is performed to
reconstruct the images. This technique allows for the
selection of the optimal reconstruction position with
minimal motion and thus minimal artefacts, resulting in
high-quality images of the heart cavities and the coronary
arteries, including their origin, course and termination.
Radiation exposures are relatively high in MDCT CA,
ranging from 5–10 mSv. Overall, the effective dose can be
reduced substantially by using the ‘‘ECG tube current
modulation’’ (reduction of tube output during the
systolic phases of each cardiac cycle) which, therefore,
compares favourably with that of conventional CA [6].
The aim of this pictorial review is to illustrate the
spectrum of MDCT findings that may be seen in subjects
with CCAs, as familiarity with the CT appearances and
an understanding of the clinical significance of these
anomalies are essential in making a correct diagnosis and
planning patient treatment.
Normal origin and course of coronary arteries
The coronary arteries are the first vessels that branch
from the aorta, normally originating below the junction
The British Journal of Radiology, March 2009
Pictorial review: Assessment of coronary artery anomalies with MDCT
between the bulbus and the ascending aorta, i.e. at the
sinotubular junction. The coronary orifices are located in
the centre of the corresponding aortic sinuses and
slightly above the free margin of the cusp (Figure 1).
Normally, an individual has two or, sometimes, three
coronary ostia. Often, the conal branch of the right
coronary artery (RCA) may arise separately from the
right sinus [7] (Figure 2). The left coronary ostium is
usually single, giving rise to the left main coronary artery
(LMCA) that branches into the left anterior descending
(LAD) and left circumflex (LCX) coronary arteries. The
LAD courses in the interventricular groove, whereas the
RCA and LCX artery course in the right and left
atrioventricular grooves, respectively (Figure 1).
The coronary arteries are vessels located in the
epicardium, although they may penetrate into the
myocardium for part of their route (myocardial bridging). The intramyocardial coronary artery segment is
termed a ‘‘tunnelled segment’’. This condition is better
visualized on curved multiplanar reformatted images in
diverse planes (Figure 3).
Types and MDCT findings of CCAs
Multiple coronary ostia
The LAD and LCX arteries may arise separately from
the left sinus of Valsalva (LSV) with an absence of the
LMCA. Separate ostia of the LAD and LCX arteries occur
in 0.41% of subjects with an otherwise normal anatomy
[8] (Figure 4). Multiple ostia in both aortic sinuses have
also been reported [7]. Multiple ostia usually present no
major clinical problems, but they may cause difficulty in
cannulating the vessels during CA.
High take-off
‘‘High take-off’’ refers to an unusually high origin of
either the RCA or the LAD artery from the ascending
aorta at a point above the junctional zone between its
sinus and the tubular part [9]. High take-off positions are
without any haemodynamic significance, but they may
lead to unexpected angiographic problems while localizing and engaging the orifices. High take-off is better
represented on the angiographic view or volumerendered reformatted images (Figure 5).
Single coronary artery
In this condition, the LMCA and RCA arise with a
common ostium from the right, left or non-coronary
sinus. This is a very rare CCA that is seen in only 0.024–
0.044% of the population [10]. The involved coronary
artery may route interarterially between the aortic root
and the pulmonary trunk before bifurcating into its
branches (Figure 6). Subjects with such an anomaly are at
increased risk for sudden death [9].
Origin from non-coronary or opposite sinus
Left and right coronary arteries may also arise from
the non-coronary sinus (Figure 7) or their opposite
coronary sinuses [11]. When the LMCA originates from
Figure 1. Normal electrocardiographic gated multidetector CT anatomy of the coronary arteries and branches. (a) Threedimensional volume-rendered image of the coronary tree shows a normal aortic root (A) and coronary artery anatomy: left main
coronary artery (LMCA), left anterior descending (LAD), left circumflex (LCX), right coronary artery (RCA), posterior descending
artery (arrowhead) and posterolateral branch (small arrow). Large arrows indicate the right (large white arrow) and left (large
open arrow) sinus of Valsalva. (b) Cardiac transparency image showing the course of the coronary arteries and their anatomical
relationship. A, aorta; D, first diagonal; LV, left ventricle; P, main pulmonary artery; RV, right ventricle.
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A R Zeina, J Blinder, D Sharif et al
Figure 2. A 53-year-old man with multiple ostia and separate origins of the right coronary artery (RCA) and conus branch (CB).
(a) Maximum intensity projection multidetector CT image shows separate ostia of the RCA and CB from the right sinus of
Valsalva (RSV). A, aorta. (b) Three-dimensional volume-rendered image of the aortic root (A) shows the separate origin of the
conus branch (arrow) from the RSV.
the opposite or non-coronary sinus, or vice versa, the
anomalous artery takes one of four aberrant pathways to
reach its proper vascular territory: (i) anterior to the right
ventricular outflow tract (Type A); (ii) interarterial
(between the aorta and pulmonary trunk; Type B); (iii)
through the crista supraventricularis portion of the
septum (Type C); and (iv) dorsal to the aorta (Type D).
The RCA arises from the LSV as a separate vessel or as
a branch of a single coronary artery in 0.03–0.17% of
patients who undergo angiography (Figure 8) [2]. The
LMCA arises from the right sinus of Valsalva (RSV) in
0.09–0.11% of patients who undergo angiography [12].
The LCX artery may arise anomalously from the RSV
(approximately 0.32–0.67% of the population), usually
passing behind the aortic root (Figure 9) [2].
Coronary artery fistulae
CAF are rare, being detected in approximately 0.1–0.2%
of coronary angiograms [13]. Most originate from the RCA
and almost always drain into low-pressure chambers of
the heart (i.e. right ventricle, right atrium and pulmonary
artery). Their aetiology is most frequently congenital;
however, acquired forms have been described after
cardiac operations or biopsies, chest irradiation or as a
complication of percutaneous coronary intervention.
Patients with small CAF remain asymptomatic, whereas
those with high-flow fistulae and enlarged vessels may
develop myocardial ischaemia and congestive heart failure. The presence of symptoms, complications and
significant left-to-right shunt are currently the main
indications for CAF closure. CAF are better represented
on 3D volume-rendered images, although one needs to
view the axial images for complete evaluation (Figures 10
and 11). When complex anatomy or intervention is
contemplated, conventional CA may not be sufficient.
Figure 3. A 56-year-old man with myocardial bridging.
Conclusion
Curved multiplanar reformatted multidetector CT image
showing a band of myocardial muscle overlying the mid left
anterior descending (LAD) artery segment, corresponding to
myocardial bridging (arrows). Inset: cross-sectional reformatted image showing the tunnelled segment completely
surrounded by muscle fibres (arrow). LCX, left circumflex;
LMCA, left main coronary artery; LV, left ventricle.
ECG-gated MDCT is a non-invasive 3D imaging
technique that provides an excellent overview of the
cardiac and complex vascular anatomy, and could be
helpful for planning future cardiovascular therapeutic
approaches, either interventional or surgical. The identification and assessment of CCAs seem to constitute an
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The British Journal of Radiology, March 2009
Pictorial review: Assessment of coronary artery anomalies with MDCT
Figure 4. A 37-year-old man with multiple ostia and separate origins of the left anterior descending (LAD) and left circumflex
(LCX) arteries. (a) Thick slab maximum intensity projection multidetector CT image shows the absence of the left main coronary
artery, with separate ostia of the LAD and LCX arteries from the left sinus of Valsalva (LSV). A, aorta. (b) Virtual angioscopy
demonstrating the LAD and LCX orifices.
Figure 5. A 45-year-old man with high take-off of the right
coronary artery (RCA). Angiographic view reformatted
multidetector CT image shows the high take-off (arrow) of
the RCA above the sinotubular junction (dashed line). A,
aorta; LM, left main coronary artery; CS, coronary sinus.
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A R Zeina, J Blinder, D Sharif et al
Figure 6. A 58-year-old man with a single coronary artery. (a) Axial thick slab maximum intensity projection image shows the
malignant course (interarterial) of the left main artery (LM) between the aorta (A) and right ventricle outflow tract (RVOT). LA,
left atrium; LAD, left anterior descending artery; LCX, left circumflex; RCA, right coronary artery. (b) Cardiac transparency image
shows the anomalous origin of the LM, its course and the detailed anatomic relationship. RA, right atrium; RV, right ventricle. (c)
Three-dimensional volume-rendered multidetector CT image of the aortic root (A) and coronary tree shows only one coronary
artery arising from the right coronary sinus (arrow). Note the high take-off of the single coronary artery above the sinotubular
junction.
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The British Journal of Radiology, March 2009
Pictorial review: Assessment of coronary artery anomalies with MDCT
Figure 7. A 58-year-old man with a left main artery arising
from the non-coronary sinus (NCS). Axial thick slab maximum
intensity projection multidetector CT shows an anomalous
left main artery (arrow) originating from the NCS and
coursing between the aorta (A) and the left atrium (LA).
Note that the right coronary artery (RCA) arises normally
from the right coronary sinus (RCS). No coronary artery is
arising from the left coronary sinus (LCS). LAD, left anterior
descending artery; LCX, left circumflex; RA, right atrium;
RVOT, right ventricle outflow tract.
Figure 9. A 59-year-old man with a left circumflex artery
(LCX) anomalous origin. Cardiac transparency multidetector
CT image shows the LCX arising separately close to the origin
of the right coronary artery (RCA) from the right coronary
sinus (arrow) and coursing below and behind the aortic root.
Figure 8. A 54-year-old man with an anomalous origin and
course of the right coronary artery (RCA). Thin slab maximum
intensity projection multidetector CT image shows an
interarterial RCA (arrows) originating directly from the left
sinus of Valsalva and coursing between the aorta (A) and the
right ventricle outflow tract (RVOT). The RCA take-off is at
an acute angle. LM, left main coronary artery.
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A R Zeina, J Blinder, D Sharif et al
Figure 10. A 26-year-old woman with total correction of the Tetralogy of fallot and a congenital left anterior descending artery
(LAD)–right ventricle fistula. (a) Oblique thick slab maximum intensity projection multidetector CT view shows a dilated and
tortuous proximal LAD draining directly into the right ventricle (RV) (arrow). A, aorta; LMCA, left main coronary artery. (b) Left
coronary angiogram shows a coronary artery fistula arising from the proximal LAD artery and emptying into the RV (arrow).
appropriate clinical use for this technology, and the
examples illustrated provide persuasive evidence in
support of this.
Acknowledgments
The authors are very grateful to Mrs Hilary Movsowitz
for her invaluable competence and assistance in the
preparation of this work.
References
Figure 11. A 58-year-old man with a complex coronary–
pulmonary artery fistula. A three-dimensional volume-rendered multidetector CT image shows a plexus of fine
tortuous vessels arising from the dilated proximal left
anterior descending artery (LAD) to form a network of
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into the right ventricle outflow tract. A feeding vessel
(arrow) originating separately from the right coronary sinus
is noted. Multiple calcified plaques are also noted along the
proximal segment of the LAD. A, aorta; LV, left ventricle;
RCA, right coronary artery; RV, right ventricle.
260
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