Advances in Computed Tomography, 2013, 2, 23-28
http://dx.doi.org/10.4236/act.2013.21005 Published Online March 2013 (http://www.scirp.org/journal/act)
MDCT Angiography Imaging Presentation of
ALCAPA in Adults
Qinyi Dai, Biao Lv, Zhaoqi Zhang
Radiology Department, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
Received November 8, 2012; revised December 20, 2012; accepted January 4, 2013
ABSTRACT
Objective: To make a pictorial presentation of the anomalous origin of left coronary artery arising from the pulmonary
artery (ALCAPA) appearances in adults on MDCT angiography. Methods: A retrospective evaluation was performed
between 2005 and 2011 by ECG-gated coronary MDCT angiography. Total 8 patients included (9 - 51 years, mean age 29
years, 7 female). Image quality was evaluated firstly. Multi planar reformations (MPRs), maximum intensity projections
(MIPs) and 3D volume-rendering techniques were used to evaluate image features. In addition, right and left coronary
artery orifices were measured for each case. Results: Total 8/70,000 cases diagnosed ALCAPA by MDCT exam, all
image qualities were acceptable. As the diagnose key point, all left coronary artery origin were clearly described, and
indirect signs such as dilated and tortuous right/left arteries and collateral vessels between them, enlarged left ventricle
were also well showed, the dilated degree of both the RCA and the LCA were marked with ages, the diameter of RCA
for each case were a mild wider than that of left one. Other combined signs like papillary muscle calcification, bronchial
arteries from aorta to the cardiac and coronary artery degeneration change were also included by MDCT angiography
findings in a single data acquisition. No combined inter cardiac malformations in our group. Conclusion: ECG-gated
MDCT angiography plays an important role as a first-line modality in assessment of ALCAPA.
Keywords: MDCT Angiography; Bland-White-Garland Syndrome; Coronary Artery Anomalous; Congenital Heart
Disease
1. Introduction
Anomalous origin of the left coronary artery arising from
the pulmonary artery (ALCAPA) is an extremely rare but
serious congenital cardiac abnormality. ALCAPA, also
known as Bland-White-Garland syndrome [1], is a rare
congenital defect, accounting for 0.25% - 0.50% of all
congenital heart disease, 1 in 300,000 live births. Al-
though magnetic resonance imaging (MRI) is considered
the technique of choice in patients with ALCAPA [2],
because of the higher spatial resolution and faster exam
time of multi-detector computed tomography (MDCT)
angiography improved capabilities for assessment of both
intra-cardiac anatomy and coronary arteries in a single
data acquisition, this modality plays an important role in
clinical practice [3]. The purpose of this article is to
make a pictorial presentation of ALCAPA appearances in
adults on MDCT angiography.
2. Materials and methods
2.1. Patient Population
A retrospective evaluation was performed to identify all
patients who underwent retrospective electrocardiogra-
phically-gated (ECG) coronary MDCT angiography be-
tween 2005 and 2011 at our cardiac-vascular specialist
hospital. Total 8 patients constitute the study group
ranged in age from 9 to 51 years (mean age, 29 years)
during nearly 70,000 cases; 7 were female. The exclusion
criteria were allergy to iodine containing contrast me-
dium, renal insufficiency (serum creatinine concentration
> 120 μmol/L) and unstable clinical condition. All pa-
tients were written the informed consent before examina-
tion.
2.2. MDCT Scanning Protocol
Patients were performed by 64-slice CT (Aquilion one,
Toshiba Medical Systems, Japan; n = 2) and dual-source
CT (DSCT, Somatom Definition, Siemens Healthcare,
Forchheim, Germany; n = 6). A 60 - 75 mL bolus of
iopamidol (370 mg/mL; Bayer Schering Pharma) fol-
lowed by 30 mL of saline solution was continuously in-
jected into an antecubital vein at a flow rate of 2.5 - 4.0
mL/s. The scanning range covered the entire heart and
MDCT angiography was triggered automatically within a
region of interest in the ascending aorta, image acquisi-
tion was initiated 5 seconds after attenuation reached the
C
opyright © 2013 SciRes. ACT

Q. Y. DAI ET AL. 24
predefined threshold of 180 Hu. Data were acquired in a
craniocaudal direction with a detector collimation (64 -
slice CT/DSCT) of 64 × 0.5 mm/2 mm × 32 mm × 0.6
mm, gantry rotation time of 400 ms/330 ms, tube voltage
of 100 - 135 kV/80 - 120 kV, and both tube current 350 -
420 mAs. Images were reconstructed with a section
thickness of 0.5/0.6 mm, both reconstruction increment
of 0.3 mm, and soft-tissue convolution kernel.
In all patients, mid-diastolic reconstructions were first
performed at 75% of the R-R interval. If image quality in
this data set was a not optimal, additional reconstruc-
tion were performed by multiple phase’s reconstructions.
2.3. MDCT Image Analysis
All data were transferred to a dedicated workstation
(Vitrea 3.8, Vital Images) applying a combination of the
original axial images, multi planar reformations (MPRs),
maximum intensity projections (MIPs) and 3D vol-
ume-rendering techniques (VRTs). Image quality for
each case was evaluated on a 3-point scale: 1) good im-
age quality with no or with minor artifacts; 2) moderate
image quality with moderate artifacts or blurring but
adequate for clinical diagnosis; and 3) poor image quality
with severe artifacts that made vessel delineation impos-
sible. Segments with score 3 were not considered for
further analysis. The consensus interpretation was per-
formed by an observer who with 10-year cardiac image
diagnostic experience. In addition, each case the proxi-
mal diameter of the right coronary artery (RCA) and the
left coronary artery (LCA) were measured by MPRs im-
ages.
2.4. Statistical Analysis
Statistical analysis was performed with software SPSS13.0.
All variables are resented as mean ± standard deviation,
counts, or percentages.
3. Results
Eight cases of MDCT angiography were successfully
performed and all patients without complications. Aver-
age heart rate during the CT scan was from 68 to 90 bpm
(average 77 ± 9 bpm). All images quality was acceptable,
including 6 cases were scale 1 and 2 cases with scale 2.
Clinical symptom were varies from chest not comfortable,
chest pain to heart failure and transient syncope history.
Besides 1 patient refused operation, other 7 patients un-
derwent surgery successfully and additional valve repair
for one of them due to moderate mitral valve regurgita-
tion.
VRTs and MPRs images to be used to describe LCA
and RCA origin, all LCA were originated from left-pos-
terior side of main pulmonary arteries (Figure 1(a)),
while RCA were arisen from the normal right coronary
sinus (Figure 1(b)). The origin diameter of RCA and
LCA were 5 - 17 mm (average 11 ± 4 mm) and 4 - 15
mm (average 9 ± 4 mm) respectively (Figure 2).
Dilated and tortuous left and right arteries and collat-
eral vessels between them were found for every case
(Figure 3 and 4); no combined cardiac malformations
were detected. All cases were showed enlarged left ven-
tricle and 1 case with marked papillary muscle calcifica-
tion (Figure 5). Two cases were detected small vascular
sup- ply to the cardiac from the aorta (Figure 3). Coro-
nary artery wall thickness with calcification changes
were found in 3 cases (Figure 5), but no severe stenosis
was detected.
4. Discussion
The ALCAPA anomaly may result from (1) abnormal sep-
tation of the conotruncus into the aorta and pulmonary
PA
Ao
LCA
Ao
RCA
(a) (b)
Figure 1. 28-year-old woman diagnosed ALCAPA by MDCT angiography. MPRs showed (a) The origin of the LCA (arrow)
from the left-posterior side of main pulmonary artery (PA) while (b) The dilated RCA arising from the normal site (arrow-
head). Measured the orifice of LCA and RCA were 9 mm and 11 mm respectively. Ao = aorta.

Q. Y. DAI ET AL. 25
0 10 20 30 40 50 60
18
16
14
12
10
8
6
4
2
0
RCA
LCA
Age
A
rtery
di
ameter
Figure 2. Right coronary artery (RCA) and left coronary artery (LCA) origin diameters (mm) in 8 cases of ALCAPA by
MDCT angiography (Age: years).
RCA
LCA
LCA
(a) (b)
Figure 3. 24-year-old woman. VRTs shows (A) dilated inter-coronary collateral arteries at the cardiac surface (long arrow),
which connect the dilated and tortuous RCA to the LCA. (B) Note the origin of the LCA from the left-posterior side of main
pulmonary artery (short arrow) and multiple dilated bronchial arteries arising from the aorta (open arrow). Measured the
orifice of LCA and RCA were 8 mm and 10 mm respectively.
artery, or from (2) persistence of the pulmonary buds
together with involution of the aortic buds that eventually
form the coronary arteries. There are two classic types of
ALCAPA: the infant type and the adult type. Infants ex-
perience myocardial infarction and congestive heart fail-
ure and approximately 90% die within the first year of
life. While in adults with well developed significant col-
lateral circulation over time from the RCA to the LCA,
however, it is still not sufficient to supply the left ventri-
cle, and then myocardial infarction, left ventricular dys-
function, mitral regurgitation or malignant arrhythmias
occurred, which can also lead to cardiac death. For adults,
risk of sudden death of between 80% and 90% at a mean
age of 35 [4], old ALCAPA ore than 70 years’ patients m

Q. Y. DAI ET AL. 26
Figure 4. 51-year-old woman. VRT anterior view of RCA with mult iple collaterals directed towards the left side of the heart.
Note the corkscrew-like appearance of the large ventricular branch of the RCA, compared with Figure 2, the diameter of
RCA and collateral vessels along the cardiac surface (arrows) were richer and more obvious for this older patient. Measured
the RCA orifice was 17 mm.
LV
(a)
LV
(c) RCA
(
b
)
Figure 5. 46-year-old woman. (( a) and (b)) MPRs showed left main artery (LM) arisi ng from the main pulmonary artery (PA),
very close to the valvular commissure, thickened myocardial wall and enlarged left ventricle (LV), note the multiple septal
collateral vessels (Figure 5(a) arrows) and the remarked papillary muscles calcified (Figure 5(b) open arrow) and dilated
RCA. (c) CPR demonstrated spot-like calcified at the distal dilated RCA (arrow).
would be found by case report [5]. Early diagnosis AL-
CAPA and prompt surgical intervention with the aim of
restoring a two-coronary-artery circulatory system have
excellent results and lead to gradual myocardial recovery.
The restoration of a two-coronary system is the objective
of the surgery. Treatment of ALCAPA consists of rec-
reation of dual coronary perfusion, either (a) direct reim-
plantation of the anomalous LCA into the aorta or (b)
creation of an intrapulmonary conduit from the left co-
ronary ostia to the aorta (Takeuchi procedure) may be used
[6].
In our study, patients average age is 29 years old and

Q. Y. DAI ET AL. 27
symptoms were varies from mild chest not comfortable
to syncope or heart failure, the lack of serious symptoms
besides well-developed collateral vessels, may also been
due in part to systemic hypertension, which preserved
antegrade blood flow in the RCA [4]. Occurrence is gen-
erally no predilection in sex or race, and is not consid-
ered an inheritable congenital heart defect. In our study,
all 8 patients are Chinese, female predominant and with-
out combined with intra-cardiac disease.
ECG-gated MDCT angiography findings of ALCAPA
in adults include direct visualization of the LCA original
from the main pulmonary artery, which is the diagnostic
key point viewed by MIPs and VRTs, the LCA typically
arises from the left-posterior aspect of the main pulmo-
nary artery beyond the pulmonary valve (Figure 1(a)),
which were the most common position, however, its po-
sition within the sinus is extremely variable, particularly
it may be very close to a valvular commissure (Figure
5(a)). Rarely, the anomalous ostium originates from the
right posterior sinus or even one of the main pulmonary
arteries. To know the exact LCA origin position may
help the surgical doctor to determine the optional opera-
tion method. In our study, 7 of 8 cases allowed operation
successfully, including direct re-implantation (n = 3) and
Takeuchi (n = 4) surgery. Such images give the surgeons
a better understanding of the complex anatomy before re-
pair.
The remarkable secondary imaging finding is the RCA
and the LCA dilated and tortuous, and dilated intracoro-
nary collateral arteries are seen along the epicardial sur-
face of the heart by VRTs (Figure 3(a)) or within the
interventricular septum by MIPs or MPRs (Figure 5(a)).
All cases represent the well-developed collateral path-
ways between the RCA and the LCA, MDCT images
offers excellent spatial resolution, which is required to
assess small vessels such as the coronary arteries. In our
study, the dilated degree of both the RCA and the LCA
marked with ages, the diameter of RCA for each case
were a mild wider than that of left one (Table 2, Figure
1 and 3), and collateral vessels along the cardiac surface
were richer for older patients (Figure 4). Moreover, the
dilated bronchial arteries from the aorta (Figure 3),
which act as systemic collateral vessels to the LCA
area’s blood supply, are best depicted at ECG-gated
MDCT angiography because of their small size.
Besides, left ventricular hypertrophy and dilatation
result from chronic myocardial ischemia also be seen in
MDCT images (Figure 5), may be used to assess left
ventricular function. If ischemia of the papillary muscles
happened and adjacent myocardium may cause mitral
insufficiency, as a finding, papillary muscles calcified
can easily be seen at MPRs besides left ventricle en-
larged (Figure 5(b)).
Due to the marked dilatation develops over time as
blood is rapidly shunted from the RCA into the LCA and
then into the low-pressure pulmonary circulation, the de-
generation change of the coronary artery could be found
in our mean age 29 years ALCAPA group (Figure 5(c)).
2D echocardiography with Doppler color flow map-
ping in some situations replaces angiography [7], echo is
sensitive to determine the mitral valve and left ventricle
function, which is also a convenient method used for fol-
low-up. Another technique used to non-invasively image
the coronary arteries is MR angiography, MR could ac-
curately depict the origin and proximal course of anoma-
lous coronary arteries [8] and no radiation exposure, even
more crucial for MR is the ability to assess myocardial
viability, which can be used as an important prognostic
factor to consider by the surgical doctor. Conventional
coronary angiography still remains as a gold standard for
the diagnosis of anomalous coronary arteries; however, it
is invasive and limited to a projection two-dimensional
view of the complex coronary artery system [9], especial-
ly for the retrograde ostium.
ALCAPA should be different with other disease which
may cause coronary artery dilated, such as Kawasaki di-
sease, coronary artery fistula or secondary to the athe-
rosclerosis change, the essential feature is to show and
determine the LCA origin area.
ECG-gated MDCT angiography plays an important
role as a first-line modality in assessment of ALCAPA,
and MDCT angiography also would be a valuable evalu-
ated post-operation condition [10]. But our study is lim-
ited both by its retrospective nature and a relatively small
number of patients. Because of potential drawbacks of
MDCT such as radiation exposure and contrast medium-
related complications, performing MDCT should be limi-
ted to patients presenting symptoms suggesting the pres-
ence of anomalous coronary arteries.
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