AJR 2000; 175:1381-1386
© American Roentgen Ray Society
Helical CT Angiography and Three-Dimensional Reconstruction of Total Anomalous Pulmonary Venous Connections in Neonates and Infants
Tae Hoon Kim1,
Yang Min Kim1,
Chang Hae Suh2,
Do Jun Cho3,
In Seung Park3,
Woong-Han Kim4 and
Young-Tak Lee4
1
Department of Radiology, Sejong Heart Institute, 91-121 Sosa-dong, Sosa-gu,
Pucheon, Kyunggi-do 422-232, 7-206 3rd St., South Korea.
2
Department of Radiology, Inha University Hospital, Shinheung-dong, Choong-ku,
Inchon, 400-103, South Korea.
3
Department of Pediatrics, Sejong Heart Institute, Sosa-gu, Pucheon, Kyunggi-do
422-232, South Korea.
4
Department of Cardiovascular Surgery, Sejong Heart Institute, Sosa-gu,
Pucheon, Kyunggi-do 422-232, South Korea.
Received February 16, 2000;
accepted after revision April 14, 2000.
Address correspondence to T. H. Kim.
Abstract
OBJECTIVE. The objective of this study was to investigate the
usefulness of helical CT angiography in the evaluation of total anomalous
pulmonary venous connections.
MATERIALS AND METHODS. Fourteen patients with total anomalous
pulmonary venous connections underwent helical CT angiography and subsequent
three-dimensional (3D) reconstruction. They ranged in age from 3 days to 8
months (median age, 2.3 months) and in weight from 2.3 to 7.1 kg (median
weight, 4.3 kg). The types of total anomalous pulmonary venous connections and
the number of pulmonary veins were evaluated on axial and 3D images.
Qualitative evaluations were performed for extent of pulmonary vascular
enhancement and contrast- or motion-induced artifacts.
RESULTS. In all patients, helical CT angiography correctly depicted
total anomalous pulmonary venous connections. Seven cases were the
supracardiac type, four cases were the cardiac type, one case was the
infracardiac type, and two cases were the mixed type. The detection rate of
the pulmonary vein in 3D reconstruction images (95-98%) was slightly lower
than that of the pulmonary vein in the axial images (100%), but the difference
between axial and 3D reconstruction images was not statistically significant
(p > 0.1). No statistically significant differences were noted
among 3D reconstruction images in the detection rates of the pulmonary vein
(p > 0.1). The extent of contrast enhancement of the pulmonary
vein was good or excellent in all patients. In five patients, there were
contrast-induced artifacts that made some surrounding vascular distortion but
did not interfere with the pulmonary vein analysis, except in one patient.
Motion-induced artifacts were observed in nine patients. One of them had an
obstacle in pulmonary vein analysis.
CONCLUSION. The combination of axial and 3D images in helical CT
angiography is helpful in the assessment of a total anomalous pulmonary venous
connection containing the individual pulmonary vein, and this combination can
be a good diagnostic tool in preoperative evaluation of neonates and infants
with a total anomalous pulmonary venous connection.
Introduction
Total anomalous pulmonary venous connection is a rare congenital cardiac
anomaly [1] in which the
pulmonary veins have no connection with the left atrium and connect directly
to the right atrium or to one of the systemic veins. In the diagnosis of total
anomalous pulmonary venous connection, the presence and severity of the venous
obstruction is important. Echocardiography is regarded as an initial screening
and diagnostic modality in patients with total anomalous pulmonary venous
connection
[2,3,4,5].
However, the evaluation of the draining vein is not easy because the vein is
located far from the anterior chest wall. Cardiac catheterization and
angiography have been considered the gold standard
[6], and they provide
comprehensive information about the drainage of pulmonary veins and the
presence of a venous obstruction. However, in patients with severe cyanosis
and the obstructive type of total anomalous pulmonary venous connection,
cardiac catheterization and angiography carry the risk of cardiac arrest and
even death. MR imaging is known to be a useful method for the evaluation of
total anomalous pulmonary venous connection
[6,7,8].
Helical CT angiography has proved its value for the evaluation of various
vascular lesions in adults
[9,10,11].
This technique provides particularly useful information concerning aortic
diseases such as aortic dissection or aortic aneurysm. However, helical CT
angiography has a limitation in pediatric patients, probably because of the
small size of patients, non—breath-hold imaging, and slow infusion rates
of contrast media [12]. Some
researchers have recently described good results for aortic arch anomalies in
pediatric patients
[12,13,14].
However, to our knowledge, helical CT angiography for a total anomalous
pulmonary venous connection has not been reported. The purpose of our study
was to investigate the usefulness of helical CT angiography in the evaluation
of total anomalous pulmonary venous connection.
Materials and Methods
Patient Selection and Preparation
From July 1997 to November 1999, helical CT angiography was performed in 14
patients with a diagnosis of total anomalous pulmonary venous connection made
on echocardiography and confirmed at surgery. They ranged in age from 3 days
to 8 months (median age, 2.3 months) and in weight from 2.3 to 7.1 kg (median
weight, 4.3 kg). Seven were boys, and seven were girls.
Before the examination, no food was given orally for 4-6 hr in all
patients. Flexible venous catheters (21-to 24-gauge) were placed in the
antecubital vein (four patients), the umbilical vein (one patient), or the
peripheral vein of the foot (nine patients). Chloral hydrate was administered
orally for sedation at the dose of 70-80 mg/kg of body weight. A mask or hood
with oxygen (3-5 L/min) was applied to all patients, all of whom had a
clinically mild to moderate degree of cyanosis and dyspnea.
CT Technique and Data Acquisition
Helical CT angiography was performed with a Somatom Plus 4 scanner (Siemens
Medical Systems, Erlangen, Germany). The patients were placed in the supine
position. To determine the range of study and to detect the status of the
lesion, we performed sequential scanning of patients' chests in 5-mm sections
without contrast material. For CT angiography, helical scanning was performed
with a 512 x 512 matrix for about 30 sec after the injection of contrast
material. The nominal slice thickness was set at 2 mm and table speed at 2-4
mm. To obtain axial images, we reconstructed the images with 10-50% overlap of
a slice thickness using a 360° linear interpolation algorithm.
An IV contrast material, iopromide (Ultravist 370; Schering, Berlin,
Germany), was injected by mechanical power injector. It was diluted with
normal saline at a ratio of 1:1. No test bolus of contrast material was used.
The injection rate was 0.4-0.9 mL/sec during scanning. Scanning began 14-16
sec after beginning injection of contrast material in the peripheral vein of
the foot and 10-11 sec after injection in the antecubital vein and umbilical
vein.
Image Processing
Axial images were transferred to an independent workstation (Magic View,
Siemens, Erlangen, Germany). Shaded surface-display (SSD) images were obtained
after manual editing of axial images to remove bone structures and other soft
tissues. The threshold for SSD images is usually set at 150 H.
Maximum-intensity-projection (MIP) images were usually obtained after editing
axial images as SSD images, but an axial slab using several axial images
without editing of data was rendered with an MIP display on the axial plane.
Multiplanar reformatted images were applied to the variable imaging planes to
simultaneously display the pulmonary veins on the same imaging plane and to
identify the draining sites of the vertical vein to the systemic veins. This
technique was usually performed in the double-oblique output setting in the
commercial programs of Magic View. Image processing was performed
independently with axial images by two radiologists experienced with helical
CT angiography. All compilations of CT images including reconstruction were
performed without knowledge of the echocardiographic findings.
Image Analysis
Qualitative evaluation was performed in a consensus manner according to the
following criteria: the extent of contrast enhancement of the common pulmonary
venous chamber, contrast-induced artifacts, and motion-induced artifacts by
respiration or cardiac pulsation. The extent of contrast enhancement was
graded as poor when the CT attenuation of the common pulmonary venous chamber
was less than 150 H, fair when the attenuation was 151-200 H, good when the
attenuation was 201-250 H, and excellent when the attenuation was greater than
251 H.
The degree of contrast-induced artifacts was graded as follows: none, no
artifacts; mild, artifacts without distortion of the surrounding vascular
structure; moderate, artifacts with distortion of the surrounding vascular
structure; and severe, artifacts preventing analysis of the pulmonary veins.
The motion-induced artifacts were ranked as none, mild (artifacts with good 3D
display images), moderate (artifacts with poor 3D display images), and severe
(artifacts with unusable 3D display images).
The number of pulmonary veins from each lung (four pulmonary veins per
patient) and the draining sites of the anomalous common pulmonary veins were
independently evaluated by two radiologists on axial and 3D reconstruction
images. Total anomalous pulmonary venous connections were classified as four
types by the draining sites of the anomalous pulmonary vein in accordance with
the method of Darling et al.
[15]. Statistical analysis of
the detection rate of the pulmonary vein was performed using the Wilcoxon's
signed rank test on each axial and 3D reconstruction. A p value of
less than 0.05 was considered statistically significant. To assess
interobserver variability, we used a kappa statistic. A kappa value of 0.40 or
less indicated poor agreement, a kappa value of 0.41-0.75 indicated good
agreement, and a kappa value greater than 0.75 indicated excellent
agreement.
Results
A total anomalous pulmonary venous connection was correctly depicted in all
patients. Types of total anomalous pulmonary venous connection were as
follows: supracardiac type in seven cases (Figs.
1A,1B,1C,1D,1E
and
2A,2B,2C),
cardiac type in four cases (Fig.
3A,3B,3C,3D),
infracardiac type in one case (Fig.
4A,4B,4C,4D),
and mixed type in two cases (Fig.
5A,5B,5C,5D,5E
and Table 1). Individual
pulmonary veins and draining sites of the common pulmonary vein were
identified in axial images as well as in 3D reconstruction images. In axial
images, 56 pulmonary veins were identified, and the detection rate for the
pulmonary vein was 100%. For the pulmonary veins
(Table 2), 3D reconstruction
images (multiplanar reformatted, SSD, and MIP) showed detection rates of
95-98%. The detection rate of the pulmonary veins among axial and 3D
reconstructions or for each 3D reconstruction technique did not show
statistically significant differences. The combination of axial and 3D
reconstructions depicted all the pulmonary veins in 14 patients. The kappa
value for the two observers was 0.78 (excellent agreement).
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Fig. 1A. —Total anomalous pulmonary venous connection to left
innominate vein in 2-week-old male neonate. Axial CT scans show four separate
pulmonary veins (arrows, B and C). Note streak artifact
at right superior vena cava (black star, A) due to high
concentration of contrast material injected via right antecubital vein.
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Fig. 1B. —Total anomalous pulmonary venous connection to left
innominate vein in 2-week-old male neonate. Axial CT scans show four separate
pulmonary veins (arrows, B and C). Note streak artifact
at right superior vena cava (black star, A) due to high
concentration of contrast material injected via right antecubital vein.
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Fig. 1C. —Total anomalous pulmonary venous connection to left
innominate vein in 2-week-old male neonate. Axial CT scans show four separate
pulmonary veins (arrows, B and C). Note streak artifact
at right superior vena cava (black star, A) due to high
concentration of contrast material injected via right antecubital vein.
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Fig. 1D. —Total anomalous pulmonary venous connection to left
innominate vein in 2-week-old male neonate. Multiplanar reformatted image
shows four pulmonary veins joining to form confluence posterior to left
atrium, which connects to left innominate vein via vertical vein (V). A =
aorta, P = pulmonary artery.
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Fig. 1E. —Total anomalous pulmonary venous connection to left
innominate vein in 2-week-old male neonate. Shaded surface-display image shows
vertical vein (V) draining into innominate vein. A = aorta, P = pulmonary
artery.
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Fig. 2A. —Total anomalous pulmonary venous connection to right superior
vena cava in 3-day-old female neonate with right isomerism, complete
atrioventricular septal defect, patent ductus arteriosus, and right aortic
arch. Axial CT scan shows vertical vein (v), which connects to right superior
vena cava (RS). Patent ductus arteriosus (arrowhead) connects from
inferior aspect of right aortic arch to proximal portion of right pulmonary
artery (not shown).
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Fig. 2B. —Total anomalous pulmonary venous connection to right superior
vena cava in 3-day-old female neonate with right isomerism, complete
atrioventricular septal defect, patent ductus arteriosus, and right aortic
arch. Shaded surface display-images show that four pulmonary veins form common
pulmonary trunk, which connects to right superior vena cava (SVC, B)
via vertical vein (V, B). Patent ductus arteriosus (d, C)
connects to proximal portion of right pulmonary artery (rpa, C). lpa =
left pulmonary artery, Ao = aorta.
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Fig. 2C. —Total anomalous pulmonary venous connection to right superior
vena cava in 3-day-old female neonate with right isomerism, complete
atrioventricular septal defect, patent ductus arteriosus, and right aortic
arch. Shaded surface display-images show that four pulmonary veins form common
pulmonary trunk, which connects to right superior vena cava (SVC, B)
via vertical vein (V, B). Patent ductus arteriosus (d, C)
connects to proximal portion of right pulmonary artery (rpa, C). lpa =
left pulmonary artery, Ao = aorta.
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Fig. 3A. —Total anomalous pulmonary venous connection to coronary sinus
in 6-week-old female infant with atrial septal defect, ventricular septal
defect, and patent ductus arteriosus. Multiplanar reformatted image shows four
pulmonary veins (v) that form confluence (cv) posterior to left atrium.
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Fig. 3B. —Total anomalous pulmonary venous connection to coronary sinus
in 6-week-old female infant with atrial septal defect, ventricular septal
defect, and patent ductus arteriosus. Maximum-intensity-projection images show
no direct communication between confluent pulmonary venous chamber (cv,
B) and left atrium (la, B). Confluent pulmonary venous chamber
drains into coronary sinus (CS, C). Size of left atrium and ventricle
(LV) is small. i = inferior vena cava, RA = right atrium, RV = right
ventricle.
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Fig. 3C. —Total anomalous pulmonary venous connection to coronary sinus
in 6-week-old female infant with atrial septal defect, ventricular septal
defect, and patent ductus arteriosus. Maximum-intensity-projection images show
no direct communication between confluent pulmonary venous chamber (cv,
B) and left atrium (la, B). Confluent pulmonary venous chamber
drains into coronary sinus (CS, C). Size of left atrium and ventricle
(LV) is small. i = inferior vena cava, RA = right atrium, RV = right
ventricle.
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Fig. 3D. —Total anomalous pulmonary venous connection to coronary sinus
in 6-week-old female infant with atrial septal defect, ventricular septal
defect, and patent ductus arteriosus. Shaded surface—display image shows
vertical vein (V) connecting to coronary sinus (cs). i = inferior vena cava,
ra = right atrium, RV = right ventricle, LV = left ventricle.
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Fig. 4A. —Total anomalous pulmonary venous connection to portal vein in
3-day-old male neonate with atrial septal defect and patent ductus arteriosus.
Tip of umbilical venous catheter through inferior vena cava from umbilical
vein is positioned in right atrium. Catheter from umbilical artery is
positioned in aorta. Severe streak artifact by catheter containing high
concentration of contrast material distorts right upper pulmonary vein
(arrow, A). Vertical vein (v, B) is positioned anterior
to descending thoracic aorta.
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Fig. 4B. —Total anomalous pulmonary venous connection to portal vein in
3-day-old male neonate with atrial septal defect and patent ductus arteriosus.
Tip of umbilical venous catheter through inferior vena cava from umbilical
vein is positioned in right atrium. Catheter from umbilical artery is
positioned in aorta. Severe streak artifact by catheter containing high
concentration of contrast material distorts right upper pulmonary vein
(arrow, A). Vertical vein (v, B) is positioned anterior
to descending thoracic aorta.
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Fig. 4C. —Total anomalous pulmonary venous connection to portal vein in
3-day-old male neonate with atrial septal defect and patent ductus arteriosus.
Multiplanar reformatted image shows disrupted configuration in proximal
portion of right upper pulmonary vein (arrow).
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Fig. 4D. —Total anomalous pulmonary venous connection to portal vein in
3-day-old male neonate with atrial septal defect and patent ductus arteriosus.
Maximum-intensity-projection image shows four pulmonary veins and vertical
vein (V) communicating with portal vein (P). Indistinct configuration is noted
at proximal portion of left upper pulmonary vein and is due to motion-related
and contrast-induced artifacts.
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Fig. 5A. —Total anomalous pulmonary venous connections to left superior
vena cava and portal vein in 2-week-old male neonate with right isomerism,
right aortic arch, dextrocardia, complete atrioventricular septal defect,
double-outlet right ventricle, and pulmonary stenosis. Axial CT scans show
that right pulmonary veins join to form common trunk (RPV, B), which
passes anteriorly to trachea and inferiorly to aortic arch and drains into
left superior vena cava (LS, A) with junctional stenosis
(arrowhead, A).
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Fig. 5B. —Total anomalous pulmonary venous connections to left superior
vena cava and portal vein in 2-week-old male neonate with right isomerism,
right aortic arch, dextrocardia, complete atrioventricular septal defect,
double-outlet right ventricle, and pulmonary stenosis. Axial CT scans show
that right pulmonary veins join to form common trunk (RPV, B), which
passes anteriorly to trachea and inferiorly to aortic arch and drains into
left superior vena cava (LS, A) with junctional stenosis
(arrowhead, A).
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Fig. 5C. —Total anomalous pulmonary venous connections to left superior
vena cava and portal vein in 2-week-old male neonate with right isomerism,
right aortic arch, dextrocardia, complete atrioventricular septal defect,
double-outlet right ventricle, and pulmonary stenosis. On
maximum-intensity-projection image, left pulmonary veins join to form another
common trunk that is connected with compressed venous channel
(arrowhead) between descending thoracic aorta and right atrium.
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Fig. 5D. —Total anomalous pulmonary venous connections to left superior
vena cava and portal vein in 2-week-old male neonate with right isomerism,
right aortic arch, dextrocardia, complete atrioventricular septal defect,
double-outlet right ventricle, and pulmonary stenosis. Shaded surface-display
images three-dimensionally display pulmonary veins and courses of anomalous
venous drainage into systemic veins. Arrowheads indicate stenotic areas. LS =
left superior vena cava, RPV = right pulmonary vein, LPV = left pulmonary
vein, Ao = aorta.
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Fig. 5E. —Total anomalous pulmonary venous connections to left superior
vena cava and portal vein in 2-week-old male neonate with right isomerism,
right aortic arch, dextrocardia, complete atrioventricular septal defect,
double-outlet right ventricle, and pulmonary stenosis. Shaded surface-display
images three-dimensionally display pulmonary veins and courses of anomalous
venous drainage into systemic veins. Arrowheads indicate stenotic areas. LS =
left superior vena cava, RPV = right pulmonary vein, LPV = left pulmonary
vein, Ao = aorta.
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Contrast enhancement of the pulmonary venous chamber was judged to be good
in six patients and excellent in the remaining eight patients.
Contrast-induced artifacts were observed in five patients who had been
injected with contrast material via the antecubital or umbilical veins.
Contrast-induced artifacts in patients injected by the antecubital venous
route caused some distortion of the surrounding mediastinal vessels, but they
did not interfere with the pulmonary vein analysis
(Fig. 1A). The contrast-induced
artifact observed in the patient injected by the umbilical venous route
interfered with the right upper pulmonary vein evaluation on the multiplanar
reformatted image (Fig. 4C)
and with the left upper pulmonary vein evaluation on MIP images
(Fig. 4D). Motion-induced
artifacts related to cardiac pulsation or respiration were observed in nine
patients. One patient had stairstep artifacts on the vascular structure on 3D
display images, which interfered with the analysis of the pulmonary veins.
However, the other eight patients had good 3D display images.
Discussion
Although CT angiography is limited in application to pediatric patients
because of restricting factors
[12], we believe that this
technique can provide useful information in patients with total anomalous
pulmonary venous connection. We could display the presence of total anomalous
pulmonary venous connection and evaluate the number of pulmonary veins and
draining sites of the common pulmonary venous trunk on helical CT angiography.
Other diagnostic modalities such as MR imaging
[6,7,8]
and echocardiography
[2,3,4,5]
are known to be useful for the evaluation of a total anomalous pulmonary
venous connection, but helical CT angiography may be an alternative
preoperative diagnostic tool for patients with a total anomalous pulmonary
venous connection. Echocardiography is a noninvasive technique regarded as an
initial screening tool in the evaluation of total anomalous pulmonary venous
connection. However, echocardiography has a small field of view and is not
always available in certain planes because of the limitation of sonic windows
[6,
7]. Recently, MR imaging has
successfully revealed total anomalous pulmonary venous connections and showed
high accuracy in the diagnosis of total anomalous pulmonary venous
connections. We usually use CT angiography and 3D reconstruction to evaluate
extracardiac abnormalities such as great vessel anomalies, airway problems, an
anomalous venous system, and abnormal findings of the grafted conduit system
in pediatric patients with congenital heart disease.
One of the important problems in performing CT angiography in pediatric
patients is how to overcome respiratory motion artifacts. It is impossible to
suspend respiration in neonates and infants (<8 months old) who are not
intubated. Helical CT angiography, which allows gentle and regular respiration
during the scanning, usually provided diagnostic image quality in this age
group [13]. In our study,
motion-induced artifacts related to respiration did not interfere with the
analysis of the anomalous pulmonary venous structure such as the total
anomalous pulmonary venous connection in most patients. One patient, who was
irritable and had moderate congestive heart failure, had a moderate degree of
motion-related artifacts that interfered with pulmonary vein analysis in 3D
display images, but other patients had no artifacts or only mild artifacts
that did not prevent venous anatomy evaluation. We supplied oxygen (3-5 L/min)
using a mask or hood to all patients with cyanosis and dyspnea, which was
helpful in improving the image quality. Cardiac pulsation artifacts somewhat
influenced the image quality, but only mildly.
Contrast material was injected with a flexible venous catheter, which was
positioned at the antecubital veins of the upper extremity, the umbilical
vein, or the peripheral veins of the foot. We preferred the pedal veins to the
antecubital veins as an injection route for contrast material because a high
concentration of contrast material directly injected into the upper systemic
veins gave rise to a streak artifact (Fig.
1A). This artifact was not visible when contrast material was
injected into the pedal veins. An umbilical venous catheter was positioned at
the right atrium in one patient, and subsequently the patient had severe
contrast-induced artifacts that distorted the upper pulmonary vein (Fig.
4A,4B,4C,4D).
Therefore, avoiding direct injection of highly concentrated contrast material
into the central vein is helpful in improving image quality.
The scan delay time was longer in the pedal veins (14-16 sec) than in the
antecubital veins (10-11 sec). To maintain balanced opacification throughout
scanning, the injection of contrast material was made with a mechanical power
injector at rates of 0.4-0.9 mL/sec for the time equal to the scan duration.
Injection rate and delay time were varied according to the patient's weight
and were not considered from the aspect of intracardiac anatomy or
right-to-left shunts of patients. This lack of consideration was a limitation
in our study, the level of peak vascular enhancement was sufficient to display
the 3D images. Image quality might not depend greatly on the injection rate of
contrast material. Other reports showed injection rates of 1-3 mL/sec
[12,
13]. In our study, because
contrast material was diluted with normal saline at a ratio of 1:1, the actual
amount of contrast material used was injected at a rate of 0.2-0.5 mL/sec.
This amount of contrast material was good or excellent with regard to
pulmonary vein enhancement in all patients. The injection method of contrast
material in our study was continuous low-dose infusion throughout scanning,
which was different from other reports. However, further studies should be
performed to optimize the delay time or injection rate of contrast
material.
We could also display 3D images by making use of axial images. SSD images
provided an anatomic impression of the pulmonary veins and their anomalous
venous drainage courses (Figs.
1E,
2B,
2C,
3D,
5D, and
5E). The multiplanar
reformatted image technique was useful to display the common pulmonary trunks
and each trunk's separate pulmonary vein on the same plane simultaneously
(Figs. 1D,
3A, and
4C). MIP images helped us to
show pulmonary veins on the axial plane through the superimposition of
relevant axial images (Figs.
3B,
3C, and
5C) or on oblique coronal
images after the editing of data (Fig.
4D). In the detection rate of the pulmonary vein, 3D display
images were slightly lower than axial images. Factors such as contrast- or
motion-induced artifacts influenced the image quality of 3D reconstructions,
which interfered with pulmonary vein analysis in some patients. However, axial
images and 3D images did not show statistically significant differences in
their rates of detection of pulmonary veins.
CT angiography has several disadvantages in patients with a total anomalous
pulmonary venous connection. We cannot evaluate the intracardiac anatomy
because of pulsation artifacts that exist because of a lack of ECG gating on
helical CT angiography. Image quality is also relatively poor in cardiac or
infracardiac types of total anomalous pulmonary venous connection.
Particularly, the image quality of 3D reconstructions showed a tendency to be
poor because of pulsation respiratory motion artifacts. The manipulation of
data for 3D reconstructions requires a large amount of time (about 40-60 min
per patient) and is operator-dependent because knowledge about congenital
heart disease is needed for accurate and comprehensive 3D reconstructions. In
spite of these disadvantages, CT angiography and 3D reconstruction are helpful
in showing the courses and draining sites of the common pulmonary venous
trunk, as well as the individual pulmonary veins of total anomalous pulmonary
venous connections. In conclusion, helical CT angiography is a good diagnostic
modality for use in the preoperative evaluation of total anomalous pulmonary
venous connections.
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Abstract
Introduction
