Keywords
congenital diseases - inferior vena cava - vertical vein
Introduction
MDCT (multidetector computed tomography) is simple and efficient method of imaging
congenital anomalies of heart and great vessels. Compared with different radiological
techniques, CT offers many advantages, as it can be undertaken even in neonates, yields
more information than MR in a very little time, is better than 2D echo, when there
is a small inter-costal window in some infants and is noninvasive.
Material and Methods
A study of 43 cases of suspected congenital diseases of heart was performed in Sahyadri
Hospital, Pune, over a period of 5 to 6 years with dual source CT in children as well
as adults. Only the images of anomalies of pulmonary veins are presented.
Introduction
A study of 43 cases of suspected congenital diseases of heart was performed in Sahyadri
Hospital, Pune, over a period of 5 to 6 years with dual source CT in adolescents well
as children. Only the images of anomalies of pulmonary veins are presented.
Settings and Design
Selection of cases—the adolescents, infants, and children, of both sexes, from day
1 to 15 years and who had clinical signs of CVS and positive 2D echo findings were
selected. The dose of contrast and radiation dose were kept as per the recommendations.
MDCT was performed on Dual Source CT (Siemens Co Ltd.) which has a high isotropic
resolution with 0.6 mm resulting into high quality orthogonal images.[1]
[2]
Introduction
Technique of MDCT Angiography
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Age group: day 1 to 15 years.
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Inclusion criteria:
Patients presenting to the hospital with congenital heart disease referred for cardiac
MDCT were included.
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3. Exclusion criteria:
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Patients coming for postoperative follow-up or complications.
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Patients coming with recurrent disease.
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Contrast enhanced CT was performed using (SIEMENS SOMATOM 64 dual source) MDCT scanner,
under light sedation if required.
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Sedation—chloral hydrate or IV sedation or general anesthesia (GA)—if SOS. Early cases
were done without GA but in some cases, study had to be repeated. Hence GA was given
in infants and con co-operative children.
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Injection of contrast—manual in neonates, 20 to 24 size needle, pressure injector
in older children (1.5–4 mL/s). It was used to dilute contrast, so that a greater
volume of 3 mL/kg could be used at a volume of 2 mL/kg.
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Pitch of 1.2, 0.75, or 1-mm slice thickness, 64 × 0.625 mm collimation, gantry rotation
0.33 seconds.
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Field of view )FOV) for cardiac anomalies—from the level of sterna notch up to diaphragm.
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If major aortopulmonary collateral arteries (MAPCA) are suspected—from neck to inferior
vena cava (IVC).
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Low radiation—80 to 120 mA, 80 to 120 KV.
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Scanning: (a) at the end for right heart and (b) bi-phasic for Lt heart: with bolus
tracking.
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Multiplanar reconstruction (MPR), maximum intensity projection (MIP) (with varying
slice thickness), axial, coronal, sagittal, or oblique recons, rotate images, volume
rendering technique (VRT) images were used.
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In some cases, conventional pulmonary angiography was performed.
Discussion
The anomalies of pulmonary veins can be grouped as follows:
Type I: Supracardiac
Anomalous pulmonary veins terminate at the supracardiac level. Pulmonary veins converge
to form a left vertical vein, which drains to either brachiocephalic vein, superior vena cava (SVC), or azygos vein. The supracardiac variant can classically depict a snowman appearance (figure of eight heart or cottage loaf heart) on a frontal chest radiograph. In this child MDCT showed the vertical vein even
when Chest X-ray was normal ([Figs. 1] and [2]).[3] This is a left to right shunt. This can be TAPVR (total anomalous pulmonary venous
return) or PAPVR (partial anomalous pulmonary venous return).
Fig. 1 A female neonate, presented with respiratory distress and cyanosis soon after birth.
MPR image of MDCT shows supracardiac type of total anomalous return of pulmonary veins
(white arrow). MDCT, multidetector computed tomography.
Fig. 2 In this child CXR was normal. CT showed supra-cardiac type of TAPVR with all pulmonary
veins on right draining into left SVC (vertical vein, marked by a white arrow), then into right brachiocephalic vein and normal SVC. TAPVR, total anomalous pulmonary
venous return.
Type II: Cardiac
Pulmonary veins drain into the coronary sinus and then the right atrium or SVC ([Figs. 3], [4], and [5]). A specific variant is a meandering pulmonary vein ([Fig. 6]). It is an anomalous pulmonary vein, taking a circuitous route through the lung
to enter into (in contrast to scimitar syndrome) the left atrium, rather than the
IVC. Meandering pulmonary veins can occur on the left side or both sides and coincide
with features of scimitar syndrome. This is a left to left shunt.
Fig. 3 A 7-year-old female with ASD. MDCT shows a small tributary of RIPV opening into SVC—cardiac
type (marked by arrows). MDCT, multidetector computed tomography.
Fig. 4 A 5-month-old male child with poor growth and lethargy and cardiomegaly on chest
X-ray. MPR images of MDCT show right superior and inferior pulmonary veins are draining
into right atrium (marked by a thick arrow) and left superior and inferior pulmonary veins draining into left atrium (marked by a thin arrow).due to partial anomalous pulmonary venous return. MDCT, multidetector computed tomography.
Fig. 5 CXR shows a curved density to the right of heart and increasing in size inferiorly,
mimicking a Turkish sword with a curved blade that broadens inferiorly. MPR image
of MDCT shows a scimitar vein to the right of RA and having a shape of a scimitar.
Fig. 6 A male neonate, presented with respiratory distress and cyanosis soon after birth.
MPR image of MDCT shows infracardiac type of total anomalous pulmonary of venous return
into portal veins.
Type III: Infracardiac
TAPVR, in which all four pulmonary veins drain abnormally to the right atrium instead
of the left atrium. This becomes a left to left shunt.
PAPVR is a congenital malformation in which pulmonary vein enters the systemic veins,
e.g., in Scimitar syndrome. This is a left to right shunt. All pulmonary veins may
drain into hepatic veins, portal vein or IVC. An inferior pulmonary vein may have a meandering course before ending in right atrium,
IVC, or even portal vein (pulmonary veno-arterial or systemic venous shunt).
Rarely the pulmonary veins may join behind the left atrium to form a common vertical
descending vein, coursing anterior to the esophagus and passing through the diaphragm
at the esophageal hiatus and then joining the portal system.
There have been a few studies in the literature describing the technique of CT of
heart in pediatric patients ([Figs. 5], [7]).
Fig. 7 CXR showed a round and lobulated density in right lower zone. On close view vascular
shadows were noted around it. Pulmonary angiography showed this to be AVM supplied
by a pulmonary artery and drained by a pulmonary vein.
Type IV—miscellaneous anomalies—pulmonary AVM and pulmonary varix ([Figs. 6], [8], and [9]).
Fig. 8 CXR in this adolescent showed a round density to the right and behind right hilum
(arrow). A nodal mass or a vascular lesion was suspected. CT showed this to be a pulmonary
venous angioma (arrowhead.). CT, computed tomography.
Fig. 9 PA view of CXR shows bilateral anomalous curvilinear vessels in the lower pulmonary
regions. MDCT with axial and coronal MIPs demonstrates bilateral pulmonary veins with
anomalous routes in the lower pulmonary regions but draining normally into the left
atrium. Coronal volume-rendering 3D reconstruction shows the anomalous veins and normal
pulmonary arteries. PA, posteroanterior; 3D, three dimensional; MDCT, multidetector
computed tomography.
Summary
A study of 43 suspected congenital diseases of heart supported by 2D echo was performed
in children and adults. Only anomalies of pulmonary veins are presented. These were
better accepted by clinicians. In most cases it tallied with 2D echo but in some cases
it did not, as there can be difference in interpretation between the two cardiologists.
