Congenital anomalies of the thoracic vascular system are an important cause of morbidity and mortality in infants and children 1.
Congenital thoracic vascular anomalies occur in the thoracic aorta and branch arteries,
thoracic systemic veins,
and the pulmonary veins 2.
In this pictorial educational exhibit,
pulmonary vascular anomalies are focussed.
Congenital pulmonary vascular anomalies:
- Pulmonary arterial anomalies
- Pulmonary venous anomalies
Pulmonary arterial anomalies:
Congenital pulmonary arterial anomalies include hypoplasia,
pulmonary artery sling,
pulmonary artery aneurysm,
These anomalies most often occur in association with complex conotruncal congenital heart lesions,
Fallot’s tetralogy and transposition of great arteries (TGA) 3.
Isolated pulmonary arterial hypoplasia and agenesis,
in the absence of complex congenital heart disease,
are often associated with pulmonary hypoplasia and hypogenetic lung syndrome.
Isolated pulmonary arterial stenosis is rare 2.
Pulmonary venous anomalies:
Abnormalities of the pulmonary veins are frequent in patients with congenital heart disease and are particularly common in patients with abnormalities of atrial and visceral situs such as heterotaxy 4.
Commonly encountered abnormalities of the pulmonary veins are as follows: (a) anomalous pulmonary venous drainage,
which includes total anomalous pulmonary venous return (TAPVR),
partial anomalous pulmonary venous return (PAPVR),
sinus venosus defect,
and malposition of the septum primum; (b) pulmonary vein stenosis or atresia,
which includes cor triatriatum,
congenital pulmonary vein atresia or stenosis,
and recurrent pulmonary vein stenosis after repair of anomalous pulmonary venous return; and (c) miscellaneous or incidental abnormalities,
which include abnormal number of pulmonary veins and abnormal course of the pulmonary veins 5.
Role of imaging:
The ability to diagnose congenital vascular thoracic anomalies has evolved tremendously in the past 20 years 2.
Echocardiography is the modality of choice to diagnose the cardiac congenital malformations,
however it has limitations with the vascular anomalies.
Conventional angiography gives the vascular overview with limitation of only visualizing the vessel lumen.
Multidetector row CT (MDCT) is a non-invasive and rapid technique used for the evaluation of paediatric vascular diseases as an alternative to conventional angiography.
Three-dimensional (3D) images allow excellent display of vascular anomalies that can be used as a vascular road map by surgeons 3.
Role of Multidetector CT (MDCT):
MDCT allows high-resolution volumetric imaging that can be acquired during a single breath-hold,
making it the imaging study of choice over conventional catheter angiography.
volumetric helical imaging allows three-dimensional reconstruction of data,
which is useful in lesion detection,
and surgical planning.
Fig. 15: SCIMITAR. Partial anomalous pulmonary venous return. Anomalous right lower pulmonary vein seen draining into IVC.
Understanding the anatomy,
and imaging appearance of pulmonary vascular lesions is essential in making the correct diagnosis and avoiding unnecessary interventions.
This pictorial essay will illustrate MDCT manifestations of a variety of pulmonary vascular congenital malformations.