Learning objectives
To discuss role of MDCT in pre operative imaging of MAPCAS along with type of pulmonary artery stenosis
To study the spectrum of MAPCAS
Background
MAPCAS or Major Aorto-Pulmonary Collateral Arteries are the alternative pulmonary circulation in the congenital cyanotic heart disease,
when ever RVOT is compromised.
They gain access to the lung through the hilum and connect with native pulmonary arteries in1) the mediastinum
2) at the lobar level
3) or at Subsegmental level.
In some patients,
MAPCAs supplement the pulmonary blood supply creating a dual supply to the lungs,
while in some they may be the sole source of blood supply as in patients of pulmonary atresia...
Findings and procedure details
IMAGING PROTOCOL
All patients underwent CT angiography on a 256 slice dual source CT scanner using optimized FLASH protocol.
Scan parameters used were 80 kV,
90 mAs.
Nonionic iodinated contrast agent ( 350 mg Iodine / ml) was at a dose of 2ml per kg body weight at rate of 0.8-1 ml/ sec injected preferably via antecubital vein.
Images were reconstructed at 0.6 mm slice thickness.
MAPCAS v/s BRONCHIAL ARTERIES
MAPCAs are tortuous and do not branch in their mediastinal course unlike bronchial arteries....
Conclusion
MDCT angiography provides adequate knowledge of MAPCAS required for pre operative assessment of the patient as needed by the referring operative surgeon.
High-quality 3D reconstructed CT images helps in the understanding of complex collaterals along with associated congenital anomalies.
References
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Hernandez.Role of CT in the Evaluation of Congenital Cardiovascular Disease...