Coarctation of aorta is a congenital anomaly characterized by a narrowing segment between the aortic arch and the descending aorta. This stenosis is responsible for upper body hypertension and the recruitment of a collateral network via the intercostal arteries to improve lower body perfusion. However, hemodynamic perturbations along the aorta have not been completely studied. The objective of this work is to analyze the collateral network of patients with aortic coarctation who required surgical repair. MRI was performed to obtain hemodynamic parameters such as the variation of flow along the descending thoracic aorta and an estimation of the collateral flow. The shape of the aorta was also studied. Both morphological elements and hemodynamic parameters of aortic coarctation may be quite useful to determine consequences of aortic narrowing and the best moment to propose surgical repair or imaging monitoring. We also expect giving more information on the collateral network to develop modelisation of this element.