Persistent sciatic artery found incidentally on hip MRI: report of 4 cases

The persistent sciatic artery is a rare anatomical variant, representing the persistence of the sciatic artery in adult life that is responsible for the major blood supply to the lower limb in early embryologic development. Such persistence may be bilateral and can remain asymptomatic for many years. However, aneurysmal degeneration has been described as a complication of the persistent sciatic artery, which may cause critical limb ischemia resulting from thrombosis or embolization of aneurysm thrombus. Digital subtraction angiography, Doppler ultrasound, computed tomography angiography and magnetic resonance angiography are the most frequently used diagnostic tools to detect, classify and determine the presence of complications of a PSA. Early detection of this vascular abnormality on imaging studies can avoid life-threatening complications. We describe 4 patients with PSA that were diagnosed as an incidental finding in magnetic resonance imaging of the hip and demonstrate its characteristic imaging appearance.