Four-dimensional flow magnetic resonance imaging is useful for assessing hemolytic anemia following surgical repair of type A aortic dissection.

Background: Four-dimensional flow magnetic resonance imaging (4D flow MRI) can directly estimate turbulent kinetic energy (TKE) which is associated with pressure loss that are not assessable by other imaging modalities.

Methods And Results: A 55-year-old woman developed hemolytic anemia after emergency ascending aortic replacement for acute type A aortic dissection. Although computed tomographic angiography or doppler echocardiography could not identify the culprit stenotic legion, 4D flow MRI revealed jet flow and highly elevated TKE at the highly stenosed proximal anastomosis of a replaced ascending aorta.

Conclusion: Our findings suggest that 4D flow MRI evaluation and TKE estimation enable more accurate and detailed assessment of abnormal flow dynamics than conventional imaging modalities.