Role of Blood Flow Imaging in Treating Congenital Heart Disease in Clinical Practice

Abstract

With recent improvements in computer technology, prominent progress has occurred in cardiovascular imag-ing. Blood flow imaging visualizes complicated blood flow inside the cardiovascular lumen via 3D color video, in addition to providing traditional geometrical information such as heart chamber size and vessel diameter. Because blood flow imaging provides detailed information about diseased flow, elucidates the pathophysiology of cardiovascular disease, and visualizes mechanical stress on the ventricular chamber or vessel intima, it has been identified as a novel tool for predictive medicine for heart valve disease, cardiomyopathy, coronary arterial disease, and aortic disease. Congenital heart disease has a complicated anatomy and physiology; thus, blood flow imaging has been expected to have clinical applicability for congenital heart disease for decades. Even with the sophistication of perioperative patient management in congenital heart disease, blood flow imaging plays an essential role in predicting long-term outcomes in patients with congenital heart disease. In this review, we explained the details of blood flow imaging, including 4D flow MRI, several types of novel echocardiography blood flow visualization software, and computational simulations. Echocardiography and MRI flow imaging are based on flow measurements, which carry limitations concerning spatial and temporal resolution. Conversely, computer simulation enables virtual surgery with sufficient resolution, but visualized flow is dependent on the calculation assumption. We also discussed effective clinical applications of these methods in patients with congenital heart disease, especially considering long-term outcomes, by reviewing the literature and introducing several complicated cases.