Magnetic resonance imaging nowadays supplies a noninvasive method in clinical applications. For tetralogy of Fallot (TOF) patients, after undergoing clinical operation, their cardiac anatomy still cannot supply sufficient blood flow in the pulmonary arteries with respect to the normal. In this study, we use phase contrast MR imaging to evaluate of regurgitation and turbulence of flow in pulmonary arteries after repair of TOF. We use parameters such as coefficient of variance (CV), regurgitant fraction (RF), and normalized area variation (NAV) to analyze the difference between repaired patients and normal controls. Our result also shows that CV and regurgitant fraction have loose relation. This study may provide more information to help doctors in clinical diagnosis. In the meanwhile, another three parameters were used to evaluate patients and normal persons. We use windkessel volume to see the difference of flow volume between inlet and outlet in the pulmonary arteries. We use pulse wave velocity (PWV) to discuss the propagating velocity of pressure wave on the vascular wall. We use pulmonary vascular resistance (PVR) to analyze the resistance of blood wall. PWV and PVR may lose information by means of insufficient points in a cardiac cycle, but the result may still be a kind of reference.

Magnetic Resonance Imaging (MRI) provides noninvasive method in clinical application. For the patients of Tetralogy of Fallot underwent surgical correction,regurgitation and turbulence in blood flow may still present in pulmonary arteries.In this study,Phase Contrast MR Imaging will be used to quantitate,and to observe blood flow in after repair Tetralogy of Fallot (TOF) patients.We use 3 parameters,which are Coefficient of Variance (CV),Regurgitant Fraction (RF) and Net Flow analysis to analyze two situations of blood flow in patients¡¦ left pulmonary artery ¡Bright pulmonary artery and main pulmonary artery.We also compare normal subjects to patients in this experiment. The pulmonary circulation is the action of blood flow from right ventricular to main pulmonary artery then to left pulmonary artery and right pulmonary artery. We use three additional parameters: rPA / lPA flow ratio¡BPeak Velocities and Total Flow to observe the pulmonary blood flow. We use rPA / lPA flow ratio to identify the tendency of blood flow, with Peak Velocities to find out Peak Velocity in normal difference between patient.Meanwhile, the measurement of Total Flow is applied to observe the flow from main pulmonary artery to left and right pulmonary artery. We hope to use these parameters that can help doctors on clinical diagnosis.

Recently magnetic resonance imaging has become more and more popular in clinical applications. In clinical studies, the heart of the TOF patient has some congenital defects. These defects lead to insufficient blood flowing into the pulmonary arteries, rendering the necessary of repair for TOF patients. However, even after repair, the blood in pulmonary arteries still cannot flow in the same way with those of normal people. For this reason, studies on the flow behavior of pulmonary arteries in TOF patients would be valuable in clinical applications. In this study, we focus on the quantitative analysis of in-plane flow in branch pulmonary arteries (left and right pulmonary arteries) after repair of tetralogy of Fallot (TOF) by means of phase-contrast MR imaging. The regurgitation and turbulence were evaluated by coefficient of variance (CV) and regurgitant fraction. Vector map of in-plane flow was also included in order to facilitate the observation of flow patterns. Our result shows a positive correlation of CV and regurgitant fraction in terms of turbulence and regurgitation. Therefore, we conclude that CV and regurgitant fraction as well as vector maps may be helpful to quantitate in-plane flow for after repair of TOF patients, providing a more accurate analysis in clinical diagnosis.