Phase contrast with valve assessment

1-Phase Contrast is a non-invasive method for the measurement of blood flow that is used for the hemodynamic evaluation of the pulmonary, aortic valve, including the quantitative assessment of the aortic valve stenosis and regurgitation, which was shown to have important prognostic implications

The technique of phase contrast is based on Velocity-encoding (VENC) gradients are used to generate a phase shift in magnetic resonance proportional to the velocity of moving protons. This phenomenon can be used to depict and measure the velocity of spins and thus flow

stationary or fixed proton has no phase shift, however the moving protons have a phase shift and the degree of positive or negative phase shift depending on the direction and the velocity

2-indication of using Phase Contrast in cardiac imaging

A- Assessment of valves like stenosis ,regurgitation , shunting or ASD

B- Flow volume quantification, velocity (peak and average velocity)

3-valver anatomy

A- axial anatomy of the heart

B- mitral valve anatomy

C-Aortic valve anatomy

4- phase contrast planning

A- to plane the aortic valve, we do need 3CH view and the LOVT view or localizer if you can see the LOVT view

B- pulmonary valve planning

• to acquire PA Q flow, we do need ROVT image which cane be obtained from  Place plane parallel to main pulmonary artery and scroll down to make sure it passes through the RVOT

5- Postprocessing in valve assessment.

by acquiring two flow directions (black&white) inferior and superior, we can draw a contour around the are of interest and getting the Q flow see below some Q flow for different case studies .

6- case studies