From: 4D flow cardiovascular magnetic resonance consensus statement
Target parameter | Description | Potential applications | Requirements and uncertainties |
---|---|---|---|
Viscous shear forces of flowing blood acting tangentially to the vessel wall | Indicator for impact of flow alterations on endothelial cell and extracellular matrix function and risk for vessel wall remodelling | Dependent on spatial resolution. Relationship to actual WSS values are unclear [127, 173]. Limited longitudinal data that demonstrates its predictive value for risk stratification. | |
Propagation speed of systolic pressure pulse in the arterial system | Marker of arterial stiffness and predictive of cardiovascular disease. | Requires high temporal resolution. Sensitive to artifacts. | |
Energy content of turbulent flow and direction-independent measure of intensity of turbulent velocity fluctuations | Estimate of turbulence-related loss of energy or pressure. Indicator of impact of turbulent flow on blood constituents or vessel wall. | The effect of intravoxel mean velocity variations affects the estimation of low TKE values. Is based on information from signal magnitude data from each individual flow-encoding segment, which are usually not obtained in standard reconstructions. | |
Relative blood pressure field | Noninvasive estimation of pressure differences | Pressure field calculations based on MR velocity data do not take turbulence effects into account and do therefore not reflect turbulence-related pressure losses that occur in stenotic flows. Computation of pressure fields is associated with several pitfalls and a best strategy has not been established. | |
Volume and Kinetic Energy of Ventricular Flow Components or Compartments [56, 57, 59] | Separation of blood that transits heart chambers according to compartmental origin and fate | Indicator of ventricular dysfunction. Risk stratification and optimization and individualization of treatment heart failure | Pathlines used to map the transit of blood through the chambers accumulate errors that are inversely related to the quality of velocity data. Mixing effects are unknown. |