Skip to main content

Table 3 Commonly used advanced analysis parameters

From: 4D flow cardiovascular magnetic resonance consensus statement

Target parameter Description Potential applications Requirements and uncertainties
Wall Shear Stress (WSS) [93, 125, 126, 193] 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.
Pulse Wave Velocity (PWV) [132, 133, 168] 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.
Turbulent Kinetic Energy (TKE) [134, 136, 137] 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 Pressure Fields [128, 129, 131] 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.