In particular, a few limitations of PC-MRI are of importance for the measured velocities: * Partial volume effects (when a voxel contains the boundary between static and moving materials) can overestimate<unk>  leading to inaccurate velocities at the interface between materials or tissues. * Intravoxel<unk>  dispersion (when velocities within a pixel are heterogeneous or in areas of turbulent flow) can produce a resultant<unk>  that does not resolve the flow features accurately. * Assuming that acceleration and higher orders of motion are negligible can be inaccurate depending on the flow field. * Displacement artifacts (also known as misregistration and oblique flow artifacts) occur when there is a time difference between the<unk>  and frequency encoding. These artifacts are highest when the flow direction is within the slice plane (most prominent in the heart and aorta for biological flows)
Phase contrast magnetic resonance imaging
Contrast-enhanced ultrasound
Magnetic field imaging
Radionuclide angiography
Synthetic MRI
Magnetic resonance angiography
Amplified magnetic resonance imaging
Contrast CT