An Improved Phase-Contrast MRI Technique

Tech ID: 29501 / UC Case 2016-050-0


UCLA researchers in the Department of Radiological Sciences have developed a phase-contrast MRI acquisition technique called Hybrid One- and Two-sided Flow Encoding Only (HOTFEO).


4D flow phase-contrast MRI (PC-MRI) is clinically used to visualize and quantify blood flow and velocity. Temporal resolution and temporal footprint determine the accuracy in velocity measurements, which is important for diagnosing clinical diseases such as carotid artery stenosis. The PC-MRI technique acquires one flow-compensated (FC) and three-directional flow-encoded echoes (FC/3FE) to update one cardiac phase, which often limits the temporal resolution and footprint. Phase contrast MRI techniques can optimize the temporal resolution and footprint, but at increased acquisition times.


UCLA researchers have developed an improved phase-contrast MRI acquisition technique, called Hybrid One- and Two-sided Flow Encoding Only (HOTFEO). The acquisition strategy uses a velocity direction constraint to provide more accurate blood flow and velocity measurements. The technique can also optimize temporal resolution and temporal footprint for PC-MRI without increasing total acquisition time. HOTFEO is an image-based reconstruction technique; therefore, other fast MRI techniques, such as parallel imaging, may be combined to achieve even higher acceleration rates.


  • Phase-contrast MRI 
  • Fast MRI techniques (parallel imaging MRI)


  • Increases temporal resolution and footprint 
  • No increase in acquisition time 
  • Combine with other fast MRI techniques to achieve higher acceleration rates

Patent Status

Country Type Number Dated Case
United States Of America Published Application 20180235485 08/23/2018 2016-050
European Patent Office Published Application 3340875 07/04/2018 2016-050

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Other Information


Phase contrast MRI, 4D-flow, temporal modulation, velocity direction constraint, hybrid one- and two-sided flow encoding only, velocity encoding, flow rate, flow quantification, temporal resolution, temporal footprint

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