Rapid flow characterization measurements using a modified CPMG measurement with incremented echo times, phase cycling...

Area of Science:

• Physics
• Engineering
• Biophysics

Background:

• Magnetic resonance (MR) offers a simple method for pipe flow characterization using spin echoes.
• Acquiring individual spin echoes leads to lengthy measurement durations, limiting practical applications.

Purpose of the Study:

• To develop a faster MR technique for measuring pipe flows.
• To reduce measurement time by employing an echo-train approach instead of individual echo acquisitions.

Main Methods:

• An echo-train approach was implemented, acquiring multiple variable τ spin echoes within a single train.
• A four-step phase cycling scheme was used to suppress coherence pathway effects.
• Incremented Carr-Purcell-Meiboom-Gill (CPMG) echo pulse spacings were utilized.

Main Results:

• The echo-train method successfully reproduced the original MR methodology's flow response (phase and magnitude vs. τ²).
• Measurement time was reduced by a factor of N (number of echoes per train), with N=3 demonstrated.
• Validation experiments confirmed results consistent with the original method for Newtonian and shear-thinning fluids.

Conclusions:

• The novel echo-train MR technique significantly accelerates pipe flow measurements.
• This method maintains the accuracy and simplicity of the original approach, enhancing its utility.
• The technique is validated for characterizing various fluid types in pipe flow.