Estimation of intravoxel incoherent motion parameters using low b-values

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Physics
• Radiology

Background:

• Intravoxel Incoherent Motion (IVIM) imaging is a valuable MRI technique for clinical applications.
• Accurate estimation of IVIM parameters, particularly at low b-values, remains a challenge.

Purpose of the Study:

• To systematically investigate the impact of varying the number of low b-values on IVIM parameter estimation.
• To compare the performance of Least-Squares (LSQ) and Bayesian Shrinkage Prior (BSP) fitting methods under different low b-value conditions.

Main Methods:

• Simulation of diffusion-weighted (DW) data with varying low b-values to analyze IVIM parameter distributions.
• Acquisition of in vivo DW data with different numbers of low b-values and number of excitations (NEX).
• Implementation of LSQ and BSP fitting methods for IVIM parameter estimation.

Main Results:

• The influence of the number of low b-values on IVIM parameters varies.
• LSQ fitting is more sensitive to the number of low b-values compared to BSP.
• BSP fitting, while less dependent on the number of low b-values, exhibits increased sensitivity to noise.

Conclusions:

• The choice of fitting method and the number of low b-values are critical for accurate IVIM parameter estimation.
• Understanding these dependencies is essential for optimizing IVIM acquisition and analysis protocols.