Distortion-free diffusion-weighted imaging using echo planar time-resolved imaging with prospective motion...

Area of Science:

• Medical Imaging
• Radiology
• Neuroimaging

Background:

• Diffusion-weighted imaging (DWI) using echo planar imaging (EPI) is standard but prone to geometric distortions and motion artifacts.
• Motion sensitivity is a significant challenge in clinical DWI, particularly in patient populations like those with anxiety or Alzheimer's disease.

Purpose of the Study:

• To evaluate the clinical feasibility and image quality of combining echo planar time-resolved imaging (EPTI) with markerless prospective motion correction (PMC).
• To compare EPTI-DWI with PMC against conventional single-shot EPI-DWI in motion-sensitive individuals.

Main Methods:

• A comparative study involving one healthy volunteer and 38 patients (24 with anxiety disorder, 14 with Alzheimer's disease).
• Image quality was assessed by two radiologists using a five-point scale, with interreader agreement evaluated by ICC.
• Apparent diffusion coefficients (ADC) were compared between EPTI-DWI and EPI-DWI using linear regression and Bland-Altman analysis.

Main Results:

• EPTI-DWI with PMC significantly reduced geometric distortion and improved diagnostic confidence and overall image quality compared to EPI-DWI (P<0.001).
• No significant difference in anatomical clarity was observed between the two methods (P=0.49).
• ADC values showed a strong correlation (r=0.89) between EPTI-DWI and EPI-DWI, with a small positive bias for EPTI-DWI.

Conclusions:

• EPTI-DWI with PMC provides high-resolution, distortion-free diffusion imaging with superior image quality compared to EPI-DWI.
• The technique is clinically feasible and beneficial for motion-sensitive patients, suggesting potential for wider clinical adoption.