Comparison between diffusion-weighted MRI (DW-MRI) at 1.5 and 3 tesla: a phantom study.

Area of Science:

• Medical Imaging
• Magnetic Resonance Imaging
• Diffusion-Weighted Imaging

Background:

• Diffusion-weighted magnetic resonance imaging (DW-MRI) is crucial for detecting and characterizing tissue microstructural changes.
• Higher magnetic field strengths, such as 3 Tesla (T), offer potential for improved signal-to-noise ratio (SNR) in MRI.

Purpose of the Study:

• To compare DW-MRI performance at 1.5T and 3T.
• Evaluation focused on image quality, apparent diffusion coefficient (ADC) reproducibility, lesion contrast, and SNR using a phantom.
• Assessed the utility of 3T DW-MRI relative to 1.5T.

Main Methods:

• A spherical diffusion phantom was utilized for qualitative and quantitative assessments.
• Image quality was evaluated, and quantitative measurements of ADC, reproducibility, contrast, and SNR were performed.
• Comparisons were made between 1.5T and 3T field strengths.

Main Results:

• Image quality at 3T was degraded by distortions and signal losses, even with optimized protocols.
• Significant differences in ADC values were observed between 1.5T and 3T (P < 0.009).
• Lesion-to-background contrast was superior at 1.5T for b=1000 s/mm², while 3T required higher b-values for comparable contrast. SNR gain at 3T may be offset by acquisition time and parallel transmission limitations.

Conclusions:

• Further phantom and in vivo studies are necessary to determine the clinical utility of DW-MRI at 3T.
• The investigation should consider achieving image quality and acquisition times comparable to 1.5T.
• Current findings suggest careful protocol optimization is needed for 3T DW-MRI.