Comparison Between 3-Scan Trace and Diagonal Body Diffusion-Weighted Imaging Acquisitions: A Phantom and Volunteer...

Area of Science:

• Magnetic Resonance Imaging
• Diffusion-Weighted Imaging Techniques
• Quantitative Imaging

Background:

• Conventional 3-scan trace diffusion-weighted imaging (tDWI) involves sequential acquisition of diffusion gradients.
• Diagonal diffusion-weighted imaging (dDWI) utilizes simultaneous application of orthogonal gradient systems, theoretically offering reduced artifacts and increased sharpness.

Purpose of the Study:

• To compare apparent diffusion coefficient (ADC) quantification and image quality between monopolar dDWI and tDWI.
• To evaluate performance across different magnetic field strengths (1.5 T and 3.0 T) and anatomical regions (phantom, abdomen, pelvis).

Main Methods:

• Monopolar dDWI and tDWI sequences were applied to a dedicated diffusion phantom and the abdomen and pelvis of two volunteers.
• ADC quantification was assessed using coefficient of variation (CV).
• Image quality and estimated signal-to-noise ratio (eSNR) were evaluated, with image quality rated by two independent observers on a 5-point scale.

Main Results:

• In the phantom, image quality and ADC quantification were similar between dDWI and tDWI (CV: 0.7%-1.4%).
• Phantom eSNR was comparable, except for lower dDWI eSNR at b900, 3.0 T (P = .006).
• Volunteer studies showed higher CV values (1.3%-13.3% abdomen, 0.6%-5.7% pelvis) but a trend towards improved dDWI image quality at higher b-values and field strengths (P = .063 to .066).

Conclusions:

• dDWI may offer superior image quality compared to tDWI in abdominal and pelvic imaging.
• ADC quantification appears unaffected by the dDWI technique.
• Further clinical validation is recommended to confirm the benefits of dDWI.