Restriction spectrum imaging: An evolving imaging biomarker in prostate MRI

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Radiology

Background:

• Restriction spectrum imaging (RSI) is an advanced diffusion-weighted MRI technique.
• It leverages water diffusion characteristics in distinct tissue compartments to visualize microarchitecture.
• RSI offers high conspicuity for tissue details.

Purpose of the Study:

• To review the acquisition, postprocessing, and interpretation of RSI for prostate MRI.
• To summarize current data on RSI's utility in prostate cancer.
• To highlight RSI's role in detection, characterization, localization, and targeting.

Main Methods:

• RSI acquisition in under 5 minutes using modern scanners and surface coils.
• Utilizes multiple field gradients and high b-values.
• Incorporates postprocessing for length-scale, geometric, compartmental, and nuclear volume fraction information.
• Employs distortion correction for fusion with T2-weighted images.

Main Results:

• RSI provides high conspicuity of tissue microarchitecture.
• Enables detailed localization by fusing with T2-weighted images.
• Demonstrates applicability in prostate cancer detection, characterization, localization, and targeting.

Conclusions:

• RSI is a rapid and effective MRI technique for prostate evaluation.
• It enhances the delineation of disease extension into critical structures.
• RSI shows significant potential for improving prostate cancer management.