Tomoelastography of the prostate using multifrequency MR elastography and externally placed pressurized-air drivers

Area of Science:

• Medical Imaging
• Biophysics
• Radiology

Background:

• Magnetic Resonance Elastography (MRE) is a non-invasive imaging technique used to measure tissue stiffness.
• Prostate cancer diagnosis often relies on imaging, but accurate stiffness assessment remains challenging.
• Current methods for prostate imaging lack quantitative stiffness mapping capabilities.

Purpose of the Study:

• To assess the feasibility of in vivo multifrequency MRE for the prostate using external drivers.
• To generate quantitative stiffness maps of the prostate.
• To evaluate the reproducibility and clinical applicability of the MRE technique.

Main Methods:

• Utilized three external pressurized-air drivers to generate shear waves at 60, 70, and 80 Hz.
• Acquired full 3D wave fields using multislice spin-echo echo-planar imaging.
• Applied tomoelastography for wave speed recovery and full field-of-view stiffness map generation.

Main Results:

• Demonstrated high reproducibility in healthy volunteers (88% intraclass correlation coefficient, 0.14 m/s repeatability).
• No significant difference in stiffness was observed between the prostate's peripheral zone and central gland.
• Stiffness maps in patients correlated with suspicious masses identified by other imaging modalities.

Conclusions:

• The developed MRE method provides reproducible quantitative prostate stiffness maps.
• The technique is suitable for integration into clinical imaging protocols.
• Clinical stiffness maps offer valuable details for prostate cancer diagnosis.