MR elastography of the prostate: initial in-vivo application

Purpose: To analyze the initial assessment of the technical feasibility of in-vivo MR elastography (MRE) of the prostate gland in healthy volunteers. Materials and Methods: Dynamic sinusoidal MR elastography was performed in 7 healthy volunteers in prone position. The mechanical wave was induced via an external oscillator attached to the public bone. A 1.5 Tesla MR system (Philips Medical Systems, Netherland) was used with 4 combined surface coils for signal reception. MRE data acquisition was performed with a motion-sensitive spin-echo MR sequence that was phase-locked to the mechanical oscillation. Subsequently, these images were used to reconstruct the local distribution of elastic-city inside the prostate gland. The applied reconstruction algorithm was tested by means of phantom measurements. Results: Sufficient penetration of the mechanical wave into the prostate gland was achieved in all volunteers, allowing the acquisition of utilizable image data sets. The reconstructed distribution of elasticity (shear-modulus) inside the healthy prostate gland correlated with the zonal anatomy of the gland. The elasticity of the central portion (2.2±0.3 kPa) appeared to be lower than the peripheral prostatic portion (3.3±0.5 kPa). Conclusion: In-vivo MRE of the prostate gland is technically feasible. The proposed experimental set-up allows the efficient insertion of the mechanical wave into the prostate gland and provides a successful MR data acquisiton. (orig.)