Tissue stiffness estimation using gaussian filters for prostate MR elastography

Introduction Manual palpation through digital rectal examination is an established method for prostate cancer screening. Unfortunately, the technique is highly subjective and has limited spatial resolution. Prostate MR Elastography (MRE) could address these shortcomings by mapping stiffness throughout the entire gland. Recent work suggests that intracavitary approaches using transurethral actuators can generate the frequency and amplitude of shear wave motion in the prostate gland necessary to detect clinically relevant tumours [1]. The Local Frequency Estimation (LFE) algorithm [2] [3] [4] has been used successfully in a number of applications to calculate shear stiffness from shear wave images acquired with MRE. In comparison with other tissue property reconstruction methods, it produces minimal amounts of image artifacts and does not require smoothing [5]. By modifying conventional LFE algorithms from the literature, elastogram resolution was increased without increasing noise, and controls are introduced where the user can, at runtime, fine-tune the tradeoff between high resolution and low noise, as the situation demands.