A new technique for automatic removal of local errors in shear modulus estimation from measurement area in liver MR elastography

Motivation: The stiffness value in two-dimensional liver MR elastography (MRE) is measured manually to avoid local errors in the stiffness estimation (dark/hot spots). Observer variability with this manual measurement is one of the obstacles to the clinical usage of MRE. Goal(s): Our goal was to automatically remove dark/hot spots from the measurement area. Approach: We introduced a new automated technique (coherent-wave auto-selection: CHASE) for measuring the stiffness value and tested it for the liver of five healthy volunteers. Results: CHASE automatically generated a measurement area scarcely including dark/hot spots, resulting in high uniformity within that area. Impact: The combination of our new technique and confidence mapping (clinical method) can reduce the process of manual measurement of stiffness value in liver MR elastography, resulting in improved variability and diagnostic performance for fibrosis staging.