Evaluating Reliability of Performance Metrics for Bias Field Correction in MR Brain Images

Vitali Zagorodnov¹, Zin Yan Chua¹, Weili Zheng¹

Performance evaluation of nonuniformity correction approaches is usually performed indirectly, on the basis of remaining tissue intensity variability. However, inconsistencies between indirect measures reported in recent studies suggest that indirect measure might be poor proxies for true correction performance. This was confirmed by reliability study reported here. Reliability can be improved by evaluating the same metrics over conservative brain tissue masks and by applying slight smoothing to suppress image noise. On real brain MR data, due to potential difficulty in obtaining a conservative GM mask, we recommend using coefficient of variation (CV) measured on smoothed conservative WM mask.