Unraveling the Compromise between Skull Stripping and Inhomogeneity Correction in 3T MR Images

Bias field (in homogeneity) correction and skull stripping are initial standard procedures in medical image analysis of the human brain. Several works have investigated the effects of prior in homogeneity correction on skull stripping using 1.5 Tesla magnetic resonance (MR) images, but this question remains unanswered for higher magnetic fields. This paper fills this gap using 3 Tesla MR-images, by proposing a novel alternate sequence of skull stripping, morphological operations, in homogeneity correction and intensity standardization, with the first at the beginning and end of the sequence, denominated Iterative Skull Stripping methodology. Conversely to what happens in 1.5T images, experimental evaluation shows that, in 3 Tesla datasets, in homogeneity effect plays an important role in stripping the brain. This observation produces a deep impact on previous and future studies that rely on skull stripping operation.