Three-dimensional strain fields in human brain resulting from formalin fixation

► We have investigated the influence of the formalin on human brain by means of MR-Imaging and registration algorithms. ► We calculated a global volume shrinkage of the whole brain of 8.1%. ► Maximal local strains were determined to be 32%. Before investigating human brains post mortem, the first preparation step is often formalin fixation of the brain. As the brain consists of inhomogeneous tissues, the fixation leads to a three-dimensional strain field within the tissue. During the single case MR-based investigation of the brain, first, the starting point with the brain post mortem but still within the cranium, was examined. Then 13 MR data sets were acquired over a fixation period of 70 days and compared to the initial data set. Based on affine registration of the data sets, the global volume shrinkage was found to be 8.1%. By means of a non-rigid registration additional maximal local volume strains of 32% were determined.