RESEARCH ARTICLE Subject Based Registration for Individualized Analysis of Diffusion Tensor MRI

Registration of subject and control brains to a common anatomical space or template is the basis for quantitatively delineating regions of abnormality in an individual brain. Normally, a brain atlas is chosen as the template. Limitations in the registration process result in persis-tent differences between individual subject brains and template, which can be a source of error in an analysis. We propose a new approach to the registration process where the sub-ject of interest is the registration template. Through this change, we eliminate errors due to differences between a brain template and a subject’s brain. We applied this method to the analysis of FA values derived from DTI data of 20 individual mTBI patients as compared to 48 healthy controls. Subject-centered analysis resulted in identification of significantly fewer regions of abnormally low FA compared to two separate atlas-centered analyses, with sub-ject-centered abnormalities essentially representing the common subset of abnormal low FA regions detected by the two atlas-centered methods. Whereas each atlas-centered approach demonstrated abnormalities in nearly every subject (19/20 and 20/20), the sub-ject-centered approach demonstrated abnormalities in fewer than half the subjects (9/20)