Neonatal brain MRI normalization with 3-D cerebral sulci registration

MR image registration (IR) has been used in brain function analysis, voxel-based-morphometry, etc. The conventional IR methods mainly use MR signal based likelihood. However, they cannot prevent miss registration of different gyri because they do not evaluate correspondence of sulci. Also, we cannot directly apply methods for adult brain to neonatal brain because there are large differences in MR signal and sulcal width. This paper focuses on neonatal brain MR images, and introduces a new feature called sulcal-distribution index (SDI), which is calculated from MR signal around the cerebral surface. Next, this paper proposes a non-rigid 3-D IR method based on a flattening with SDI. The likelihood used is mutual information of SDI. The new method evaluates the correspondence of cerebral sulci. And, the method will be effective for neonatal brain in which the accurate delineation of cerebral surface is difficult because the method evaluates the MR signal around the cerebral surface. Results in 3 neonates (modified age; 3-5 weeks) showed that the method registered one brain with the other brain successfully.