Construction of population-specific Indian MRI brain template: Morphometric comparison with Chinese and Caucasian templates.
Bhalerao GV., Parlikar R., Agrawal R., Shivakumar V., Kalmady SV., Rao NP., Agarwal SM., Narayanaswamy JC., Reddy YCJ., Venkatasubramanian G.
OBJECTIVE: Spatial normalization of brain MR images is highly dependent on the choice of target brain template. Morphological differences caused by factors like genetic and environmental exposures, generates a necessity to construct population specific brain templates. Brain image analysis performed using brain templates from Caucasian population may not be appropriate for non-Caucasian population. In this study, our objective was to construct an Indian brain template from a large population (N = 157 subjects) and compare the morphometric parameters of this template with that of Chinese-56 and MNI-152 templates. In addition, using an independent MRI data of 15 Indian subjects, we also evaluated the potential registration accuracy differences using these three templates. METHODS: Indian brain template was constructed using iterative routines as per established procedures. We compared our Indian template with standard MNI-152 template and Chinese template by measuring global brain features. We also examined accuracy of registration by aligning 15 new Indian brains to Indian, Chinese and MNI templates. Furthermore, we supported our measurement protocol with inter-rater and intra-rater reliability analysis. RESULTS: Our results showed that there were significant differences in global brain features of Indian template in comparison with Chinese and MNI brain templates. The results of registration accuracy analysis revealed that fewer deformations are required when Indian brains are registered to Indian template as compared to Chinese and MNI templates. CONCLUSION: This study concludes that population specific Indian template is likely to be more appropriate for structural and functional image analysis of Indian population.