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MGH Neonatal/Pediatric ADC Atlases (0-6 years)
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Reference
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Y Ou, N Reynolds, R Gollub,, R Pienaar, Y Wang, T Wang, D Sack, K Andriole, S Pieper, C Herrick, S Murphy, P Grant, L Zollei, "Developmental Brain ADC Atlas Creation From Clinical Images". Organization for Human Brain Mapping (OHBM). (2014)  [PDF: http://www.nmr.mgh.harvard.edu/~you2/publications/BabyAtlasing_OHBM14.pdf]


The journal version pending.


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Population and Age Groups
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Totally 308 ADC maps from 308 subjects were queried and collected using the mi2b2 workbench (https://www.nmr.mgh.harvard.edu/lab/mi2b2). These subjects were divided into the following 10 age groups:

- neonates (first 2 weeks of life)
- the rest of the quarter 1
- quarter 2
- quarter 3
- quarter 4
- year 1-2
- year 2-3
- year 3-4
- year 4-5
- year 5-6


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Atlases Reconstruction
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In each age group, all ADC maps were group-wise registered to create a (virtual) space representing the mean anatomy/geometry of all subjects in this age group. In this mean space (atlas space), we have derived the voxel-wise mean ADC values (the atlas) and the voxel-wise standard deviation ADC values.

We released all atlases (mean and stdev maps) in its original space and rigidly aligned in the year1-2 atlas space.


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Imaging Protocol
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Diffusion weighted images were acquired on a Siemens Trio 3T scanner at MGH. The imaging protocol  was: time of repetition (TR) – 7500~9500 ms, echo time (TE) – 80~115 ms, b value – 1000 s/mm2, image  size – 256x256x60 voxels, voxel size – 0.86x0.86x2.0 mm3. ADC maps were generated by scannerembedded diffusion tensor imaging software. We directly used them in our study. 



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Folder Structures and File Conventions
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There are three folders:
|- MGH_ADC_Atlases_nativespace         : atlases are in their own space
|- MGH_ADC_Atlases_registered_rigid    : atlases are all rigidly registered into the space of the atlas for the first age group (week0-1)
|- MGH_ADC_Atlases_registered_4Ddramms : atlases are deformably  registered into the space of the atlas for the first age group (week0-1)
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   |--- alldeformations               : all deformations from the follow-up atlases into the atlas of the first age group (week0-1)
   |--- allatlases.nii.gz             : 4D stack of all atlases rigidly aligned in the space of atlas_week0-1
   |--- reg_allatlasesdramms4D.nii.gz : 4D stack of all atlases deformably aligned in the space of atlas_week0-1
   |--- 4Djacobians_forTBM.nii.gz     : 4D stack of all jacobian determinant maps which encode voxel-wise volumtric expansion or shrinkage ratio (follow-up_atlases:atlas_week01