Neuroimaging Data Processing/Data/Storage/Filetypes/DICOM

Digital Imaging and Communications in Medicine (DICOM)
Digital Imaging and Communications in Medicine (DICOM) is a standard of medical images and it normally severs to the output file format of AMI scanners. DICOM generally stores each slice as a separate file; these files are conventially named using numbers reflecting the slice number. Instead of separating the storage of raw image and metadata into two files, DICOM format keeps them together in one file, and the extraction of header informaiton is possible by special software. DICOM image data can be compressed to reduce the image size. Files can be compressed using lossy or lossless variants of the JPEG format, as well as a lossless Run-Length Encoding format, and the compression informaiton can be found in the header referring to "Transfer Syntax Unique Identification". Although DICOM is the standard for MRI scanners, it can't be used directly by most analysis softwares because of its slice storage form consuming huge space. So normally the DICOM format needs to be converted to other analysis format such as the popular NIfTI file format. DCM2NII is one of the software capable to convert images from the DICOM to NIfTI format used by FSL, SPM, MRIcron and many other brain imaging analysis tools. DCM2NII is a stand-alone program that is distributed with MRIcron, and it is compatible to Windows, Linux x86, Mac OSX PPC and Mac OSX x86.

Reference
1. Wiki-DICOM

2. http://www.mccauslandcenter.sc.edu/mricro/dicom/

3. http://www.mccauslandcenter.sc.edu/mricro/mricron/dcm2nii.html