MRI volume and coordinate-system I/O (volumes, voxel geometry, transforms).
constexpr int MRI_MGH_VERSION
constexpr float COR_PIXEL_SIZE
constexpr int MGH_TAG_OLD_MGH_XFORM
constexpr int MRI_ALL_FRAMES
constexpr int MRI_MGH_DATA_OFFSET
constexpr int MGH_TAG_OLD_SURF_GEOM
constexpr int MGH_TAG_MGH_XFORM
constexpr int MRI_NO_FRAMES
constexpr int MRI_MGH_HEADER_FIXED_SIZE