code: def call_dcm2nii(work_dir, arguments=''):
      
      if not op.exists(work_dir):
          raise IOError('Folder {} not found.'.format(work_dir))
  
      cmd_line = 'dcm2nii {0} "{1}"'.format(arguments, work_dir)
      log.info(cmd_line)
      return subprocess.check_call(cmd_line, shell=True)
docs: Converts all DICOM files within `work_dir` into one or more
      NifTi files by calling dcm2nii on this folder.
  
      Parameters
      ----------
      work_dir: str
          Path to the folder that contain the DICOM files
  
      arguments: str
          String containing all the flag arguments for `dcm2nii` CLI.
  
      Returns
      -------
      sys_code: int
          dcm2nii execution return code