Subject and scan information from a DICOM header to ASCII file

USAGE
dicom_get_info_from_header
dicom_get_info_from_header(dcm_files)
dicom_get_info_from_header(dcm_files,file_name)

INPUT
DICOM_GET_INFO_FROM_HEADER by itself will ask for the DICOM files
- DCM_FILES: list of DICOM files (cell array)
- FILE_NAME: output file name. Default: 'dicom_hdr_info'

OUTPUT
FILE_NAME with (if it is not given, 'dicom_hdr_info' in the same folder as the first DICOM file):
- file directory
- file name
- file size (kB)
- subject name
- subject ID
- gender
- birthday
- acquisition date
- age (in years)
- scan dimensions

Tested with DICOM files from Philips Achieva 3T R2.6