Annex U Secure Digital Card Removable Devices

U.1 DICOM Mapping to media formats

Only one DICOM file set shall be stored in the first partition of a partitioned device. If the device is not partitioned, only one DICOM file set shall be stored on the device.

U.1.1 File System

The file system employed on these media shall be the FAT16 file system. The cluster, sector, head, and related information obtained from the boot sector of this partition shall be utilized by the file system to determine proper access to this media (see Annex A).

Filenames shall be further restricted to be in compliance with the File ID rules specified in Part 10. The File ID shall be the same as the filename.

Notes: 1. These rules limit the character set to being a subset of the DICOM default G0 character set, limit the filenames to be no more than 8 characters, and limit the directory tree to be no more than 8 levels deep. All of these restrictions are needed to comply with the most limited of the removable media. The selection of FAT16 reflects the actual usage of these newer media.

2. Some operating systems default their format command for larger capacity media to FAT32. FAT32 is not always compatible with FAT16 and should not be used.


U.2.1 Partitioning

These media may be partitioned or unpartitioned. The more common usage is partitioned.

Note: Operating system support for unpartitioned media varies. Most current operating systems expect partitioned media. Some restrict their support further and only support access unpartitioned media or to the first partition of partitioned media.

U.3 Physical Media interface

The physical, electrical, signaling, and software interface shall comply with the SD Card Specification 1.0 and shall in addition have the following characteristics:

  1. The size shall be a “normal” SD card (24mm x 32mm x 2.1mm)