Annex A Example of DICOMDIR File Content(Informative)

This Annex provides an example of a File content that is based on selected aspects of the example introduced in PS 3.3 for the Basic Directory Information Object. This is not a normative Annex. It is only an illustration, which is simply intended to help the reader better understand the organization of a DICOM Directory stored in a DICOMDIR File.

A.1 Simple Directory Content Example

Table A.1-1 shows in a simplified manner, the content of a simple DICOMDIR File. Values of elements are noted between square brackets (e.g. [1.2.840.10008.34.7.6]). Byte Offsets are shown by symbolic Values noted between brackets (e.g. {1493}).

Table A.1-1Directory Content Example

Meta-Info 128 bytes 4 bytes 0002,0000 0002,0001 0002,0002 0002,0003 0002,0010 0002,0012 ... File Preamble [all bytes set to 00H] DICOM Prefix [DICM] Group Length File Meta-Information Version [0001] SOP Class UID [1.2.840.10008.1.3.10] SOP Instance UID [1.2.840.23856.36.45.3] Transfer Syntax UID [1.2.840.10008.1.1] Implementation Class UID [1.2.840.23856.34.90.3] ...
File-set Identification 0004,1130 ... File-set ID [EXAMPLE] ...
General Directory Information 0004,1200 0004,1202 0004,1212 ... 0004,1220 Offset of First Record of Root Directory Entity {1829} Offset of Last Record of Root Directory Entity {6F18} File-set Consistency Flag [0000H] ... Directory Record Sequence. This Data Element Value includes the following Sequence of Items.

{1829} Item Tag FFFE,E000 Item Data Element (includes the following Data Elements)
Study 1 Directory Record 0004,1400 0004,1410 0004,1420 ... Offset of the next Dir. Record in Dir. Entity (not shown in example) Record In-use Flag [FFFFH] Offset of Referenced Lower Level Directory Entity {2299} ...
0004,1430 Directory Record Type [STUDY]
Selection Keys 0020,000D 0020,0010 ... Study Instance UID [1.2.840.4656.23.4568745] Study ID [srt78UJ] ....
Item Del. Tag FFFE,E00D Item Delimitation Tag is present only if Item is of undefined length

{2299} Item Tag FFFE,E000 Item Data Element (includes the following Data Elements)
Series 1 Directory Record 0004,1400 0004,1410 0004,1420 ... Offset of the next Dir. Record in Dir. Entity (not shown in example) Record In-use Flag [0FFFFH] Offset of Referenced Lower Level Directory Entity {2681} ...
0004,1430 Directory Record Type [SERIES]
Selection Keys 0008,0060 0020,0011 ... Modality [NM] Series Number [2] ...
Item Del. Tag FFFE,E00D Item Delimitation Tag is present only if Item is of undefined length

{2681} Item Tag FFFE,E000 Item Data Element (includes the following Data Elements)
Image 1 Directory Record 0004,1400 0004,1410 0004,1420 ... Offset of the next Dir. Record in Dir. Entity {3419} Record In-use Flag [FFFFH] Offset of Referenced Lower Level Directory Entity [00000000H] ...
0004,1430 Directory Record Type [IMAGE]
0004,1500 0004,1510 0004,1511 0004,1512 Referenced File ID [DIR\TDRI\3856G3] Referenced SOP Class UID in File [1.2.840.10008.5.1.4.1.1.5] Referenced SOP Instance UID in File [1.2.840.34.56.78999654.234] Referenced Transfer Syntax UID in File [1.2.840.10008.1.2.1]
Selection Keys 0008,0018 0020,0013 ... Image SOP Instance UID [1.2.840.34.56.78999654.234] Image Number [1] ...
Item Del. Tag FFFE,E00D Item Delimitation Tag is present only if Item is of undefined length

{3419} Item Tag FFFE,E000 Item Data Element (includes the following Data Elements)
Image 2 Directory Record 0004,1400 0004,1410 0004,1420 ... Offset of the next Dir. Record in Dir. Entity (not shown in example) Record In-use Flag [FFFFH] Offset of Referenced Lower Level Directory Entity [00000000H] ...
0004,1430 Directory Record Type [IMAGE]
0004,1500 0004,1510 0004,1511 0004,1512 Referenced File ID [DIR\TDRI\3856G7] Referenced SOP Class UID in File [1.2.840.10008.5.1.4.1.1.5] Referenced SOP Instance UID in File[1.2.840.34.56.78999654.235] Referenced Transfer Syntax UID in File [1.2.840.10008.1.2.2]
Selection Keys 0008,0018 0020,0013 ... Image SOP Instance UID [1.2.840.34.56.78999654.235] Image Number [2] ...
Item Del. Tag FFFE,E00D Item Delimitation Tag is present only if Item is of undefined length

{6F18} Item Tag FFFE,E000 Item Data Element (includes the following Data Elements)
Patient C Directory Record 0004,1400 0004,1410 0004,1430 ... Offset of the next Dir. Record in Dir. Entity {00000000H} Record In-use Flag [FFFFH] Directory Record Type [PATIENT] ...
Selection Keys 0010,0010 0010,0020 .... Patient Name [Patient C] Patient ID [523-61-8765] ....
Item Del. Tag FFFE,E00D Item Delimitation Tag is present only if Item is of undefined length

Sequence Delimitation Tag FFFE,E0DD Used only if the Directory Record Sequence (0004,1220) is of undefined length to delimit the end of the Value of the Directory Record Sequence Data Element.
A.2 Example of DICOMDIR File Content with Multiple Referenced Files

This section was previously defined in DICOM. It is now retired. See PS 3.3-1998.