Life Cycle Management - Brief Proposal

1. Proposed Workitem: Life Cycle Management

• Proposal Editor: Pim Philipse
• Editor: Pim Philipse, Kinson Ho
• Date: N/A (Wiki keeps history)
• Version: N/A (Wiki keeps history)
• Domain: Radiology

2. The Problem

The life cycle of a radiological image often spans a much longer time than the life cycle of a PACS. Moreover, since the tail of the image life cycle mostly has to do with medico-legal reasons, older images are preferably stored on slow media on specialized storage systems, Long Term Archives (LTA) It is hard to convey the changes in storage requirements of images (online->nearline->offline->removed) between different systems.

3. Key Use Case

• A department wants to replace its PACS. It has stored the end-of-retention date of a number of studies in the PACS. These are studies that have to be kept for a longer time than the one that would be generated by applying the standard rules (age of image, patient, etc.). When the studies are sent to the LTA this information is lost, since it was stored in a proprietary way.
• Storage cost cold also be reduced if the PACS is able to convey to the LTA when a study moves from 'active' (patient is still being treated for problem related to the study) to 'inactive' (patient is considered cured), which can result in the study being moved to slower but cheaper storage media.
• The UK Imaging Informatics group is requesting the functionality of displaying, communicating and extending the end-of-retention date in its PACS Specification [1]:

6. CULLING OF IMAGES The PACS MUST be able to cull data from its archive based on local policies relating to data retention periods. PACS MUST be able to display the date of culling for an exam for ANY clinical user to see PACS must be able to inform other systems which also may store the same data (Backup Vendor Neutral DICOM archive, Hosted Datacentres etc)—using standard IOCM profile of IHE, when data is culled. The onus is on the medicolegal departments, Research Trials departments, Oncolology, and other departments if they wish to extend the date of deletion beyond the minimum retention periods of 8years or 25years after birth. Trust local processes/policies need to be in place so that these departments/clinicians can make a request to the PACS Office/PACS Team to manually extend the date of deletion at patient level.

EXAMPLE: Simple algorithm (choose the later date from the 4 dates below) to cull the patients IMAGE FOLDER

1. 8 years after last visit to X-ray dept
2. 25 years after DOB
3. 25 years after an obstetric ultrasound exam
4. Manual Extension of date of culling (medicolegal, oncology, research trials, slow growing tumour, hip replacement etc)

4. Standards and Systems

Systems: Image Manager / Image Archive, Image Display (viewing EOR date), Administrator (modifying EOR date), Life Cycle Manager. Standards: DICOM (SR?)

5. Discussion

The life cycle information can be conveyed through a DICOM Structured Report. A template can be defined that specifies sections in the SR for EOR date, active/inactive status, patient's death date, name of requestor. The use of Digital Signature should be considered. The SR has an author, this attribute can be used for traceability.

The Life Cycle Manager actor has to be aware that there can be multiple requests and that the latest request (content date of the SR) should be honoured. It can periodically scan the PACS and LTA for studies older than the minimum retention period, and delete those that do not fall under the standard extension rules, do not contain an EOR extension object, or contain a set of EOR objects of which the latest has an EOR date that lies in the past.