PS 3.15: E.2 then defines the Basic Application Level Confidentiality Profile which describes how to apply the scheme above with a number of options that determine the scope of protection that is provided. These definitions allow a system to follow a standard procedure and document in a standard way the behavior of that system.
TCIA utilizes the RSNA Clinical Trials Processor (CTP) software in conjunction with caBIG's National Biomedical Imaging Archive (NBIA) to de‐identify and host the images in the archive. The Cancer Imaging Program's Informatics Team has been working closely with the developer of CTP since 2009 to incorporate support for this standard as it was being defined by WG18. A full summary and time line of this project can be found athttps://wiki.nci.nih.gov/display/CIP/Incorporation+of+DICOM+WG18+Supplement+142+into+CTP.
- Clean Descriptors Option: Removal of identification information from descriptive tags which contain unstructured plain text values over which an operator has control
- Retain Modified Longitudinal Temporal Information Options: Modification of tags that contain dates or times
- Retain Patient Characteristics Option: Retention of physical characteristics of the patient that are descriptive rather than identifying information (e.g. metabolic measures, body weight, etc.)
- Retain Device Identity Option: Retention of information about the characteristics of the device used to perform the acquisition
- Retain Safe Private Option: Retention of Private Attributes confirmed not to contain PHI
DICOM Tag Sniffer
In order to simplify our ability to implement some of the "clean" instructions specified in DICOM PS 3.15 a new tool was developed to help inspect the contents of DICOM elements which allow free text entry by a technician and Private Tags for potential PHI. This tool scans a folder and included subfolders for DICOM objects and produces several different outputs that depend on the mode used and input profiles. The software reads each DICOM object and iterates through each public and private element. The software then uses the profiles below to determine whether to retain the value of the element for later inspection:
We believe this tool might be useful to the rest of the research community and so it's been made freely available as an open source application. We have also created documentation for how a researcher could utilize in the context of their own projects. This can be found at https://mirgforge.wustl.edu/gf/project/dicomtagsniffer/.
TCIA De-identification Work Flow