Header Image
Home / ISIC Project / ISIC Melanoma Project: Metadata Working Group

ISIC Melanoma Project: Metadata Working Group

Aim

The aim of this working group is to develop a metadata model for digital images for dermatology.

Deliverables

  1. Metadata specification(s) for digital dermatology images that is informed by
    • Existing DICOM modules
    • ISIC Melanoma Project Technology and Technique standards Working Group and
    • Existing vendor metadata attributes
  2. EXIF to DICOM mapping
  3. Knowledge transfer and education (e.g. conference presentations, meeting presentations, publications) on the use of DICOM in dermatology to allow the dermatology community to become aware of DICOM and how it functions; thereby allowing persons to form a favourable or unfavourable attitude toward the use of DICOM.

Strategy

There is general consensus from members of the ISIC Melanoma project that the metadata initiative is best advanced using the Digital Image Communication in Medicine (DICOM) metadata model.

Adopting the DICOM metadata model involves developing an Information Object Definition (IOD) for digital dermatology images. An IOD is a specification that documents metadata attributes and logically groups and structures these attributes.

DICOM creates an IOD for every different type of DICOM object (e.g. CT image IOD, MR image IOD, Ophthalmic Photograph IOD, Softcopy presentation state IOD, Basic Text Structured Report IOD). Many of the modules that have been created for other IODs can be re-used when we create a dermatology specific IOD. The reusable modules include: patient, general study, general series, general equipment and general image.

Hence, the scope of our work is to create a Dermatology Photography IOD but more specifically create the dermatology specific modules for this IOD and re-use the already defined modules (patient, general study, general series, general equipment and general image).

To create the dermatology specific modules we will follow a bottom-up approach. That is, we will identify the attributes we want to store and then organise these into modules. We need to cross reference the identified attributes with the DICOM data dictionary to check if the attribute already exists. (There is the possibility that many of the photographic attributes will exist as there is a mature Ophthalmic Photography IOD). If the attributes do not need to exist we need to propose them as new DICOM attributes.

How will we identify which attributes we need to store?

The metadata working group have identified a two-step strategy to identify dermatology specific attributes.

Step 1: Technology and techniques standards from the ISIC Melanoma project

The ISIC technology and technique working groups will establish standards for dermatological imaging which may include:

  • Technical parameters for images (e.g. spatial resolution, colour resolution, image compression algorithms etc.)
  • Acquisition parameters (e.g. flash, light source, aperture, focal length etc.)
  • Imaging techniques (e.g. patient orientation, pose,  having object of known size” to be included in the image for scaling, flag indicating if the patient is identifiable from image)

The outcomes of this working group will inform us of many of the attributes that will need to be stored in the metadata model— for example, if a minimum spatial resolution is recommended by technology and technique working group we will need to store spatial resolution in the metadata. This will allow auditing of dermatology images to ensure the meet the recommended metrics for spatial resolution.

Step 2: Identify metadata attributes from IODs implemented by dermatology imaging vendors

The metadata working group will compile a list of digital dermatology imaging products. Products will be assessed for use of DICOM.  Example images from the vendor +/- the products DICOM conformance statement will be examined for metadata attributes that could contribute to the dermatology specific IOD. It is envisaged that these attributes may be stored in private (proprietary) elements due to there being no dermatology specific IOD available for use.

Identifying the source of metadata attributes

Exchangeable image file format (EXIF) is a metadata standard that is supported by almost all digital camera manufacturers including smartphone devices. EXIF metadata tags are stored within the image file (e.g. JPEG, TIFF) produced by the device.

The metadata working group will map EXIF metadata elements to DICOM attributes. The rationale of performing this mapping is to allow the DICOM metadata attributes to be populated “automatically” by parsing the image file as opposed to the manual entry of metadata element.

Education and knowledge transfer

If DICOM is adopted by the dermatology community there is the potential to not only to use the DICOM metadata model but to also use other aspects of the DICOM standards. DICOM is the “building block” of picture archiving and communication systems (PACS). Hence, there is the potential to:

  • manage dermatology images within an existing radiology (or a new dermatology specific) PACS;
  • to utilize teleradiology systems for teledermatology;
  • leverage off existing work to integrate DICOM images into the patient electronic medical record;
  • use the DICOM quality control processes to calibrate monitors to ensure the consistent display of images (e.g. color softcopy presentation state, color display function); and
  • use DICOM workflows processes (e.g. DICOM modality worklists) for efficient, accurate and scalable imaging workflows.

A standard image format would allow dermatological images from different modalities (e.g. dermoscopy, clinical macro photography, regional overview photography, whole body imaging, photomicrographs, reflectance confocal microscopy and multispectral imaging) to be viewed side-by-side on a single non-proprietary workstation thereby allow cross-modality validation of diagnosis. For further reading on the advantages and disadvantages of DICOM see Why DICOM? .

There are probably few dermatologists who have used DICOM. Hence, DICOM may be seen as unnecessarily complicated and cumbersome. (see Dermatologists have options for storing and accessing photos in their records ).  One of the key roles of the metadata working group is knowledge transfer and education (e.g. conference presentations, meeting presentations, publications) on the use of DICOM in dermatology. This is  to allow the dermatology community to become aware of DICOM and how it functions thereby allowing persons to form a favourable or unfavourable attitude toward the use of DICOM.

The key innovation adoption criteria of trialability and observability will also need to increase for the dermatology community to make informed decision. Innovations such as a DICOM camera that natively acquires images in DICOM format (and stores them to a PACS archive) may increase exposure to DICOM.

Resources and further reading

ISIC Metadata Working Group publications

Article / news item Author Publication location
 Presentation: ISIC Working Group Liam Caffery ISIC Meeting, San Francisco, USA 2015
 Presentation: Metadata Working Group Update Liam Caffery ISIC Meeting, Vancouver, Canada,  2015
 The Relationship Between Imaging Workflow, DICOM objects, and metadata Liam Caffery RadAIM conference, Gold Coast, Australia 2015
 Why DICOM? Liam Caffery RadAIM conference, Gold Coast, Australia 2015

 

Public domain resources and readings

Article / news item Author/s Publication location Year
An Analysis of DICOM and Its Use for Image Management and Communication in Store-and-Forward Telehealth Liam Caffery Caffery LJ An Analysis of DICOM and Its Use for Image Management and Communication in Store-and-Forward Telehealth In: Telemedicine: Emerging Technologies, Applications and Impact on Health Care Outcomes, Eds. Raad HK Nova Science, 2015.

[Book chapter]

2015
Review of Dicompass DICOM Camera App for Android Dawn Cram, Richard Stratton and Shawn Clark Journal Digital Imaging †

[Journal Editorial]

2015
Dicompass  DICOM camera app MEDORO s.ro. Google App store

[App store]

2015
Imaging experts mull over color challenges David Clunie Auntminnie.com

[Website] †

2015
A DICOM file contains everything? David Clunie (Moderator) comp.protocols.DICOM

(Google Groups – DICOM)

[Website] †

2015
Dermatologists have options for storing and accessing photos in their records Morris Stemp American Academy of Dermatology Association †

[Website]

2012
Teledermatology PACS

 

 

Liam Caffery Soyer HP, Binder M, Smith AC and Wurm EMT (Eds). Telemedicine in Dermatology, Springer Press, 2012. †

[Book Chapter]

2012
DICOM Tutorial Roni DICOM is easy

[Website]

2011
DICOM Dermatology Whitepaper –  A proposal for DICOM  Working Group 19 Brian C Madden DICOM Home Page – NEMA

[Website]

2009
Teledermatology project moves toward DICOM standards Wayne Forrest Auntminnie.com †

[Website]

2008

† Access to this resource may require the user to create an account or have library access.

 

 

 

Top