Enhanced DICOM Objects - Brief Proposal
1. Proposed Workitem: Enhanced DICOM Image Profile
- Proposal Editor: <Name of author/editor/contact for the proposal>
- Editor: <Name of candidate Lead Editor for the Profile, if known>
- Domain: Radiology
2. The Problem
The original DICOM cross-sectional and multi-frame projectional objects needed a significant revision because of technology advancements, and the introduction of new acquisition protocols for which there was no standard description.
DICOM has created a new "enhanced family" of multi-frame image objects for MR, CT, PET, and most recently XA, XRF and 3D X-Ray (cone beam CT and tomosynthesis), and there is a new 3D Ultrasound object in development. In addition, new types of data such as raw data and MR spectroscopy can now be stored in a standard manner. Products have now entered the market that are capable of creating some of these new objects. There is a need to promote their adoption for storage in and retrieval from Image Managers and Archives as well as their display by Image Displays.
It is desirable to profile the multitude of possible clinical acquisition protocols supported by these objects in order to constrain alternative means of encoding the same information and to make feasible and interoperable the consistent hanging and display on workstations.
Additional profiles for improved query requirements for these objects, as well as per-frame retrieval of image contents may also be warranted.
3. Key Use Case
Profiles for a few clinical use cases have already be defined by WG16 and the committee for the advancement of DICOM, and have been demonstrated at the SCAR and RSNA conference by a number of vendors. DICOM WG16 and the NEMA (MITA) Advanced CT/MR Taskforce has requested that these profiles be elaborated and promoted to IHE profiles:
3.1 CT/MR Cardiac Imaging
New CT/MR cardiac images containing standard attributes for location and timing information.
3.2 MR Diffusion
MR diffusion images containing standard attributes for diffusion B values, direction and diffusion image type.
3.3 CT/MR Contrast Perfusion
Intra-venous contrast enhanced images containing standard attributes for timing and phase.
3.4 Multi-stack Spine Imaging
Images are acquired at multiple disk space levels of the spine such that multiple slices at each level are parallel to the disk space, each in a separate stack from slices at different angles through other disks. These images are exchanged in an interoperable way with standard attributes describing the stacks and their geometries.
3.5 MR Spectroscopy
Single-voxel, multi-voxel or multi-slice 1D MR spectra are exchanged with reference and metabolite images that contain information to allow correct display, post-processing and analysis.
Consider adding PET-CT to this growing list (Comment added by J. Wallis)
4. Standards & Systems
For the use-cases proposed, the Enhanced CT, MR and MR Spectroscopy SOP Classes provide the necessary functionality to be profiled.
For additional query and retrieval, DICOM Sup 119, Instance and Frame Level Retrieve SOP Classes, may or may not be sufficiently advanced in its process through the standardization process to use in this profile.
The use cases may constitute the basis for a new IHE CT/MR Image profile, which specifies for each all that are applicable of the following:
- The required attributes (mostly already defined as mandatory in the standard),
- The relevant functional grouping
- The content of the dimension module
- The use of a Real World Values LUT
- The use of a Supplemental Color LUT
- The relevant attributes for display on a workstation