Multimodality Registration for Radiation Oncology-II

Multimodality Registration for Radiation Oncology-II (MMRO-II) registers image sets specifically for Radiation Oncology.

Summary

Transmitting image registration information within the Radiation Oncology domain is important to the process of external beam radiation treatments. Currently, registration can be performed on individual workstations designed for that purpose and planning systems, but the results are not readily transferable between systems, often due either to proprietary or inconsistent implementations. This profile addresses the ability to convey registered data from one system to another for further processing. This profile addresses issues dealing with multiple coordinate systems but does not specifically address the issue of repeatable fused displays. A collection of DICOM objects exists to address the problem. Their use is constrained and clarified to avoid misinterpretation and promote compatibility.

Benefits

Defines how DICOM objects for spatial registration and the images themselves are created, stored, queried, retrieved, processed and displayed
Allows multiple systems to use a single Spatial Registration Object, improving consistency between systems for region-of-interest and radiation dose display
Verifies the consistency and correctness of patient orientation displays
Improves safety by specifying images within a Frame of Reference that are associated with the Frame of Reference Definition

Details

This Integration Profile specifies how images, RT Structure Sets, RT Doses, and associated spatial registration information can be exchanged, stored, processed and displayed. For a display workstation, it is essential that a workstation correctly identifies the corresponding image sets, matches data from single-slice and multi-slice datasets, matches coordinate systems, and performs spatial translations. The use of relevant DICOM objects (Spatial Registration) is clarified and constrained in order to avoid misinterpretation.

Image Registration Integration Profile focuses on content for image registration and does not define a registration workflow. Such workflow could be managed by using mechanisms described in the Post-Processing Workflow Integration Profile. The Image Registration Integration Profile currently only handles rigid registration. The intention is to add deformable registration as an extension to the Profile in the future.

The Image Registration Profile does not specify the use of quantification methods for the image data that is created or displayed. In particular interoperability for PET Standard Uptake Values (SUV) is considered a relevant future work item for IHE. Note that vendors may wish to provide SUV capability even though not required under this Profile.

NOTE: This profile supercedes the MMRO profile. It corrects MMRO for changes made in the DICOM Spatial Registration Object in 2010. In addition, it requires that images known to be consistent with a Frame-of-Reference in an SRO be listed. This allows a user to know that the SRO referenced can be trusted with these specific images.