X3D and Volume Rendering
The reproduction of volume-rendered presentations of medical image data across platforms and the healthcare enterprise presents several challenges, especially due to data and view incompatibilities and lock-in to proprietary systems. But, explicit 3D visual presentations of medical images can provide significant advantages because this type of rendering is more truly representational of the object being imaged (the human body), it is a more intuitive and easily-read format. It is increasingly common to render a three dimensional (3D) model from a CT, MRI, PET and X-Ray scan to better interpret the size, orientation and other spatial relationships of the patient’s anatomy as necessary for diagnosis and therapy.
Until recently, there was little hope of interoperability for interactive 3 and 4 -D presentations to break out of the hospital PACS and to be archived and shared across the enterprise. With the continual advancement in computing and graphical power over the last decade, specialized workstations and software capacity has become available to display this type of 3D imaging on a common laptop. It is an imminent future when the handheld tablets on the market are capable of sustained hardware-accelerated graphics performance.
Our original work (Web3D.org) for TATRC (W81XWH-06-1-0096) developed and demonstrated the integration of expressive, volume rendering over the web and across several client platforms. This set of functionalities was validated by industry experts and formalized into a specification with two separate, multi-platform implementations. The new component includes an expressive range of volume rendering styles as well as means to assign separate styles to different segments, and to create isosurfaces within the volume. In 2012, this specification has ultimately become an official part of ISO X3D 3.3.
Much of the required functionality is specified in the X3D 3.3 draft International Standard, including the Texturing3D Component (Clause 33) and the Volume Rendering Component Clause 41) to support several compose-able styles for Volume Rendering for Medical Imaging, geology and other non-invasive sensing modalities. A Medical Interchange Profile of X3D nodes is also defined in Annex L : http://www.web3d.org/files/specifications/19775-1/V3.3/Part01/MedInterchange.html. The node set of the X3D 3.3. Medical Interchange Profile collects nodes for volume and polygon rendering, lighting, text and animation; it has been demonstrated to meet the requirements of several key clinical and research applications including diagnosis, surgical planning, education and training and informed consent.
Recent Resource Releases
- Technical Report from Virginia Tech Computer Science on the capabilities and requisite techniques for X3D Volume rendering: Polys, Dr. Nicholas and Wood, Mr. Andrew and Shinpaugh, Mr,. Patrick (2011) Cross-Platform Presentation of Interactive Volumetric Imagery. Technical Report TR-12-03, Computer Science, Virginia Tech Advanced Research Computing.
- X3D-Edit 3.2 supports the Texturing3D and Volume Component nodes by DTD and Schema!
- A presentation made at the SIGGRAPH 2011 Medical BOF is available here
- A video of compiled examples from Virginia Tech (rendered w/ H3D.org) is available here (64 MB)