The Latest Developments in Osteoarthritis Imaging

I will be at the 2010 World Congress on Osteoarthritis in Brussels later this week. This conference, organized by the Osteoarthritis Research Society International (OARSI), runs from September 23 to September 29 and is a great opportunity to identify some of the new osteoarthritis imaging work that is going on in the field.

Osteoarthritis (OA) is a common degenerative disease of the joints that is characterized by cartilage breakdown. It affects about 10% of adults in Western countries.  Interestingly last year a work force put together by the FDA to further characterize OA defined it as a disease of the whole joint and not just focused on the cartilage.

One of the areas that I am involved with is the development of imaging techniques that will aid drug development for OA.   The aim is to detect changes in disease progression or regression, so that clinical trials can be done over short periods of time and show drug efficacy in early stages of the disease.

At BioClinica, we collaborate with Chondrometrics to provide cartilage segmentation from MRI scans.  This allows us to generate quantitative endpoints and quantitative parameters for characterizing cartilage morphology in OA.

The current imaging modality of choice in OA research is magnetic resonance imaging (MRI).  This can be used to assess the biochemical state of cartilage.  However, for registration studies with the FDA plain films have to be used, and we are also finding that there is more information about the disease in the plain films from just the basic joint space narrowing.

One of the problems with using MRI for this is that it is usually invasive and requires the injection of a contrast agent.  To overcome this, researchers have looked at the properties associated with sodium ions that are present in cartilage and have sought to develop MRI techniques that measure these. Researchers have, however, run into problems differentiating between sodium ions in cartilage and in the synovial fluid. Those problems appear to be have been solved by a team at NYU, in a recent paper published in the Journal of Magnetic Resonance.

In their paper on the use of sodium inversion recovery MRI of the knee joint in vivo at 7T, a team led by Alain Jerschow at NYU was able to isolate two pools of sodium ions and obtain images exclusively from cartilage tissue.

The technique uses a 7T MRI which is only available in research centers, rather than the more standard 3T magnet.  While this OA imaging technique could be useful for the elucidation of therapeutic effectiveness, I don’t think it is going to be too useful for the clinical diagnosis or management of a disease that is mainly driven by the symptoms.

However, I will be monitoring the progress of this research and its potential application to osteoarthritis clinical trials, in particular the cost/benefit compared to existing OA imaging techniques.

I look forward to reporting back from Brussels on the latest developments in OA imaging that are presented at OARSI. If you are attending the meeting, do let me know as I would be pleased to meet up if you have an interest in this area.

Sources:

1. http://www.oarsi.org/meetings/10Congress/secondary.php?section=Preliminary_Program
2. http://www.oarsi.org/
3. chondrometrics.com/4613.html
4. Madelin G, Lee J, Inati S, Jerschow A. Sodium inversion recovery MRI of the knee joint in vivo at 7T. JMR. Published online. Aug. 13, 2010. http://dx.doi.org/10.1016/j.jmr.2010.08.003