I recently attended the 2012 European League Against Rheumatism (EULAR) Annual Congress of Rheumatology in Berlin where a lot of novel clinical research on osteoarthritis, arthritis, and rheumatism was presented. Dr. Harris Ahmad, my colleague at BioClinica, and I co-authored two posters with Desiree van der Heijde and her team.
If you are interested in this area, the abstracts from Berlin and past Congresses are freely available on a searchable website.
One of the many abstracts that caught my attention in the osteoarthritis imaging and diagnostics procedures session at EULAR 2012 was the oral presentation from Torsten Lowen (Friedrich-Alexander-Universität Erlangen-Nürnberg): "QCT indicates locally increased bone mineral density (BMD) in regions of bone marrow lesions (BML) segmented on MR images."
Bone marrow lesions (BML) are one of the hallmarks of osteoarthritis (OA). These are edema-like lesions and cysts in the subchrondal bone, and in established osteoarthritis (OA) are associated with knee pain, cartilage loss on MRI images and radiological progression of OA. New insights into the pathophysiology of OA may come from research into subchondral bone and the relationship between BMLs and bone mineral density (BMD).
Lowen and his German research colleagues, in a scientifically clever study, fused CT images with MRI scans. They used the CT images to obtain quantitative CT (QCT) and hence bone mineral density (BMD) of defined regions. They used the fused images to map the BML’s identified on MRI to the CT scans and were therefore able to elucidate the BMD in and around the identified BML's. They compared 18 BMLs detected on the MR images of 14 patients with knee OA, to CT scans in a reference group of patients without BMLs. The conclusion of the research was that, "locally increased BMD at the BML locations seems to be present in patients with knee OA."
Despite the elegance of the osteoarthritis imaging methodology, however, I am not convinced that the results of increased BMD can be relied upon. In the Q&A session the researchers stated that they had not checked patient histories concerning the appearance and resolution of BMLs. BML's are not stable findings and can come and go in a matter of weeks. Therefore, they could not be sure that any of the control group images did not contain a BML that had resolved. This means that without knowing more about the subject's history and prior images, we can’t be sure that BMLs have a higher density, as was their conclusion.
BMLs are an important target in the prevention and treatment of osteoarthritis, so I look forward to hearing more about developments in this specific area of osteoarthritis imaging at future scientific meetings and report back to you what I learn.
Colin Miller will attend the Osteoarthritis Research Society International (OARSI) 6th International Workshop on Osteoarthritis Imaging combined with the OARSI OA Biomarkers Workshop III – Imaging Biomarker Validation and Quantification July 12 – 14 in Hilton Head, South Carolina. Dr. Miller will conduct a pre-course workshop on the Practical Use of Imaging Biomarkers in Clinical Studies/Trials.