Ashok Srinivasan MD, Presenter: Nothing to Disclose

Suyash Mohan MD, Abstract Co-Author: Nothing to Disclose

Younghen Lee MD, Abstract Co-Author: Nothing to Disclose

Sarah Berini, Abstract Co-Author: Nothing to Disclose

David Irani, Abstract Co-Author: Nothing to Disclose

Tiffany Braley, Abstract Co-Author: Nothing to Disclose

Benjamin Segal, Abstract Co-Author: Nothing to Disclose

To analyze the differences in diffusion tensor imaging (DTI) derived metrics of the corpus callosum in relapsing remitting and secondary progressive multiple sclerosis patients with enhancing and non-enhancing lesions

The study was approved by the IRB. DTI images of 32 patients with relapsing remitting MS (RRMS) and 14 patients with secondary progressive MS (SPMS) were retrospectively analyzed on a GE Advantage workstation to generate fractional anisotropy (FA) and mean diffusivity (MD) maps. FA and MD values were calculated by freehand regions of interest at the level of genu, mid-body and splenium of corpus callosum by two neuroradiologists who were blinded to clinical information. The conventional images were also reviewed to enable generation of 4 groups:- I - RRMS with no lesion enhancement II - RRMS with enhancing lesions III - SPMS with no lesion enhancement IV- SPMS with enhancing lesions Differences in FA and MD between groups I and II, and between III and IV were studied using the unequal variance independent samples t-test. Differences were evaluated in all three regions of the corpus callosum.

Significant differences were seen in mean FA values in all three regions of the CC between groups III and IV by reader I (p=0.004, 0.01 and 0.005 for genu, body and splenium) and in the genu and splenium of CC by reader II (p =0.04, 0.001 respectively). All three regions of the CC demonstrated lower FA values in group IV (enhancing SPMS) compared to group III. No significant differences in MD values were seen between groups III and IV in all CC regions by both readers. Also, none of the regions in the CC showed significant differences in MD and FA values between groups I and II (for both readers). 

Fractional anisotropy of SPMS patients with enhancing lesions appears to be significantly lower than that seen in SPMS patients with no actively enhancing foci, suggesting that there may be more white matter damage in the former. Hence we may be able to use FA as a marker for disease activity and possibly for follow-up. We are presently studying longitudinal FA changes prospectively in SPMS patients and its correlation with clinical outcome measures to better understand pathophysiology of SPMS.

FA of the corpus callosum can serve as a marker for disease activity in SPMS patients thereby facilitating prognostication, management decisions and follow-up.

Srinivasan, A, Mohan, S, Lee, Y, Berini, S, Irani, D, Braley, T, Segal, B, Diffusion Tensor Imaging of the Corpus Callosum in Multiple Sclerosis Patients: Differences between Enhancing and Nonenhancing Cohorts.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9001605.html