Fernanda Cristina Rueda Lopes MD, Presenter: Nothing to Disclose

Raquel Ribeiro Batista MD, Abstract Co-Author: Nothing to Disclose

Tadeu Takao Almodovar Kubo, Abstract Co-Author: Nothing to Disclose

Roberto Cortes Domingues MD, Abstract Co-Author: Nothing to Disclose

Romeu Cortes Domingues MD, Abstract Co-Author: Nothing to Disclose

Emerson L. Gasparetto MD, Abstract Co-Author: Nothing to Disclose

To investigate with the diffusion tensor MR imaging (DTI) parameters the differentiation between acute, subacute and chronic demyelinating plaques in patients with MS.

DTI parameters were evaluated in 60 demyelinating plaques (20 acute, 20 subacute and 20 chronic) in 20 patients (15 females and 5 males; mean age 37 years) with relapsing-remising MS using a 1.5T scanner. They were compared to 20 healthy controls, sex and age matched. Based on conventional MR imaging features, the acute, subacute and chronic plaques were defined following criteria previously described. The DTI raw data were post-processed and similar regions of interest (ROI) were placed in all plaques subtypes, as well as in the same topography of controls brains. The eigenvalues (E1, E2 and E3), fractional anisotropy (FA), mean diffusivity (MD) and radial diffusion (RD) values were obtained in all these ROIs. The statistical analysis compared these variables in the acute, subacute and chronic plaques, as well as in the surrounding NAWM of all types of plaque, and p<0.01 was considered statistically significant. Pearson correlation was used to correlate FA with RD and axial diffusion (AD).

The eigenvalues made possible the differentiation between all plaques subtypes (p<0.01). FA and MD values were not statistically significant for acute and subacute plaque differentiation. The comparison among the NAWM around plaque among plaques subtypes was not statistically significant (p>0.1). The Pearson coefficient showed statistical significant high correlation between FA values and RD in acute(r=-0.758), subacute(r=-0.828) and chronic(r=-0.837) plaques and also moderate correlation between FA and AD in chronic plaques(r=-0.583).

The DTI can demonstrate differences between acute, subacute and chronic demyelinating plaques in patients with MS, but not in the surrounding NAWM. The eigenvalues may have more sensitivity than FA and MD for this characterization. The FA is mostly influenced by RD in acute and subacute plaques, probably reflecting predominance of demyelination process. The influence of AD on FA at chronic plaques may also represent the addition of axonal loss to the histopathological process

Multiple sclerosis (MS) is characterized by demyelinating plaques. Clinical symptoms may be correlated with enhancing plaques location but also with lesions with T2 hyper signal intensity.

Lopes, F, Batista, R, Kubo, T, Domingues, R, Domingues, R, Gasparetto, E, Diffusion Tensor MR Imaging in the Differentiation of Acute, Subacute, and Chronic Demyelinating Plaques in Patients with Multiple Sclerosis.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9007967.html