Abstract Details

Title Paramagnetic Rims in Treatment Naïve Persons Around the Time of Multiple Sclerosis Diagnosis

Topic Multiple Sclerosis

Presentation(s) S26 - MS Imaging (2:24 PM-2:36 PM)

Poster/Presentation
Number 008

Background PR represent a subset of chronic multiple sclerosis (MS) lesions with a partial/complete rim of signal surrounding a demyelinated core. They can be detected on SWI, QSM, R2* and phase maps. Questions remain regarding the most optimal imaging sequence to capture PR and whether fPR and pPR differ pathologically.

Objective To compare the detection of paramagnetic rims (PR) on susceptibility-weighted imaging (SWI) to multi-echo gradient echo (ME-GRE) derived quantitative susceptibility mapping (QSM), R2* and phase maps and to assess differences in volume and the degree of demyelination among full PR (fPR), partial PR (pPR) and non-PR.

Design/Methods 20 treatment-naïve persons around the time of MS diagnosis (mean age=39 years) had 7T MRI: pre- and post-contrast T2-FLAIR and MP2RAGE, SWI, ME-GRE (from which QSM, R2* and phase maps were derived) and selective inversion recovery quantitative magnetization transfer (SIR-qMT). All lesions were manually segmented on T2-FLAIR and assessed for PR on SWI, QSM, R2* and phase maps. Each lesion was classed as: fPR (continuous rim on ≥1slice), pPR and non-PR. Mean lesion volume and SIRqMT-derived pool size ratio (PSR) values were calculated. One way ANOVA/Kruskal-Wallis assessed group differences.

Results

Out of 373 lesions studied, 92(24.7%) had PR on SWI, 98(26.3%) on QSM, 78(20.1%) on R2* and 100(26.8%) on phase. The 92 SWI PR accounted for 54.0% of the total lesion volume and half were fPR and half were pPR. 12 patients had ≥1 SWI PR (median=4.5 PR).

PSR values were different among non-PR (mean=9.5±3.4), fPR (mean=8.2±3.0,p>0.05) and pPR (mean=7.3±3.2,p<0.001) but not between fPR and pPR (p=0.387). Lesion volume was significantly different between the lesion types (p<0.001) with larger volumes reported for PR than non-PR but not between fPR and pPR (p=0.246).

Conclusions Our initial results show that the detection of PR varies across different imaging protocols. FPR and pPR appear to have similar levels of pathology.

Authors/Disclosures
Margareta A. Clarke, PhD (Vanderbilt University Medical Center) PRESENTER	The institution of Dr. Clarke has received research support from National Multiple Sclerosis Society.
Rachael E. Cheek, MS	No disclosure on file
	No disclosure on file
	No disclosure on file
Joy Derwenskus, DO (Vanderbilt University Medical Center)	Dr. Derwenskus has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Bristol Myers Squibb.
James E. Eaton III, MD (Vanderbilt University)	Dr. Eaton has received personal compensation in the range of $0-$499 for serving as a Consultant for Uniqure.
	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Seth A. Smith, PhD (Vanderbilt University Institute of Imaging Science)	Dr. Smith has nothing to disclose.
Francesca Bagnato, MD (Vanderbilt University Medical Center)	Dr. Bagnato has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Sanofi-Genzyne. Dr. Bagnato has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Dr. Bagnato has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Jenseen. Dr. Bagnato has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merk-Serono.