Weiwei Chen, Presenter: Nothing to Disclose

Susan Gauthier, Abstract Co-Author: Nothing to Disclose

Chu Pan MD, Abstract Co-Author: Nothing to Disclose

Ketao Mu PhD, Abstract Co-Author: Nothing to Disclose

Tian Liu PhD, Abstract Co-Author: Nothing to Disclose

Yi Wang PhD, Abstract Co-Author: Nothing to Disclose

Wenzhen Zhu MD, PhD, Abstract Co-Author: Nothing to Disclose

To quantify the susceptibility of normal appearing white matter (NAWM) by quantitative susceptibility mapping (QSM) to study its correlation with clinical features in MS patients.  

Seventy consecutive clinical confirmed RRMS patients (23M/47F, 40.6±10.6yrs, EDSS: 0-6; disease duration 0-43yrs) and 26 age and gender matched healthy controls (HCs) (9M/15F, aged:39.0±11.42yrs) were retrospectively selected. White matter regions without an abnormal signal on T2w, T1w, and T2FLAIR images were assumed to be NAWM for MS patients and normal white matter (NWM) for healthy controls. Region-of-interests (ROIs) of NAWM/NWM and CSF were drawn in bilateral frontal and parietal white matter, in the genu and splenium of the corpus callosum, and in the body of lateral ventricle manually by two neuroradiologists on T2-weighted images. The ROIs were overlaid onto QSM and NAWM/NWM susceptibility was calculated as its susceptibility difference from the corresponding patient/HC CSF susceptibility to eliminate possible constant offsets in susceptibility maps. The mean value of NAWM/NWM susceptibility was calculated for each patient. The significance of difference in NAWM/NWM susceptibility was assessed by t-test and One-Way ANOVA with Bonferroni adjustment.

A total of 511 NAWM ROIs were drawn in 70 MS patients and 208 NWM ROIs in 26 HCs. Of 70 MS patients, 15 patients had one or more Gadolium-enhanced MS lesions, the remaining 55 had no Gadolium-enhanced MS lesion. The NAWM of MS patients showed significantly higher susceptibility than NWM of HCs (-19.96 ± 8.29ppb vs. -28.56 ± 5.44ppb, p<0.001). However, the NAWM of patients with Gd-enhanced lesions showed a similar susceptibility to healthy controls NWM (-25.97 ± 6.19ppb vs. -28.56 ± 5.44ppb, p=0.802), while the NAWM of MS patients without Gd-enhanced lesions showed significantly higher susceptibility than both healthy controls NWM (-18.29 ± 8.06ppb vs. -28.56 ± 5.44ppb, p<0.001) and the NAWM of patients with Gd-enhanced lesions (-18.29 ± 8.06ppb vs. -25.97 ± 6.19ppb, p=0.001) (figure 1).

The susceptibility of NAWM increased in MS patient compared to HCs. However, the susceptibility of NAWM increased only in patient without Gadolium-enhanced lesions, while closed to that of HCs in patient with Gadolium-enhanced lesions.

QSM enable quantify the susceptibility of NAWM in MS patient, which might contribute to better understanding of MS pathogenesis.

Chen, W, Gauthier, S, Pan, C, Mu, K, Liu, T, Wang, Y, Zhu, W, Quantification of Multiple Sclerosis Normal-appearing White Matter on Quantitative Susceptibility Mapping (QSM).  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045790.html