5T or lower field platforms.37 In our study, the 3T platform showed promise in improving such correlations, particularly when compared to 1.5T in the same subjects. Correlations between FLLV at 3T and multiple cognitive domains including visual perception and spatial processing (JLO), informational processing speed/working memory (SDMT, PASAT2), verbal learning and memory (CVLT LD), and executive function (DKEFS CS) suggest that global high

field assessments of MS brain lesional pathology are valuable. Though moderate Spearman rank correlations with PASAT3 (Lazeron r=−.41, P < .001; Sperling r=−.66, P=.001) and SDMT (Lazeron r=−.50, P < .001; Sperling r=−.45, P= .02) have been VX-770 price reported using T2 lesion assessments at 1.5T,10,11 the cohorts were more disabled and contained more progressive than found in the present study. Lazeron et al.’s population was also less educated (mean = 11 years) Lumacaftor cost while the level of education in Sperling et al.’s study mirrored our own. Though many other studies

have explored MRI cognition-correlations, differing cognitive tests or reported results did not permit a more direct comparison. Two studies in this regard should be specifically noted because they employed FLAIR rather than T2 sequences. Rovaris et al.38 demonstrated that cognitively impaired patients had a significantly higher FLAIR lesion load when compared with patients classified as unimpaired by cognitive testing, while Lazeron et al.39 were unable to obtain a correlation between overall FLAIR lesion volume and cognitive impairment using the Brief Repeatable Battery. At 3T our findings of a relationship between lesion volume and cognitively impairment subgroup were similar to those reported by Rovaris et al., though this was not the case at 1.5T. Like Lazeron et al., at 1.5T correlations between cognitive tests and FLAIR lesion MCE volume were generally nonsignificant in our study. The most likely cause of the increased sensitivity of 3T versus 1.5T in the demonstration of FLAIR hyperintense lesions in our preliminary study was the improved detection of small lesions missed

by 1.5T, particularly those in the periventricular white matter, cortical, or juxtacortical areas. In view of the fact that correlations with clinical status were stronger at 3T, we hypothesize that these small lesions, detected mostly at 3T only, are clinically relevant. Several studies have emphasized the generally poor correlations between conventional MRI-defined cerebral lesion load and measures of physical disability such as EDSS score.8,9 Most of these studies showing this clinical-MRI paradox are based on 1.5T or lower field strength systems and spin-echo T2-weighted images. With the advent of FLAIR and its ability to better detect lesions than T2-weighted images,19,40,41 combined with the use of higher MRI field strength, we report improved correlations with EDSS score at 3T.