Dark Rims: Novel Sequence Enhances Diagnostic Specificity in Multiple Sclerosis

Abstract

Background and Purpose To determine whether a novel double inversion recovery MRI technique has the potential to increase the specificity of diagnostic criteria distinguishing MS from non-MS white matter lesions. Materials and Methods This is a cross-sectional observational study. MRI data were acquired between 2011 and 2016. A novel double-inversion-recovery sequence that suppresses CSF and GM signal was used (GM-DIR). We compared WM lesions in a group of patients with multiple sclerosis and in a second group of positive controls (PC) with white matter lesions that did not have a diagnosis of MS. The presence of a rim on GM-DIR MRI sequence was combined with the 2001 and 2010 McDonald DIS criteria. Multiple MRI markers including lesion location, size and presence of rim were compared between groups as well as quantitative measure of lesion T1-hypointensity. Results MRI scans from 107 patients with RRMS (median age 32) and 36 positive control (PC, median age 39) subjects were analyzed. No significant differences were present in age and sex. In MS, 1120/3211 lesions (35%) had a rim on GM-DIR; the PC group had only 9/893 rim lesions (1%). Rims were associated with a decrease in lesion T1-ratio. Using the 2010 MRI criteria plus the presence of rims on GM-DIR, we achieved 78% and 97% specificity in subjects with ≥ 1 and ≥ 2 rim-lesions respectively. Conclusion The addition of a novel GM-DIR technique enhanced specificity for diagnosing MS compared to established MRI criteria.

The Prognostic Value of White-Matter Selective Double Inversion Recovery MRI Sequence in Multiple Sclerosis: An Exploratory Study

“…The so-called “dark rim lesions” (DRLs) were noted in more than half of the patients (59%), with higher occurrence in PPMS and older patients (>50 years), accounting, overall, for about 20% of the total WM lesions. These data are slightly different from a previous study [ 8 ] in which a similar sequence was used, and in which DRLs accounted for 35% of the total WM lesions, and almost all patients (97%) showed at least one DRL. These discordant results could be explained, at least partially, by the higher spatial resolution offered by 3.0 T with respect to 1.5 T MRI.…”

“…As suggested by Tillema et al [ 8 ], the dark rim on the inversion recovery sequence could be a consequence of different T1-relaxation time between some MS lesions with long T1 times (likely because of axonal loss or edema) and adjacent NAWM, known as “boundary effects” [ 21 ].…”

“… White-matter selective DIR, FLAIR and T1w sequences were obtained using PAchieva scanners (, Philips Healthcare, Best, The Netherlands) at both MRI field strengths. For the sake of clarity, the WM-DIR sequence used in this work serves the same purpose as the GM-DIR sequence used in [ 8 ]. The DIR sequence is usually used for cortical lesion load assessment that involves mainly the GM tissue, whereas the WM-DIR sequence enhances the WM tissue and permits the detection of DRLs.…”

“…An appropriate choice of inversion times permits suppressing both CSF and GM signals to enhance WM [ 4 ]. The value of this technique in MS was investigated in one single study emphasizing the presence of a hypointense signal at the border (“dark rim”) of a subset of WM MS lesions, and hence improved the specificity of diagnostic criteria [ 8 ].…”

Iron Rims as an Imaging Biomarker in MS: A Systematic Mapping Review

“…Eleven papers reported whether the IRLs expand or shrink without accurately specifying the time frame [ 14 , 32 , 34 , 37 , 42 , 47 , 51 , 52 , 53 , 54 , 55 ]. However, six papers reported a different duration for expansion and shrinkage [ 12 , 14 , 18 , 32 , 42 , 52 ] ( Figure 7 ).…”