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Updated: Mar 31, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Quantitative MRI for Analysis of Active Multiple Sclerosis Lesions without Gadolinium-Based Contrast Agent
I Blystad1, I Håkansson2, A Tisell3
1From the Departments of Radiology and Medical and Health Sciences (I.B., Ö.S.) Centre for Medical Image Science and Visualization (I.B., A.T., Ö.S., P.L., E.-M.L.) ida.blystad@regionostergotland.se.
Background And Purpose:
Contrast-enhancing MS lesions are important markers of active inflammation in the diagnostic work-up of MS and in disease monitoring with MR imaging. Because intravenous contrast agents involve an expense and a potential risk of adverse events, it would be desirable to identify active lesions without using a contrast agent. The purpose of this study was to evaluate whether pre-contrast injection tissue-relaxation rates and proton density of MS lesions, by using a new quantitative MR imaging sequence, can identify active lesions.
Materials And Methods:
Forty-four patients with a clinical suspicion of MS were studied. MR imaging with a standard clinical MS protocol and a quantitative MR imaging sequence was performed at inclusion (baseline) and after 1 year. ROIs were placed in MS lesions, classified as nonenhancing or enhancing. Longitudinal and transverse relaxation rates, as well as proton density were obtained from the quantitative MR imaging sequence. Statistical analyses of ROI values were performed by using a mixed linear model, logistic regression, and receiver operating characteristic analysis.
Results:
Enhancing lesions had a significantly (P < .001) higher mean longitudinal relaxation rate (1.22 ± 0.36 versus 0.89 ± 0.24), a higher mean transverse relaxation rate (9.8 ± 2.6 versus 7.4 ± 1.9), and a lower mean proton density (77 ± 11.2 versus 90 ± 8.4) than nonenhancing lesions. An area under the receiver operating characteristic curve value of 0.832 was obtained.
Conclusions:
Contrast-enhancing MS lesions often have proton density and relaxation times that differ from those in nonenhancing lesions, with lower proton density and shorter relaxation times in enhancing lesions compared with nonenhancing lesions.
Insights
New MRI techniques can identify active multiple sclerosis (MS) lesions without contrast agents. Quantitative imaging reveals differences in relaxation rates and proton density between enhancing and non-enhancing MS lesions.
Area of Science:
- Neuroimaging
- Radiology
- Multiple Sclerosis Research
Background:
- Contrast-enhancing lesions on MRI are key indicators of active inflammation in multiple sclerosis (MS).
- Current methods rely on intravenous contrast agents, which incur costs and potential adverse events.
- There is a need for non-contrast methods to identify active MS lesions.
Purpose of the Study:
- To evaluate the utility of pre-contrast tissue-relaxation rates and proton density in identifying active MS lesions.
- To determine if a novel quantitative MRI sequence can differentiate active from inactive lesions without contrast administration.
Main Methods:
- Forty-four patients with suspected MS underwent standard and quantitative MRI at baseline and 1-year follow-up.
- Regions of interest (ROIs) were placed in both enhancing and non-enhancing MS lesions.
- Longitudinal relaxation rate, transverse relaxation rate, and proton density were measured using the quantitative sequence; statistical analyses included mixed linear models, logistic regression, and ROC analysis.
Main Results:
- Enhancing MS lesions exhibited significantly higher mean longitudinal relaxation rates (1.22 ± 0.36 vs. 0.89 ± 0.24) and transverse relaxation rates (9.8 ± 2.6 vs. 7.4 ± 1.9) compared to non-enhancing lesions.
- Non-enhancing lesions showed a significantly higher mean proton density (90 ± 8.4 vs. 77 ± 11.2).
- Receiver operating characteristic analysis yielded an area under the curve of 0.832, indicating good discriminatory power.
Conclusions:
- Pre-contrast quantitative MRI parameters, specifically relaxation times and proton density, can distinguish between enhancing and non-enhancing MS lesions.
- Enhancing lesions are characterized by lower proton density and shorter relaxation times compared to non-enhancing lesions.
- These findings suggest a potential for contrast-free identification of active MS lesions using quantitative MRI.
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