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Updated: Mar 11, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Patient-specific 3D FLAIR for enhanced visualization of brain white matter lesions in multiple sclerosis
Refaat E Gabr1, Amol S Pednekar2, Koushik A Govindarajan1
1Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA.
Purpose:
To improve the conspicuity of white matter lesions (WMLs) in multiple sclerosis (MS) using patient-specific optimization of single-slab 3D fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI).
Materials And Methods:
Sixteen MS patients were enrolled in a prospective 3.0T MRI study. FLAIR inversion time and echo time were automatically optimized for each patient during the same scan session based on measurements of the relative proton density and relaxation times of the brain tissues. The optimization criterion was to maximize the contrast between gray matter (GM) and white matter (WM), while suppressing cerebrospinal fluid. This criterion also helps increase the contrast between WMLs and WM. The performance of the patient-specific 3D FLAIR protocol relative to the fixed-parameter protocol was assessed both qualitatively and quantitatively.
Results:
Patient-specific optimization achieved a statistically significant 41% increase in the GM-WM contrast ratio (P < 0.05) and 32% increase in the WML-WM contrast ratio (P < 0.01) compared with fixed-parameter FLAIR. The increase in WML-WM contrast ratio correlated strongly with echo time (P < 10-11 ). Two experienced neuroradiologists indicated substantially higher lesion conspicuity on the patient-specific FLAIR images over conventional FLAIR in 3-4 cases (intrarater correlation coefficient ICC = 0.72). In no case was the image quality of patient-specific FLAIR considered inferior to conventional FLAIR by any of the raters (ICC = 0.32).
Conclusion:
Changes in proton density and relaxation times render fixed-parameter FLAIR suboptimal in terms of lesion contrast. Patient-specific optimization of 3D FLAIR increases lesion conspicuity without scan time penalty, and has potential to enhance the detection of subtle and small lesions in MS.
Level Of Evidence:
1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:557-564.
Insights
Patient-specific optimization of 3D FLAIR MRI significantly improves the visibility of white matter lesions in multiple sclerosis (MS). This technique enhances lesion contrast without increasing scan time, aiding in the detection of subtle MS lesions.
Area of Science:
- Radiology
- Neuroimaging
- Medical Physics
Background:
- Multiple sclerosis (MS) is characterized by white matter lesions (WMLs) that can be challenging to visualize.
- Conventional fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) protocols may not optimally detect all WMLs due to patient-specific tissue variations.
Purpose of the Study:
- To enhance the conspicuity of WMLs in MS by employing patient-specific optimization of single-slab 3D FLAIR MRI.
- To improve the contrast between WMLs and normal-appearing white matter (WM).
Main Methods:
- A prospective 3.0T MRI study involved 16 MS patients.
- FLAIR inversion time and echo time were automatically optimized per patient based on proton density and relaxation times.
- Optimization aimed to maximize gray matter (GM)-WM contrast while suppressing cerebrospinal fluid, thereby enhancing WML-WM contrast.
Main Results:
- Patient-specific optimization yielded a 41% increase in GM-WM contrast (P < 0.05) and a 32% increase in WML-WM contrast (P < 0.01) compared to fixed-parameter FLAIR.
- Higher WML-WM contrast correlated strongly with optimized echo time (P < 10-11).
- Neuroradiologists reported substantially higher lesion conspicuity on patient-specific FLAIR images, with no degradation in image quality.
Conclusions:
- Fixed-parameter FLAIR is suboptimal due to variations in proton density and relaxation times.
- Patient-specific 3D FLAIR optimization increases lesion conspicuity without extending scan time.
- This approach has the potential to improve the detection of subtle and small lesions in MS patients.
