Related Experiment Video
Updated: Jul 7, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Does high-field MR imaging improve cortical lesion detection in multiple sclerosis?
Jeroen J G Geurts1, Erwin L A Blezer, Hugo Vrenken
1Department of Radiology, VU University Medical Center, De Boelelaan 1117, Amsterdam, The Netherlands. j.geurts@vumc.nl
Objective:
Cortical lesions in multiple sclerosis (MS) are notoriously difficult to visualize with standard MR imaging (MRI) techniques. However, the use of higher field-strengths with intrinsically higher signal-to-noise, which can partly be used to increase spatial resolution, may improve cortical lesion detection. Therefore, in this post mortem study, the sensitivity of high field-strength MRI (4.7 T) for cortical lesions was investigated, and compared to that of standard field-strength (1.5 T).
Methods:
At 1.5 T, dual-echo T2-weighted spin-echo, as well as 3D-FLAIR images of seventeen formalin-fixed coronal MS and four control hemispheres were acquired. At 4.7 T, the same specimens were imaged with a mainly proton-density (PD)- weighted sequence. Proteolipid protein (PLP)-stained tissue sections (10 microm) of the same brain slices were matched to the corresponding MR images, and cortical lesions were scored on all three MR sequences (blinded to histology) and in tissue sections (blinded to MRI). Sensitivity of the sequences for four cortical lesion types was calculated. Additionally, an unblinded, retrospective MR scoring was performed.
Results:
Sensitivity for purely intracortical lesions (histological lesion types II, III, and IV; n = 128) was below 10 % for both 1.5 T and 4.7 T MRI, while mixed gray matter-white matter (type I) lesions (n = 5) were detected in four out of five cases. All lesion counts increased upon retrospective (unblinded) scoring. However, up to 80% of the intracortical lesions still remained undetected.
Conclusions:
MRI sensitivity for post mortem detection of cortical lesions is low, even when a higher field-strength was used. It varies, however, for different subtypes of cortical lesions.
Insights
High-field MRI (4.7 T) shows low sensitivity for detecting multiple sclerosis (MS) cortical lesions post mortem. Even with advanced techniques, many intracortical lesions remain undetected, highlighting imaging challenges.
Area of Science:
- Neuroimaging
- Neuropathology
- Magnetic Resonance Imaging
Background:
- Cortical lesions in multiple sclerosis (MS) are challenging to detect using standard MRI.
- Higher magnetic field strengths may improve spatial resolution and lesion detection.
- This study investigates MRI sensitivity for post mortem MS cortical lesions.
Purpose of the Study:
- To compare the sensitivity of high-field (4.7 T) MRI versus standard-field (1.5 T) MRI for detecting post mortem cortical lesions in MS.
- To assess the impact of field strength on the detection of different cortical lesion subtypes.
Main Methods:
- Post mortem formalin-fixed MS and control brain hemispheres were imaged at 1.5 T and 4.7 T.
- MRI sequences included dual-echo T2-weighted spin-echo and 3D-FLAIR at 1.5 T, and PD-weighted at 4.7 T.
- Histological sections (PLP-stained) were used for comparison, with blinded and unblinded lesion scoring.
Main Results:
- Sensitivity for purely intracortical lesions (types II, III, IV) was below 10% at both 1.5 T and 4.7 T.
- Mixed gray/white matter lesions (type I) were detected in 4 out of 5 cases.
- Unblinded scoring increased lesion counts, but up to 80% of intracortical lesions remained undetected.
Conclusions:
- Post mortem MRI has low sensitivity for detecting MS cortical lesions, even at higher field strengths.
- Sensitivity varies significantly depending on the subtype of cortical lesion.
- Further advancements in MRI techniques are needed for improved detection of MS cortical pathology.
