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Updated: Apr 18, 2026
Magnetic Resonance Imaging of Multiple Sclerosis at 7.0 Tesla
Published on: February 19, 2021
Weekly multimodal MRI follow-up of two multiple sclerosis active lesions presenting a transient decrease in ADC
Salem Hannoun1, Jean-Amédée Roch2, Francoise Durand-Dubief1
1CREATIS - CNRS UMR 5220 & INSERM U1044, Université Claude Bernard-Lyon1 Villeurbanne, France ; Service de Neurologie A & EDMUS Coordinating Center for Multiple Sclerosis, Hôpital Neurologique Pierre Wertheimer Bron, France.
Background And Purpose:
Blood-brain barrier disruption during the earliest phases of lesion formation in multiple sclerosis (MS) patients is commonly ascribed to perivenular inflammatory activity and is usually accompanied by increased diffusivity. Reduced diffusivity has also been shown in active lesions, albeit less frequently. This study aimed to characterize the development and natural history of contrast-enhanced lesions by weekly following five relapsing remitting (RR) MS patients.
Materials And Methods:
Diffusion tensor imaging (DTI), perfusion imaging, FLAIR and contrast-enhanced 3D T1-weighted MR, were weekly performed on five untreated patients recently diagnosed with RR MS.
Results:
All five patients showed significant increases of the apparent diffusion coefficient (ADC) in the lesions compared to the first time point. One of the five patients presented 98 active lesions on ADC maps among which 36 had a volume larger than 10 mm(3). In two of these lesions, a 1 week transient decrease in ADC was detected at the time of the first gadolinium enhancement. Also, the perfusion analysis showed a concomitant increase in the relative cerebral blood volume.
Conclusions:
The infrequency detection of such ADC decrease in a new lesion is probably due to its very short duration. This observation may be consistent with a hyper-acute inflammatory stage concomitant with an increased reactional perfusion.
Insights
In multiple sclerosis (MS) active lesions, a transient decrease in apparent diffusion coefficient (ADC) may indicate a hyper-acute inflammatory stage with increased blood flow, though it is rarely detected.
Area of Science:
- Neuroimaging
- Multiple Sclerosis Pathophysiology
- Inflammatory Demyelination
Background:
- Blood-brain barrier disruption in multiple sclerosis (MS) lesions is typically linked to inflammation and increased diffusivity.
- Reduced diffusivity in active MS lesions is observed less frequently.
- Understanding early lesion development is crucial for MS management.
Purpose of the Study:
- To characterize the development and natural history of contrast-enhanced lesions in relapsing-remitting MS (RRMS) patients.
- To investigate changes in diffusion and perfusion during early lesion formation.
- To correlate imaging findings with inflammatory processes in MS.
Main Methods:
- Weekly MRI scans including diffusion tensor imaging (DTI), perfusion imaging, FLAIR, and contrast-enhanced T1-weighted imaging.
- Study included five treatment-naive, recently diagnosed RRMS patients.
- Analysis focused on apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV).
Main Results:
- All patients exhibited increased ADC in lesions over time.
- One patient showed numerous active lesions on ADC maps.
- A transient ADC decrease was observed in two lesions coinciding with initial gadolinium enhancement, alongside increased rCBV.
Conclusions:
- The transient ADC decrease in early MS lesions is likely brief and therefore infrequently detected.
- This finding suggests a hyper-acute inflammatory phase associated with increased reactive perfusion.
- Early detection of these changes may offer insights into MS lesion dynamics.
