Weekly multimodal MRI follow‐up of two multiple sclerosis active lesions presenting a transient decrease in ADC

• Published in: Brain and behavior Vol. 5; no. 2; pp. e00307 - n/a
• Main Authors: Hannoun, Salem, Roch, Jean‐Amédée, Durand‐Dubief, Francoise, Vukusic, Sandra, Sappey‐Marinier, Dominique, Guttmann, Charles R.G., Cotton, Francois
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01-02-2015; Wiley Open Access; BlackWell Publishing Ltd
• Subjects: Adult; Apparent diffusion coefficient; Bioengineering; Blood-Brain Barrier - metabolism; Blood-Brain Barrier - pathology; Brain Diseases - metabolism; Brain Diseases - pathology; Cytotoxicity; Diffusion; diffusion tensor imaging; Edema; Female; Follow-Up Studies; Humans; Hypoxia; Imaging; Inflammation; lesions; Life Sciences; Longitudinal Studies; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Metabolism; Multiple sclerosis; Multiple Sclerosis - metabolism; Multiple Sclerosis - pathology; Neurobiology; Neurons and Cognition; Original Research; Patients; perfusion; Prospective Studies; relative cerebral blood volume; Software; diffusion tensor imaging; perfusion; lesions; relative cerebral blood volume; multiple sclerosis; Apparent diffusion coefficient; diffusion; Correspondence; tensor imaging
• ISSN: 2162-3279; 2162-3279
• DOI: 10.1002/brb3.307

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 mm3. 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.
Weekly follow‐up of two active lesions of a multiple sclerosis patient using multimodal analysis revealed a transient decrease in ADC values and a higher rCBV values at the 6th week when lesion appeared with injected T1‐weighted image. 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.