RT Journal Article
SR Electronic
T1 Magnetic resonance frequency shifts during acute MS lesion formation
JF Neurology
JO Neurology
FD Lippincott Williams & Wilkins
SP 211
OP 218
DO 10.1212/WNL.0b013e31829bfd63
VO 81
IS 3
A1 Vanessa Wiggermann
A1 Enedino Hernández Torres
A1 Irene M. Vavasour
A1 G.R. Wayne Moore
A1 Cornelia Laule
A1 Alex L. MacKay
A1 David K.B. Li
A1 Anthony Traboulsee
A1 Alexander Rauscher
YR 2013
UL http://n.neurology.org/content/81/3/211.abstract
AB Objective: We investigated the evolution of new multiple sclerosis (MS) lesions over time using frequency shifts of the magnetic resonance (MR) signal.Methods: Twenty patients with relapsing-remitting MS were serially scanned for 6 months at 1-month intervals. Maps of MR frequency shifts were acquired using susceptibility-weighted imaging. New lesions were identified by enhancement with gadolinium (Gd).Results: Forty new lesions were identified as areas of signal increase on Gd-enhanced scans. Up to 3 months before lesion appearance, the frequency in areas of future Gd enhancement was not detectably different from the frequency in normal-appearing white matter. Rapid increase in MR frequency was observed between 1 month before and 1 month after Gd enhancement. Two months postenhancement and later, the frequency stabilized and remained at a constantly increased level.Conclusions: These findings suggest that an increase in MR frequency does not simply reflect blood-brain barrier disruption or edema; rather, it reflects a change of tissue architecture as a consequence of new lesion formation. The data demonstrate that the MR frequency of focal MS lesions is increased before the lesions appear on conventional MRI. Unlike many other advanced imaging techniques, the images for frequency mapping can be rapidly acquired at high spatial resolution and standardized on most clinical scanners.DAWM=diffusely abnormal white matter; FLAIR=fluid-attenuated inversion recovery; FOV=field of view; Gd=gadolinium; GM=gray matter; MR=magnetic resonance; MS=multiple sclerosis; MT=magnetization transfer; NAWM=normal-appearing white matter; NWM=normal white matter; ROI=region of interest; TE=echo time; TR=repetition time; WM=white matter; WM(D)=normal WM that corresponds to areas of DAWM in patients