Multiple sclerosis lesion geometry in quantitative susceptibility mapping (QSM) and phase imaging.

Publication Type	Academic Article
Authors	Eskreis-Winkler S, Deh K, Gupta A, Liu T, Wisnieff C, Jin M, Gauthier S, Wang Y, Spincemaille P
Journal	J Magn Reson Imaging
Volume	42
Issue	1
Pagination	224-9
Date Published	08/30/2014
ISSN	1522-2586
Keywords	Brain, Diffusion Tensor Imaging, Image Interpretation, Computer-Assisted, Imaging, Three-Dimensional, Multiple Sclerosis, White Matter
Abstract	PURPOSE: To demonstrate the phase and quantitative susceptibility mapping (QSM) patterns created by solid and shell spatial distributions of magnetic susceptibility in multiple sclerosis (MS) lesions. MATERIALS AND METHODS: Numerical simulations and experimental phantoms of solid- and shell-shaped magnetic susceptibility sources were used to generate magnitude, phase, and QSM images. Imaging of 20 consecutive MS patients was also reviewed for this Institutional Review Board (IRB)-approved MRI study to identify the appearance of solid and shell lesions on phase and QSM images. RESULTS: Solid and shell susceptibility sources were correctly reconstructed in QSM images, while the corresponding phase images depicted both geometries with shell-like patterns, making the underlying susceptibility distribution difficult to determine using phase alone. In MS patients, of the 60 largest lesions identified on T2 , 30 lesions were detected on both QSM and phase, of which 83% were solid and 17% were shells on QSM, and of which 30% were solid and 70% were shell on phase. Of the 21 shell-like lesions on phase, 76% appeared solid on QSM, 24% appeared shell on QSM. Of the five shell-like lesions on QSM, all were shell-like on phase. CONCLUSION: QSM accurately depicts both solid and shell patterns of magnetic susceptibility, while phase imaging fails to distinguish them.
DOI	10.1002/jmri.24745
PubMed ID	25174493
PubMed Central ID	PMC4733654