BACKGROUND: Magnetic resonance (MR) phase imaging using high field MR scanners has demonstrated excellent contrast in multiple sclerosis (MS) lesions that is thought to be closely correlated to the local iron content. This pilot study acquired serial in vivo MR scans at 7T to track the evolution of phase contrast as MS lesions progress. METHODS: Five MS patients with relapsing-remitting MS were serially scanned for about 2.5 years at 7T using a high resolution T2*-weighted gradient-echo sequence. Magnitude and phase images were reconstructed for each scan and co-registered to their baseline study. RESULTS: Five non-enhancing ring and 70 nodular phase lesions were found in the five patients at baseline. None of the baseline phase lesions (including all five ring phase lesions) showed obvious qualitative variation on phase images during the study. Of note, we observed that three magnitude lesions, not initially read as abnormal signal, were either better appreciated using phase contrast imaging (two lesions) or preceded (one lesion) by phase changes. CONCLUSION: The observation that ring phase lesions remained unchanged over 2.5 years of follow-up challenges the notion that such lesions reveal the presence of acute activated iron-rich macrophages. It suggests that either different phenotypes of macrophages persist longer than previously expected or other mechanisms related to tissue injury contribute to the phase contrast.
BACKGROUND: Magnetic resonance (MR) phase imaging using high field MR scanners has demonstrated excellent contrast in multiple sclerosis (MS) lesions that is thought to be closely correlated to the local iron content. This pilot study acquired serial in vivo MR scans at 7T to track the evolution of phase contrast as MS lesions progress. METHODS: Five MSpatients with relapsing-remitting MS were serially scanned for about 2.5 years at 7T using a high resolution T2*-weighted gradient-echo sequence. Magnitude and phase images were reconstructed for each scan and co-registered to their baseline study. RESULTS: Five non-enhancing ring and 70 nodular phase lesions were found in the five patients at baseline. None of the baseline phase lesions (including all five ring phase lesions) showed obvious qualitative variation on phase images during the study. Of note, we observed that three magnitude lesions, not initially read as abnormal signal, were either better appreciated using phase contrast imaging (two lesions) or preceded (one lesion) by phase changes. CONCLUSION: The observation that ring phase lesions remained unchanged over 2.5 years of follow-up challenges the notion that such lesions reveal the presence of acute activated iron-rich macrophages. It suggests that either different phenotypes of macrophages persist longer than previously expected or other mechanisms related to tissue injury contribute to the phase contrast.
Authors: Martina Absinta; Pascal Sati; Matthew Schindler; Emily C Leibovitch; Joan Ohayon; Tianxia Wu; Alessandro Meani; Massimo Filippi; Steven Jacobson; Irene C M Cortese; Daniel S Reich Journal: J Clin Invest Date: 2016-06-06 Impact factor: 14.808
Authors: Àlex Rovira; Mike P Wattjes; Mar Tintoré; Carmen Tur; Tarek A Yousry; Maria P Sormani; Nicola De Stefano; Massimo Filippi; Cristina Auger; Maria A Rocca; Frederik Barkhof; Franz Fazekas; Ludwig Kappos; Chris Polman; David Miller; Xavier Montalban Journal: Nat Rev Neurol Date: 2015-07-07 Impact factor: 42.937
Authors: Iris D Kilsdonk; Alexandra Lopez-Soriano; Joost P A Kuijer; Wolter L de Graaf; Jonas A Castelijns; Chris H Polman; Peter R Luijten; Jeroen J J G Geurts; Frederik Barkhof; Mike P Wattjes Journal: J Neurol Date: 2014-04-29 Impact factor: 4.849
Authors: J Kuchling; T Sinnecker; I Bozin; J Dörr; V I Madai; J Sobesky; T Niendorf; F Paul; J Wuerfel Journal: Nervenarzt Date: 2014-04 Impact factor: 1.214