title: Within-lesion differences in quantitative MRI parameters predict contrast enhancement in multiple sclerosis.
abstract: OBJECTIVE
  To investigate the relationship between quantitative magnetic resonance imaging (qMRI) and contrast enhancement in multiple sclerosis (MS) lesions. We compared maps of T1 relaxation time, proton density (PD), and magnetization transfer ratio (MTR) between lesions with and without contrast enhancement as quantified by the amount of T1 shortening postcontrast agent (CA).
  
  
  METHODS
  In 17 patients with relapsing-remitting MS (RRMS), 15 with progressive MS (PMS), and 17 healthy controls, T1, PD, and MTR were measured at 3T and T1-mapping was repeated after CA administration. Manually drawn MS-lesions (3D-FLAIR) were labeled as enhancing if post-CA T1-shortening exceeded mean T1-shortening in normal-appearing white matter (NAWM) by at least 2 standard deviations. Precontrast T1, PD, and MTR were compared in enhancing lesions, nonenhancing lesions, NAWM, and gray matter.
  
  
  RESULTS
  Precontrast T1, PD, and MTR differed significantly between enhancing and nonenhancing lesions in RRMS and PMS patients (all P < 0.01). In PMS patients, PD of NAWM, enhancing, and nonenhancing lesions and MTR and T1 of gray matter differed significantly from RRMS and controls. Only MTR of gray matter differed between RRMS and controls.
  
  
  CONCLUSIONS
  Contrast enhancement in MS quantified by relative T1 shortening may be predicted by precontrast abnormalities of T1, PD, and MTR and likely represents blood-brain barrier damage.
authors.affiliation: Institute of Neuroradiology, Goethe University, Frankfurt am Main, Germany.
authors.forename: Alina
authors.initials: A
authors.lastname: Jurcoane
authors.forename: Marlies
authors.initials: M
authors.lastname: Wagner
authors.forename: Christoph
authors.initials: C
authors.lastname: Schmidt
authors.forename: Christoph
authors.initials: C
authors.lastname: Mayer
authors.forename: Rene-Maxime
authors.initials: RM
authors.lastname: Gracien
authors.forename: Marc
authors.initials: M
authors.lastname: Hirschmann
authors.forename: Ralf
authors.initials: R
authors.lastname: Deichmann
authors.forename: Steffen
authors.initials: S
authors.lastname: Volz
authors.forename: Ulf
authors.initials: U
authors.lastname: Ziemann
authors.forename: Elke
authors.initials: E
authors.lastname: Hattingen
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology*; D009474:Neurons / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D005682:Gadolinium
keywords: T1 mapping; blood brain barrier; magnetization transfer ratio; multiple sclerosis; proton density; quantitative magnetic resonance imaging