title: Lesion detection at seven Tesla in multiple sclerosis using magnetisation prepared 3D-FLAIR and 3D-DIR.
abstract: OBJECTIVE
  To examine the feasibility and value of 7 T 3D T2-weighted Fluid Attenuated Inversion Recovery (FLAIR) and Double Inversion Recovery (DIR) MR sequences for lesion detection in multiple sclerosis (MS).
  
  
  METHODS
  High-resolution 3D-FLAIR and 3D-DIR MR sequences at 7 T were obtained using magnetisation preparation (MP), and compared with 2D-T2-weighted and 3D-T1-weighted sequences in 10 MS patients and five healthy controls. We determined contrast ratios and counted lesions according to anatomical location.
  
  
  RESULTS
  MR imaging at 7 T was safe and allowed multi-contrast imaging within clinically acceptable imaging times. Lesion to white matter (WM) and grey matter (GM) contrast ratios were higher in 3D-MP-FLAIR and 3D-MP-DIR compared with 2D-T2 and 3D-T1. Cortical (mixed+intra-cortical) and total lesion counts were 97/592 on 3D-MP-FLAIR and 100/558 on 3D-MP-DIR compared with 84/384 on 2D-T2 and 42/442 on 3D-T1. More juxta-cortical lesions were seen with 3D-MP-FLAIR (205) and 3D-MP-DIR (133) than with 2D-T2 (125) and 3D-T1 (70). Finally, higher numbers of lesions were found for deep WM lesions: 176 for 3D-MP-FLAIR and 196 for 3D-MP-DIR vs. 155 for 2D-T2 and 131 for 3D-T1.
  
  
  CONCLUSIONS
  Near isotropic 3D-MP-FLAIR and 3D-MP-DIR allows high quality T2-weighted MR imaging in MS at 7 T, improving (cortical) lesion detection.
authors.affiliation: Department of Radiology, VU University Medical Center Amsterdam, De Boelelaan 1117, NL-1081 HV, Amsterdam, the Netherlands. W.deGraaf@vumc.nl
authors.forename: Wolter L
authors.initials: WL
authors.lastname: de Graaf
authors.forename: Jaco J M
authors.initials: JJ
authors.lastname: Zwanenburg
authors.forename: Fredy
authors.initials: F
authors.lastname: Visser
authors.forename: Mike P
authors.initials: MP
authors.lastname: Wattjes
authors.forename: Petra J W
authors.initials: PJ
authors.lastname: Pouwels
authors.forename: Jeroen J G
authors.initials: JJ
authors.lastname: Geurts
authors.forename: Chris H
authors.initials: CH
authors.lastname: Polman
authors.forename: Frederik
authors.initials: F
authors.lastname: Barkhof
authors.forename: Peter R
authors.initials: PR
authors.lastname: Luijten
authors.forename: Jonas A
authors.initials: JA
authors.lastname: Castelijns
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000473:pathology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000473:pathology; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D012680:Sensitivity and Specificity; D055815:Young Adult