title: Usefulness of optimized gadolinium-enhanced fast fluid-attenuated inversion recovery MR imaging in revealing lesions of the brain.
abstract: OBJECTIVE
  The purpose of this study was to compare the contrast enhancement of lesions of the brain revealed by gadolinium-enhanced optimized fast fluid-attenuated inversion recovery (FLAIR) MR imaging with that of lesions on gadolinium-enhanced optimized T1-weighted spin-echo MR imaging.
  
  
  METHODS
  Using computer simulations, we optimized the fast FLAIR parameters (TR, TEeff, and inversion time) and the T1-weighted spin-echo parameters (TR and TE) to provide maximum difference in signal intensity between enhancing lesions of the brain and white matter. Seventy-six consecutive patients referred for single-dose gadolinium-enhanced MR imaging of the brain underwent both optimized techniques, which were matched for spatial resolution, bandwidth, and number of excitations. The gadolinium-enhanced fast FLAIR and T -weighted spin-echo MR images were evaluated independently by two observers for number and size of enhancing lesions and for the degree of gray-white matter differentiation. Contrast-to-noise ratios were measured for enhancing lesions 1.0 cm or larger in diameter using 8 x 8 pixel regions of interest in the enhancing lesions and normal white matter.
  
  
  RESULTS
  The most revealing parameters for fast FLAIR MR imaging proved to be a TR of 1500 msec, an inversion time of 683 msec, and a TEeff of 16 msec. For T1-weighted spin-echo MR imaging, the optimized parameters were a TR of 550 msec and a TE of 16 msec. In 28 patients, we saw enhancing lesions of the brain with at least one MR imaging technique. More lesions were seen on the T1-weighted spin-echo sequence (n = 141) than on the fast FLAIR sequence (n = 94) (p < .03). Gray-white matter differentiation was significantly better on the fast FLAIR sequence (p < .001). Contrast-to-noise ratios of enhancing lesions were greater on the T1-weighted spin-echo sequence (p < .001).
  
  
  CONCLUSIONS
  In this study, optimized gadolinium-enhanced conventional T1-weighted spin-echo MR imaging proved superior to gadolinium-enhanced fast FLAIR MR imaging in revealing lesions of the brain.
authors.affiliation: Department of Radiology, Boston University Medical Center, MA 02118, USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Melhem
authors.forename: R J
authors.initials: RJ
authors.lastname: Bert
authors.forename: R E
authors.initials: RE
authors.lastname: Walker
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D001921:Brain / Q000473:pathology*; D001927:Brain Diseases / Q000175:diagnosis*; D003198:Computer Simulation; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA