title: In vivo single scan detection of both iron-labeled cells and breast cancer metastases in the mouse brain using balanced steady-state free precession imaging at 1.5 T.
abstract: OBJECTIVE
  To simultaneously detect iron-labeled cancer cells and brain tumors in vivo in one scan, the balanced steady-state free precession (b-SSFP) imaging sequence was optimized at 1.5 T on mice developing brain metastases subsequent to the injection of micron-sized iron oxide particle-labeled human breast cancer cells.
  
  
  METHODS
  b-SSFP sequence parameters (repetition time, flip angle, and receiver bandwidth) were varied and the signal-to-noise ratio, contrast between the brain and tumors, and the number of detected iron-labeled cells were evaluated.
  
  
  RESULTS
  Optimal b-SSFP images were acquired with a 26 msec repetition time, 35° flip angle, and bandwidth of ±21 kHz. b-SSFP images were compared with T(2) -weighted 2D fast spin echo (FSE) and 3D spoiled gradient recalled echo (SPGR) images. The mean tumor-brain contrast-to-noise ratio and the ability to detect iron-labeled cells were the highest in the b-SSFP images.
  
  
  CONCLUSIONS
  A single b-SSFP scan can be used to visualize both iron-labeled cells and brain metastases.
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada.
authors.forename: Emeline J
authors.initials: EJ
authors.lastname: Ribot
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Martinez-Santiesteban
authors.forename: Carmen
authors.initials: C
authors.lastname: Simedrea
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Steeg
authors.forename: Ann F
authors.initials: AF
authors.lastname: Chambers
authors.forename: Brian K
authors.initials: BK
authors.lastname: Rutt
authors.forename: Paula J
authors.initials: PJ
authors.lastname: Foster
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology*; D003287:Contrast Media / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D009362:Neoplasm Metastasis
chemical_list: D003287:Contrast Media; D007501:Iron