title: Comparison of MR imaging sequences for liver and head and neck interventions: is there a single optimal sequence for all purposes?
abstract: OBJECTIVE
  To compare the appropriate pulse sequences for interventional device guidance during magnetic resonance (MR) imaging at 0.2 T and to evaluate the dependence of sequence selection on the anatomic region of the procedure.
  
  
  METHODS
  Using a C-arm 0.2 T system, four interventional MR sequences were applied in 23 liver cases and during MR-guided neck interventions in 13 patients. The imaging protocol consisted of: multislice turbo spin echo (TSE) T2w, sequential-slice fast imaging with steady precession (FISP), a time-reversed version of FISP (PSIF), and FISP with balanced gradients in all spatial directions (True-FISP) sequences. Vessel conspicuity was rated and contrast-to-noise ratio (CNR) was calculated for each sequence and a differential receiver operating characteristic was performed.
  
  
  RESULTS
  Liver findings were detected in 96% using the TSE sequence. PSIF, FISP, and True-FISP imaging showed lesions in 91%, 61%, and 65%, respectively. The TSE sequence offered the best CNR, followed by PSIF imaging. Differential receiver operating characteristic analysis also rated TSE and PSIF to be the superior sequences. Lesions in the head and neck were detected in all cases by TSE and FISP, in 92% using True-FISP, and in 84% using PSIF. True-FISP offered the best CNR, followed by TSE imaging. Vessels appeared bright on FISP and True-FISP imaging and dark on the other sequences.
  
  
  CONCLUSIONS
  In interventional MR imaging, no single sequence fits all purposes. Image guidance for interventional MR during liver procedures is best achieved by PSIF or TSE, whereas biopsies in the head and neck are best performed using FISP or True-FISP sequences.
authors.affiliation: Department of Radiology, University Hospitals of Cleveland, 11100 Euclid Avenue, Case Western Reserve University, Cleveland, OH 44106-5056, USA.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Boll
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Lewin
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Duerk
authors.forename: Andrik J
authors.initials: AJ
authors.lastname: Aschoff
authors.forename: Elmar M
authors.initials: EM
authors.lastname: Merkle
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D001808:Blood Vessels / Q000002:abnormalities; D001927:Brain Diseases / Q000473:pathology; D003560:Cysts / Q000473:pathology*; D005260:Female; D005355:Fibrosis; D006257:Head / Q000098:blood supply / Q000473:pathology*; D006258:Head and Neck Neoplasms / Q000473:pathology; D006801:Humans; D008099:Liver / Q000473:pathology*; D008107:Liver Diseases / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000473:pathology*