title: Visualization of magnetic resonance-compatible needles at 1.5 and 0.2 Tesla.
abstract: OBJECTIVE
  For two types of passively visualizable magnetic resonance (MR)-compatible needles, the size of susceptibility artifacts was investigated at 0.2 and 1.5 Tesla (T) and assessed regarding their suitability for needle visualization.
  
  
  METHODS
  Phantom trials were performed using T1-weighted spin echo (SE), turbospin echo (TSE) and gradient echo (GE) sequences and different angles beta between the needles and the main magnetic field (B0).
  
  
  RESULTS
  Depending on the needle angle beta and the applied pulse sequence, we found artifact diameters of 0-9.7 mm employing SE, of 1.7-9.4 mm employing TSE, and of 1.4-20.6 mm employing GE at 1.5 T. At 0.2 T, we found artifact diameters of 0-5.7 mm employing SE, of 0-6.3 mm employing TSE, and of 0-11.3 mm employing GE.
  
  
  CONCLUSIONS
  Comparing artifact sizes at 1. 5 T and 0.2 T, low field strength is superior for passive visualization of the needles tested-especially if GE imaging is performed.
authors.affiliation: Medizinische Universität zu Lübeck, Institut für Radiologie, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Frahm
authors.forename: H B
authors.initials: HB
authors.lastname: Gehl
authors.forename: U H
authors.initials: UH
authors.lastname: Melchert
authors.forename: H D
authors.initials: HD
authors.lastname: Weiss
mesh_terms: D016477:Artifacts; D002858:Chromium Alloys / Q000737:chemistry; D004867:Equipment Design; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D009339:Needles; D019047:Phantoms, Imaging; D015642:Radiology, Interventional
chemical_list: D002858:Chromium Alloys