title: Image-guided spinal injection procedures in open high-field MRI with vertical field orientation: feasibility and technical features.
abstract: OBJECTIVE
  We prospectively evaluated the feasibility and technical features of MR-guided lumbosacral injection procedures in open high-field MRI at 1.0 T.
  
  
  METHODS
  In a CuSO(4).5H(2)O phantom and five human cadaveric spines, fluoroscopy sequences (proton-density-weighted turbo spin-echo (PDw TSE), T1w TSE, T2w TSE; balanced steady-state free precession (bSSFP), T1w gradient echo (GE), T2w GE) were evaluated using two MRI-compatible 20-G Chiba-type needles. Artefacts were analysed by varying needle orientation to B(0), frequency-encoding direction and slice orientation. Image quality was described using the contrast-to-noise ratio (CNR). Subsequently, a total of 183 MR-guided nerve root (107), facet (53) and sacroiliac joint (23) injections were performed in 53 patients.
  
  
  RESULTS
  In vitro, PDw TSE sequence yielded the best needle-tissue contrasts (CNR = 45, 18, 15, 9, and 8 for needle vs. fat, muscle, root, bone and sclerosis, respectively) and optimal artefact sizes (width and tip shift less than 5 mm). In vivo, PDw TSE sequence was sufficient in all cases. The acquisition time of 2 s facilitated near-real-time MRI guidance. Drug delivery was technically successful in 100% (107/107), 87% (46/53) and 87% (20/23) of nerve root, facet and sacroiliac joint injections, respectively. No major complications occurred. The mean procedure time was 29 min (range 19-67 min).
  
  
  CONCLUSIONS
  MR-guided spinal injections in open high-field MRI are feasible and accurate using fast TSE sequence designs.
authors.affiliation: Department of Radiology, Charité, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117 Berlin, Germany. florian.streitparth@charite.de
authors.forename: F
authors.initials: F
authors.lastname: Streitparth
authors.forename: T
authors.initials: T
authors.lastname: Walter
authors.forename: U
authors.initials: U
authors.lastname: Wonneberger
authors.forename: S
authors.initials: S
authors.lastname: Chopra
authors.forename: F
authors.initials: F
authors.lastname: Wichlas
authors.forename: M
authors.initials: M
authors.lastname: Wagner
authors.forename: K G
authors.initials: KG
authors.lastname: Hermann
authors.forename: B
authors.initials: B
authors.lastname: Hamm
authors.forename: U
authors.initials: U
authors.lastname: Teichgräber
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007278:Injections, Spinal / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D015641:Radiography, Interventional / Q000379:methods