title: Diffusion-weighted imaging of the appendicular skeleton with a non-Carr-Purcell-Meiboom-Gill single-shot fast spin-echo sequence.
abstract: OBJECTIVE
  The objective of our study was to prospectively evaluate the signal-to-noise ratio (SNR) improvement in diffusion-weighted imaging (DWI) of the appendicular skeleton with the use of a newly developed non-Carr-Purcell-Meiboom-Gill (non-CPMG) single-shot fast spin-echo (SSFSE) sequence and to evaluate its effect on apparent diffusion coefficient (ADC) measurements.
  
  
  METHODS
  DWI of the bone was performed in 32 patients with an echo-planar imaging (EPI)-based sequence followed by a non-CPMG SSFSE technique. SNR and ADC values were measured over a lesion-free right femoral head. A score was assigned for each set of images to assess image quality. When a bone lesion was present, contrast-to-noise ratio (CNR) and ADC were also measured. Paired Student's t tests were used for statistical analysis.
  
  
  RESULTS
  The mean (+/- SD) SNR values were 9.89 +/- 2.20 and 81.68 +/- 4.87 for EPI and non-CPMG SSFSE DWI, respectively. SNR values associated with the non-CPMG SSFSE technique were found to be significantly higher than those measured with the EPI-based DWI technique (p < 0.01). Mean ADCs of the bone were 0.57 +/- 0.20 and 0.29 +/- 0.15 x 10(-3) mm2/s, respectively, for EPI and non-CPMG SSFSE DWI. Image quality scores were higher for the non-CPMG SSFSE DWI technique (p < 0.05) than for the EPI-based DWI technique. Overall lesion CNR was found to be higher in DWI performed with the non-CPMG SSFSE technique.
  
  
  CONCLUSIONS
  The non-CPMG SSFSE technique provides a significant improvement over the currently used EPI-based DWI technique and has the potential to be a powerful tool in imaging the appendicular skeleton.
authors.affiliation: Department of Radiology, Gazi University School of Medicine, Besevler, Ankara 06510, Turkey. yusuf@tr.net
authors.forename: Ali Yusuf
authors.initials: AY
authors.lastname: Oner
authors.forename: Levent
authors.initials: L
authors.lastname: Aggunlu
authors.forename: Sergin
authors.initials: S
authors.lastname: Akpek
authors.forename: Turgut
authors.initials: T
authors.lastname: Tali
authors.forename: Azim
authors.initials: A
authors.lastname: Celik
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000175:diagnosis*; D010020:Osteonecrosis / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity