title: T2-weighted MR imaging of the liver: qualitative and quantitative comparison of SPACE MR imaging with turbo spin-echo MR imaging.
abstract: OBJECTIVE
  To qualitatively and quantitatively compare T2-weighted MR imaging of the liver using volumetric spin-echo with sampling perfection with application-optimized contrast using different flip angle evolutions (SPACE) with conventional turbo spin-echo (TSE) sequence for fat-suppressed T2-weighted MR imaging of the liver.
  
  
  METHODS
  Thirty-three patients with suspected focal liver lesions had SPACE MR imaging and conventional fat-suppressed TSE MR imaging. Images were analyzed quantitatively by measuring the lesion-to-liver contrast-to-noise ratio (CNR), and the signal-to-noise ratio (SNR) of main focal hepatic lesions, hepatic and splenic parenchyma and qualitatively by evaluating the presence of vascular, respiratory motion and cardiac artifacts. Wilcoxon signed rank test was used to search for differences between the two sequences.
  
  
  RESULTS
  SPACE MR imaging showed significantly greater CNR for focal liver lesions (median=22.82) than TSE MR imaging (median=14.15) (P<.001). No differences were found for SNR of hepatic parenchyma (P=.097), main focal hepatic lesions (P=.35), and splenic parenchyma (P=.25). SPACE sequence showed less artifacts than TSE sequence (vascular, P<.001; respiratory motion, P<.001; cardiac, P<.001) but needed a longer acquisition time (228.4 vs. 162.1s; P<.001).
  
  
  CONCLUSIONS
  SPACE MR imaging provides a significantly increased CNR for focal liver lesions and less artifacts by comparison with the conventional TSE sequence. These results should stimulate further clinical studies with a surgical standard of reference to compare the two techniques in terms of sensitivity for malignant lesions.
authors: Department of Body and Interventional Imaging, Hôpital Lariboisière, AP-HP, 2 Rue Ambroise Paré, 75475 Paris Cedex 10, France; Université Paris-Diderot, Sorbonne Paris Cité, 10 Rue de Verdun, 75010 Paris, France; UMR INSERM 965, Hôpital Lariboisière, 2 Rue Amboise Paré, 75010 Paris, France. Electronic address: anthony.dohan@lrb.aphp.fr.
authors: Anthony
authors: A
authors: Dohan
authors: Jean-Philippe
authors: JP
authors: Gavini
authors: Vinciane
authors: V
authors: Placé
authors: Delphine
authors: D
authors: Sebbag
authors: Alexandre
authors: A
authors: Vignaud
authors: Christine
authors: C
authors: Herbin
authors: Lounis
authors: L
authors: Hamzi
authors: Mourad
authors: M
authors: Boudiaf
authors: Philippe
authors: P
authors: Soyer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016477:Artifacts; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D013113:Spin Labels
keywords: Extended echo trains; Liver imaging; MR imaging technique; SPACE