title: Breath-hold T2-weighted MRI of the liver at 3T using the BLADE technique: impact upon image quality and lesion detection.
abstract: OBJECTIVE
  To compare image quality and lesion detection in the liver using magnetic resonance imaging (MRI) at 3T between T2-weighted imaging using a standard rectilinear k-space trajectory (standard T2WI) and using the BLADE technique (BLADE-T2WI), a technique that employs periodically rotated overlapping parallel lines with enhanced reconstruction for motion correction.
  
  
  METHODS
  Twenty-eight consecutive patients who underwent MRI examination of the liver at 3T including standard T2WI and BLADE-T2WI, both performed using multiple breath-holds, comprised the study cohort. Images were reviewed in consensus by two radiologists during separate sessions for a number of measures regarding artefacts and image quality. These two readers also assessed the two image sets for the presence of liver lesions and measured liver-to-lesion contrast. Binary logistic regression for correlated data was used to compare the sequences in terms of sensitivity and positive predictive value (PPV) for lesion detection.
  
  
  RESULTS
  BLADE-T2WI received significantly higher scores than did standard T2WI for in-plane respiratory motion (p=0.0195), other ghosting artefacts (p<0.0001), sharpness of the liver edge (p=0.0004), sharpness of intra-hepatic vessels (p<0.0001), flow signal suppression (p<0.0001), and overall image quality (p<0.0001). There was a non-significant trend toward improved B(1)-inhomogeneity artefact with BLADE-T2WI (p=0.0571). There was no difference in through-plane respiratory motion (p=0.6836). BLADE-T2WI demonstrated a significant improvement in PPV for lesion detection (p=0.0129) as well as in liver-to-lesion contrast (p=0.0054). There was no difference regarding lesion sensitivity (p=1.0).
  
  
  CONCLUSIONS
  Use of the BLADE technique for T2-weighted MRI of the liver at 3T may lead to a significant improvement in image artefacts and improved PPV for lesion detection.
authors.affiliation: Department of Radiology, NYU Langone Medical Center, 560 First Avenue, New York, NY 10016, USA. rosena23@nyumc.org
authors.forename: A B
authors.initials: AB
authors.lastname: Rosenkrantz
authors.forename: L
authors.initials: L
authors.lastname: Mannelli
authors.forename: D
authors.initials: D
authors.lastname: Mossa
authors.forename: J S
authors.initials: JS
authors.lastname: Babb
mesh_terms: D016477:Artifacts; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity