title: Echo planar MR imaging of the liver: comparison of images with and without motion probing gradients.
abstract: OBJECTIVE
  To determine whether MR images with motion-probing gradients (MPGs) usefully improve lesion detection in comparison with MR images without MPGs.
  
  
  METHODS
  Echo planar (EP) images without MPGs and with small and intermediate MPGs (gradient factor b = 2, 18, and 188 second/mm(2), respectively) were acquired for 61 hepatic lesions (21 hepatocellular carcinomas (HCCs), 19 metastases, eight hemangiomas, and 13 cysts). The lesion-to-liver signal intensity ratios (SIRs) of these lesions were calculated using EP images with and without MPGs. Qualitative analysis for detection of HCCs and metastases were also performed between the images without MPGs and with small MPGs.
  
  
  RESULTS
  The SIRs of HCCs and metastases for the images with small MPGs were significantly higher than the values for the images without MPGs (P < 0.05), although no significant differences were found in the case of hemangiomas and cysts. In comparison to images without MPGs, images with small MPGs improved lesion detection of three metastases and six HCCs, and worsened lesion detection of two HCCs.
  
  
  CONCLUSIONS
  Images with small MPGs may improve HCC and metastasis detection over images without MPGs.
authors.affiliation: Department of Diagnostic Radiology, Gunma University Hospital, Maebashi, Gunma, Japan. motekitakao@jcom.home.ne.jp
authors.forename: Takao
authors.initials: T
authors.lastname: Moteki
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Sekine
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis; D003560:Cysts / Q000175:diagnosis; D017352:Echo-Planar Imaging; D005260:Female; D006391:Hemangioma / Q000175:diagnosis; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results