title: Manually respiratory-triggered single-shot fast spin-echo: a non-breath-hold T2-weighted method for liver lesion detection.
abstract: OBJECTIVE
  To determine whether manual respiratory triggering of a T2-weighted single-shot fast spin-echo sequence (M-SSFSE) improves detection and characterization of liver lesions compared with conventional breath-held single-shot fast spin-echo (C-SSFSE) technique.
  
  
  METHODS
  M-SSFSE is performed by manually triggering a series of single-slice acquisitions through the liver at end of expiration. There were 171 hepatic lesions in 49 patients. Images were randomized and reviewed by 3 radiologists. Lesions were characterized as hemangiomas, cystic or solid. Dynamic gadolinium-enhanced sequences were used as the reference standard. Contrast-to-noise ratios (CNR) were calculated for all lesions that measured 1 cm or more.
  
  
  RESULTS
  M-SSFSE was more sensitive than C-SSFSE in the detection of liver lesions (48%-58% v. 37%-46%, p < 0.001). There were no significant differences in the specificity of lesion detection between the 2 sequences. Artifacts were significantly less severe for M-SSFSE compared with C-SSFSE (p = 0.001). The CNR was significantly higher for all liver lesions on M-SSFSE compared with C-SSFSE (p < 0.001).
  
  
  CONCLUSIONS
  M-SSFSE significantly improved hepatic lesion detection and, in particular, improved characterization of solid liver lesions and hemangiomas compared with C-SSFSE imaging.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, London Health Care Sciences, University of Western Ontario, London.
authors.forename: Elaine
authors.initials: E
authors.lastname: O'Riordan
authors.forename: Masoom A
authors.initials: MA
authors.lastname: Haider
authors.forename: Martin E
authors.initials: ME
authors.lastname: O'Malley
authors.forename: Korosh
authors.initials: K
authors.lastname: Khalili
authors.forename: Kevin
authors.initials: K
authors.lastname: Ibach
authors.forename: Gina A
authors.initials: GA
authors.lastname: Lockwood
authors.forename: Babak
authors.initials: B
authors.lastname: Bahadorani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D017352:Echo-Planar Imaging; D005189:False Positive Reactions; D005260:Female; D006391:Hemangioma / Q000175:diagnosis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D011856:Radiographic Image Enhancement; D015656:Respiratory Mechanics / Q000502:physiology; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media