title: Water excitation MPRAGE: an alternative sequence for postcontrast imaging of the abdomen in noncooperative patients at 1.5 Tesla and 3.0 Tesla MRI.
abstract: OBJECTIVE
  To evaluate the diagnostic image quality of postgadolinium water excitation-magnetization-prepared rapid gradient-echo (WE-MPRAGE) sequence in abdominal examinations of noncooperative patients at 1.5 Tesla (T) and 3.0T MRI.
  
  
  METHODS
  Eighty-nine consecutive patients (48 males and 41 females; mean age +/- standard deviation, 54.6 +/- 16.6 years) who had MRI examinations including postgadolinium WE-MPRAGE were included in the study. Of 89 patients, 33 underwent noncooperative protocol at 1.5T, 10 underwent noncooperative protocol at 3.0T, and 46 underwent cooperative protocol at 3.0T. Postgadolinium WE-MPRAGE, MPRAGE, and three-dimensional gradient-echo sequences of these three different groups were qualitatively evaluated for image quality, extent of artifacts, lesion conspicuity, and homogeneity of fat-attenuation by two reviewers retrospectively, independently, and blindly. The results were compared using Wilcoxon signed rank and Mann-Whitney U tests. Kappa statistics were used to measure the extent of agreement between the reviewers.
  
  
  RESULTS
  The average scores indicated that the images were diagnostic for WE-MPRAGE at 1.5T and 3.0T in noncooperative patients. WE-MPRAGE achieved homogenous fat-attenuation in 31/33 (94%) of noncooperative patients at 1.5T and 10/10 (100%) of noncooperative patients at 3.0T. WE-MPRAGE at 3.0T had better results for image quality, extent of artifacts, lesion conspicuity and homogeneity of fat-attenuation compared with WE-MPRAGE at 1.5T, in noncooperative patients (P = 0.0008, 0.0006, 0.0024, and 0.0042; respectively). Kappa statistics varied between 0.76 and 1.00, representing good to excellent agreement.
  
  
  CONCLUSIONS
  WE-MPRAGE may be used as a T1-weighted postgadolinium fat-attenuated sequence in noncooperative patients, particularly at 3.0T MRI.
authors.affiliation: Department of Radiology, University of North Carolina at Chapel Hill, North Carolina 27599-7510, USA.
authors.forename: Ersan
authors.initials: E
authors.lastname: Altun
authors.forename: Richard C
authors.initials: RC
authors.lastname: Semelka
authors.forename: Brian M
authors.initials: BM
authors.lastname: Dale
authors.forename: Jorge
authors.initials: J
authors.lastname: Elias
mesh_terms: D000005:Abdomen; D016477:Artifacts; D001834:Body Water; D016009:Chi-Square Distribution; D003287:Contrast Media; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media