title: Fast T2*-weighted MRI of the prostate at 3 Tesla.
abstract: OBJECTIVE
  To describe a rapid T2*-weighted (T2*W), three-dimensional (3D) echo planar imaging (EPI) sequence and its application in mapping local magnetic susceptibility variations in 3 Tesla (T) prostate MRI. To compare the sensitivity of T2*W EPI with routinely used T1-weighted turbo-spin echo sequence (T1W TSE) in detecting hemorrhage and the implications on sequences sensitive to field inhomogeneities such as MR spectroscopy (MRS).
  
  
  METHODS
  B(0) susceptibility weighted mapping was performed using a 3D EPI sequence featuring a 2D spatial excitation pulse with gradients of spiral k-space trajectory. A series of 11 subjects were imaged using 3T MRI and combination endorectal (ER) and six-channel phased array cardiac coils. T1W TSE and T2*W EPI sequences were analyzed quantitatively for hemorrhage contrast. Point resolved spectroscopy (PRESS MRS) was performed and data quality was analyzed.
  
  
  RESULTS
  Two types of susceptibility variation were identified: hemorrhagic and nonhemorrhagic T2*W-positive areas. Post-biopsy hemorrhage lesions showed on average five times greater contrast on the T2*W images than T1W TSE images. Six nonhemorrhage regions of severe susceptibility artifact were apparent on the T2*W images that were not seen on standard T1W or T2W images. All nonhemorrhagic susceptibility artifact regions demonstrated compromised spectral quality on 3D MRS.
  
  
  CONCLUSIONS
  The fast T2*W EPI sequence identifies hemorrhagic and nonhemorrhagic areas of susceptibility variation that may be helpful in prostate MRI planning at 3.0T.
authors: Department of Radiology, University of Texas Health Science Center, San Antonio, TX, USA. hardmanr@uthscsa.edu
authors: Rulon L
authors: RL
authors: Hardman
authors: Fadi
authors: F
authors: El-Merhi
authors: Adam J
authors: AJ
authors: Jung
authors: Steve
authors: S
authors: Ware
authors: Ian M
authors: IM
authors: Thompson
authors: Harry T
authors: HT
authors: Friel
authors: Qi
authors: Q
authors: Peng
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001706:Biopsy; D003287:Contrast Media / Q000494:pharmacology; D017352:Echo-Planar Imaging / Q000379:methods*; D006470:Hemorrhage / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology*
chemical_list: D003287:Contrast Media