title: Readout-segmented echo-planar imaging for diffusion-weighted imaging in the pelvis at 3T-A feasibility study.
abstract: OBJECTIVE
  Diffusion-weighted imaging (DWI) of the pelvis at 3T is prone to artifacts that diminish the image quality. Readout-segmented echo-planar imaging (RS-EPI) is a new DWI technique that can reduce the artifacts associated with standard single-shot echo-planar imaging (SS-EPI) DWI. The purpose of this study was to evaluate the feasibility and image quality of RS-EPI in pelvic DWI compared to SS-EPI on a 3T imaging system.
  
  
  METHODS
  Thirty patients underwent pelvic DWI on a 3T scanner with SS-EPI and RS-EPI techniques. Two blinded readers independently assessed each set of images for geometric distortion, image blurring, ghosting artifacts, lesion conspicuity, and overall image quality on a 7-point scale. Qualitative image scores were compared using paired Wilcoxon signed rank test. Interreader correlation was assessed by Spearman rank correlation.
  
  
  RESULTS
  Geometric distortion, imaging blurring, ghosting artifacts, lesion conspicuity, and overall image quality were rated significantly better by both readers for RS-EPI technique (P < .01 for all parameters). There was moderate-high correlation between the readers (r = 0.649-0.752) for all parameters apart from lesion conspicuity (r = 0.351). Both readers preferred the RS-EPI set of DWI images in most of the cases (reader 1: 0.87, 95% CI 0.74-0.99; reader 2: 0.77, 95% CI 0.61-0.93). Mean difference and limits of agreement between apparent diffusion coefficient (ADC) values obtained from the two methods were 0.01 (-0.08, 0.10) × 10(-3) mm(2)/s.
  
  
  CONCLUSIONS
  RS-EPI DWI images showed improved image quality compared to SS-EPI technique at 3T. RS-EPI is a feasible technique in the pelvis for producing high-resolution DWI.
authors.affiliation: Department of Diagnostic Imaging, National University Hospital Singapore, 5 Lower Kent Ridge Rd, Singapore 119074 Singapore. Electronic address: ylthian@gmail.com.
authors.forename: Yee Liang
authors.initials: YL
authors.lastname: Thian
authors.affiliation: Department of Nuclear Medicine, Singapore General Hospital, Singapore, Singapore.
authors.forename: Wanying
authors.initials: W
authors.lastname: Xie
authors.affiliation: Imaging and IT Division, Healthcare Sector, Siemens AG, Erlangen, Germany.
authors.forename: David A
authors.initials: DA
authors.lastname: Porter
authors.affiliation: Department of Diagnostic Imaging, National University Hospital Singapore, 5 Lower Kent Ridge Rd, Singapore 119074 Singapore.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Weileng Ang
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010386:Pelvic Neoplasms / Q000473:pathology*; D010388:Pelvis / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D055815:Young Adult
keywords: Readout-segmented; artifacts; diffusion magnetic resonance imaging; echo-planar imaging; pelvis