title: Diffusion-weighted imaging with reverse phase-encoding polarity: the added value to the conventional diffusion-weighted imaging in differentiating acute infarctions from hyperintense brainstem artifacts.
abstract: OBJECTIVE
  The aim of our study was to assess the value of diffusion-weighted imaging with reverse phase-encoding polarity (R-DWI) in addition to conventional DWI using forward phase-encoding polarity (F-DWI) in differentiating acute brainstem infarctions from hyperintense artefacts.
  
  
  METHODS
  Seventy-six patients with 38 hyperintense brainstem artefacts and 38 acute brainstem infarctions that had undergone F-DWI and R-DWI were retrospectively selected based on the clinicoradiological diagnosis. Four radiologists independently rated their confidence in diagnosing acute infarctions and ruling out brainstem artefacts in a blind manner, and then compared the diagnostic performance and confidence between F-DWI alone and F-DWI with R-DWI.
  
  
  RESULTS
  The areas under the curve determined for F-DWI with R-DWI in diagnosing infarctions were significantly higher than F-DWI alone for all readers (resident 1, 0.908 vs 0.776; resident 2, 0.908 vs 0.789; neuroradiologist, 0.961 vs 0.868; emergency radiologist, 0.934 vs 0.855, all p < 0.05). All readers were more confident using F-DWI with R-DWI than F-DWI alone (all p < 0.05) for diagnosing acute brainstem infarction, and three readers (readers except the neuroradiologist) were more confident using F-DWI with R-DWI for ruling out brainstem artefacts (p ≤ 0.001).
  
  
  CONCLUSIONS
  The addition of R-DWI to F-DWI is a valuable method for differentiating acute brainstem infarctions from hyperintense artefacts.
  
  
  CONCLUSIONS
  • Hyperintense brainstem artefacts can be confused with acute infarctions on DWI. • Additional R-DWI to F-DWI reduces inter-reader variability in diagnosing brainstem infarctions. • Additional R-DWI improves performance and confidence for discriminating infarctions from artefacts.
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
authors.forename: Gil-Sun
authors.initials: GS
authors.lastname: Hong
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea. cwlee@amc.seoul.kr.
authors.forename: Choong Wook
authors.initials: CW
authors.lastname: Lee
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
authors.forename: Mi-Hyun
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Jang
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
authors.forename: Sae Rom
authors.initials: SR
authors.lastname: Chung
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
authors.forename: Ga Young
authors.initials: GY
authors.lastname: Yoon
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Korea.
authors.forename: Jeong Kon
authors.initials: JK
authors.lastname: Kim
mesh_terms: D000368:Aged; D019540:Area Under Curve; D016477:Artifacts; D020526:Brain Stem Infarctions / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Acute brainstem infarctions; Diffusion-weighted imaging; Hyperintense brainstem artefacts; Magnetic susceptibility artefacts; Reverse phase-encoding polarity