title: Readout-segmented echo-planar imaging in diffusion-weighted MR imaging of acute infarction of the brainstem and posterior fossa: comparison of single-shot echo-planar diffusion-weighted sequences.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the clinical usefulness of readout-segmented echo-planar imaging (rs-EPI) in the diagnosis of acute infarction of the brainstem and posterior fossa, by comparing its results with those of single-shot echo-planar imaging (ss-EPI) at 3-T magnetic resonance imaging.
  
  
  METHODS
  Twenty-nine patients with acute infarctions of the brainstem and posterior fossa underwent both ss-EPI and rs-EPI. Two readers independently assessed two sets of diffusion-weighted (DW) images for the qualitative comparison of image quality. Signal-to-noise ratio (SNR), lesion contrast, and contrast-to-noise ratio (CNR) were calculated for the assessment of image parameters.
  
  
  RESULTS
  There were no significant differences in the conspicuity of acute infarction upon qualitative comparison; however, distinctions of anatomical structures, susceptibility artifact, the presence of uncertain high signal intensity in the brain parenchyma, and overall image quality were significantly better in rs-EPI DW images. There were no significant differences in SNR, lesion contrast, CNR, and apparent diffusion coefficient values of acute infarction and normal thalamus between rs-EPI and ss-EPI.
  
  
  CONCLUSIONS
  rs-EPI DWI is a clinically useful technique for evaluating lesions in the brainstem and posterior fossa by producing high-resolution DW images with reduced susceptibility artifact. However, there are no significant differences in the conspicuity of acute infarctions in the brainstem and posterior fossa between rs-EPI and ss-EPI.
authors.affiliation: Department of Radiology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Korea.
authors.forename: Jonghyun
authors.initials: J
authors.lastname: Byeon
authors.affiliation: Department of Radiology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. Electronic address: jeeyoungkim@catholic.ac.kr.
authors.forename: Jee Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Neurology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: A-Hyun
authors.initials: AH
authors.lastname: Cho
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001921:Brain / Q000473:pathology*; D020520:Brain Infarction / Q000473:pathology*; D001933:Brain Stem / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D059629:Signal-To-Noise Ratio
keywords: Bran stem; Diffusion-weighted MRI; Infarction; Magnetic resonance imaging