title: Improved image quality and detection of acute cerebral infarction with PROPELLER diffusion-weighted MR imaging.
abstract: OBJECTIVE
  To compare periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) multishot fast spin-echo diffusion-weighted magnetic resonance (MR) imaging with single-shot echo-planar diffusion-weighted MR imaging for image quality and visualization of acute cerebral infarction.
  
  
  METHODS
  Seventy subjects (35 men, 35 women; mean age, 55 years +/- 24 [SD]) who were suspected of having acute cerebral infarction (symptom duration, 2.8 days +/- 2.7) underwent PROPELLER and echo-planar MR imaging (b = 1,000 sec/mm(2)). Two neuroradiologists compared unlabeled images for presence of artifacts, visualization of infarction, and their preference of images. Interobserver agreement and image comparison were assessed by using the kappa statistic and the chi(2) test, respectively.
  
  
  RESULTS
  PROPELLER MR imaging reduced susceptibility artifacts (n = 70 subjects), which limited visualization of temporal (echo-planar, n = 64; PROPELLER, n = 0; P <.01, chi(2) test), frontal (echo-planar, n = 58; PROPELLER, n = 1; P <.01), and parietal lobes (echo-planar, n = 5; PROPELLER, n = 0; P <.05) and cerebellum (echo-planar, n = 36; PROPELLER, n = 0; P <.01) and brainstem (echo-planar, n = 23; PROPELLER, n = 0; P <.01). Acute infarction (n = 31 subjects) was better demonstrated at PROPELLER MR imaging (PROPELLER better, n = 18; echo-planar better, n = 1; PROPELLER and echo-planar equal, n = 12; P <.01, chi(2) test). PROPELLER MR imaging was preferred in all (n = 70) but one case in which the lesion lay within the intersection gap (PROPELLER preferred, n = 69; echo-planar preferred, n = 1; P <.01, chi(2) test).
  
  
  CONCLUSIONS
  With a short increase in imaging time, PROPELLER MR imaging offers better image quality and detection of acute cerebral infarction than does echo-planar MR imaging.
authors.affiliation: Division of Neuroradiology, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ 85013, USA.
authors.forename: Kirsten P
authors.initials: KP
authors.lastname: Forbes
authors.forename: James G
authors.initials: JG
authors.lastname: Pipe
authors.forename: John P
authors.initials: JP
authors.lastname: Karis
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Heiserman
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D016477:Artifacts; D002544:Cerebral Infarction / Q000175:diagnosis*; D003625:Data Collection; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011786:Quality Control; D012680:Sensitivity and Specificity