title: Susceptibility-weighted imaging in grading brain astrocytomas.
abstract: OBJECTIVE
  To evaluate the value of intratumoral vessels and micro-hemorrhage shown in susceptibility weighted imaging (SWI) for grading brain astrocytomas and to analyze the difference between SWI and conventional imaging techniques.
  
  
  METHODS
  22 patients with astrocytomas were diagnosed with surgical specimens, 9 of which were grades I-II, and 13 were grades III-IV. All examinations were performed on Signa DEx 3.0 T MRI scanner. Conventional imaging techniques (T1WI, T2WI, T2FLAIR, CE-T1WI) and SWI sequence were used. The parameters of SWI sequence were the following: TR=35 ms, TE=20 ms, FA=15 degrees, slice thickness=2 mm. The small vessels and blood products of the tumors in SW images were analyzed. The differences between the two groups in SW images were analyzed statistically.
  
  
  RESULTS
  The findings in SW images of brain astrocytomas were correlated strongly with pathology. SWI was more sensitive compared to conventional imaging techniques for showing small vessels and micro-hemorrhage in brain astrocytomas. Statistical comparison showed that the small vessels and micro-hemorrhage of two groups of brain astrocytomas in SW images differed significantly.
  
  
  CONCLUSIONS
  SWI is superior to conventional imaging techniques at showing the small vessels and micro-hemorrhage in brain astrocytomas, which plays an important role in the tumor grading.
authors.affiliation: Shandong Medical Imaging Research Institute, Jinan, 250021, China. lichuanting@yeah.net
authors.forename: Chuanting
authors.initials: C
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Ai
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Hengtao
authors.initials: H
authors.lastname: Qi
authors.forename: Lebin
authors.initials: L
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001254:Astrocytoma / Q000175:diagnosis*; D001932:Brain Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult