title: [The effect of the field strength on standardized MRI of the brain to demonstrate cranial nerves and vessels: a comparison of 1.5 and 3.0 Tesla].
abstract: OBJECTIVE
  Comparison of MR images acquired as routine examinations at a field strength of 3.0 T and 1.5 T to determine whether and to which degree the image quality improves at the higher field strength of 3.0 T.
  
  
  METHODS
  Routine MR images of 200 patients were examined retrospectively, with 100 images obtained at 1.5 T and 100 obtained at 3.0 T. The examinations were performed with a quadrature head coil and focused on the basal cisterns because of the abundance of small distinct structures in this region. We selected the T2-weighted 2D-FSE sequence in transverse direction for comparison. At both field strengths, the same section thickness of 5 mm and a matrix of 512 x 388 (FOV: 220 mm) were used. The quality of the images was evaluated with regard to depicting the cranial nerves N. III, V - X, the AICA and PICA. For comparison, image quality was rated with a score from 1 (well defined) to 5 (not depicted).
  
  
  RESULTS
  A score of 1 was obtained in 46 % of the anatomic structures examined at 3.0 T and in only 9.2 % at 1.5 T. A score of 2 was given in 27.6 % of the anatomic structures at 3.0 T vs. 23.5 % at 1.5 T, a score of 3 in 17.2 % vs. 28.1 %, a score of 4 in 8.6 % vs. 28.7 %, and a score of 5 in 0.4 % vs. 10.3 %, respectively. The Mann-Whitney U test showed significance at p < 0.001 for the comparison of images at 1.5 and 3.0 Tesla.
  
  
  CONCLUSIONS
  Routine magnetic resonance imaging using the same quadrature coil technique and similar acquisition times at 3.0 T and 1.5 T shows an improvement for T2-weighted images at the higher field strength.
authors.affiliation: Klinik für Strahlenheilkunde, Campus Virchow-Klinikum, Charité Universitätsmedizin Berlin. rainer.roettgen@charite.de
authors.forename: R
authors.initials: R
authors.lastname: Röttgen
authors.forename: K
authors.initials: K
authors.lastname: Haltaufderheide
authors.forename: R J
authors.initials: RJ
authors.lastname: Schröder
authors.forename: M
authors.initials: M
authors.lastname: Lorenz
authors.forename: H
authors.initials: H
authors.lastname: Herzog
authors.forename: F
authors.initials: F
authors.lastname: Neumann
authors.forename: L
authors.initials: L
authors.lastname: Lehmkuhl
authors.forename: L
authors.initials: L
authors.lastname: Winter
authors.forename: R
authors.initials: R
authors.lastname: Felix
authors.forename: H
authors.initials: H
authors.lastname: Bruhn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000033:anatomy & histology* / Q000098:blood supply; D002536:Cerebral Arteries / Q000033:anatomy & histology*; D002550:Cerebral Veins / Q000033:anatomy & histology*; D002648:Child; D002675:Child, Preschool; D002946:Cisterna Magna / Q000033:anatomy & histology*; D003391:Cranial Nerves / Q000033:anatomy & histology*; D004574:Electromagnetic Fields; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity