title: The U sign: tenth landmark to the central region on brain surface reformatted MR imaging.
abstract: OBJECTIVE
  Identification of the central region is of special importance to avoid neurologic deficits in brain surgery. Brain surface reformatted images (Mercator view) map the frontoparietal brain surface in 1 view and provide a synopsis of the most important landmarks. In this view, the U-shaped subcentral gyrus appears as a distinctive anatomic structure enclosing the Sylvian end of the central sulcus. The purpose of this study was to add the subcentral gyrus as a new landmark to the central region (U sign) and to compare its frequency and applicability with common landmarks in healthy hemispheres.
  
  
  METHODS
  Mercator views of 178 hemispheres in 100 patients were generated from 3D MR imaging datasets. The hemispheres were evaluated on Mercator views for the presence or absence of each of the 9 common landmarks and the new U sign identifying the central region.
  
  
  RESULTS
  The new landmark U sign was most common (96.6%), followed by the thin postcentral gyrus sign (95.5%). The least common landmark was the Ω-shaped handknob (54.5%). None of the landmarks could be identified in all hemispheres. All landmarks could be identified bilaterally in only 1.3% of patients.
  
  
  CONCLUSIONS
  On the Mercator view, the new U sign is an applicable and even the most frequent landmark to identify the central region. Considering the variability of the anatomic structures of the brain, including the motor hand area, the synopsis of all 10 landmarks on this surface-reformatting projection is a helpful adjunct to standard MR imaging projections to identify the central region.
authors: Institute of Neuroradiology, University Hospital, Goethe University Frankfurt, D-60528 Frankfurt am Main, Germany. marlies.wagner@kgu.de
authors: M
authors: M
authors: Wagner
authors: A
authors: A
authors: Jurcoane
authors: E
authors: E
authors: Hattingen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks / Q000033:anatomy & histology*; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D005625:Frontal Lobe / Q000033:anatomy & histology*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods / Q000592:standards; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards*; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000033:anatomy & histology*; D012016:Reference Values; D055815:Young Adult