title: Enhanced gray-white matter differentiation on non-enhanced CT using a frequency selective non-linear blending.
abstract: BACKGROUND
  The aim if this study is to find out if contrast between gray (GM) and white matter (WM) on non-enhanced brain CT (NECT) can be enhanced by using a frequency selective non-linear blending.
  
  
  METHODS
  Thirty consecutive patients (40 % female; mean age 67.73 ± 12.71 years), who underwent NECT of the brain, were retrospectively included in this study. Brain scan readings were performed by two radiologists independently, for NECT and subsequently the images were read using a new frequency selective non-linear blending algorithm (best contrast, BC). Optimal settings of BC for enhanced delineation of anatomical structures were set at an averaged center of 30 HU, averaged delta of 5 HU, and a slope of 5. For contrast-to-noise ratio calculation (CNR), gray and white matter attenuation values were measured for both NECT and BC in different anatomical structures.
  
  
  RESULTS
  CNR increase in the gray matter was 5.91 ± 2.45 for the cortical gray matter and 4.41 ± 1.82 for the basal ganglia. The contrast ratio between cortical gray and white matter was 1.87 and 1.7 (basal ganglia/WM) for BC quantification vs. 1.43 (cortex/WM) and 1.33 (basal ganglia/WM) for standard NECT (both p < 0.0001). Improved CNR did not depend on the anatomical structures measured.
  
  
  CONCLUSIONS
  Frequency selective non-linear blending allows better discrimination between WM and GM and therefore may enhance diagnostic accuracy of NECT.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany. georghomann@web.de.
authors.forename: Georg
authors.initials: G
authors.lastname: Bier
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany.
authors.forename: Malte Niklas
authors.initials: MN
authors.lastname: Bongers
authors.affiliation: Imaging & Therapy Division, Siemens AG Healthcare Sector, Forchheim, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Ditt
authors.affiliation: Department of Neuroradiology, Eberhard Karls-University Tuebingen, Tuebingen, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bender
authors.affiliation: Department of Neuroradiology, Eberhard Karls-University Tuebingen, Tuebingen, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Ernemann
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard Karls-University Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tuebingen, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Horger
mesh_terms: D000368:Aged; D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging*; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D061330:Multidetector Computed Tomography / Q000379:methods*; D017711:Nonlinear Dynamics; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D066127:White Matter / Q000000981:diagnostic imaging*
keywords: Contrast-to-noise-ratio; Gray matter; Image post-processing; Multidetector computed tomography; White matter