title: Low-Dose CT of the Paranasal Sinuses: Minimizing X-Ray Exposure with Spectral Shaping.
abstract: OBJECTIVE
  Shaping the energy spectrum of the X-ray beam has been shown to be beneficial in low-dose CT. This study's aim was to investigate dose and image quality of tin filtration at 100 kV for pre-operative planning in low-dose paranasal CT imaging in a large patient cohort.
  
  
  METHODS
  In a prospective trial, 129 patients were included. 64 patients were randomly assigned to the study protocol (100 kV with additional tin filtration, 150mAs, 192x0.6-mm slice collimation) and 65 patients to the standard low-dose protocol (100 kV, 50mAs, 128 × 0.6-mm slice collimation). To assess the image quality, subjective parameters were evaluated using a five-point scale. This scale was applied on overall image quality and contour delineation of critical anatomical structures.
  
  
  RESULTS
  All scans were of diagnostic image quality. Bony structures were of good diagnostic image quality in both groups, soft tissues were of sufficient diagnostic image quality in the study group because of a high level of noise. Radiation exposure was very low in both groups, but significantly lower in the study group (CTDIvol1.2 mGy vs. 4.4 mGy, p < 0.001).
  
  
  CONCLUSIONS
  Spectral optimization (tin filtration at 100 kV) allows for visualization of the paranasal sinus with sufficient image quality at a very low radiation exposure.
  
  
  CONCLUSIONS
  • Spectral optimization (tin filtration) is beneficial to low-dose parasinus CT • Tin filtration at 100 kV yields sufficient image quality for pre-operative planning • Diagnostic parasinus CT can be performed with an effective dose <0.05 mSv.
authors.affiliation: Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany. wolfgang.wuest@uk-erlangen.de.|Radiological Institute, Maximiliansplatz 1, 91054, Erlangen, Germany. wolfgang.wuest@uk-erlangen.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wuest
authors.affiliation: Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: May
authors.affiliation: Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Saake
authors.affiliation: Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Brand
authors.affiliation: Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Uder
authors.affiliation: Radiological Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D010256:Paranasal Sinuses / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D011446:Prospective Studies; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation; D012852:Sinusitis / Q000000981:diagnostic imaging*; D014965:X-Rays; D055815:Young Adult
keywords: CT; Low dose; Parasinus CT; Spectral shaping; Tin filtration