title: Imaging of the temporal bone in children using low-dose 320-row area detector computed tomography.
abstract: BACKGROUND
  The aim of this study was to compare the image quality obtained using low-dose and standard-dose 320-row temporal bone computed tomography (CT) in paediatric patients.
  
  
  METHODS
  Thirteen low-dose CT (120 kV/50 mAs) and nine standard-dose CT (120 kV/100 mAs) images from children up to 5 years of age were compared for their image quality. The noise and signal-to-noise ratio for bone, fat and air were measured. Two observers assessed the overall image quality and ability to visualize 14 small anatomic structures using a 5-point scale, with a score of 3-5 indicating imaging of diagnostic quality.
  
  
  RESULTS
  Noise was significantly higher and the signal-to-noise ratio was significantly lower with low-dose CT. Although the overall image quality and visibility of several structures on low-dose CT were significantly reduced when compared with standard-dose CT, all the image quality scores were 3 or >3. The dose-length products for low-dose CT and standard-dose CT were 59.6 mGy·cm and 119.3 mGy·cm, respectively.
  
  
  CONCLUSIONS
  Low-dose CT of the temporal bone using 320-row CT provides images of diagnostic quality for assessment of middle and inner ear anatomy, similar to that provided by the standard-dose protocol, in spite of increased image noise.
authors.affiliation: Department of Radiology, Okayama University Medical School, Okayama, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Tada
authors.affiliation: Department of Radiology, Okayama University Medical School, Okayama, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Sato
authors.affiliation: Department of Radiology, Okayama University Medical School, Okayama, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Masaoka
authors.affiliation: Department of Radiology, Okayama University Medical School, Okayama, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D059629:Signal-To-Noise Ratio; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: 320-row detector; computed tomography; dose reduction; temporal bone