title: Impact of iterative reconstruction on image quality and radiation dose in multidetector CT of large body size adults.
abstract: OBJECTIVE
  To compare image quality and radiation dose using Adaptive Statistical Iterative Reconstruction (ASiR) and Filtered Back Projection (FBP) in patients weighing ≥ 91 kg.
  
  
  METHODS
  In this Institution Review Board-approved retrospective study, single-phase contrast-enhanced abdominopelvic CT examinations of 100 adults weighing ≥ 91 kg (mean body weight: 107.6 ± 17.4 kg range: 91-181.9 kg) with (1) ASiR and (2) FBP were reviewed by two readers in a blinded fashion for subjective measures of image quality (using a subjective standardized numerical scale and objective noise) and for radiation exposure. Imaging parameters and radiation dose results of the two techniques were compared within weight and BMI sub-categories.
  
  
  RESULTS
  All examinations were found to be of adequate quality. Both subjective (mean = 1.4 ± 0.5 vs. 1.6 ± 0.6, P < 0.05) and objective noise (13.0 ± 3.2 vs.19.5 ± 5.7, P < 0.0001) were lower with ASiR. Average radiation dose reduction of 31.5 % was achieved using ASiR (mean CTDIvol. ASiR: 13.5 ± 7.3 mGy; FBP: 19.7 ± 9.0 mGy, P < 0.0001). Other measures of image quality were comparable between the two techniques. Trends for all parameters were similar in patients across weight and BMI sub-categories.
  
  
  CONCLUSIONS
  In obese individuals, abdominal CT images reconstructed using ASiR provide diagnostic images with reduced image noise at lower radiation dose.
  
  
  CONCLUSIONS
  • CT images in obese adults are noisy, even with high radiation dose. • Newer iterative reconstruction techniques have theoretical advantages in obese patients. • Adaptive statistical iterative reconstruction should reduce image noise and radiation dose. • This has been proven in abdominopelvic CT images of obese patients.
authors.affiliation: Department of Abdominal Imaging and Intervention, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, White 270, Boston, MA 02114, USA.
authors.forename: Gaurav S
authors.initials: GS
authors.lastname: Desai
authors.forename: Raul N
authors.initials: RN
authors.lastname: Uppot
authors.forename: Elaine W
authors.initials: EW
authors.lastname: Yu
authors.forename: Avinash R
authors.initials: AR
authors.lastname: Kambadakone
authors.forename: Dushyant V
authors.initials: DV
authors.lastname: Sahani
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D049628:Body Size; D001835:Body Weight; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D016347:Medical Records Systems, Computerized; D008858:Microscopy, Phase-Contrast / Q000379:methods; D008875:Middle Aged; D009765:Obesity; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media