title: Pure Iterative Reconstruction Improves Image Quality in Computed Tomography of the Abdomen and Pelvis Acquired at Substantially Reduced Radiation Doses in Patients With Active Crohn Disease.
abstract: We assessed diagnostic accuracy and image quality of modified protocol (MP) computed tomography (CT) of the abdomen and pelvis reconstructed using pure iterative reconstruction (IR) in patients with Crohn disease (CD).
  
  
  METHODS
  Thirty-four consecutive patients with CD were referred with suspected extramural complications. Two contemporaneous CT datasets were acquired in all patients: standard protocol (SP) and MP. The MP and SP protocols were designed to impart radiation exposures of 10% to 20% and 80% to 90% of routine abdominopelvic CT, respectively. The MP images were reconstructed with model-based IR (MBIR) and adaptive statistical IR (ASIR).
  
  
  RESULTS
  The MP-CT and SP-CT dose length product were 88 (58) mGy.cm (1.27 [0.87] mSv) and 303 [204] mGy.cm (4.8 [2.99] mSv), respectively (P < 0.001). Median diagnostic acceptability, spatial resolution, and contrast resolution were significantly higher and subjective noise scores were significantly lower on SP-ASIR 40 compared with all MP datasets. There was perfect clinical agreement between MP-MBIR and SP-ASIR 40 images for detection of extramural complications.
  
  
  CONCLUSIONS
  Modified protocol CT using pure IR is feasible for assessment of active CD.
authors.affiliation: From the *Department of Radiology, Cork University Hospital, Wilton, Cork; †Department of Radiology, University College Cork, Cork, Ireland; ‡GE Healthcare - Technologies, Hertfordshire, United Kingdom; and §Department of Medicine, University College Cork, Cork, Ireland.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: McLaughlin
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Murphy
authors.forename: Maria
authors.initials: M
authors.lastname: Twomey
authors.forename: Siobhan B
authors.initials: SB
authors.lastname: OʼNeill
authors.forename: Fiachra
authors.initials: F
authors.lastname: Moloney
authors.forename: Owen J
authors.initials: OJ
authors.lastname: OʼConnor
authors.forename: Kevin
authors.initials: K
authors.lastname: OʼRegan
authors.forename: Sean
authors.initials: S
authors.lastname: McSweeney
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: McGarrigle
authors.forename: Niamh
authors.initials: N
authors.lastname: Moore
authors.forename: Jackie
authors.initials: J
authors.lastname: Bye
authors.forename: Fergus
authors.initials: F
authors.lastname: Shanahan
authors.forename: Michael M
authors.initials: MM
authors.lastname: Maher
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003424:Crohn Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D011860:Radiography, Abdominal / Q000379:methods*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult