title: Impact of model-based iterative reconstruction on low-contrast lesion detection and image quality in abdominal CT: a 12-reader-based comparative phantom study with filtered back projection at different tube voltages.
abstract: OBJECTIVE
  To evaluate the impact of model-based iterative reconstruction (MBIR) on image quality and low-contrast lesion detection compared with filtered back projection (FBP) in abdominal computed tomography (CT) of simulated medium and large patients at different tube voltages.
  
  
  METHODS
  A phantom with 45 hypoattenuating lesions was placed in two water containers and scanned at 70, 80, 100, and 120 kVp. The 120-kVp protocol served as reference, and the volume CT dose index (CTDIvol) was kept constant for all protocols. The datasets were reconstructed with MBIR and FBP. Image noise and contrast-to-noise-ratio (CNR) were assessed. Low-contrast lesion detectability was evaluated by 12 radiologists.
  
  
  RESULTS
  MBIR decreased the image noise by 24% and 27%, and increased the CNR by 30% and 29% for the medium and large phantoms, respectively. Lower tube voltages increased the CNR by 58%, 46%, and 16% at 70, 80, and 100 kVp, respectively, compared with 120 kVp in the medium phantom and by 9%, 18% and 12% in the large phantom. No significant difference in lesion detection rate was observed (medium: 79-82%; large: 57-65%; P > 0.37).
  
  
  CONCLUSIONS
  Although MBIR improved quantitative image quality compared with FBP, it did not result in increased low-contrast lesion detection in abdominal CT at different tube voltages in simulated medium and large patients.
  
  
  CONCLUSIONS
  • MBIR improved quantitative image quality but not lesion detection compared with FBP. • Increased CNR by low tube voltages did not improve lesion detection. • Changes in image noise and CNR do not directly influence diagnostic accuracy.
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: André
authors.initials: A
authors.lastname: Euler
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Bram
authors.initials: B
authors.lastname: Stieltjes
authors.affiliation: Institute of Radiology, Hospital Centre of Biel, Biel, Switzerland.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Szucs-Farkas
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Reto
authors.initials: R
authors.lastname: Eichenberger
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Clemens
authors.initials: C
authors.lastname: Reisinger
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Hirschmann
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Zaehringer
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Achim
authors.initials: A
authors.lastname: Kircher
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Streif
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Sabine
authors.initials: S
authors.lastname: Bucher
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Buergler
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Luigia
authors.initials: L
authors.lastname: D'Errico
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Sebastién
authors.initials: S
authors.lastname: Kopp
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Wilhelm
authors.affiliation: Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland. sschindera@aol.com.|Institute of Radiology, Cantonal Hospital Aarau, Aarau, Switzerland. sschindera@aol.com.
authors.forename: Sebastian T
authors.initials: ST
authors.lastname: Schindera
mesh_terms: D000465:Algorithms; D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000592:standards*
keywords: Filtered back projection; Low-contrast detection; Model-based iterative reconstruction; Multidetector computed tomography; Radiological phantom