title: Improved Liver Lesion Conspicuity With Iterative Reconstruction in Computed Tomography Imaging.
abstract: Studies on iterative reconstruction techniques on computed tomographic (CT) scanners show reduced noise and changed image texture. The purpose of this study was to address the possibility of dose reduction and improved conspicuity of lesions in a liver phantom for different iterative reconstruction algorithms. An anthropomorphic upper abdomen phantom, specially designed for receiver operating characteristic analysis was scanned with 2 different CT models from the same vendor, GE CT750 HD and GE Lightspeed VCT. Images were obtained at 3 dose levels, 5, 10, and 15mGy, and reconstructed with filtered back projection (FBP), and 2 different iterative reconstruction algorithms; adaptive statistical iterative reconstruction and Veo. Overall, 5 interpreters evaluated the images and receiver operating characteristic analysis was performed. Standard deviation and the contrast to noise ratio were measured. Veo image reconstruction resulted in larger area under curves compared with those adaptive statistical iterative reconstruction and FBP image reconstruction for given dose levels. For the CT750 HD, iterative reconstruction at the 10mGy dose level resulted in larger or similar area under curves compared with FBP at the 15mGy dose level (0.88-0.95 vs 0.90). This was not shown for the Lightspeed VCT (0.83-0.85 vs 0.92). The results in this study indicate that the possibility for radiation dose reduction using iterative reconstruction techniques depends on both reconstruction technique and the CT scanner model used.
authors.affiliation: The Intervention Centre, Rikshospitalet, Oslo, Norway; Institute of Physics, University of Oslo, Oslo, Norway. Electronic address: uxjekr@ous-hf.no.
authors.forename: Kristin
authors.initials: K
authors.lastname: Jensen
authors.affiliation: The Intervention Centre, Rikshospitalet, Oslo, Norway.
authors.forename: Hilde Kjernlie
authors.initials: HK
authors.lastname: Andersen
authors.affiliation: Department of Medical Radiation Physics, Skåne University Hospital, Lund University, Malmö, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Tingberg
authors.affiliation: Department of Radiology and Nuclear Medicine, Radiumhospitalet, Oslo, Norway.
authors.forename: Claudius
authors.initials: C
authors.lastname: Reisse
authors.affiliation: The Intervention Centre, Rikshospitalet, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Erik
authors.initials: E
authors.lastname: Fosse
authors.affiliation: The Intervention Centre, Rikshospitalet, Oslo, Norway; Institute of Physics, University of Oslo, Oslo, Norway.
authors.forename: Anne Catrine T
authors.initials: AC
authors.lastname: Martinsen
mesh_terms: D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*