title: Phantom Validation of Tc-99m Absolute Quantification in a SPECT/CT Commercial Device.
abstract: Aim. Similar to PET, absolute quantitative imaging is becoming available in commercial SPECT/CT devices. This study's goal was to assess quantitative accuracy of activity recovery as a function of image reconstruction parameters and count statistics in a variety of phantoms.Materials and Methods. We performed quantitative99mTc-SPECT/CT acquisitions (Siemens Symbia Intevo, Erlangen, Germany) of a uniform cylindrical, NEMA/IEC, and an anthropomorphic abdominal phantom. Background activity concentrations tested ranged: 2-80 kBq/mL. SPECT acquisitions used 120 projections (20 s/projection). Reconstructions were performed with the proprietary iterative conjugate gradient algorithm. NEMA phantom reconstructions were obtained as a function of the iteration number (range: 4-48). Recovery coefficients, hot contrast, relative lung error (NEMA phantom), and image noise were assessed.Results. In all cases, absolute activity and activity concentration were measured within 10% of the expected value. Recovery coefficients and hot contrast in hot inserts did not vary appreciably with count statistics. RC converged at 16 iterations for insert size > 22 mm. Relative lung errors were comparable to PET levels indicating the efficient integration of attenuation and scatter corrections with adequate detector modeling.Conclusions. The tested device provided accurate activity recovery within 10% of correct values; these performances are comparable to current generation PET/CT systems.
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Silvano
authors.identifier: 0000-0002-6547-3824
authors.initials: S
authors.lastname: Gnesin
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Paulo
authors.initials: P
authors.lastname: Leite Ferreira
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Jerome
authors.initials: J
authors.lastname: Malterre
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Priscille
authors.initials: P
authors.lastname: Laub
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: John O
authors.initials: JO
authors.lastname: Prior
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Francis R
authors.initials: FR
authors.lastname: Verdun
mesh_terms: D000005:Abdomen / Q000503:physiopathology; D000465:Algorithms; D000886:Anthropometry; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology; D016011:Normal Distribution; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results; D000072098:Single Photon Emission Computed Tomography Computed Tomography / Q000295:instrumentation / Q000379:methods*; D013667:Technetium / Q000737:chemistry*
chemical_list: D013667:Technetium