title: A 3D-printed anatomical pancreas and kidney phantom for optimizing SPECT/CT reconstruction settings in beta cell imaging using111In-exendin.
abstract: BACKGROUND
  Quantitative single photon emission computed tomography (SPECT) is challenging, especially for pancreatic beta cell imaging with111In-exendin due to high uptake in the kidneys versus much lower uptake in the nearby pancreas. Therefore, we designed a three-dimensionally (3D) printed phantom representing the pancreas and kidneys to mimic the human situation in beta cell imaging. The phantom was used to assess the effect of different reconstruction settings on the quantification of the pancreas uptake for two different, commercially available software packages.
  
  
  METHODS
  3D-printed, hollow pancreas and kidney compartments were inserted into the National Electrical Manufacturers Association (NEMA) NU2 image quality phantom casing. These organs and the background compartment were filled with activities simulating relatively high and low pancreatic111In-exendin uptake for, respectively, healthy humans and type 1 diabetes patients. Images were reconstructed using Siemens Flash 3D and Hermes Hybrid Recon, with varying numbers of iterations and subsets and corrections. Images were visually assessed on homogeneity and artefacts, and quantitatively by the pancreas-to-kidney activity concentration ratio.
  
  
  RESULTS
  Phantom images were similar to clinical images and showed comparable artefacts. All corrections were required to clearly visualize the pancreas. Increased numbers of subsets and iterations improved the quantitative performance but decreased homogeneity both in the pancreas and the background. Based on the phantom analyses, the Hybrid Recon reconstruction with 6 iterations and 16 subsets was found to be most suitable for clinical use.
  
  
  CONCLUSIONS
  This work strongly contributed to quantification of pancreatic111In-exendin uptake. It showed how clinical images of111In-exendin can be interpreted and enabled selection of the most appropriate protocol for clinical use.
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box: 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: Wietske
authors.initials: W
authors.lastname: Woliner-van der Weg
authors.affiliation: Department of surgery, Rijnstate Hospital, Arnhem, The Netherlands.
authors.forename: Laura N
authors.initials: LN
authors.lastname: Deden
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box: 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: Antoi P W
authors.initials: AP
authors.lastname: Meeuwis
authors.affiliation: Department of Robotics and Mechatronics, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.|Department of Vascular Surgery, Medical Spectrum Twente, Enschede, The Netherlands.
authors.forename: Maaike
authors.initials: M
authors.lastname: Koenrades
authors.affiliation: Department of Rehabilitation, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Laura H C
authors.initials: LH
authors.lastname: Peeters
authors.affiliation: Department of Robotics and Mechatronics, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Henny
authors.initials: H
authors.lastname: Kuipers
authors.affiliation: Department of Robotics and Mechatronics, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Geert Jan
authors.initials: GJ
authors.lastname: Laanstra
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box: 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: Gotthardt
authors.affiliation: Department of Robotics and Mechatronics, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
authors.forename: Cornelis H
authors.initials: CH
authors.lastname: Slump
authors.affiliation: Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box: 9101, 6500 HB, Nijmegen, The Netherlands. eric.visser@radboudumc.nl.
authors.forename: Eric P
authors.initials: EP
authors.lastname: Visser
keywords: 111In-exendin; 3D printing; Beta cell imaging; Quantification; SPECT