Image registration accuracy of an in-house developed patient transport system for PET/CT plus MR and SPECT plus CT imaging

Objective The aim of this study was to investigate the registration accuracy of a newly developed patient shuttle system that can integrate different scanners by patient transfer without repositioning for 'hardware'-based image fusion. We aimed to assess the registration accuracy of image fusion in two different settings: a trimodality PET/CT + MR system and a SPECT + CT system. Materials and methods In this prospective study, 43 patients underwent either sequential PET/CT and MR (n = 31) or sequential SPECT and diagnostic CT (D-CT) (n = 12). A side-loading patient shuttle system was used for patient transport. For PET/CT + MR, hardware-only coregistration was performed and then validated with anatomical landmarks on CT and MR. SPECT + D-CT image fusion was performed with external cobalt-57 markers and manual fusion. Registration accuracy was analysed by anatomical landmarks on the attenuation correction CT and the D-CT. Results For the PET/CT + MR system, the mean offset between original CT and MR images in all 31 patients was 8.1 +/- 5.7 mm in the X-axis, 5 +/- 4mm in the Y-axis and 4.9 +/- 5.6 mm in the Z-axis. The validation of the cobalt-57 marker-assisted SPECT+ D-CT fusion yielded offsets of 0.7 +/- 1.7 mm in the X-axis, 2.1 +/- 1.7 mm in the Y-axis and 0.8 +/- 1.8 mm in the Z-axis. Conclusion Sequential PET/CT + MR and SPECT + D-CT imaging using a dedicated patient shuttle system is feasible, resulting in mean offsets between data sets of 10.7 mm using the gantry laser system and 2.4 mm with fiducial markers. Nucl Med Commun 36: 194-200 (C) 2015 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.