Nanospect ct scanner

A total 4 mice were scanned as exemplary cases for in vivo SPECT/CT imaging. Under isoflurane anesthesia (1%–2% isoflurane in 2:1 O2:N₂O volume ratio) tracer injection and whole-body imaging was performed 2 h and 4 h after injection with a 4-head NanoSPECT/CT scanner (Mediso Ltd.). SPECT scans were acquired using a multipinhole collimator set (SCIVIS), each collimator with 9 pinholes (1.4-mm pinhole diameters). SPECT imaging was performed with an energy window of 140 keV ± 5% and an acquisition time of 60 min. Images were reconstructed with isotropic voxel output sizes of 300–448 µm, depending on count rates (HiSPECT; SCIVIS). CT scans were acquired at 98 µm detector resolution and reconstructed at isotropic voxel sizes of 200 µm (InVivoScope 1.43; Bioscan). Further on, six non-tumor bearing mice were scanned to qualitatively evaluate the thyroid uptake of tracers.

Mice were anaesthetised and whole-body SPECT/CT scans were acquired using a NanoSPECT/CT scanner (Mediso, Hungary). CT images were acquired using a 45 kilo volt peak (kVp) X-ray source, 500 ms exposure time in 180 projections, a pitch of 1.5 with an acquisition time of 7 minutes. SPECT images were obtained with a 4-head scanner with nine 1.4 mm pinhole apertures in helical scan mode using a time per view of 60–90 seconds resulting in a scan time of 36–60 minutes and respiration was monitored throughout the scan and body temperature maintained with a warm air blower. CT images were reconstructed in voxel size 124 × 124 × 124 μm using Bioscan InVivoScope (Bioscan, USA) software, whereas SPECT images were reconstructed in a 256 × 256 matrix using HiSPECT (ScivisGmbH, Bioscan). Images were fused and analysed using InVivoScope (Version 1.44, Bioscan). 3D ROIs were created for brain, lungs, liver and kidney for each time point using VivoQuant (inviCRO version 2.5 patch 1) software. After correcting for ¹¹¹In decay, the 3D ROIs were calculated as the percentage of injected dose per mm³ (%ID mm^–3). Representative maximum intensity projection (MIP) images were presented using %ID mm^–3 as color scale after decay correction and Guassian filtering of 0.8 by utilising the same software.

Animals were scanned under isoflurane anesthesia (1.0–1.5 % in 2:1 O₂:N₂O volume ratio) with the CT functionality of a NanoSPECT/CT scanner (Mediso Ltd., Budapest, Hungary). CT scans were made at 45 kVp, 1.77 μA, with 180 projections, 500 ms per projection and 96 μm pixel size. Images were reconstructed with the InVivoScope (vs.1.43) at isotropic voxel sizes of 100 μm and analyzed with the DICOM viewers Osirix (Pixmeo SARL, Bernex, Switzerland, v.5.1.7 64-bit) and the open source program AMIDE: A Medical Imaging Data Examiner (amide.exe 1.0.4, ^©Andreas Loening, http://amide.sourceforge.net/; GNU GPL).