Quantitative SPECT Imaging with Tissue Segmentation

SPECT data were reconstructed with Flash3D with attenuation and scatter correction (Siemens, Germany) as the standard reconstruction for clinical use. Quantitative uptake maps were reconstructed with xSPECT Quant and xSPECT Bone (both Siemens, Germany), and include attenuation and scatter correction and standardized calibration for absolute quantification. xSPECT Bone uses the CT information to provide images with improved tissue boundary resolution. It uses a zone map derived from the CT data to segment the anatomical image into five specific tissue classes “zones”: cortical bone, spongiosa, soft tissue, fat tissue and air [23 (link), 24 ]. For attenuation correction, CT density data with and without metal artefact reduction [25 , 26 (link)] were used.
Planar scintigraphies were obtained with a triple phase protocol using the same SPECT/CT scanner system: perfusion phase immediately after tracer injection, blood pool phase ~ 3 min post-injection and delayed phase ~ 3 h post-injection.