Ge discovery 670

The study population consists of 1334 patients who underwent bone scintigraphy between 2012–2021 in four Finnish nuclear medicine units. The data were collected using standard clinical single-photon emission computed tomography (SPECT) scanners: Philips/ADAC Forte (Philips Healthcare, Eindhoven, The Netherlands; N = 100), Philips Brightview (N = 200), Siemens e.cam (Siemens Healthcare, Erlangen, Germany; N = 547), Siemens Symbia (N = 372), GE Infinia Hawkeye (GE Healthcare, Waukesha, Wisconsin, USA; N = 96), and GE Discovery 670 (N = 19). Low-energy high-resolution (LEHR) collimators were used in all scanners.
Of all participants, 1319 were scanned using a whole-body bone scintigraphy protocol, and 15 patients with thoracic planar scintigraphy included in the clinical cardiac amyloidosis imaging protocol. The emphasis of patient selection was in the inclusion of patients with positive cardiac uptake as their prevalence is low in overall population. All studies were performed using [99mTc]Tc-HMDP imaged at three-hours post-injection. The administered activity was 500–700 MBq. Both visual and CNN analysis of bone scintigraphy data were done for research purposes only. The study was approved by the ethics committee of Helsinki University Hospital and was conducted according to the Declaration of Helsinki.

Data from 10 patients treated with ${}^{90}$ Y SIRT were acquired at Oxford University Hospitals NHS Foundation Trust (OUH), UK, using the GE Discovery 670 for SPECT/CT data and GE Discovery 710 for PET/CT data. The cases were a mixture of treatments with SIR-Spheres (SIRTeX) ( $n=6$ ) and TheraSpheres (BTG) ( $n=4$ ) [29 (link)]. Images were acquired approximately 18 h following SIRT administration with PET/CT followed by SPECT/CT. The SPECT data were acquired for 30 min using a medium energy collimator and a energy window range 50–150 keV [30 (link)]. The PET data were acquired for 15 min per bed position with two bed positions acquired [29 (link), 31 (link)]. Figure 2 shows the CT, SPECT and PET images of one patient.Fig. 2

Magnified CT, SPECT and PET images for patient 1 with volume of interests. The CT and SPECT images are the one used as side information for HKEM and MHKEM. L1 is a lesion in the proximity of the liver surface, L2 is a lesion with the maximum voxel value, and BGR is the background VOI. On the top row, the segmented VOI is superimposed to the fused PET-CT image. The fused images are magnified to better show the VOIs