Brightspeed 16 ct scanner

COVID-19 patients infected by the omicron variant of SARS-CoV-2 were hospitalized and treated as reported (17 (link)). Blood cell analysis was conducted by an automated XN1000 hematology analyzer (SYSMEX, Japan), and biochemical indicators were analyzed using VITROS 350 autoanalyzer (Johnson &. Johnson, USA). Computed tomography (CT) was performed using BrightSpeed 16 CT Scanner (GE Healthcare, USA). The scanning parameters were set as 120 kVp, 80 mA, 1.5-mm collimation, reconstruction matrix of 512 × 512, slice thickness of 5.0 mm, scan field of view (FOV) of 25 × 25 cm, and high spatial resolution algorithm. For most of admitted COVID-19 patients in TFPHS, two types of inactivated vaccines (Sinovac or Sinopharm) have been administered. Serological tests of patients based on detection of SARS-CoV-2-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) were conducted, using 2019-nCoV Ab test kit (colloidal gold), manufactured by Innovita Biological Technology Co. Ltd., China.

All imaging acquisitions were performed with a SPECT/CT Discovery NM/CT 670 (General Electric [GE] Healthcare), including a BrightSpeed 16 CT scanner and a 3/8-inch NaI(Tl) crystal, according to the acquisition protocol previously described [12 (link)]. Briefly, nuclear medicine images were acquired using a medium-energy general purpose parallel-hole collimator. A 20% energy window centred on the 208 keV photopeak and a 10% scatter correction window centred on 177 keV were applied. NM acquisitions were performed using a body contour option, rotation of 180° per detector, total of 60 projections and 45 s each. For attenuation correction, CT images were acquired (120 kV, automatic mA regulation with a max at 200 mA, noise index at 6.43, slice thickness of 5 mm, rotation time of 0.8 s, pitch 1.375, 512 × 512 pixels matrix), with standard reconstruction.
The application “Preparation for Dosimetry Toolkit” was used for SPECT/CT image reconstruction for both dosimetry approaches. The Ordered Subset Expectation Maximization iterative reconstruction algorithm was used with 6 iterations and 10 subsets, attenuation, scatter, recovery resolution corrections and a Gaussian post-filter of 0.11 cm [12 (link)].