Abstract: Objective · To investigate the feasibility of single-photon emission computed tomography/computed tomography (SPECT/CT) quantitative imaging in the determination of SUV uptake and thyroid volume in patients with Graves' disease. Methods · Sixty-four Graves' disease patients were selected, including 21 males and 43 females, aged (44.1±14.1) years. All subjects were tested for serum FT3 and FT4 levels, as well as 131I rate at 2 h and 24 h. All patients underwent neck SPECT/CT and planar imaging after intravenous injection of (5.5±0.5)mCi [(204.2±16.8) MBq] 99mTcO4- radiograph. Thyroid quantitative SUVmean, SUVmax and three-dimensional thyroid volume (Vol3D) of Graves' disease patients were determined by 40% threshold method, and the correlation between SUVmean, SUVmax and serum thyroid hormone levels, 131I rate was analyzed. Vol3D and Vol2D thyroid volume were measured by Xeleris workstation (GE Healthcare) and conventional formulas, respectively, analyzed and compared. Results · The quantitative values of SUVmean and SUVmax in patients with Graves' disease were (262.5±110.2) g/mL and (471.4±192.1) g/mL, respectively. There was no significant correlation between serum thyroid hormone levels (FT3 and FT4), SUVmean and SUVmax (all P>0.05). There was week correlation between iodine uptake rate and SUVmean, SUVmax (all r >0 and all P=0.000). In addition, there was a positive correlation between thyroid Vol3D and Vol2D (r=0.853, P=0.000). Conclusion · Quantitative imaging of 99mTcO4- SPECT/CT for the determination of three-dimensional thyroid volume and quantitative uptake of SUV is simple and feasible, providing clinical basis for the diagnosis and treatment dose assessment of Graves' disease, which has important clinical diagnostic significance.

Key words: Graves&apos, disease, single-photon emission computed tomography/computed tomography (SPECT/CT), emission computer, single photon, standard uptake value (SUV)