Biograph mct 64 slice pet ct scanner

¹¹C-4DST and ¹⁸F-FDG were produced using an automated synthesis system with HM-18 cyclotron (QUPID; Sumitomo Heavy Industries Ltd., Tokyo, Japan). The ¹¹C-4DST was synthesized using the method mentioned by Toyohara et al. (2011 (link)).
All acquisitions were performed using a Biograph mCT 64-slice PET/CT scanner (Siemens Medical Solutions USA Inc., Knoxville, TN, USA), which has an axial field of view of 21.6 cm. The mean time interval between ¹¹C-4DST and ¹⁸F-FDG PET/CT scans was 6 days (range 0–24 days).
Patients were instructed to fast for at least 5 h before ¹⁸F-FDG administration. A normal glucose level in the peripheral blood was confirmed before the injection. PET emission scanning (2 min per bed position) was performed 15 min after intravenous injection of ¹¹C-4DST (7.4 MBq/kg) and 90 min after intravenous injection of ¹⁸F-FDG (3.7 MBq/kg) from the midcranium to the proximal thighs, and co-registered with an unenhanced CT of the same region (Quality Reference mAs: 100 mAs [using CARE Dose4D]; reconstructed slice thickness: 5 mm). The PET data were reconstructed with a baseline ordered-subset expectation maximization algorithm, incorporating correction with point-spread function and time-of-flight model (2 iterations, 21 subsets). A Gaussian filter with a full-width at half-maximum of 5 mm was used as a post-smoothing filter.

16α-[¹⁸F]fluoro-17β-estradiol (¹⁸F-FES) was prepared by the WCM PET Radiochemistry Group using established methods for synthesis and quality assurance^{55 (link),56 (link)} [https://imaging.cancer.gov/programs_resources/cancer-tracer-synthesis-resources/FES_documentation.htm]. ¹⁸F-FES scans were acquired using a Siemens BioGraph mCT 64-slice PET/CT scanner [70 cm transverse FOV, 16.2 cm axial FOV] operating in 3D mode. All scans were performed after a 4-hour fasting to decrease biliary uptake. One hour before PET imaging, an antecubital venous catheter was positioned for tracer injection. No arterial blood sampling was performed. Participants lied down on the scanner bed with eyes closed and ears unplugged, in the quiet and dimly lit scan room. Following a low-dose CT scan, a dose of approximately 6 mCi (222 MBq) of ¹⁸F-FES was infused intravenously in a volume of 20 mL isotonic phosphate buffered saline containing less than 15% of ethanol by volume over 2 minutes. Dynamic imaging was performed for 90 minutes, and consisting of 30 frames: 4x15, 4x30, 3x60, 2x120, 5x240, 12x300 sec. All images were corrected for attenuation, scatter and radioactive decay.