Biograph 6 truepoint pet

Detailed descriptions of FTP and PiB-PET acquisition are available in previous publications^{66 (link),67 (link)}. In the present study, only OA underwent PET scanning. All PET scans were acquired at LBNL on a Siemens Biograph 6 Truepoint PET/CT scanner in 3D acquisition mode. Prior to each PET scan a low-dose CT scan was collected for attenuation correction. FTP was synthesized at the LBNL Biomedical Isotope Facility (BIF) using a GE TracerLab FXN-Pro synthesis module with a modified protocol based on an Avid Radiopharmaceuticals protocol supplied to the facility. Participants were injected with 10 mCi of tracer and scanned in listmode 80–100 min post-injection (4 × 5 min frames). [¹¹C]PiB was also synthesized at the LBNL BIF^{68 (link)}. Beginning at the start of an injection of 15 mCi of PiB into an antecubital vein, 90 min of dynamic emission data were acquired and subsequently binned into 35 frames (4 × 15 s, 8 × 30 s, 9 × 60 s, 2 × 180 s, 10 × 300 s and 2 × 600 s). FTP and PiB images were reconstructed using an ordered subset expectation maximization algorithm with weighted attenuation and smoothed with a 4 mm Gaussian kernel with scatter correction (image resolution 6.5 × 6.5 × 7.25 mm³).

All PET scans were acquired at the Lawrence Berkeley National Laboratory on a Siemens (Erlangen, Germany) Biograph 6 Truepoint PET/computed tomography (CT) scanner in 3D acquisition mode. FTP was synthesized using a TracerLab FXN-Pro (GE Medical Systems, Milwaukee, WI) synthesis module with a modified protocol based on an Avid Radiopharmaceuticals (Philadelphia, PA) protocol. Participants were injected with 10 mCi of tracer and scanned in list mode from 75 to 105 min post-injection. Data was subsequently reconstructed as 4 × 5-min frames within 80 to 100 min post-injection. PiB was also synthesized according to a previously published protocol [18 (link)]. Immediately after the intravenous injection of approximately 15 mCi of PiB, 90 min of dynamic acquisition frames were obtained (4 × 15, 8 × 30, 9 × 60, 2 × 180, 10 × 300, and 2 × 600 s). Both FTP and PiB images were reconstructed using an ordered subset expectation maximization algorithm with weighted attenuation and smoothed with a 4-mm Gaussian kernel with scatter correction (image resolution = 6.5 × 6.5 × 7.25 mm³).
T1-weighted structural MRI images were acquired on a 1.5-T Siemens Magnetom.
Avanto scanner using a magnetization-prepared rapid gradient echo sequences with the following parameters: repetition time = 2110 ms, echo time = 3.58 ms, flip angle = 15°, voxel size = 1mm isotropic.