Biograph 64 pet ct

Based on the preclinical findings, we enrolled AD patients and healthy control subjects in performing a PET study after the injection of [¹⁸F]DRKXH1. The present study aimed to evaluate the effectiveness of [¹⁸F]DRKXH1 in distinguishing AD patients from healthy individuals. This study complied with the Declaration of Helsinki and was approved by the Ethics Committee Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (approval no. XHEC-F-2019–120). All subjects signed informed consent before participation in the study.
The AD patients were recruited, examined, and diagnosed by qualified attending neurologists. All physicians abided by the uniform diagnostic criteria, including detailed medical history and mini-mental state examination (MMSE).
All subjects underwent a PET assessment at 45 min after intravenous bolus injection of [¹⁸F]DRKXH1(370 MBq). Siemens Biograph 64PET/CT (Erlangen, Germany) was used for three-dimensional (3D) scanning. Before PET scanning, a low dose CT transmission scan was performed, and attenuation correction was performed. The image reconstruction was carried out by ordered subset expectation maximization 3D (OSEM 3D) method.

One week before or after the neuropsychological assessments, all patients underwent ¹¹C-CFT PET and then underwent ¹⁸F-FDG PET on the following day. No anti-parkinsonian medications were administered to the patients within 12 h prior to PET imaging. To prepare for ¹⁸F-FDG PET, subjects were additionally required to fast for at least 6 h before the PET scan. The patients underwent a Siemens Biograph 64 PET/CT (Siemens, Munich, Germany) in 3D mode. A low-dose CT transmission scan was performed for attenuation correction. Then, PET scanning was acquired during the interval of 60–75 min after 350–400 MBq of ¹¹C-CFT was intravenously injected. For ¹⁸F-FDG, a 10-min PET scan was acquired at 45 min post injection (150–200 MBq). Image reconstruction was obtained by the ordered subset expectation maximization 3D (OSEM 3D) method. All patients were placed in a quiet, dimly lit room to rest.

Whole body PET/CT images were obtained using a PET/CT scanner Biograph 64 PET/CT (Siemens Healthcare Sector, Erlangen, Germany) as previously reported (Stecco et al., 2016 (link)). Patients fasted for at least 6 h before tracer injection. After injection of 2.22∼4.44 MBq/kg of ¹⁸F-FDG, PET images were obtained after an approximately 60-min uptake period with the patient’s arms raised to cover the orbitomeatal line to the proximal third of the femurs. After obtaining a scout view (120-140 kVp, 30 mAs), the PET protocol comprised five to six bed positions (3 min each) depending on the patients height. Three-dimensional image reconstructions were acquired using the iterative reconstruction algorithms. The duration of PET/CT acquisition was approximately 20 min.

Eight scans, 5 control and 3 injury pigs, were performed using a Siemens Biograph 64 PET/CT. Following administration of 185 MBq of 18F-TPP⁺ as a single intravenous bolus, scanning was performed over 120 minutes in list mode. CT angiography was performed for anatomic reference. List mode data were framed as a dynamic series of 12x3, 9x5, 7x10, 15x30 second frames. PET/CT data were reconstructed using a filtered back projection algorithm with CT-based attenuation correction to yield a radioactivity concentration map in units of Bq/cc with 83 slices and a voxel size of 2.14x2.14x3 mm³. f_ECS was measured in 3 injury pigs with CT scanning using a bolus plus infusion iodinated contrast protocol [36 (link)].

MRI scans were performed using a 3-T General Electric Signa scanner (GE, USA). Resting-state fMRI was obtained with the following parameters: TR = 2,000 ms, TE = 35 ms, flip angle = 90°, slice number = 45, field of view (FOV) = 240 × 240 mm, voxel size = 3.3 × 3.3 × 4.0 mm³, 240 time points (8 min). During the scanning, subjects were instructed to keep still with their eyes closed but not to fall asleep. High-resolution 3D T1-weighted anatomical images in the sagittal orientation were acquired with a magnetization-prepared rapid gradient-echo sequence (repetition time = 2,300 ms, echo time = 2.98 ms, flip angle = 9°, FOV = 256 × 256 mm², matrix size = 256 × 256, slice thickness = 1 mm, without interslice gap, voxel size = 1 × 1 × 1 mm³ and 176 slices).
PET scans were performed with a Siemens Biograph 64 PET/CT (Siemens, Germany) in 3D mode. First, these subjects were still and resting in a room that was quiet and had dim lighting. Then an intravenous bolus injection of 185 MBq of FDG was administered. CT transmission scan was performed to allow attenuation correction. Next, The PET scan was started 45 min after the injection and lasted 10 min. Hanning filters were used with filtered-back projection for image reconstruction, resulting in a transaxial and axial cut-off frequency of 0.5. Additional technical details on the scanner were reported elsewhere (13 (link), 14 (link)).