Mmwp workstation

A Siemens MMWP workstation was used for post-processing. Visual analysis was used to determine the general biodistribution and the temporal and inter-subject stability. Regions of interest (ROIs) were drawn manually on the site of lesions using 3D ellipsoid isocontour on each image with the assistance of the corresponding CT images by two experienced nuclear medical physicians. They were different from the physicians who previously recruited the patients and interpreted the images through consensus reading and blinded to the history, other examinations, and pathologic diagnosis of the patients. Per-lesion analysis was performed for the diagnosis of breast lesions, lung, liver and bone metastases. Per-region analysis was adopted for the diagnosis of lymph node metastases because of the difficulty to correlate the lymph nodes lesion by lesion between the images and pathologic diagnosis. For semi-quantitative analysis, the results were expressed as mean and maximum standardized uptake value (SUV_mean and SUV_max).

The macrocyclic chelator, 1,4,7-triaza cyclononane-N, N', N”-triacetic acid (NOTA) conjugated BBN-RGD was synthesized according to a method described in our previous publication 17 (link). ⁶⁸Ga-BBN-RGD was prepared following the procedure reported previously 24 (link). The radiochemical purity was greater than 95%.
No specific subject preparation, such as fasting, was requested on the day of ⁶⁸Ga-BBN-RGD PET/CT. Each patient was intravenously injected with ⁶⁸Ga-BBN-RGD in a dosage of approximately 1.85 MBq (0.05 mCi) per kilogram of body weight, ranging from 75.9 to 148.0 (114.7 ± 17.1) MBq. PET/CT was performed at 25~35 min after tracer administration by using Biograph 64 Truepoint TrueV system (Siemens Medical Solutions, Knoxville, TN, USA). After a low-dose CT scan (120 kV, 35 mA, 3 mm layer, 512 × 512 matrix, 70 cm FOV), whole body PET acquisition was performed with 2 min per bed position (five to six bed positions depending on the height of the patient). The emission data were corrected for randoms, dead time, scattering, and attenuation. The conventional reconstruction algorithm was used and the images were zoomed with a factor of 1.2. The images were transferred to a MMWP workstation (Siemens) for analysis.

¹⁸F-FES was prepared as described previously.^{13 (link)} PET/CT imaging was performed from the skull base to the upper thigh using a Discovery PET/CT 690 or 710 scanner (GE Healthcare), 80–100 min after an intravenous injection of 111–222 MBq (3–6 mCi) of ¹⁸F-FES.^{14 (link)} PET/CT images were reconstructed using a manufacturer-provided iterative algorithm with four iterations and 18 subsets.¹⁸F-FDG (¹⁸F-fluorodeoxyglucose) PET/CT images were obtained from the skull base to the upper thigh using one of several different PET/CT scanners (Biograph Sensation 16 or Biograph TruePoint 40, Siemens Healthineers; or Discovery PET/CT 690, 690 Elite, or 710, GE Healthcare), 50 min–70 min after an intravenous injection of 5.2 MBq/kg–7.4 MBq/kg (0.14 mCi/kg–0.2 mCi/kg) of ¹⁸F-FDG as described previously.^{15 (link)} The reconstructed images were displayed on coronal, horizontal, sagittal, and three-dimensional (3D) volumetric films and reviewed independently by two nuclear medicine physicians. SUV was calculated automatically (SUV = average radioactivity per gram of tissue/radioactivity of the injected nuclides/mass). Regions of interest (ROIs) were drawn automatically by the Siemens MMWP workstation. To reduce the partial volume effect, the SUVmax corresponded to all pixels in an ROI, and the ¹⁸F-FES SUVmax of the corresponding lesions was measured.

Imaging images were observed and analyzed by 2 experienced imaging physicians, and a unified opinion was reached on the abnormal perfusion area. Siemens MMWP workstation was used for calculation. The middle cerebral artery was the input artery and the internal jugular vein was the output vein. The location and size of possible lesions were determined manually, and vascular calcification and old infarcted tissue were avoided as far as possible. Quantitative function graphs and perfusion parameters such as cerebral blood flow (CBF), cerebral blood volume (CBV), mean peak time (MTT) and peak time (TTP) were automatically generated by computer. Then, the mirror image method was used to place the region of interest on the opposite side, and the circular region of interest on the corresponding part of the opposite side was placed, and the average value was taken. The relative parameter values of lesions (rCBF, rCBV, rMTT, rTTP) were obtained by comparing the parameters of lesions with those of normal lesions.