Gemini tf pet ct system

Preoperative PET/CT was performed using a Gemini TF PET/CT system (Philips). After fasting for at least six hours and resting for 60 minutes, an intravenous injection of 3.7 MBq of 18FDG/kg bodyweight was administered. PET/CT data was obtained from patients in the supine position. Emission images were acquired after CT scanning, and an emission scan was performed in eight to10 bed positions with one minute per step. The FDG uptake of tumor was visually compared with that of the surrounding tissue in areas devoid of prominent artifacts and overlapping increased FDG uptake organs. A team of experienced radiologists reviewed the integrated PET/CT images independently. The SUVmax of the primary tumor and SUVmax of hilar lymph nodes were recorded, respectively. A tumor was defined central if its center was located in the inner one third of the lung parenchyma on transverse CT imaging and peripherally located tumors were identified as those centered in the outer two thirds. Definitions of solid or subsolid nodules used in the classification of lung adenocarcinoma were based on the Fleishner Society glossary of terms.15 All integrated PET/CT imaging was performed within fourweeks before surgery.

Preoperative PET/CT examinations were conducted using a Gemini TF PET/CT system manufactured by Philips. Prior to the procedure, patients observed a minimum fasting period of 6 hours and underwent a 60-minute resting period. Subsequently, an intravenous injection of 3.7 MBq of 18FDG/kg of body weight was administered. Patients assumed a supine position during PET/CT data acquisition. Emission images were obtained subsequent to CT scanning, and the emission scan comprised 8 to 10 bed positions, each lasting 1 minute per step. The FDG uptake of the tumor was visually assessed in comparison to the surrounding tissue in regions devoid of significant artifacts and overlapping increased FDG uptake organs. Independent evaluation of integrated PET/CT images was conducted by a team of experienced radiologists. The SUVmax of the primary tumor was meticulously recorded. All integrated PET/CT imaging procedures were conducted within the 4-week interval preceding the scheduled surgery.

The Philips Gemini TF PET-CT system (Philips Medical Systems, Cleveland, Ohio, USA) is comparable to the PET unit of the PET-MRI. Scanning is started with a whole body PET (skull base to mid-thigh), with data being reconstructed by means of a raw action ordered subset expectation maximization algorithm using default reconstruction parameters. Time of flight (TF) information is used during reconstruction. Reconstructed images have an image matrix size of 144X144, a voxel size of 4X4 mm and a slice thickness of 5 mm. The acquisition time per bed position is adjusted for the time interval between the start of PET-CT and FDG injection and will usually be 2–3 min/bed position.