Advantage windows workstation

PET was performed using a PET/CT system (Discovery STE; GE Medical Systems, Milwaukee, WI, USA). All patients fasted for at least 5 hours before PET imaging. Image acquisition started 1 hour after intravenous administration of FDG (3.7 MBq/kg body weight). CT scans from the brain to the pelvis were performed immediately before the PET scans using a multi-detector spiral CT scanner (3.75 mm slice thickness, pitch of 1.75, 120 keV, and 30–200 mA depending on the patient’s total body mass). We performed whole-body PET scans, covering an area identical to that covered by the CT scan. All PET/CT images were interpreted at the workstation (Advantage Windows workstation; GE Healthcare).

All the FDG PET/CT images were obtained from the US GE Discovery STE 16 PET/CT scanner. The patients were fasted for at least 6 h prior to the intravenous injection of ¹⁸F-FDG (4.07–5.55 M Bq/kg). Patients’ blood glucose levels were checked just before the injection of FDG. Blood.
glucose level had to be < 11 mmol/L before injection in all patients. After intravenous injection of ¹⁸F-FDG for an average of 60 ± 10 min, imaging data were obtained using low-dose CT (140 kV, 120 mA, transaxial FOV 70 cm, pitch 1.75, rotation time 0.8 s, slice thickness 3.75 mm), followed.
By PET emission images, 2–3 min per bed position. The acquired data were reconstructed using an iterative algorithm in transverse, coronal, and sagittal planes and transferred to Advantage Windows Workstation (Advantage Windows Server 4.5; GE Healthcare) for processing and interpretation. The PET and coregistered PET/CT images were interpreted both visually and semiquantitatively by 10-year and 24-year experienced two nuclear medicine physicians. The maximum standardized uptake value (SUVmax), representing the FDG uptake degree, was measured by drawing a region of interest from the trans axial slice with the highest uptake of FDG for each abnormal colonic FDG uptake site in the attenuation-corrected PET data. Besides, ≥ 3 mm for the colon and ≥ 5 mm for the rectum were considered as increased wall thickness.

The perfusion data post processing was performed on a commercially available Perfusion-4 software package on an Advantage Windows Workstation version 4.0 (General Electric Medical Systems, Milwaukee, WI, USA). An oval region of interest was placed in the internal carotid artery to generate the contrast arterial enhancement curve. Radiologist 1 (a fellowship trained neuroradiologist with 15 years of experience in head and neck imaging) drew additional freehand regions of interest contouring the tumor along its margin on all axial images where the tumor was visible, and an oval region of interest in normal muscle tissue. An example of the region of interest through the tumor is demonstrated in Figure 1 and Figure 2. The perfusion data were post processed by a deconvolution-based method into maps that represented permeability surface area product (PS), blood flow (BF), blood volume (BV), mean transit time (MTT), and time-to-maximum (Tmax).

All renal MRI imaging were performed on a 3.0-T MRI scanner (Ingenia MR system; Philips, Best, Netherland). The MRI protocol included sshT2W, IDEAL, non-contrast enhanced T1W, and dynamic contrast enhanced MRI sequences. Following this acquisition of pre-gadolinium images, 0.1 mmol/kg gadobutrol (Gadovist; 1.0 mmol/mL) was injected at 1mL/s. The post-gadolinium dynamic imaging was acquired in three initial phase (25, 40, and 60 s after contrast administration), and then after a delay of 3, 5, and 10 min, with a bolus tracking technique and fat saturation. Kidney volumes were measured by manually tracing the kidney contours using volume analysis solfware implemented on an Advantage Windows Workstation (4.4, GE Healthcare, Buc, France) as previously prescribed in the study protocol [30 (link)]. The sshT2W images were used by the experience radiologists for measuring kidney volumes since this non gadolinium MRI sequence provided reliable kidney volume measurement [30 (link)].