Adw4.5 workstation

¹⁸F-FDG was intravenously administered at a dose of 3.7 MBq/kg after fasting for at least 6 h. The blood glucose concentration was lower than 11 mmol/L before injecting ¹⁸F-FDG. PET/CT imaging was performed on a PET/CT scanner (Discovery 690 PET/CT, GE) at 60 ± 5 min after FDG administration. Whole-body images were obtained from the base of the skull to mid-thigh by means of an integrated PET/CT tomography (5–7 bed positions with 2 min per bed position). A low-dose helical CT scan (120 kV; 120 mA; slice thickness, 3.75 mm) was performed for anatomical correlation and attenuation correction. Reconstructed images were then displayed on a GE ADW4.5 workstation. Tumor mass was identified as the volume with elevated ¹⁸F-FDG uptake compared to normal lung parenchyma or other mediastinal structures. SUVmax was defined as the highest pixel value of PET imaging. Tumor burden was calculated by drawing a three-dimensional volume of interest (VOI) on the volume of tumor-related metabolic activity and applying a percentage threshold at 30% of SUVmax.

IVIM parameter values were calculated using the following equation:
Where S_b and S₀ are the signal intensities without and at a given b value, respectively. D is the true water molecule difusion coefcient; D* is the perfusion coherence difusion coefcient, i.e., pseudodispersion, which can refect changes in blood perfusion. f is the perfusion-related volume fraction, representing the volume ratio of the difusion caused by the microcirculation perfusion efect in the overall difusion efect of the voxel.
The IVIM sequence image raw data were transmitted to the functool software and MADC postprocessing software of GE’s ADW 4.5 workstation for image postprocessing and analysis, and the IVIM parametric images were obtained (Figure 1). The values of IVIM parameters were independently measured by two radiologists with 15 years and 20 years of diagnostic imaging experience. The detailed method for ROI delineation has been described in a previous study (26 ).

End-diastolic and end-systolic volumes (EDV, ESV) and ejection fraction (EF) were evaluated by helical computed tomography angiography (CTA, GE Discovery VCT, General Electric Medical Systems, Wankesha, WI, USA) with iodinated contrast agent (Omnipaque 350 mg I/mL, Amersham Health AS, Nydalen, Oslo, Norway). Contrast agent (100 mL) was administered at 4 mL/s via the ear vein and flushed with 100 mL of physiological saline. CTA scanning was performed during breath-hold and started immediately when contrast agent appeared into the LV. A 3-lead ECG was used for cardiac triggering and CTA images were reconstructed with retrospective gating at 0–90% at 10% interval relative to the cardiac cycle. Left ventricular EDV and ESV were calculated by tracing the endocardial borders with semi-automated analysis software (CardIQ Function Xpress) and ADW 4.5 work station (GE Medical Systems, Milwaukee, WI, USA).