Syngo acquisition workplace

Visual and semiquantitative analyses were performed by two physicians (specialized in nuclear medicine and molecular imaging) with an experience of >9 years in the use of the Siemens Syngo Acquisition Workplace equipment workstation with processing software for volumetric analysis. The tumor/background (T/Bmax) uptake ratio was calculated by quantifying the number of maximum counts obtained by delimiting volumetric regions (3D) of interest (VOI) with the isocontour around the entire tumor area (T) and in the contralateral brain region (B).

Two dual-source CT scanners (SOMATOM Definition Flash or SOMATOM Force; Siemens, Germany) were used to examine all patients. The non-ionic contrast media used were iopamidol (370 mgI/mL; Bayer Healthcare, Germany) or iomeprol (350 mgI/mL; Eisai, Japan). An automated power injector was used to administer 100 mL of non-ionic contrast medium at a flow rate of 22.2 mgI/kg/s and an additional 40-mL bolus of 0.9% saline solution at the same flow rate through a 22-gauge catheter.
The automatic bolus tracking method with a region of interest (ROI) placed on the pulmonary artery trunk, which triggered 250 Hounsfield units (HU), was used, and the CTPA scan of CTPA started 10 s after the trigger.
The following parameters were used in the SOMATOM Definition Flash: tube voltage, 140 and 100 kV; detector collimation, 2 × 64 mm × 0.6 mm; rotation time, 330 ms; and pitch, 0.55. The following parameters were used in the SOMATOM Force: tube voltage, 150 and 90 kV; detector collimation, 2 × 64 mm × 0.6 mm; rotation time, 280 ms; and pitch, 0.55. Lung iodine distribution (iodine map) and LPBV images were generated using a workstation (Syngo Acquisition Workplace; Siemens, Germany). LPBV images were created by the fusion of iodine maps and lung CTPA images.

Quadriphasic CT images were acquired using Siemens dual energy CT scanner (Somatom Definition Flash; Siemens Healthcare, Erlangen, Germany). The CT scanning parameters were as follows: detector collimation 128 mm × 0.6 mm, reconstruction at slice thickness of 3 mm and 3-mm slice intervals, and 120 kVp, quality reference 210 mAs for dose modulation system (CareDose 4D; Siemens Medical Solutions). A total of 100 to 150 mL of nonionic contrast medium (350 mgI/mL) was injected at the rate of 4 mL/second through an 18-gauge IV cannula using a power injector. Scan delay was according to an automatic bolus triggering software program (Syngo Acquisition Workplace; Siemens Healthcare, Erlargen, Germany). The late arterial phase scanning and portal venous phase scanning were started at 15 and 55 seconds, respectively, after the trigger threshold was reached (100 Hounsfield units on the abdominal aorta). The delayed phase scanning was performed 180 seconds after the initiation of the contrast material injection.