Ict 256 scanner

All study participants underwent multiphase CT (iCT256 scanner, Philips Healthcare, Amsterdam, Netherlands) scanning immediately after the MRI. All participants were positioned head-first in supine position. After completion of non-contrast scanning 90-100 ml of the contrast agent Ioversol 320 (JIANGSU HENGRUI MEDICINE CO., LTD., Lianyungang, Jiangsu, China) was injected at the rate of 3 ml/s via an anterior elbow vein by an automated injector pump (Spectris Solaris EP, Medrad, Warrendale, PA, USA). The patients were asked to drink a cup of water through a straw immediately before the CT procedure. Covering the view from sternoclavicular joint to Lumbar 1 vertebrae, the arterial phase scanning (optimal for visualization of the tumor) was performed by tracking the aortic peak, followed by the venous (to detect mediastinal lymphadenopathy and distant metastasis) and delayed phase (to determine the benign nature of the stenosis) scanning at 30s and 2 min after the beginning of the arterial phase, respectively. CT scanning parameters were as follows: slice thickness = 5 mm, slice interval = 5 mm, voltage = 120KV, tube current = 300mAs, detector = 128 × 0.625, pitch = 0.993, FOV = 300 mm.

A Philips iCT 256 scanner (Brilliance, Philips, USA) was used for generating the CT scans. Initially, FOV of 400 mm, section thickness, and interval, 1.0 and 1.0 mm, respectively were applied for the routine CT scans. To identify the specific lung nodules, the following parameters were set for the target scans: 0.6–0.8 s scan time; matrix, 1,024 × 1,024; FOV, 140 mm; 120 kVp; and 250 mA. The reconstruction algorithms for the routine and target HRCT scans were referred to the previous study (17 (link)).

All patients underwent a multiphase contrast-enhanced CT examination before the operation. Abdominal CT scans were performed on an iCT 256 scanner (Philips, Amsterdam, Netherlands) with a tube voltage of 120 kV, a tube current of 251 mAs, a collimator thickness of 80 mm, a rotation time of 0.5 s, a screw pitch of 1.150:1 and a reconstructed layer thickness of 1.0 mm. The matrix size of CT was 512 × 512, the voxel size was 0.887 × 0.887 × 1.00 mm³, the field of view (FOV) was 450 mm. The scanning phase includes NC and enhancement scans. Enhanced scan was performed using a power-injector to inject intravenous iohexol (1 ml/kg) through the antecubital fossa at an injection rate of 3.5–4.5 ml/s. The AP and VP were scanned at 25–30 s and 60–70 s, respectively, after the injection of contrast.
The original images of NC, AP and VP were stored in the corresponding folders in DICOM format. One abdominal radiologist (Y T C) performed three-dimensional (3D) radiomics segmentation on NC, AP and VP images using ITK-SNAP software (version 3.6.0; www.itksnap.org). The window width and window level were seted at 40 and 300, respectively. For radiomics segmentation, the ROI was manually delineated on each slice of the tumor. Finally, each tumor generated three ROIs (NC, AP and VP).