Lightspeed plus

The bone mineral density (BMD) of all the collected tibiae was analyzed using quantitative computed tomography (QCT) at the college of Veterinary Medicine, Konkuk University (Korea, Seoul). Three positions of each tibia including neck (section of the mastoid arthrodesis), 1/3 of the proximal portion, and 2/3 of the distal portion were scanned using a CT scanner (LightSpeed Plus, GE Healthcare, Amersham, UK). The scanning conditions were as follows: 120 kV and 200 mA, slice thickness 1.25 mm, slice interval 1.25 mm, pitch 1.5:1, rotation time 0.6 s, and scanning speed 7.5 mm/rotation. The scanned images were archived in DICOM (Digital Imaging and COmmunications in Medicine) format and were evaluated by using a 3D slicer software (Version 4.6.2 r25516, National Alliance for Medical Image Computing). The Hounsfield unit (HU) values of each standard point of the three positions in a tibia were taken and the trend equation was obtained using a single-layer computerized photograph through QCT calibration phantom (QRM-BDC/3, QRM GmbH, Moehrendorf, Germany). The HU values obtained from the QCT scans were used to calculate BMD (mg/cm³).

All patients underwent contrast enhanced CT examination of their chest, abdomen and pelvis (GE Lightspeed Plus or GE Lightspeed VCT) following injection of 100 ml of an iodinated contrast agent (Omnipaque 300, Iohexol, GE Healthcare, Princeton, NJ, USA) at a rate of 3 ml/s via an automated injector.
Images of the thorax were analyzed in arterial phase (25-s delay) and images of the abdomen and pelvis were analyzed in portal venous phase (70-s delay) with the following acquisition parameters: 120 kV; auto mA and Smart mA (angular and z-axis modulation); pitch 0.75:1 and 0.9:1; 20 mm collimation, 5 mm slice thickness and 40 mm collimation reconstructed; scan field of view (FOV) 50 cm and display FOV adjusted to patient size; matrix: 512x512 (pixel spacing: 0.933 mm). Region of interest (ROI) was drawn by a radiologist with 6 years of experience of reporting abdominal CT who was blinded to the clinical outcome. Each ROI was drawn on the slice through the largest diameter of the tumor site.

Fluoroscopic images for angiography were acquired using a portable C-arm unit. Computed tomography data were acquired on a 4-slice Lightspeed Plus scanner (General Electric Medical Systems, Milwaukee, WI, USA) at 120 kVp with a slice thickness of 5 mm. DICOM images were then post-processed using Osirix MD 8.5.1 (Pixmeo, Geneva, Switzerland). Reformats were produced in various projections with sculpting of extraneous tissue performed to disclose the liver. This was then windowed and leveled using a pseudo-color scheme to depict the distribution of embolic material in the liver.

All patients were placed in the supine position and scanning was performed at end-inspiration. One unit (HiSpeed Advantage; GE Medical Systems, Milwaukee, Wisconsin, USA) was used in eight patients with the following parameters: section thickness = 1 mm; gap = 10 mm; scanning time per section = 1 or 2 s; 120 kV; and 240 mA. Another unit (Lightspeed plus; GE Medical Systems) was used in three patients with the following parameters: section thickness = 1.3 mm; gap = 10 mm; scanning time per section = 1 s; 120 kV; and 264 mA. A third unit (Philips Ingenuity; Philips, Netherlands) was used in three patients with the following parameters: section thickness = 1.0 mm; gap = 10 mm; scanning time per section = 1 s; 120 kV; and 269 mA. The images were photographed at lung (window width = 1000–  1600 HU; window level = – 600 HU) and mediastinal (window width = 350 HU; window level = 35– 40 HU) settings.

As shown in Figure 2, 62 patients from Harbin (Heilongjiang Province) were scanned using a 256-slice CT scanner (Philips Healthcare, Cleveland, OH, US), 30 patients from Shuangyashan (Heilongjiang Province) were scanned with a Somatom Balance CT scanner (Siemens Healthcare, Forchheim, Germany), 27 patients from the Uygur autonomous region (Xinjiang Province) were examined with LightSpeed Plus (GE, Medical System, Milwaukee, USA), 21 patients from Chengdu (Sichuan Province) were examined with a 128-slice dual-source CT (Siemens Healthcare, Forchheim, Germany), and 10 patients from Xinxiang (Henan Province) were imaged with a Somatom definition 64 slice CT scanner (Siemens Healthcare, Forchheim, Germany). Twenty-five patients from Ankang (Shaanxi Province) were imaged with 16 slice, Optimal CT 520 (GE, Medical System, Milwaukee, USA), 34 patients from Langfang (Hebei Province) were imaged with BrightSpeed (GE, Medical System, Milwaukee, USA), and 12 patients from Tianjin (Hebei Province) were imaged with Aquilion 16 slice CT scanner (TOSHIBA, Medical Systems, Tokyo, Japan). All these CT images were reconstructed into a slice thickness of 1.0–5.0 mm. Scan were performed in the supine position during end-inspiration.