Mct plus

All of the CT examinations were performed on a 16-multislice unit (LightSpeed, GE HealthCare, Milwaukee, Wisconsin, USA) with the helical acquisition, automatic mA, 100 or 120 kV, rotation time 0.5—0.7 s, slice thickness 1.25—3.75 mm, pitch 0.938 or 1.375, reconstructed in a soft-tissue algorithm. The DFOV was customised to the size of the patient, and the matrix was 512 × 512. All images were displayed in a soft-tissue window (WW 350, WL 50). All of the dogs received iodine non-ionic contrast medium iomeprol in a dose of 600 mg I/kg (Iomeron 300, Bracco Imaging Deutschland GmbH, Konstanz, Germany). Contrast medium was administered into the cephalic vein with a power injector (MCT Plus, Medrad, Indianola, IA, USA) at a rate of 3 ml/s. All of the postcontrast series used in the study were acquired 90 to 120 s after the contrast medium administration. All of the settings in postcontrast series were the same as for the precontrast examinations. Dogs were scanned in sternal recumbency.

All helical CT images were obtained with a 64 detector-row (LightSpeed VCT; GE Healthcare, Waukesha, WI, USA) CT scanner using the following parameters: detector collimation, 1.25 or 0.625 mm; field of view, 36 cm; 125 mA; 120 kVp; beam width, 10–20 mm; beam pitch, 1.375–1.5; section thickness 2.5 mm; and matrix, 512 × 512 mm. All patients underwent chest CT at full inspiration through breath hold to minimize the effect of the tumor motion due to breathing. Chest CT scanning was obtained 90 seconds after the administration of contrast material. A total of 1.5 mL/kg (body weight) Iomeron 300 (Iomeprol, 300 mg iodine/mL; Bracco; Milan, Italy) was injected at an infusion rate of 3 mL/s using a power injector (MCT Plus; Medrad; Pittsburgh, PA, USA). Image data were reconstructed with a soft-tissue algorithm for mediastinal window ranges and a bone algorithm for lung window images. Both mediastinal (width, 300 Hounsfield units [HU]; level, 20 HU) and lung (width, 1500 HU; level −700 HU) window images were displayed for tumor assessment. Chest CT images were obtained every two cycles (8 weeks) during the course of treatment.

CT studies were performed using various helical CT scanners (mostly 16- to 64-MDCT scanners) from several vendors. The scanning parameters were 120 kVp and 170 to 200 mA under automatic exposure control; beam width, 10 to 20 mm; and rotation time, 0.3 to 0.4 seconds. Image data were reconstructed using standard soft-tissue algorithms; the data were reformatted with a section thickness of 2.5 to 3.0 mm for transverse images. Both enhanced and unenhanced CT scans were obtained. IV contrast medium injection was given in all patients: 1.5 mL/kg of body weight of iobitridol (300 mg I/mL; Xenetics, Guerbet) was injected at an infusion rate of 3 mL/s using a power injector (MCT Plus, Medrad). The interval time between the initiation of contrast injection and scanning was 45 seconds. The reconstructed images were then sent directly to a PACS (Centricity 3.0, GE Healthcare). Images were viewed on monitors in both mediastinal (width, 400 HU; level, 20 HU) and lung (width, 1500 HU; level, –700 HU) window settings.