256 slice spiral ct

A Phillips 256-slice spiral CT was used. The patient was in a supine position during the scan. A single end-expiratory breath-holding scan with retrospective ECG gating technique was performed. The breath-holding time was 5–7 s, and the scanning area began from 0.5 cm below the bifurcation of the autonomous trachea to the diaphragm of the heart. The intelligent tracking method was used to set the threshold of aortic layer to 150 HU, and the formal scan was started at 6 s after reaching the threshold. The non-ionic contrast agent Iohexol (350 mgI/ml) was injected with a double-barrel high-pressure injector at a rate of 4–5 ml/s. The dose was 0.8 ml/kg. Scanning parameters were as follows: tube current 320 mAs/revolution, tube voltage 120 kV, detector collimation 128 × 0.625, pitch 0.18, matrix 512 × 512, rotation time 330 ms, scanning field of vision 250 mm. The images of systolic phase (45% cardiac phase) and the images of diastolic phase (75% cardiac phase) were reconstructed.

Enhanced CT scans were performed on all nude mice the day before sacrifice. The hydrothermal method was used for preparation of monodisperse nanoparticles Yb(OH)CO₃ [8 (link)], and the in vitro hemolysis analysis method [9 (link)] was used for verification of nanoparticle Yb(OH)CO₃. Then, it was used as a contrast agent, and all nude mice were injected with 1 mL Yb(OH)CO₃ solution with a concentration of 50 mg/mL. A Philips 256-slice spiral CT was used for scanning. The scanning voltage was 120 kV, the scanning current was 300 mA, the layer thickness was 0.9 mm, and the pitch was 0.99. The tube rotation time was 0.5 s. All original images obtained by CT scanning were transferred to the Wizard workstation for image postprocessing.