The application study of scan technique of perspective ECG-gating of spiral CT with 64 slices in the CHD / 中国医学装备

ABSTRACT

Objective: To explore the setting of the scan mode of prospective electrocardiography (ECG)-gating of spiral CT with 64 slices for the adults with congenital heart disease (CHD) so as to obtain satisfying images and scanning parameters. Methods: 18 adults with CHD were scanned by using spiral CT with 64 slices. The flow rate of contrast agent was 4mL/s, and 20 mL normal saline (NS) was injected after 70 mL contrast agent was injected, and then 15mL contrast agent was injected following with NS, and 25mL NS was used for tracing injection. The prospective ECG-gating and intelligence tracing of contrast agent were adopted to scan. The descending aorta that has same height with crotch of weasand should be chosen as interesting position, and the threshold value was 130 HU, the scan mode of triggering threshold was adopted in the research. The post processing workstation (Philips EBW) was applied to adopt reestablishment of sagittal view, coronal view and axial view, and to carry out reconstruction of 3D multiplanar reformation (MPR), curved planar reformation (CPR), maximum intensity projection (MIP) and volume rendering (VR) so as to observe the situations of heart cavity and peripheral vessel of patients. Results: Each atrium and ventricle has clear construction, and the relationship with peripheral vessel was clearness, and the aortic valve and atrioventicular septum could be observed. And the diagnostic result by using reconstruction technique could be identical with image of Doppler echocardiography. Conclusion: The scan technique of perspective ECG-gating of spiral CT with 64 slices could obtain images, that conformed to requirement of diagnosis and had value, of each atrium, ventricle and peripheral vessel. In the scan, the accurate and suitable parameters, the appropriate dosage and usage of contrast agent, the scan speed, scan time and setting of triggering threshold were the key factors of obtaining image with high quality.