ABSTRACT. Three-dimensional (3D) reconstruction and rapid prototyping technology (RPT) of multislice spiral computed tomography angiography (CTA) was applied to prepare physical models of the heart and ventricular septal defects of tetralogy of Fallot (ToF) patients in order to explore their applications in the diagnosis and treatment of this complex heart disease. CTA data of 35 ToF patients were collected to prepare l:l 3D solid models using digital 3D reconstruction and RPT, and the resultant models were used intraoperatively as reference. The operations of all 35 patients were completed under the guidance of the 3D solid model, without difficulty. Intraoperative findings of the patients were consistent with the morphological and size changes of the 3D solid model, and no significant differences were found between the patches obtained from the 3D solid model and the actual intraoperative measurements (t = 0.83, P = 0.412). 3D reconstruction and RPT of multislice spiral CTA can accurately and intuitively reflect the anatomy of ventricular septal defects in ToF patients, providing the foundation for a solid model of the complex congenital heart.

The precipitate in ULC-BH steels was analyzed by the phase analysis, the expressions for calculation of solution C content in the ULC-BH steel treated by Ti and Nb was developed. The test result indicates that the BH2 value was improved with the increasing of solution C content. The BH2 value can be improved by enhancing the temperature of annealing and cooling rate. The steel has higher BH2 value when the coiling temperature was 640℃ compared with 710℃ and the annealing temperature and cooling rate have more effect on bake hardening value than coiling temperature.