Three-dimensional reconstruction of digitized human liver: based on Chinese Visible Human.

BACKGROUND: Comparing with two dimensional (2D) imaging, both in diagnosis and treatment, three dimensional (3D) imaging has many advantages in clinical medicine. 3D reconstruction makes the target easier to identify and reveals the volume and shape of the organ much better than 2D imaging. A 3D digitized visible model of the liver was built to provide anatomical structure for planing of hepatic operation and for realizing accurate simulation of the liver on the computer. METHODS: Transverse sections of abdomen were chosen from the Chinese Visible Human dataset. And Amira software was selected to segment and reconstruct the structures of the liver. The liver was reconstructed in three-dimensions with both surface and volume rendering reconstruction. RESULTS: Accurately segmented images of the main structures of the liver were completed. The reconstructed structures can be displayed singly, in small groups or as a whole and can be continuously rotated in 3D space at different velocities. CONCLUSIONS: The reconstructed liver is realistic, which demonstrates the natural shape and exact position of liver structures. It provides an accurate model for the automated segmentation algorithmic study and a digitized anatomical mode of viewing the liver.

The use of virtual reality for the functional simulation of hepatic tumors (case control study).

OBJECTIVE: To develop a technique for converting computed tomography (CT) data into a fully three-dimensional (3D) virtual reality (VR) environment. Preoperative simulation in 3D VR facilitates liver resection owing to the ability to view the tumor and its relative vessels. METHODS: 3D-reconstruction of the liver was restored from spiral CT data by using LiVirtue software and the Dextrobeam (Volume Interactions Pte Ltd, Singapore) was applied to view this 3D model in the VR environment. In order to design a rational plan of operation, the liver and its anatomic structure were reconstructed to illuminate the location of the tumor and its related vessels. RESULTS: In our series of 38 hepatic resections, there was no significant difference between preoperatively calculated volumes of virtual resection part and actual volumes of resected specimen's weight. The LiVirtue can provide accurate and rapid results of individual hepatic volume and the character of anatomy structures. These models can be viewed and manipulated in the VR environment and on a personal computer. This preoperative simulation allowed surgeons to dissect the liver with reduced complications. Preoperative planning and intra-operative navigation based on this technique ensured the safety of liver resection. CONCLUSIONS: 3D models of the liver and its detailed structure articulate the possibility of intricate liver resection and the risk of the operation. This preoperative estimation from a 3D model of the liver benefits complicated liver resections greatly.

[Preventive and therapeutic effect of genetic vaccine based on recombinant alpha virus against mouse mastocytoma P815].

AIM: To explore the immunological effect of genetic vaccine based on alpha-virus and to seek out better forms of gene vaccines. METHODS: Expression plasmid P1A/pSMART2a and packaging plasmid helper were cotransfected into mammalian 293 cells by calcium phosphate precipitation method and high level of recombinant alpha-virus P1A/SFV was prepared. Following identification of rSFV and its expression, BALB/c mice were inoculated with rSFV, and the production of antigen-specific antibody and the cytotoxic effect of CTLs were determined. In the preventive and therapeutic experiments, the percents of tumor-free and of survival mice immunized with rSFV were observed. RESULTS: The recombinant SFV could express correctly in cultured cells. After being inoculated into the mice, rSFV could prime stronger CTL response than that in control mice. When the ratio of E/T cells was 100:1, the (51)Cr release rate reached 75%. No antibody could be detected in mice from all groups. The immunological effect of P1A/SFV among all groups was the best in both preventive and therapeutic experiment within experimental deadline. On 60th day in preventive experiment, the percent of tumor-free animal in P1A/SFV group reached 60%, whereas that was only 20% in P1A/pCI-neogroup. On 60th day in therapeutic experiment, survival rate of mice in P1A/SFV group reached 50%, but only 10% mice could survive in all control groups. CONCLUSION: Compared with common gene vaccines, the genetic vaccine based on recombinant SFV has the best immunological effect, which provides some new strategies for clinical genetic therapy of tumors.