VTK is not only an open-source code but also a powerful toolkit for visualization.According to the requirement of medical image processing and on the basis of visualization and display function of VTK,VC++6.0 is used to design and implement a three-dimensional system which can be integrated into PACS.This system is useful for advancing the post-processing function of PACS.

Objective To present a new algorithm for multidimensional medical image registration from global registration to local registration in sequence. Methods Firstly, the global registration was achieved by the method of affine transformation composed of B-splines,whose knots were the four vertexes of the medical image. Then the knots of the B-splines were increased, and the transformation function was more complex and elastic than ever,which completed the elastic aligning for the detail of the medical image. Results The whole registration algorithm represented the principle aligning from global registration to local registration. Conclusion It is proved by experiments that the presented algorithm can decrease the time of calculation and increase the robustness of registration.

Objective To develop a virtual endoscopy system which can be integrated into PACS.Methods Key techniques on virtual endoscopy were researched and we implemented a virtual endoscopy system with the help of the Visualization Toolkit VTK.Results The Virtual endoscopy system was integrated into PACS and the post-processing function of PACS was advanced.Conclusion As a novel medical image post-processing technology,virtual endoscopy provides a completely non-invaded inspection,so it has broad application prospects in the computer-aided medical teaching,surgical navigation,surgical planning and clinical diagnosis.

Objective To investigate the evolution of monkey brain isehemic penumbra(IP)area.Methods Seyen monkeys were used to make middle cerebral artery occlusion(MCAO)model by interventional methods.CT perfnsion imaging,MR diffusion weighted-imaging (DWI),perfusion weighted imaging(PWI)and T2W1 were performed at 1,5,10;15,20 and 24 h after MCAO respectively.Four regions of interest of infarct lesion were measured.Point 1 was at the infarct core.point 3 was at the infamt margin,and point 2 was at the midpoint between point 1 and 3.Point 4 demonstrated normal signal intensity adjacent to high signal intensity.Parameters measured included cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), apparent diffusion coefficient (ADC) and negative enhancement integral (NEI).The relative ratios between infarct lesions and the corresponding contralateral normal brain were calculated(rCBF, rCBV, rMTY, rADC and rNEI).The IP areas were calculated by two methods: IP thresholds combined with self-made computer software, and PWI( MrlT)-DWI mismatch.ANOVA and ROC analysis were used. Results Five of 7 monkey MCAO models were made successfuUy. There were signitlcanfly difference of rCBF and rNEI within 20 h, of rCBV within 15 h, of rADC within 10 h, of rMTT at24 h (P＜0.05).ROI 1,2 and 3 values as following: rCBF: 1 h(0.160 ±0.034, 0.310 ±0.037,0.540±0.107), 5 h(0.098±0.029, 0.157 ± 0.052, 0.427 ±0.116), 10 h(0.072 ±0.023, 0.097 ±0.028, 0.209 ± 0.070), 15 h(0.054 ± 0.017, 0.069 ± 0.015, 0.166 ± 0.049), 20 h(0.038 ± 0.011,0.026± 0.007, 0.092±0.013); rNEI: 1 h(0.219 ± 0.085, 0.303 ± 0.099, 0.463 ± 0.132), 5 h (0.143±0.057, 0.195± 0.055, 0.348±0.127), 10 h(0.127 ± 0.029, 0.171 ± 0.058, 0.259 ±0.079), 15 h(0.128 ±0.024, 0.164 ±0.031, 0.217 ±0.030), 20 h(0.075±0.019, 0.147±0.058,0.129 ±0.045) ; rCBV: 1 h(0.594 ± 0.199, 0.804 ± 0.099, 1.021 ±0.169), 5 h(0.457±0.103,0.462±0.145, 0.815±0.201), 10 h(0.222 ±0.046, 0.249±0.065, 0.529 ±0.135), 15 h(0.201 ±0.047, 0.187 ±0.055, 0.361 ±0.083) ; rADC: 1 h(0.515 ±0.115, 0.667±0.097, 0.761 ±0.106),5 h(0.488 ±0.100, 0.539 ±0.107, 0.674 ±0.099), 10 h(0.456 ±0.057, 0.549 ±0.049, 0.590 ±0.081 ) ; 24 h rMTT(4.163 ± 1.179, 4.192± 1.607, 2.397±0.909).The thresholds of IP were 0.203 of rCBF, 0.483 of rCBV, 0.571 of rADC and 0.250 of rNEI respectively.The values measured using the method of IP thresholds combined with software were larger than PWI(MTr)-DWI mismatch region before 15 hours, but were smaller at 20 h and 24 h. The area of IP was 20%-38% of infarct area at 1 h,15%-35% at 5-10 h, 13%-25% at 15 h, 9%-15% at 20 h, and 3%-12% at 24 h.Conclusion The time window of IP in monkey MCAO model was 15%-20 hours.At the early phase of infarction, IP was present within the region of high signal intensity on DWI.PWI-DWI mismatch method could not estimate IP areas accurately.Areas evaluated with CT perfusion (MrIT) and DWI mismatch were much closer to the actual IP areas.

Objective: 3D segmentation is an important part of medical image analysis and visualization. It also continues to be large challenge in the medical image segmentation. While level sets have demonstrated a great potential for 3D medical image segmentation, these algorithms have a large computational burden thus are not suitable for real time processing requirement. To solve this problem, we propose a parallel accerelated method based on CUDA. Methods: We implement C-V level set algorithm in the CUDA environment which is the NVIDIA's GPGPU model.The segmentation speed can greatly improved by using independence of image pixel and concurrence of partial differential equation .The paper shows the flow chart of the parallel computing and gives the detailed introduction of the C-V level set algorithm which is implemented in the CUDA environment. Results: Realizing the C-V level set parallel accerelated algorithm. This method has faster segmentation speed while preserving the qualitative results, Conclusions: This method is viable and makes the fast 3D medical image segmentation come hue.

Objective: Real time medical image registration technique is one of the key techniques in image based surgery navi-gation system. While in medical image analysis, image registration is usually a very time-cousuming operation, and this is not conducive to clinical real-time requirements. This paper studies and realizes the acceleration of the process of image registra-tion. Methods: In order to improve the regisWation rate, in this paper, we propose a new technology which is based on CUDA (Compute Unified Device Architecture) programming model to accelerate the process of registration in hardware, using paral-lel methods to achieve pixel coordinate transformation, linear interpolation, and calculate the corresponding pixel gray value residuals. Results: The registration is up to the sub-pixel level and the GPU-based registration is dozens or even hundreds of times faster than CPU-based registration. Conclusions: This method greatly enhances the speed of rigid registration without changing the alignment accuracy.

Objective To compare the difference in bioavailability of microemulsion and pill by detecting the concentration of andrographolide in rabbit plasma.Methods RP-HPLC was used to detect the concentration of andrographolide in rabbits plasma at different time,and software 3p87 was used to analyze the pharmacokinetics parameter.Results The pharmacokinetics parameters of andrographolide oral microemulsion and andrographolide pill were as follows::AUC0-7=1 406.72 ? g? mL-1? min,Tpeak=27.08 min,Cmax=5.37 ? g/mL for microemulsion;AUC0-7=877.37 ? g? mL-1? min,Tpeak=61.04 min,Cmax=3.06 ? g/mL for the pill.Conclusion Oral microemulsion of andrographolide has a shorter peak time and higher biological availability than the pill.

Objective To study the pharmacokinetics and the relative bioavailabi lity of micro-emulsified genistein in rabbits. Methods Rabbits received gastric gavage of micro-emulsified genistein and CMC-Na suspension of genistein. Then the genistein content in rabbit plasma at different time was determined by HPLC ,concentration-time curve was drafted,and the pharmacokinetic parameters and the relative bioavailability were calculated. Results The main parameters of mic ro-emulsified genistein and CMC-Na suspension of genistein were as follows:AU C0→10h being(24.90?1.24)and(10.71?0.86)?g?h?mL-1,Cmax being(4.02?0.20)a nd(0.99?0.04)?g?mL-1,Tmax being 2 h and 4 h,respectively. The relative bio availability of micro-emulsified genistein was 232.49 %. Conclusion Micro-emu lsified genistein system can improve the bioavailability of genistein evidently.

We propose an effective algorithm for accurate 3D segmentation of CT liver images based on statistical and specific information. We present a new intensity model which combines patient-specific intensity information of boundary with the statistical information for liver segmentation. Compared to the traditional methods, our approach not only produces excellent segmentation accuracy, but also increases the robustness.
Algorithms ; Humans ; Imaging, Three-Dimensional ; methods ; Liver ; diagnostic imaging ; Liver Diseases ; diagnostic imaging ; Liver Neoplasms ; diagnostic imaging ; Models, Statistical ; Radiographic Image Interpretation, Computer-Assisted ; methods ; Tomography, X-Ray Computed ; methods