1.Dosimetric Study of the Different Radiotherapy Ways for Postoperative Patients with Cervical Carcinoma
Yuhai ZHANG ; Yuemin LI ; Huosheng XIA ; Shouyun HAN ; Ping LI ; Zhichen LIU
Chinese Journal of Medical Physics 2010;27(1):1583-1587
Objective:To compare the dosimetric differences of the planning target volume(PTV)and the organs at risk(OAR)for postoperative patients with cervical cancer on intensity-modulated radiotherapy(IMRT)and conventional 4 fields(4F)or 2 fields(2F)radiotherapy.Methods:Six postoperative patients with cervical cancer were chosen randomly.The next steps were CT scan,PTV and OAR contouring.The treatment protocols were designed into conventional 4F,2F and IMRT by TPS.Finally,the doso distribution and DVH were compared.Results:About the conformability of PTV,IMRT showed a significantly superior dose distribution over conventional 4F(P=0.015),and conventional 4F was superior to 2F(P=0.043).IMRT as compared with conventional 4F or 2F protocols,the received dose of the 50%volume of bladder was reduced by 25.8%and 27.5%,the rectum was reduced by 12%and 14.3%,the small intestine was reduced by 36.5%and 50%.But the differences of the femoral head(left & right)and the ilium have no statistical significance.Conclusion:in postoperative radiotherapy for cervical cancer,IMRT have Inore dosimetric advantages than conventional radiotherapy.
2.Summing up Experiences and Pushing the Development of Clinical Hemorheologic of my Nation in Depth
Chinese Journal of Medical Physics 2010;27(2):1821-1824
Objective: Pushing the development of scientific research, education and clinical applying of hemorheologic in eath part comprehensively and in depth. Methods: Summarizing the experiences, lessons and questions in scientific research, edu-cation and clinical applying of hemorheologic in twenty and more years, clarifying the harm of high viscosity to health. Re-sults: Stating the foundation, necessity and feasibility of the overall and deep development have been possessed. Conclusions: Hemorheologic can be developed comprehensively and in depth provided that studying good experiences, cultivating talent, playing the role of learning organizations and conquering the existing questions.
3.The Pulse Monitoring System Based on MCU and GSM
Yinghua CHEN ; Guofeng LI ; Hongpeng CHEN
Chinese Journal of Medical Physics 2010;27(2):1766-1768
Objective: This thesis describes a pulse monitoring system based on MCU and GSM. Methods: Monitoring system is a wireless remote monitoring devices which using the SMS in GSM mobile communications network. The signal of pulse is acquisited by Acquisition Circuit, after timing and counting by MCU, pulse rate above the standard is directly transmited to family cell or Dr Mobile by GSM. Results: If the patient arises suddenly heart disease, monitor can be promptly sent to the pulse rate above the standard for family cell or Dr Mobile so that patients receive timely aid. Monitor has advantages of a wide coverage, economic and convenience. Conclusions: The monitor will greatly reduce the burden on the patient's family and hospital, This pulse monitoring system can meet with demands of service in the family and villa nursing and hospital.
4.A Research on Key Problem of Integrated 3-D Virtual Surgical System
Chinese Journal of Medical Physics 2007;24(2):102-105
The virtual surgical system is a surgical simulated software adopting image processing and 3-D visualization technology. It can help the surgeons to determine the operating position, simulate operation and plan for a optimal operation. VTK which exhibits high performance in visualization and ITK which has strong ability in image processing were integrated to solve the key problems such as image segmentation, image registration and fusion, 3-D reconstructing and virtual cropping. Experiments indicated that the integrated 3-D virtual surgical system can help surgeons to observe the surgical process and improve its reliability and quality.
5.Spinal Sequence Automatic Stitching Based on Biorthogonal Wavelet Transform and Feature Matching
Xue MENG ; Zhensheng DENG ; Xin GUO
Chinese Journal of Medical Physics 2010;27(2):1726-1730
Objective: An automatic seamless stitching method with spinal X-ray image sequence is presented in this paper. Methods: First, biorthogonal wavelet transform is used to implement decomposing of the multi-resolution and the effective edge of the image can be extracted by this method combined with Canny operator. The feature points of the image can be obtained by calculating the edge contour matrix E and the value matrix H. Second, the roughly matching of feature points can be achieved by using Normalized Cross Correlation (NCC) algorithm and the random sample consensus (RANSAC) algorithm is introduced to remove false matching pairs and to achieve precisely matching. Third, the image sequence is automatically sorted with the improved genetic algorithm to achieve automatic stitching. At last, the weighted average fusion algorithm is appfied to achieve smooth and seamless image stitching. This algorithm is robust for the weak-contrast X-ray image sequence. Results: Experimental results show that high-quality and fast image sequence stitching can be obtained automatically by using this method. Conclusions: To a certain extent, it overcomes the shortcomings of X-ray image sequence such as the strong image noise, concentration of values ofpixels, blurred boundaries, large overlap area and the sequence constraint, and therefore it may be applied to in medical imaging field widely.
6.Depth-dose Distribution of Secondary Effects in Photon Transport Process
Xiaoning FENG ; Chengjun GOU ; Qing HOU
Chinese Journal of Medical Physics 2009;26(6):1467-1471
Objective: Simulating the photon transport process, recording the distribution of the dose which is caused by various of interactions and secondary particles, summarizing and analyzing the weightiness of each contribution. Methods: The PENELOPE package provides the basic Monte Carlo(MC) code which simulates the processes of photon and electron transport Considering the concerned physical problems, the author modifies the PENELOPE program to simulate the track of photon transport process, meanwhile records the contribution of dose which is provided by various of interactions and secondary particles in this article. Results: Firstly, in the same condition, recording the distribution from 4 source different energies(30 keV, 40keV, 50 keV, 60 keV), the distribution of the central axis total dose and the distributions which are caused by secondary Soft collision and secondary hard inelastic collision, and the distribution of the central axis dose provided by secondary particles. Secondly, in the same condition, recording the distribution of the central axis dose caused by secondary Compton scattering and secondary Photonelectric scattering. Conclusion: In different source of energy, the distribution of the central axis dose proffered by secondary soft collision play a major role; the contribution of secondary Photonelectric scattering decreased with the ascent of energy; the contribution from the first generation secondary particles is stronger than others.
7.Realizing generalized registration of medical sequence image using mutual information criterion
Chenguang ZHAO ; Wufan CHEN ; Weipeng LI
Chinese Journal of Medical Physics 2001;18(1):23-26
Mutual information(MI) is a tool of measuring the statistical dependence between two random variables. MI between two images, being considered as two random fields, can be calculated to determine the degree of information redundancy between the image intensities of corresponding pixels in both images. In this paper, we utilize the MI criterion to realize the generalized registration between two neighboring slices in a medical image sequence (CT, MR et al) and consider that they match with each other if the MI between them is maximal. Experimental results confirm performance of our algorithm.
8.Progress on Medical Image Registration and its Application
Chinese Journal of Medical Physics 2009;26(6):1485-1489
Objective: To summarize the major progress in medical image registration in recent years. Furthermore, based on the recent advances in this field, this paper can provide a reference in following domains: three-dimensional medical image reconstruction, medical image visualization, quantitative analysis. Methods: Firstly, referring to a myriad of latest papers on medical image registration. Secondly, analyzing traits and exiting problems of techniques which presented in those papers. Finally, putting forward some efficient methods for solving these problems. Results: This paper compares the characteristics of some typical algorithms and its application and looks forward to the future research work. Conclusion: Using optimization strategy to improve the quality of image registration and studying on non-rigid image registration are the directions for future research in medical image registration field.
9.The development of an intelligent EEG monitor
Chinese Journal of Medical Physics 2001;18(1):54-55
This paper introduces consistents of an intelligent EEG monitor, including its hardware and software. Emphasis is put on the discussion about the detection of epilepsy waves with wavelet transform. At last, analysis of clinical EEG data show that this system has achievedhighsensitivity and selectivity.
10.The integral term of the information entropy unadapted for being a measuring index
Hang YU ; Yang HONG ; Zhi QU ; Li LIU
Chinese Journal of Medical Physics 2001;18(1):57-59
The information entropy, H = - Pk log Pk, has been proved in this paper to be always positive and invariant for a linear coordinate transformation, so that it can be used as a measuring index. On the contrary, the integral term of the information entropy, H(x) = -f(x) log f(x) dx, is not always positive and invariant for a linear coordinate transformation. Therefore, H(x) can not be used as a measuring index. An example of a probability density function for response of nerve to electric current with different intensities is given to confirm above conclusions.