Purpose: Cannot observe the dose intuitionally is a limitation of the existing 2D pre‐implantation dose planning. Meanwhile, a navigation module is essential to improve the accuracy and efficiency of the implantation. Hence a 3D Image Guided Brachytherapy Planning System conducting dose planning and intra‐operative navigation based on 3D multi‐organs reconstruction is developed. Methods: Multi‐organs including the tumor are reconstructed in one sweep of all the segmented images using the multiorgans reconstruction method. The reconstructed organs group establishs a three‐dimensional visualized operative environment. The 3D dose maps of the three‐dimentional conformal localized dose planning are calculated with Monte Carlo method while the corresponding isodose lines and isodose surfaces are displayed in a stereo view. The real‐time intra‐operative navigation is based on an electromagnetic tracking system (ETS) and the fusion between MRI and ultrasound images. Applying Least Square Method, the coordinate registration between 3D models and patient is realized by the ETS which is calibrated by a laser tracker. The system is validated by working on eight patients with prostate cancer. The navigation has passed the precision measurement in the laboratory. Results: The traditional marching cubes (MC) method reconstructs one organ at one time and assembles them together. Compared to MC, presented multi‐organs reconstruction method has superiorities in reserving the integrality and connectivity of reconstructed organs. The 3D conformal localized dose planning, realizing the “exfoliation display” of different isodose surfaces, helps make sure the dose distribution has encompassed the nidus and avoid the injury of healthy tissues. During the navigation, surgeons could observe the coordinate of instruments real‐timely employing the ETS. After the calibration, accuracy error of the needle position is less than 2.5mm according to the experiments. Conclusion: The speed and quality of 3D reconstruction, the efficiency in dose planning and accuracy in navigation all can be improved simultaneously.
Simultaneous contrast enhancement and speckle suppression in optical coherence tomography (OCT) are of great significance to medical diagnosis. In this paper, we propose a selective weighted variational enhancement (SWVE) model to enhance the structural parts of OCT images, and then present a shape-preserving fourth-order-oriented partial differential equations (SP-FOOPDE) algorithm to suppress speckle noise. To be specific, in the SWVE model, we first introduce the fast and robust fuzzy c-means clustering (FRFCM) algorithm to generate masks based on the gray-level histograms of the reconstructed OCT images and utilize the masks to distinguish the structural parts from the background. Then the retinex-based weighted variational model, combined with gamma correction, is adopted to enhance the structural parts by multiplying the estimated reflectance with the adjusted illumination. In the despeckling process, we present an SP-FOOPDE algorithm with the fidelity term modified by the shearlet transform to strike a splendid balance between noise suppression and structural preservation. Experimental results show that the proposed method performs well in contrast enhancement and speckle suppression, with better quality metrics of the MSE, PSNR, CNR, ENL, EKI, and ν and better noise immunity than the related method. Moreover, the application to the segmentation preprocessing exhibits that the retinal structure of the OCT images processed by the proposed method can be completely segmented.
In this paper we present a new auto -microscope system controlled by microcomputer for image processing. The microstructure of objects can be observed and processed. A charge-coupled device (CCD) array is used as the photoelectric detector. This auto -microscope system can complete autofocusing, recognizing or screening out pattern in the field of view and automatic measuring for photomicrographing by the light intensity information sampling by CCD array.For this auto -microscope system we designed the scanning mechanism of microscope stage, adjustable holder of CCD in 5-Dimention, autofocusing mechanism and a auto -photomicrograph camera with large cassette. The autofocusing discrimination function constructed by means of self entropy is better suitable for low contrast image produced by microscope system. The geometrical features of the microscope image are selected for composing the discrimination function and this discrimination function is used for classifing the patterns in the microscope field of view by training samples. Automatically measuring light for photomicrograph is realized by the same CCD array and the controlling circuit, interface circuit and other circuits of this system are developed. Some experiments results: autofocusing, auto -screening the cell pattern in the microscope field of view are given.The functions of controlling box are: providing power of all parts of the system and the microcomputer, controlling circuits. All operating and displaying are given on operating panel. The schematic diagram of the controlling box is shown in Fig.2. In Fig.2, driving circuit drives the CCD array sample data of image. Sampling circuit realizes amplifying and A/D converting, sampled data signals by CCD array are put in the microcomputer.Step motors 1, 2, 3, 4 and 5 control scanning of microscope stage in x and y directions, scanning of image, autofocusing, automatic rolling films of the camera respectively. The alarms display on the panel is indicational system which displays the ABSTRACT In this paper we present a new auto-microscope system controlled by microcomputer for image processing. The microstructure of objects can be observed and processed. A charge-coupled device (CCD) array is used as the photoelectric detector. This auto-microscope system can complete autofocusing, recognizing or screening out pattern in the field of view and automatic measuring for photomicrographing by the light intensity information sampling by CCD array. Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/27/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx SPIE Vol. 1161 New Methods in Microscopy and Low Light Imaging (1989) / 311 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/27/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx SPIE VoL 1161 New Methods In Microscopy and Low Light Imaging (1989) / 317 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/27/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx
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