AIM:To evaluate the potential usefulness of acoustic radiation force impulse (ARFI) images for evaluation of hepatocellular carcinomas (HCC)-associated radiofrequency ablation. METHODS:From January 2010 to June 2010,a...AIM:To evaluate the potential usefulness of acoustic radiation force impulse (ARFI) images for evaluation of hepatocellular carcinomas (HCC)-associated radiofrequency ablation. METHODS:From January 2010 to June 2010,a total of 38 patients with HCC including recurred HCCs after RFA underwent ARFI elastography. The brightness of tumor was checked and the shear wave velocity was measure-d for the-quantification of stiffne-ss. According to theb-rightne-ss,the-tumors we-re-classifie-d as b-righte-r,samecolor and darker compared with adjacent parenchyma. Using the same methods,8 patients with recurred HCCs after RFA state were evaluated about the brightness compared with adjacent RFA ablation area. RESULTS:In the 38 patients with HCCs,20 (52.6%)were brighter than surrounding cirrhotic parenchyma. Another 13 (34.2%) were darker. The others (5 cases,13.2%) were seen as the same color as the adjacent liver parenchyma. Post-RFA lesions were darker than previous tumor and surrounding parenchyma in all 38 cases. However,recurred HCCs were brighter than the treated site in all 8 cases. CONCLUSION:Using ARFI technique is helpful for differential diagnosis in order to detect recurred HCCs more easily in patients with confusing status.展开更多
Four data fusion methods, principle component transform (PCT), brovey transform (BT), smoothing filter-based intensity modulation(SFIM), and hue, saturation, intensity (HSI), are used to merge Landsat-7 ETM+ multispec...Four data fusion methods, principle component transform (PCT), brovey transform (BT), smoothing filter-based intensity modulation(SFIM), and hue, saturation, intensity (HSI), are used to merge Landsat-7 ETM+ multispectral bands with ETM+ panchromatic band. Each of them improves the spatial resolution effectively but distorts the original spectral signatures to some extent. SFIM model can produce optimal fusion data with respect to preservation of spectral integrity. However, it results the most blurred and noisy image if the coregistration between the multispectral and pan images is not accurate enough. The spectral integrity for all methods is preserved better if the original multispectral images are within the spectral range of ETM+ pan image.展开更多
A method using spectrum illumination to reconstruct 3-D object image is a new concept in the field of computer vision. The design of optical illumination system is crucial in this method. Several ways to achieve multi...A method using spectrum illumination to reconstruct 3-D object image is a new concept in the field of computer vision. The design of optical illumination system is crucial in this method. Several ways to achieve multi-color spectrum illumination are discussed. A prism illumination system is designed by means of aligning symmetrically the prism at the mid-wavelength (n d=1.806 274) of light path and using reflection collimating lens, cylindrical expending lens and two optical shutters. The relations between deviation angles and light wavelengths are given, and some 3-D reconstruction results are presented.展开更多
An improved approach for JSEG is presented for unsupervised segmentation of homogeneous regions in gray-scale images. Instead of intensity quantization, an automatic classification method based on scale space-based cl...An improved approach for JSEG is presented for unsupervised segmentation of homogeneous regions in gray-scale images. Instead of intensity quantization, an automatic classification method based on scale space-based clustering is used for nonparametric clustering of image data set. Then EM algorithm with classification achieved by space-based classification scheme as initial data used to achieve Gaussian mixture modelling of image data set that is utilized for the calculation of soft J value. Original region growing algorithm is then used to segment the image based on the multiscale soft J-images. Experiments show that the new method can overcome the limitations of JSEG successfully.展开更多
With the scaling development of the minimum lithographic size,the scaling trend of CMOS imager pixel size and fill factor has been computed according to the Moore rule.When the CMOS minimum lithographic feature scales...With the scaling development of the minimum lithographic size,the scaling trend of CMOS imager pixel size and fill factor has been computed according to the Moore rule.When the CMOS minimum lithographic feature scales down to 0.35 μm,the CCD image pixel size is not so easy to be reduced and but the CMOS image pixel size benefits from the scaling minimum lithographic feature. However, when the CMOS technology is downscaled to or under 0.35 μm,the fabrication of CMOS image sensors will be limited by the standard CMOS process in both ways of shallow trench isolation and source/drain junction,which results in pixel crosstalk.The impact of the crosstalk on the active pixel CMOS image sensor is analyzed based on the technology scaling.Some suppressed crosstalk methods have been reviewed.The best way is that combining the advantages of CMOS and SOI technology to fabricate the image sensors will reduce the pixel crosstalk.展开更多
基金Supported by Research Funds from Dong-A university
文摘AIM:To evaluate the potential usefulness of acoustic radiation force impulse (ARFI) images for evaluation of hepatocellular carcinomas (HCC)-associated radiofrequency ablation. METHODS:From January 2010 to June 2010,a total of 38 patients with HCC including recurred HCCs after RFA underwent ARFI elastography. The brightness of tumor was checked and the shear wave velocity was measure-d for the-quantification of stiffne-ss. According to theb-rightne-ss,the-tumors we-re-classifie-d as b-righte-r,samecolor and darker compared with adjacent parenchyma. Using the same methods,8 patients with recurred HCCs after RFA state were evaluated about the brightness compared with adjacent RFA ablation area. RESULTS:In the 38 patients with HCCs,20 (52.6%)were brighter than surrounding cirrhotic parenchyma. Another 13 (34.2%) were darker. The others (5 cases,13.2%) were seen as the same color as the adjacent liver parenchyma. Post-RFA lesions were darker than previous tumor and surrounding parenchyma in all 38 cases. However,recurred HCCs were brighter than the treated site in all 8 cases. CONCLUSION:Using ARFI technique is helpful for differential diagnosis in order to detect recurred HCCs more easily in patients with confusing status.
文摘Four data fusion methods, principle component transform (PCT), brovey transform (BT), smoothing filter-based intensity modulation(SFIM), and hue, saturation, intensity (HSI), are used to merge Landsat-7 ETM+ multispectral bands with ETM+ panchromatic band. Each of them improves the spatial resolution effectively but distorts the original spectral signatures to some extent. SFIM model can produce optimal fusion data with respect to preservation of spectral integrity. However, it results the most blurred and noisy image if the coregistration between the multispectral and pan images is not accurate enough. The spectral integrity for all methods is preserved better if the original multispectral images are within the spectral range of ETM+ pan image.
文摘A method using spectrum illumination to reconstruct 3-D object image is a new concept in the field of computer vision. The design of optical illumination system is crucial in this method. Several ways to achieve multi-color spectrum illumination are discussed. A prism illumination system is designed by means of aligning symmetrically the prism at the mid-wavelength (n d=1.806 274) of light path and using reflection collimating lens, cylindrical expending lens and two optical shutters. The relations between deviation angles and light wavelengths are given, and some 3-D reconstruction results are presented.
文摘An improved approach for JSEG is presented for unsupervised segmentation of homogeneous regions in gray-scale images. Instead of intensity quantization, an automatic classification method based on scale space-based clustering is used for nonparametric clustering of image data set. Then EM algorithm with classification achieved by space-based classification scheme as initial data used to achieve Gaussian mixture modelling of image data set that is utilized for the calculation of soft J value. Original region growing algorithm is then used to segment the image based on the multiscale soft J-images. Experiments show that the new method can overcome the limitations of JSEG successfully.
文摘With the scaling development of the minimum lithographic size,the scaling trend of CMOS imager pixel size and fill factor has been computed according to the Moore rule.When the CMOS minimum lithographic feature scales down to 0.35 μm,the CCD image pixel size is not so easy to be reduced and but the CMOS image pixel size benefits from the scaling minimum lithographic feature. However, when the CMOS technology is downscaled to or under 0.35 μm,the fabrication of CMOS image sensors will be limited by the standard CMOS process in both ways of shallow trench isolation and source/drain junction,which results in pixel crosstalk.The impact of the crosstalk on the active pixel CMOS image sensor is analyzed based on the technology scaling.Some suppressed crosstalk methods have been reviewed.The best way is that combining the advantages of CMOS and SOI technology to fabricate the image sensors will reduce the pixel crosstalk.
