| High Intensity Focused Ultrasound(HIFU)technology has started a new era of noninvasive treatment,it has been widely used in clinical medicine,which has a significant effect on the therapy of benign tumors and malignant tumors.Fea-tured with ultrasonic cavitation effect,thermal effect,mechanical effect and other comprehensive effects,High focused ultrasound can make the temperature of the tumor target instantly reach from 65? to 100?.At the same time,HIFU can lead to irreversible lesion of target tissue instead of obvious lesion of the surround-ing tissue,and the lesion tissue can be gradually reduced.B-mode ultrasound monitoring is often applied to HIFU treatment.Due to the low resolution,low contrast of the B-mode image and noise problem,there is a difficult to make an objective assessment of therapeutic effect accurately.In order to monitor and evaluate the therapeutic effect of HIFU accurately during the HIFU treatment,it is necessary to enhance the B-mode image.This paper was based on the experiment of fresh pork tissue in vitro irradiated by ultrasonic transducer.The ultrasonic images before HIFU radiation were collected by means of B-mode ultrasonic scanner and the computer configured with image acquisition card.Then the enhancement to the pretreated B-mode image was conducted.Main work was:Firstly,the related theories are presented for high intensity focused ultra-sound,including fundamentals,research background,present situation and basic approaches of HIFU treatment.Then by analyzing the current situation of HIFU therapeutic effect,enhancing B-mode ultrasound image after HIFU treatment is put forward.Secondly,the traditional image enhancement method of ultrasound mainly exist the following problems.Although the brightness of the image can be improved and the noise of the image can reduced,image distortion of effective region is serious and the detail of image also become blurred.To solve these problems,an improved method of ultrasound image enhancement is proposed in this paper.Thirdly,the principle and method of image denoising based on fractional order differential are presented.Then,an improved fractional differential denois-ing algorithm is proposed.In this paper,the single direction of the fractional order differential Tiansi mask operator is decomposed into eight directions of mask operator.And Mask operator is improved,its order should be adjusted for image denoising.Lastly,the basic principle of independent component analysis and pseudo-color processing are presented.A method combined with improved Fast ICA algorithm and pseudo-color processing about HIFU treatment region image en-hancement is proposed.Fast ICA algorithm is improved by dividing image com-ponent into background image component and treatment area image component.Firstly,treatment area image component is extracted by Fast ICA algorithm.Then,it can be realized to find the best magnification according to image fea-tures through iteration steps.Meanwhile,highlighting useful region of B-mode ultrasound image is possible.Finally,the resolving power can be improved by the combination of improved Fast ICA algorithm and pseudo-color processing.Thus,medical staff can observe focal area of the image detail accurately.Through the analysis,we found that improved fractional differential can not only greatly reduce the B-mode ultrasound image noise,but also retain the im-age edge information and effective area well.Then through improved Fast ICA algorithm and pseudo-color processing,contrast and edge retention has improved greatly,and treatment area are enhanced obviously.What' s more,image resolu-tion becomes more higher.It can accurately observe the image detail of treatment area,and provide reliable basis for clinical treatment,which has a practical value. |
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