Ultrasonogram Texture Analysis On Rabbit VX2Breast Tumor HIFU Ablation Based On Wavelet Transform

As a new non-invasive technology,high intensity focused ultrasound isused to treat the benign and malignant tumors,and makes the treatment ofbreast-conserving be possible. HIFU needs the imaging technology as areal-time monitoring,and the ultrasound is the method which is used mostcommonly.However, ultrasound pattern exists the situation that the tissuebecomes coagulation necrosis but the gray does not change significantly,itcan result in a total overdose, prolonged treatment and arousecomplications, etc.According by analysis of the target area ofultrasonographic on texture,this study will explore a more accurate way forthe evaluation of efficacy,so as to improve the accuracy and sensitivity ofultrasound real-time monitoring, and provide the experimental basis forclinical studies.ObjectiveBy means of judging the situation of coagulation necrosis of the targetarea by wavelet analysis texture parameters during the high intensityfocused ultrasound (HIFU) treatment, discusses the multi-resolution of judging successfully, and improves the accuracy and sensitivity of thejudging.Methods1.1Experimental equipmentThe JC200focused ultrasound tumor therapy system, this systemincludes five parts: a power source, ultrasonic real-time monitoring of thecoupling device of positioning, the combination of probes, the treatment ofmotion control devices,and the treatment bed and the sound.Theparameters:the treatment head of the frequency is0.9MHz, the diameter is220mm, the focal length is140mm.GE LOGIQ9ultrasonic diagnostic apparatus (Provided by XinqiaoHospital, The Third Military Medical University)Matlab2010and WEKA3.71.2Establishment of animal model120New Zealand healthy female rabbits.Cut the rabbits’ liver cancer tissue under sterile conditions, wash it bynormal saline, and place it in a glass dish filled with saline, then take thevigorous growth tissue which is like fish from its tumor edge, cut it intopieces with ophthalmic scissors, then inject it in20ml syringe with thesaline together, so the tissue mass suspension is made.1.3Experimental procedures1.3.1After the rabbit is hocussed, using a needle inject the tissue suspension1ml in its each of the bilateral breast. After2weeks the regionof breast will turn up diameter of10mm mass, after the rabbit ishocussed,place it in the treatment bed, then start the B ultrasonic diagnosticapparatus to locate breast tumors. At last, irradiate the VX2to locate it andadjust the focus in the tumor internal, manually point play scanning,powerset for90W,120W,150W respectively, irradiate3s.1.3.2Collecting the instant ultrasonogram of every sample before andafter irradiating.1.3.3After irradiating the HIFU,cut the breast tumor,choose samplesfrom the irradiated target,then observe whether they are the coagulationnecrosis with HE staining,optical microscope and electronicmicroscope.Take the result as the gold standard to judge whether they arethe coagulation necrosis.1.3.4Use the software to analyse the image, use the software Matlab tointercept ROI (region of interest, ROI), transform it twice by wavelet; takethe samples’ results of ultrasonographic parameters before and afterirradiating input WEKA3.7, use the support vector machine (SVM) toestablish decision-making flat, and analyse the samples. Through thetraining,toolbox of SVM can obtain the plane of classification decisions,and analyse the samples.At last,compared the results of texture analysiswith the evaluation of gray. 1.4Statistical analysisUse the statistical software SPSS17.0,compared the results of textureanalysis with the evaluation of gray,use a chi-square test, when theoryfrequency is greater than5, use the un-correction formulaχ2to test by αis equal to0.05, it is of statistical significance when P is less than0.05.ResultsThe accuracy and sensitivity of the judging for the coagulation necrosisof HIFU ablated tissues by ultrasonogram texture parameters extracted bywavelet transformation is higher than gray scale evaluation, and thedifference is of statistical significance that PP is less than0.05.（1）Multi-resolution wavelet transform sentenced on the rate of86.67%, higher than the grayscale sentence on the rate of60.83%, thedifference was statistically significant (P=0.000);（2）Tamura on the judgments of coagulation necrosis was80.83%higher than the gray sentenced on the rate of60.00%, the difference wasstatistically significant (P=0.000);（3）Contrast conditions, the multi-resolution wavelet transformtexture analysis methods to determine the coagulation necrosis sensitivityof84.6%, Tamura, judgment coagulation necrosis sensitivity80.7%,53.6%of the gray-scale sensitivity, the difference was statistically significant (P=0.023and P=0.034).was not statistically significant difference between thetwo texture methods.Conclusions The accuracy and sensitivity of the judging for the coagulation necrosisof HIFU ablated tissues by ultrasonogram texture parameters extracted bywavelet transformation is higher than gray scale evaluation.