| PART ONE MAGNETIC RESONANCE GENERIC SEQUENCE IS APPLIED TO VALUE THE HIFU TREATMENT OF RABBIT VX2 LIVER TUMOR MODELObjective:Analysis to investigate the change of tumor signal in MRI routine sequence pri-and post-HIFU treatment of rabbit VX2 liver cancer model.Materials and methods:New Zealand white rabbit VX2 liver cancer model, the model set up before 2-3 weeks after success in HIFU treatment, treatment after 12 hours (scope of HIFU treatment to completely cover the tumor),1,3,7,14,21 days after treatment,5 each observation point,9 experimental rabbits in each observation point, a total of 45 rabbits. All rabbits scanned by using a 1.5 T superconducting magnetic resonance imaging and 8 channel body phase front circle on T1 WI, T2WI sequence of MRI, respectively. Scanning mode includs transection, coronal and sagittal scanning. In five points after completion of each sequence MRI were executed each observation point of all experimental rabbits. Pathology examination is use to observe the five observation point model of rabbit VX2 liver cancer before MRI signal and HIFU treatment of tumor signal change, and comparison analysis with pathological results.Result:This experiment object to 60 New Zealand white rabbits, successful cultivation for 56 experimental rabbit VX2 liver cancer model, planting of the success rate was 93.3%; After HIFU treatment before MR scanning sequence each selected 6 experimental rabbits VX2 liver cancer model executed and pathology examination, used in the model of observation of VX2 liver pathology; 50 rabbits VX2 liver cancer model live 45 only after HIFU treatment, the experimental success rate was 75%. HIFU treatment after 1,3,7,14 and 21 days observation point of 45 cases of rabbit VX2 liver cancer model before HIFU treatment slightly low signal on T1WI images show the shadow 45 cases (45/45,100%), slightly high signal on T2WI images show the shadow 42 cases (42/45,93.3%); performance for mixed signal shadow 3 cases.(3/45,6.7%). HIFU treatment in all observation point of 45 cases of rabbit VX2 liver cancer model demonstrated slightly low signal on T1WI images show the shadow 45 cases (45/45100), slightly low signal on T2WI of shadow 32 cases (32/45 states%), including the pathology examination for coagulation necrosis tissue up to 25 cases (25/32,78%). Pathology examination is not completely coagulation necrosis tissue in 7 cases (7/32,22%). Rabbit VX2 liver cancer model in performance for mixed signal on T2WI shadow 13 cases (13/45,29%), including pathological examination of coagulation necrosis tissue completely 4 cases (4/13,31%). Pathology examination is not completely coagulation necrosis tissue 9 cases (9/13,69%).Conclusion:MR conventional sequence Tl WI, T2WI of rabbit VX2 liver cancer model has a high sensitivity, can be accurately found lesions,. The tumor coagulated necrosis after HIFU treatment, the residual/recurrent tumor tissues with high sensitivity. MR routine scan sequence in the rabbit VX2 liver cancer model after HIFU treatment follow-up has a certain value.PART TWO 1H-MRS IS APPLIED TO VALUE THE HIFU TREATMENT OF RABBIT VX2 LIVER TUMOR MODELObjective:Application of magnetic resonance hydrogen proton spectroscopy (1 h-MRS) study of rabbit VX2 liver cancer model in HIFU treatment before and after the change of tumor tissue metabolites.Materials and methods:All New Zealand white rabbit VX2 liver cancer model was set up before 2-3 weeks after success in HIFU treatment, treatment after 1,3,7,14 and 21 days 5 observation point, each observation point had 9 experimental rabbits, a total of 45 rabbits. All scanned by using a 1.5 T superconducting magnetic resonance imaging (Signa Echospeed Excite â…¡, GE Healthcare, Milwaukee, USA) and 8 channel body phase front circle of line scanning, magnetic resonance spectrum sequence spectrum data transmission to MRS saker post-processing software (provided by GE company) the reprocessing, on line smooth baseline, main metabolite peaks can be clearly distinguishable as scanning success, measuring 3.2 PPM Cho peak area and 1.3 PPM in Lip area under the peak, Cho/Lip ratio calculation.After HIFU treatment 5 observation point 1H-MRS scans were executed after the completion of each observation point of all experimental rabbit. Pathology examination was observed in five spots to rabbit VX2 liver cancer model before and after HIFU treatment tumor Cho area under the peak, peak area under Lip and Cho/Lip ratio change, paired sample t test, if P< 0.05 the difference is statistically significant, and contrast analysis with the pathological results.Result:This experiment object to 60 New Zealand white rabbits, successful cultivation for 56 experimental rabbit VX2 liver cancer model, the success rate of planting is 93.3%. After HIFU treatment before MR scanning sequence each selected 6 experimental rabbit VX2 liver cancer model only executed and the pathology inspection, to confirm the rabbit VX2 liver cancer model before HIFU treatment pathology types,50 rabbit VX2 liver cancer model live 45 only after HIFU treatment, the experimental success rate was 75%.45 rabbit VX2 liver cancer model before and after HIFU treatment received 90 VOI satisfaction of spectral lines, smooth its baseline, main metabolic wave can identify, visible to the 4.6 parts per million of water peak,3.2 parts per million of Cho peak and Lip peak 1.3 PPM. HIFU treatment in all observation point of all 45 cases of rabbit VX2 liver tumor model absolutely coagulated necrosis.29 cases after HIFU treatment compared with before treatment:Cho area under the peak is decreased obviously (P< 0.05). Under Lip peak area increased significantly (P< 0.05);Cho/Lip ratio significantly decreased (P< 0.05). HIFU treatment in all tumor model,16 cases did not completely coagulated necrosis, after HIFU treatment compared with before treatment:Cho peak area under lower (P< 0.05). The Lip area under the peak increased (P< 0.05); Cho/lower Lip ratio (P< 0.05). HIFU treatment in all time point and all cases of rabbit VX2 liver cancer model completely coagulated tumor necrosis. Incomplete comparison:Cho/lower Lip ratio (P< 0.05).Conclusion:1H-MRS can accurately reflect the rabbit VX2 liver cancer model of HIFU treatment before and after the change of tumor tissue and necrotic tissue metabolites, combined magnetic resonance imaging sequences can be used as other HIFU in the treatment of rabbit VX2 liver cancer model follow-up important monitoring method. Part three:BOLD-fMRI is applied to value the HIFU treatment of rabbit VX2 liver cancer modelPART THREE BOLD fMRI-IS APPLIED TO THE VALUE OF RABBIT VX2 LIVER TUMOR MODEL OF HIFU TREATMENTObjective:Application of blood oxygen level dependent functional magnetic resonance imaging (fMRI) (blood oxygenation leveldependent functional magnetic resonance imaging, BOLD fMRI) in the study of rabbit VX2 liver cancer model in HIFU treatment before and after the change of tumor tissue oxygen content.Materials and methods:New Zealand white rabbit VX2 liver cancer model is successfully established in 2-3 weeks after HIFU treatment before and after treatment 1,3,7,14 and 21 days, a total of 5 observation point, each observation point had 9 experimental rabbits, a total of 45. All rabbits were scanned by using a 1.5 T superconducting magnetic resonance imaging (Signa Echospeed Excite II, GE Healthcare, Milwaukee, USA) and 8 channel body phase front circle line of magnetic resonance (NMR) blood oxygen level dependent on scanning imaging sequences, the BOLD image data transmission to AW4.1 workstation (GE Healthcare, Milwaukee, USA), through R2* software of image processing, the software automatically generated figure and R2 T2* figure, after HIFU treatment on T2* diagram of each observation point for each object of low signal area and high signal area were set up three interested area (region of interest, ROI), at the same time is set in the corresponding part of the HIFU treatment before the same three ROI, get each object corresponding parts in HIFU treatment before and after treatment of T2* value and R2* value. After HIFU treatment 5 observation point BOLD sequence scan respectively for the death of each observation point after the completion of all experimental rabbit. Pathology examination was used to observe the five observation point model of rabbit VX2 liver cancer before and after HIFU treatment T2* and the change of the R2* value, paired sample t test, if P< 0.05 the difference is statistically significant, and contrast analysis with the pathological results.Results:Among all 60 New Zealand white rabbit, successful cultivation for 56 experimental rabbit VX2 liver cancer model, the success rate of planting is 93.3%. After HIFU treatment before MR scanning sequence each selected 6 experimental rabbit VX2 liver cancer model only executed and the pathology inspection, to confirm the rabbit VX2 liver cancer model before HIFU treatment pathology types.50 rabbit VX2 liver cancer model live 45 only after HIFU treatment, the experimental success rate was 75%. Before HIFU treatment of 45 cases of rabbit VX2 liver cancer model in a high signal on T2* diagram or mixed signal. On the R2* figure show low signal or mixed signals.HIFU treatment after 1 day,3 days, 7 days, five days 14 and 21 days observation point of 45 cases of rabbit VX2 liver tumor model absolutely coagulation necrosis,29 cases T2* figure show the low signal (R2* at high signal), after HIFU treatment compared with before treatment corresponding area:T2* value lower (P< 0.05), R2* value increases (P< 0.05). HIFU treatment in all rabbit VX2 liver tumor model, there was not fully coagulated necrosis in 16 cases, T2* performance for mixed signal (R2* in mixed signal), T2* after HIFU treatment figure high signal in low signal area (R2*) compared with the corresponding area before treatment:T2* value and R2* value had no difference (P> 0.05);After HIFU treatment T2* figure low signal area (R2* the graph is high signal) compared with the corresponding area before treatment T2* value lower (P< 0.05), and R2* value increased (P< 0.05).Conclusion:magnetic resonance imaging can reflect blood oxygen level dependent on rabbit VX2 liver cancer model before and after HIFU treatment of tumor tissue and necrotic tissue blood oxygen content changes, can serve as important means to monitor the efficacy of HIFU treatment of rabbit VX2 liver cancer. |
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