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Part I: single voxel proton magnetic resonance spectroscopy (SV- 1 H MRS) in a rabbit model of limb VX2 soft tissue sarcoma interventional therapy evaluation Objective: To establish a rabbit limbs VX2 soft tissue sarcoma model, by comparing intervention before treatment, after 6 hours and 24 hours after treatment parameters (choline peak / lipid peak height ratio, choline peak / peak area under the mass ratio of purpose) investigate changes in the quality of conventional magnetic resonance imaging and single proton magnetic resonance spectroscopy (Single voxel protonmagnetic resonance spectroscopy, SV- 1 H MRS) in soft tissue sarcoma model interventional therapy evaluation. Materials and Methods: 40 New Zealand white rabbits, 2-3 months of age ,1.5-2 .5 kg weight, the former upper limb (unilateral 25, left upper limb, male or female; Bilateral 15, limited to male) injection of VX2 tumor tissue suspension liquid 0.15-0.2ml. 2-3 weeks after planting tumor conventional magnetic resonance imaging of tumors and SV- 1 HMRS imaging. MRS using point resolved spectroscopy method (PRESS), voxel (VOI) Size Control in 1.5-2.25cm 3 , full width at half maximum (FWHM) of 7-14HZ, water suppression (WS) is greater than 95% . Of which 15 bilateral tumors grown rabbits interventional chemoembolization, 10 rabbits survived more than a day, respectively, in intervention and 24 hours after six conventional magnetic resonance imaging and magnetic resonance spectroscopy examination. All images will be transmitted MRS ADW 4.3 workstation using SAGE software post-processing. Using SPSS15.0 software package for the analysis of the data (using single factor analysis of variance). Results: In this group of 55 animal models (unilateral 25, bilateral 15), in addition to an animal not stuck tumor growth, the more than 54 models are tumors success. 14,21,28 days after tumor types, tumor diameter was approximately 2,4,5.5 cm. Two weeks, tumor diameter smaller hard texture, necrosis rare. Conventional magnetic resonance image display, T 1 WI tumor parenchyma showed mostly other signals, tumor hemorrhage rare; T 2 WI showed tumor parenchyma showed heterogeneous high signal tumor internal and visible signal higher peritumoral edema and necrosis; enhanced significantly enhanced tumor parenchyma, the tumor edge enhancement more pronounced. SV- 1 H MRS revealed 49 cases can distinguish at 3.2ppm at the obvious choline (Choline) peak (peak exceeds the peak creatine), choline peak and lipid peak (Choline / Lipid ) peak height ratio and peak area ratio (expressed as mean ± standard deviation) were: 0.38 ± 0.17,0.22 ± 0.16; intervention before treatment and after 6 hours and 24 hours, Choline / Lipid peak of the peak height ratios area ratios were decreased, respectively, 0.37 ± 0.14,0.28 ± 0.13,0.24 ± 0.11 and 0.25 ± 0.18,0.17 ± 0.22,0.10 ± 0.14, but the statistics showed that among the three groups there was no significant statistical difference. Pathological examination showed tumor light microscope densely distributed peripheral cells, arranged in nests, large and deeply stained nuclei, cytoplasm scarce, partly visible in mitotic cells, tumor necrosis intervention compared with the contralateral side obviously. Conclusion: single voxel proton magnetic resonance spectroscopy (SV- 1 H MRS) can be used for soft tissue tumors VX2 rabbit limbs interventional treatment efficacy evaluation. Compared with the surrounding normal muscle tissue, tumor tissue MRS spectra there are obvious Choline peak. Interventional Therapy Choline / Lipid peak height ratio and peak area ratios were decreased gradually. Statistical tests were not significant, may be related to a variety of factors, which used as the internal standard peak Lipid difficult to accurately reflect the tumor cells after treatment of early intervention metabolic changes. And immunohistochemical staining (CD34). Post-processing in ADW 4.3 workstation using perfusion software package for post-processing. Comparing tumor tissue and surrounding normal muscle tissue differences in the relevant parameters (NI maximum signal drop of equivalent relative blood volume; MSD maximum signal down slope, representing the relative blood flow); calculating tumor tissue and normal muscle tissue or the MSD NI relative ratio (rNI, rMSD) and with the MVD (microvessel density) the relative ratio (rMVD) correlation analysis. Using SPSS15.0 software package for statistical analysis, statistical methods using paired T-test, signed-rank test and pearson correlation test. Results: 23 animals successfully conducted perfusion-weighted imaging. The results showed that the tumor tissue and surrounding normal muscle tissue NI and MSD values ??were 234.32 ± 175.46,114.61 ± 94.40:393.73 ± 227.30,154.44 ± 69.20. NI tumor tissue was significantly greater than the muscle tissue, the difference was statistically significant (t = -3.285, P = 0.003); tumor tissue was significantly greater than the value of MSD muscle tissue between the two statistically significant difference (z = - 4.167, P = 0.000). rNI with rMVD significant positive correlation (r = 0.779, P = 0.008), rMSD room with rMVD not shown a significant correlation. Conclusion: PWI describes blood vessels in the organization's first pass perfusion can noninvasively evaluate tissue perfusion. This study shows that the soft tissue tumor in a rabbit model for perfusion weighted imaging is feasible. Experimental results show that the tumor tissue and normal hemodynamic parameters of muscle tissue there is a significant statistical difference, but there are issues such as the contrast agent leakage. Magnetic resonance perfusion-weighted imaging in tumor recurrence and postoperative fibrosis discrimination, the differential diagnosis of benign and malignant tumors and tumor anti-angiogenesis drug efficacy evaluation has certain application prospect. The third part of the diffusion-weighted magnetic resonance imaging (DWI) in rabbit VX2 soft tissue sarcoma model interventional therapy Evaluation Objective: Through the establishment of VX2 rabbit limb soft tissue sarcoma model to investigate the diffusion-weighted magnetic resonance imaging (Diffusion-weighted MR imaging, DWI) in the diagnosis of soft tissue sarcoma model application. By choosing the right can be used for the diagnosis of soft tissue tumors b-value, compared to normal muscle tissue, tumor parenchyma, necrotic tissue ADC (apparent diffusion coefficient) values ??differences and interventional treatment of early intervention and control groups of tumor parenchyma ADC value changes evaluate the efficacy of intervention. Materials and Methods: 40 New Zealand white rabbits, 2-3 months of age ,1.5-2 .5 kg weight, the former upper limb (unilateral left upper limb 25, male or female; bilateral upper extremity 15, male) injection of VX2 tumor tissue suspension 0.15-0.2ml. 2-3 weeks after planting tumor conventional magnetic resonance imaging for tumor imaging and DWI, b value were taken 200,400,600,800 and 1000s/mm 2 . On 15 rabbits with bilateral tumors grown interventional chemoembolization one side, the other side as the control group, respectively, in 3,6,24 hours after interventional treatment on both sides of the animal models of conventional magnetic resonance and diffusion weighted imaging. Compared to normal muscle tissue, necrotic tissue tumor parenchyma and the difference between ADC values ??and interventional treatment of early intervention and control groups tumor parenchyma ADC value changes. All images will be transmitted to the post-processing workstation ADW 4.3. With SPSS15.0 software package for statistical analysis. Results: DWI image, when b is smaller (200s/mm 2 ) is affected by T 2 Effects and perfusion through the obvious impact, b value is relatively large (1000s/mm 2 ) when the image SNR decreased significantly; b value 200,400,600,800,1000 s / mm 2 when the ADC values ??(mean ± standard deviation) were : 1.56 ± 0.11,1.32 ± 0.12,1.25 ± 0.10,1.19 ± 0.08,1.14 ± 0.07. And with the increase of the b value, ADC values ??gradually decreased. Experimental results show that the b value is 600 or 800s/mm 2 , the image quality is better. b value takes 600 or 800s/mm 2 when the tumor parenchyma, and edema of the surrounding muscle tissue necrosis between ADC values ??were statistically significant differences exist, the maximum ADC value of necrotic tissue, tumor parenchyma ADC value was significantly less than necrotic area and surrounding muscle tissue ADC value. Intervention group regardless of b is 600 or 800s/mm 2 , the treatment before and after treatment, 3 hours, 6 hours and 24 hours, ADC values ??were statistically significant differences in intervention early after the tumor tissue of the ADC is a significant change in the control group, each group was no significant difference between the ADC values. Conclusion: DWI can be used VX2 rabbit limb soft tissue sarcoma diagnosis. b value of 600 or 800s/mm 2 , the availability of good DWI images, both diffuse enough weight, have a higher signal to noise ratio. ADC values ??of different organizations significantly different diffusion-weighted imaging can identify different organizations. Early after interventional therapy, tumor tissue ADC values ??have significant changes, so DWI receive interventional treatment efficacy evaluation of quantitative indicators. DWI in soft tissue tumor diagnosis and prognosis, necrotic tissue and tumor parenchyma, changes and recurrence after treatment of benign and malignant soft tissue tumors and the identification has a certain value.
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