Measuring Perfusion In Benign Or Malignant Tumor Of Bone And Soft Tissue By Using TSA

Objective: Differentiating malignant tumor from benign tumor is important and then assist in selecting treatment strategy as well as determine the prognosis. Research have confirmed that the pattern of vascularity in benign and malignant tumor is different: the vascular density is higher in peripheral of the malignant tumor,the angiogenesis probably begins in venules and capillaries from the pre-existing vessels of neighboring normal tissue,the vessels are mostly mature and the blood supply is abound; however, the vascular density is lower in the center, there are mostly the neovascularity participated by the tumor cells. The vessels are immature and lacking the endothelial cell and smooth muscle, so that it will result in inadequate vascular supply and hypoxia; In contrast, the vascular of benign tumor is mature, the density is homogeneous, and do not show different blood supply between the two areas. Some CT and MR perfusion researches have confirmed the difference perfusion model of benign and malignant tumor. So that we can different malignant tumor from benign tumor depend on the characteristic of perfusion.But,the methods all need contrast media,the application of contast agent will not only extra increase the burden but also has potentially severe side effects. BOLD-fMRI as a non-invasive examination method is depend on the proportion of hemoglobin and deoxygenated hemoglobin, deoxygenated hemoglobin is a paramagnetic substance, it can be used as a endogenous contrast media, which can decreace the value of T2 star. In this study, we use rest BOLD-fMRI to detect the solid tumor of bone and soft tissues, and analysis the feature of the signal to find out the difference between benign and malignant tumor and the difference of BOLD signal in different areas.Methods: The 3D-T1 WI images and the BOLD-fMRI images of 28 patients with bone and soft tissue tumor were preformed by the 3.0Tesla magnetic resonance scanner(Magnetom Verio, Siemens, Erlangen, Germany). 1).3D-T1 WI images used the turbo FLASH(turbo fast low angled shot) squence with the scan parameters as follows: repetition time(TR)=1900 ms, echo time(TE)=2.46 ms, thickness/gap=1/0.5 mm, flip angle=15°, number of slices=176 slices, field of view(FOV)=192 mm × 192 mm, matrix=192×192. 2).The SE-EPI-BOLD sequence was performed with the following parameters: TR=1600ms, TE=40ms, thickness/gap=3/0.75 mm, the voxel size=3.0 mm × 3.0 mm ×3.75 mm, FOV=192 mm × 192 mm, matrix= 64 × 64, number of slices=20, scanning time=6 min. Preprocessing and analysis of fMRI data was carried out using DPARSFA, REST,MICA toolbox based on SPM8 and Matlab. After removing the unqualified cases, there were 26 patients, including 16 cases malignant tumors and 10 cases benign masses.We use MATELAB software to calculate the TSA value of the central and peripheral areas ROI of different tumors. We completed the statistical tests by Paired-samples t test on TSA between the center and peripheral of benign tumor and the center and peripheral of malignant tumor, and then the ROC analysis was performed.Result: The result of the Paired-samples t test shows that the TSA between the center and peripheral of malignant tumor have significant difference(P=0.024?P=0.03), there is no significant difference of the TSA between the center and peripheral of begin tumor. In the later ROC analysis shows that the P-Value is greater than 0.05.Conclusion: The TSA between the center and peripheral of malignant tumor have significant difference and no significant difference of the TSA between the center and peripheral of begin tumor. TSA could be a potential indicator.