BOLD Was Used To Identify Benign Or Malignant Of The Limb Bone And Soft Tissue Tumor

Objective:Bone tumors occurred in the bone or its subsidiary organizations (blood vessels, nerves, bone marrow, etc.) of the tumor. Soft-tissue tumor occur in the mesoderm origin fibrous tissue, fat, muscle, vascular, synovial membrane and the mesothelial organizations identify benign and malignant limb bone and soft tissue mass,and many scholars use different methods to identify them. As with CT or MR enhancement perfusion imaging,we compare the perfusion rates at the center-edge of the region between the benign and malignant tumor. DTI was also used to compare Cancer Center-the edge of the region anisotropy (FA) and volume ratio anisotropy values (VrA) in order to identify benign and malignant tumor. BOLD-fMRI has been first used in the brain function and cognitive neuroscience research subjects in the recent years with its wide range of applications, such as the evaluation in different states under different types of tumor oxygenation level, as well as BOLD signal change research for limb skeletal muscle system in different states. The proximal end of the limb bone and soft tissue tumor was pressured by a sleeve tourniquet to change the blood supply within a short time, using BOLD-fMRI tumor continuous resting state, transient ischemic state, reactive hyperemia state three times per-6-minute scan, and observe the difference of BOLD signal change in response to ischemia and ischemic time between the benign and malignant tumor, as well as the difference of BOLD signal change in different regions of the same tumor.Methods:20 patients (14 males,6 females) with limb bone and soft tissue tumor were preformed by Germany's Siemens 1.5T superconductive MRI machine (Siemens, AVANTO) for BOLD-fMRI examination. Using sleeve tourniquet The proximal end of the tumor was compressed and slacked rapidly, resulting in blood oxygen saturation change of the tumor and the surrounding area. The lesion was programed by the BOLD-fMRI at resting-state, transient ischemic and reactive hyperemia state,and every period for 6 minutes scan. BOLD-fMRI scan parameters:TR 2000ms, TE 400ms, slice:5mm, dist.factor:20%, scanning layers:20, FOV:220mm×220mm, Voxel size 3.4 mm×3.4mm×5.0mm, matri×64×64, scan time 6min (177 time points). We use SPM5 (Statistical Parametric Mapping, http://www.fil.ion.ucl.ac.uk/spm/) software to preprocess the data, including the dimensions of slice timing, realign. Excluding the patients whose mobile mobility greater than 3mm. Calculated the signal ratio ofΔSI (ΔSI1= limitations BOLD signal intensity of ischemic resting state of the signal intensity ratio,ΔSI2=reactive BOLD signal intensity during hyperemia resting signal intensity ratio) of the centeral and peripheral areas ROI of different tumors for 6 minutes (177 time points) by MATLAB software. We obtained the curve charts connected by 177 time points of ischemia and reactive hyperemia period. The peak time of theΔSI2 in every ROI during reactive hyperemia was obtained to calculate the Cancer Center-the edge ofΔSI2 peak time difference (ΔT). Analysis the BOLD signal characteristics between the benign and malignant in the resting state, transient ischemic and reactive hyperemia and trying to figure out the difference. SPSS 16.0 was used for statistical tests for the data obtained.Results:In the ischemia period, it was inconsistent of the signal curveΔSI1 in different tumors and in different regions of the same tumor. In the reactive hyperemia period, there was a significant difference ofΔSI2 peak time between the tumor regions and surrounding normal tissue area (the central area P=0.000; peripheral area P=0.009). There was no difference of theΔSI2 peak time between the central and peripheral areas of Benign tumor (P= 0.965). There was a significant difference of theΔSI2 peak time between the central area and peripheral area of the malignant tumor(P=0.009). There was a difference of the center-peripheral ofΔSI2 peak time interval difference (AT) between the benign and malignant tumor (P=0.023). There was a significant difference of the BOLD signal coefficient of variation under quiescent condition at the peripheral area of the Benign and malignant tumor(P= 0.009).Conclusion:BOLD-fMRI was first used for the research of the limb bone and soft tissue tumor. The results show there was significant difference of the limb bone and soft tissue tumor BOLD signal change of reactive hyperemia compared with the surrounding normal tissue. There is difference of the center-edge ofΔSI2 peak time interval difference (ΔT) in the reactive hyperemia period of benign and malignant tumor. It is similar with the results in identifying bone and soft tissue tumor by the previous CT or MR perfusion imaging, and it may be related to the heterogeneity of tumor blood vessels and the different distribution of the tumor. There was significant difference of the BOLD signal coefficient of variation at resting state between benign and malignant peripheral zone, and it may be related to its seldom stable state of the tumor oxygenation in the resting state and the different change tumor oxygenation in resting state. BOLD-fMRI use the body's own hemoglobin as a contrast agent, to achieve non-invasive, and has a high time resolution for the future occurred in the clinical diagnosis of limb bone and soft tissue malignant tumor to provide a new means of image identification.