2009 Fiscal Year Final Research Report
Early parediction of chemotherapy for tumor cell using ECR technique -experimental study-
Project/Area Number |
20790905
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Research Category |
Grant-in-Aid for Young Scientists (B)
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Allocation Type | Single-year Grants |
Research Field |
Radiation science
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Research Institution | Nara Medical University |
Principal Investigator |
NISHIOFUKU Hideyuki Nara Medical University, 医学部・附属病院, 研究員 (80458041)
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Project Period (FY) |
2008 – 2009
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Keywords | MRI / 分子イメージング / 細胞密度 / VX2腫瘍 / 消化器癌 |
Research Abstract |
Purpose : Equivalent cross-relaxation rate (ECR) imaging (ECRI) is one of the measurement techniques that can be used to quantitatively evaluate a change in the structural organization and cellular density by MRI. The aim of this study was to evaluate a correlation between ECR value and cellular density in the rabbit VX2 tumor model. Materials and Methods : Five rabbits implanted into the femur muscles with 10 VX2 tumors were included in this study. We adopted the off-resonance technique for the single saturation transfer pulse frequency was employed at the frequency 7 ppm downfield from the water resonance. The ECR value was defined as the percentage of signal loss between unsaturated and saturated images. The ECRI were constructed on the basis of the percentage of ECR values. The pathological specimens were divided into 34 areas and classified into two groups ; viable group and necrotic group. The ECR value was measured and was compared between the two groups. The correlation between ECR values and cellular density was determined. Results : Median ECR value was significantly higher in the viable group than in the necrotic group (61.2% vs. 35.8%). With the threshold determined as less than 48.3%, the, receiver-operating curve analysis showed high sensitivity and specificity values for necrosis (96.0% and 100%, respectively). The regression graph showed a linear relationship between ECR values and cellular density ; the correlation coefficient (r2) was 0.729. Conclusion : ECRI is a potentially useful technique to depict the viable and necrotic area accurately, and there is a strong association between ECR values and cellular density in VX2 tumor.
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