Evaluation Of Clinical Application Of Diagnosis Of Glial Tumor Using Dynamic Contrast-enhanced Perfusion MR Imaging

[Objective] The angiogenesis of tumor played an important role in the stages of origination ,progress, infiltration and metastasis and even exerted a remarkable influence on the biological activity and prognosis. Dynamic contrast-enhanced perfusion MR imaging could provides the information on the microcirculation of tumors that cannot be acquired from the conventional MR imaging. Our study was to explore the value of in dynamic contrast-enhanced perfusion MR imaging in grading of glial tumors and in differentiating various intracranial tumors.[ Materials and Methods ] 76 cases of glial tumor including 36 low-grade glial tumors(WHO grade II), 20 anaplastic glial tumors(grade III) and 20 glioblastoma multiforms(grade IV) and 51 ones with other intracranial tumors comprising 20 metastases, 20 meningiomas, 8 lymphomas and 3 hemangiopericytomas were selected. All the patients underwent conventional MR imaging and dynamic contrast-enhanced perfusion MR imaging before surgical resection or stereotactic biopsy and all the ones proved pathologically. Obtain thecurve of signal intensity changes over times in the maximum perfusion area located in the regional cerebral blood volume (rCBV) mapping. Compare the characteristic of curves of various tumors and analysis the values of the maximum rCBV among the gliomas of various grades, the metastases and lymphomas. The maximum ones at the peritumoral areas between the high-grade glial tumors and metastases were also compared.[Results] The maximum rrCBV values of glial tumors of the II, III and IV grade are 1.379 0.739 , 2.654 1.072, 3.218 1.565 respectively and the difference among them was statistically significant(Kruskal-Wallis H , Mann-Whitney U P<0.000). The value of the low-grade glial tumors was lowest while the one of the globlstoma multiforms was highest. There existed significant correlation between the rrCBV and the grade of the glial tumors (Spearman's rank correlation coefficient =0.601 ,p<0.000 ) . The desired cutoff value that differentiated the low-grade and high-grade gliomas was 1.898. A significant difference in the rrCBV was found between the high-grade glial tumor and the intracranial primary lymphoma showing low or iso-level in the rCBV mapping. The value of the primary lymphoma( 1.496 1.048) is relatively lower. Although there here exist no difference between value of rrCBV in the high-grade gliomas and the one in metastases(2.342 1.971), the rrCBV located in the peritumoral edema exist remarkable difference between them (P<0.05). The extra-axial tumors showed marked high-level perfusion area. That the signal intensity-time curve during the first pass did not return to the baseline revealed an immediate and persist leakage of contrast agent into the interstitial space due to complete absence of the blood-brain-barrier.[ conclusion ] Dynamic contrast-enhanced perfusion MR imaging can quantitative the angiogenisis and reveal the lesion vascular distribution of thetumor and provide valuable information for diagnosis. The maximum rrCBV is helpful for the grading of the glioma and to difference the glial tumor from the metastases, lymphoma and extra axial tumors.