The Correlative Study Between CT Perfusion Imaging and Microvascular Density of Astrocytoma

Objective To!analyze the relationship between the CT perfusion imaging and microvascular density (MVD) of astrocytomas,and to evaluate the value of CT perfusion on grading of astrocytomas before operation.Methods 18 patients with astrocytoma underwent CT examinations 2d~8d before operation. CT examination including: scout view, plain scan, enhanced dynamic scan and enhanced scan. The perfusion 2 software was used for the dynamic data analysis; The cerebral blood flow(CBF),cerebral blood volume(CBV),mean transit time (MTT)and permeability surface(PS) mapping images were acquired. The HE and immunohistochemistry staining of the specimen were acquired after operation. The MVD of the tumors were calculated with the Weidner’s technique.Results There were 7 cases of low-grade (WHO, grade Ⅱ) astrocytoma tumors and 11cases of high-grade(WHO,grade Ⅲ～Ⅳ)astrocytoma tumor. The values of CBF, CBV and PS of the astrocytoma tumors were higher than that of white matters; the values of CBF, CBV and PS of the high grade astrocytoma tumors were higher than that of low grade astrocytoma tumors. There were positive correlation between the tumor MVD and tumor CBF, CBV, and PS. Conclusion CT perfusion imaging is helpful for astrocytoma grading before operations and can be used to distinguish the low-grade astrocytoma and high-grade astrocytoma. It may offer useful informations on differential diagnosis between the tumorous lesions and non-tumorous lesions.