The Diagnostic Value Of ASL In High Grade Astrocytic Tumors

Part one Correlation of arterial spin labeling and dynamic susceptibilityweighted contrast-enhanced MR imaging in astrocytic tumorObjective:To probe the correlation of three-dimensional arterial spinlabeling(3D-ASL) and dynamic susceptibility weighted contrastenhanced(DSC) magnetic resonance imaging in astrocytic tumors. Methods70cases of astrocytic tumors confirmed pathologically or clinically underwent3.0T (Discovery MR750,GE healthcare) conventional MRI,3D-ASL andDSC.According to the World Health Organization(WHO)) classification ofcentral nervous system tumor and grading criteria:4cases of pilocyticastrocytoma (grade Ⅰ),28cases of astrocytoma (grade II),22cases ofanaplastic astrocytoma (grade III) and16cases of glioblastoma (grade Ⅳ)were included.Maximum rCBF were measured in the solid region andperitumoral region of the tumor,the correlation between the two perfusionmethods were analyzed by the Spearman analysis.Results:The rCBF value(median,interquartile range) of3D-ASL andDSC of solid region in70astrocytic tumors were (3.069,2.151) and(3.7943,3.825)(r=0.944,P<0.01) and the peritumoral region were(0.913,0.576) and (1.095,0.783) respectively (r=0.732,P<0.01).The rCBFvalue of3D-ASL and DSC of solid region in38HGG were (3.662,2.054) and(4.179,3.468)(r=0.918,P<0.01) and those in the immediate peritumoral regionwere (1.171,0.760) and (0.974,0.703) respectively (r=0.757P<0.01).TherCBF value of3D-ASL and DSC of solid region in32LGG were (2.109,2.205)and (2.591,3.988)(r=0.931,P<0.01) and the peritumoral region were(0.781,0.438) and (0.965,0.944) respectively(r=0.840,P<0.01). ConclusionThe value of rCBF of DSC and3D-ASL of astrocytic tumors was closelycorrelated,indicating that the assessment of3D-ASL for astrocytes tumors is reliable. Part two Diagnostic value of of3D-ASL for differentiation ofhigh-grade glioma from solitary metastases of brainObjective: To probe differentiation value of3D-ASL between high-gradeglioma and solitary metastases of brain.Methods: The study included86HGG and metastases (50men;36women,median age,41.5years) which confirmed pathologically. All thesepatients underwent3.0T (Discovery MR750,GE healthcare) conventionalMRI and3D-ASL. According to WHO classification of central nervoussystem tumor and grading criteria:22anaplastic astrocytomas (grade III) and26glioblastomas (grade Ⅳ),38metastases (14lung cancers,8breast cancers,6colon cancers,4esophageal cancers,6renal carcinomas) were included. Alllesions of these cases were enhanced in ring type accompanying withperitumoral edema and were difficult to be differentiated with each other whensolely based on conventional MRI findings.Maximum rCBF were measured inthe solid region and peritumoral region of the tumor,to determine whetherthere was a statistical difference between high-grade gliomas and solitarymetastases. A receiver operating characteristic (ROC) curve analysis was usedto determine the cutoff value of rCBF that had the best combination ofsensitivity and specificity for distinguishing between high-grade glioma andsolitary metastases.Results: The rCBF value (median,interquartile range) of3D-ASL ofsolid region in48high-grade gliomas and38solitary metastases were(3.612,2.100) and (3.123,5.99) and the peritumoral region were (1.101,0.900)and (0.720,0.280) respectively.There were significant difference of peritumoral rCBF between high-grade glioma and solitary metastases (P<0.05).According to ROC curve analysis,a cutoff value of0.895for the minimumperitumoral rCBF value generated the best combination of sensitivity (70.8%)and specificity (84.2%) for distinguishing between high-grade glioma andsolitary metastases.Conclusion: Peritumoral rCBF measured by3D-ASL may play animportant role in differentiating high-grade gliomas from solitary metastaseswhile the solid rCBF provides not enough information about thedifferentiation.