The Study Of Arterial Spin Labeling And Diffusion Kurtosis Imaging In Pediatric Brain Tumors

Objective: To analyze MRI findings of children brain tumors and explore the value of arterial spin labeling(ASL)perfusion imaging and diffusion kurtosis imaging(DKI)in children brain tumor grading.Methods: Patients with clinically diagnosed brain tumors from the affiliated hospital of Zunyi Medical University between July 2018 and December 2019 were collected.All patients underwent conventional MRI,ASL and DKI examinations before surgery.All patients were confirmed as brain tumors by postoperative pathology and WHO grade was obtained,WHO III-IV were high grade,WHO I-II were low grade.The differences in the location(supratentorial and infratentorial)and MRI features(hemorrhage,cystic/necrosis,degree of enhancement,and peritumor edema)were analyzed,and the absolute and relative values of ASL and DKI parameters were measured.The location and MRI features of brain tumors in children and adults were compared by Fisher’s exact probability method,the parameter values of ASL and DKI were tested by independent sample t test if they were normally distributed,and Mann-Whitney U test if they were not normally distributed,ROC curve analysis was performed for the parameters with good diagnostic performance,then determine its cut-off value,and its corresponding sensitivity and specificity.Results: In the children group,a total of 19 cases were included,12 cases of high grade and 7 cases of low grade,2 cases of DKI sequences were excluded because of patient noncooperation(1 case of high grade and 1 case of low grade).A total of 19 adults were included,11 cases of high grade and 8 cases of low grade.There were statistically differences in location(supratentorial/subtentorial)of brain tumors between children and adults(P=0.042),there were no statistically differences in MRI features(hemorrhage,cystic/necrosis,degree of enhancement,and peritumor edema)of high and low grade brain tumors in children group,while there were statistically differences between cystic/necrosis(P= 0.018),degree of enhancement(P=0.001),and peritumor edema(P=0.006)in the adult group.There were statistically differences between MK,rMK,AK,rAK,RK,rRK,MD,rMD,CBF and rCBF values of high and low brain tumors in children,and the AUC was0.879,0.864,0.924,0.848,0.833,0.909,0.924,0.924,0.810 and 0.845,respectively.AK has the highest diagnostic efficiency,when the cut-off value of AK is 0.682,the sensitivity was 90.9% and the specificity was 83.3%.When we use the cut-off value CBF=29.205ml/100g/min or rCBF = 0.591,the sensitivity and specificity were both 91.7 % and71.4 %,respectively.There were statistically differences between MK、rMK、AK、rAK、RK、rRK、FA、rFA、MD、rMD、CBF and rCBF values of high and low brain tumors in adult,and the AUC was 0.989,0.989,0.989,0.989,0.989,1.000,0.841,0.795,1.000,1.000,0.909 and 0.932,respectively.Conclusion: The CBF value and rCBF value of ASL parameters and AK value of DKI parameters can be more accurately predicting the pathological grade of brain tumor in children,and providing basis for preoperative diagnosis and treatment protocols of brain tumor in children.