Application of amide proton transfer-weighted MRI for grading of brainstem glioma in children / 中华全科医师杂志

ABSTRACT

Objective:To evaluate the application of amide proton transfer weighted (APTw) magnetic resonance imaging(MRI) for grading of brainstem glioma (BSG) in children.Methods:Twenty-five children (16 males and 9 females) aged 0.7-12.4(5.6±3.3)years were diagnosed as BSG by surgery or biopsy in Beijing Children′s Hospital from December 2019 to March 2022, including 13 cases of low-grade BSG and 12 cases of high-grade BSG. APTw imaging and conventional MRI were performed on a 3.0 T MRI scanner. The differences in gender distribution, age, conventional MRI appearance, APTw signal intensity and apparent diffusion coefficient (ADC) between children with high and low grade BSG were analyzed. Receiver operating characteristic (ROC) curve was used to analyze the efficacy of APTw signal intensity in the differential diagnosis of high and low grade BSG, and Youden index was calculated to obtain the optimal diagnostic threshold. Pearson′s correlation coefficient analysis was used to evaluate the correlation between APTw signal intensity and Ki-67 expression.Results:There was no significant difference in age and gender distribution between high-grade and low-grade BSG patients. The maximum diameter of high-grade BSG was significantly larger than that of low-grade BSG [(4.7±0.9) vs. (3.1±1.7)cm; t=-2.94, P=0.007]; the maximum signal intensity of APTw (APTw max) in high-grade BSG was significantly higher than that in low-grade BSG [(4.9±0.6)% vs. (3.0±1.2)%; t=-5.14, P<0.001]; the average signal intensity of APTw (APTw mean) in high-grade BSG was significantly higher than that in low-grade BSG[(3.6±0.4%) vs. (2.7±1.1)%; t=-2.66, P=0.014].The area under the curve(AUC)of APTw max in distinguishing high-and low-grade BSG was 0.897; with 4.07% as the optimal diagnostic threshold of APTw max, the sensitivity for the diagnosis of high-grade BSG was 0.917 and specificity was 0.846. The AUC of APTw mean in distinguishing high-and low-grade BSG was 0.769; with 2.85% as the optimal diagnostic threshold of APTw mean, the sensitivity for the diagnosis of high-grade BSG was 0.917 and specificity was 0.692. There was a positive correlation between the value of APTw max and Ki-67 expression( r=0.453, P=0.023). Conclusion:APTw imaging is helpful to distinguish high-grade and low-grade BSG in children. APTw max value can be used to effectively evaluate the proliferative activity of BSG in children.