To determine the utility of the amide proton transfer-weighted MR imaging in differentiating the WHO grade and predict proliferative activity of meningioma.
Fifty-three patients with WHO grade I meningiomas and twenty-six patients with WHO grade II meningiomas underwent conventional and APT-weighted sequences on a 3.0 Tesla MR before clinical intervention. The APT-weighted (APTw) parameters in the solid tumor region were obtained and compared between two grades using the t-test, the receiver operating characteristic (ROC) curve was used to assess the best parameter for predicting the grade of meningiomas. Pearson’s correlation coefficient was calculated between the APTw max and Ki-67 labeling index in meningiomas.
The APTw max and APTw mean values were not significantly different between WHO grade I and grade II meningiomas ( P=0.103 and P=0.318). The APTw min value was higher and the APTw max-mim value was lower in WHO grade II meningiomas than in WHO grade I tumors. ( P=0.027 and P=0.019). But the APTw min was higher and the APTw max-min was lower in microcystic meningiomas than in WHO grade II meningiomas( P= 0.001 and P=0.006). The APTw min combined with APTw max-min showed the best diagnostic performance in predicting the grade of meningiomas with an AUC of 0.772. The APTw max value was positively correlated with Ki-67 labeling index (r=0.817, P<0.00l) in meningiomas, the regression equation for the Ki-67 labeling index (%) (Y) and APTw max (%)(X) was Y=4.9×X-12.4 (R 2 =0.667, P< 0.001).